freebsd-nq/sys/i386/xen/pmap.c

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/*-
* Copyright (c) 1991 Regents of the University of California.
* All rights reserved.
* Copyright (c) 1994 John S. Dyson
* All rights reserved.
* Copyright (c) 1994 David Greenman
* All rights reserved.
* Copyright (c) 2005 Alan L. Cox <alc@cs.rice.edu>
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department and William Jolitz of UUNET Technologies Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
*/
/*-
* Copyright (c) 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Jake Burkholder,
* Safeport Network Services, and Network Associates Laboratories, the
* Security Research Division of Network Associates, Inc. under
* DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA
* CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Manages physical address maps.
*
* Since the information managed by this module is
* also stored by the logical address mapping module,
* this module may throw away valid virtual-to-physical
* mappings at almost any time. However, invalidations
* of virtual-to-physical mappings must be done as
* requested.
*
* In order to cope with hardware architectures which
* make virtual-to-physical map invalidates expensive,
* this module may delay invalidate or reduced protection
* operations until such time as they are actually
* necessary. This module is given full information as
* to which processors are currently using which maps,
* and to when physical maps must be made correct.
*/
#include "opt_cpu.h"
#include "opt_pmap.h"
#include "opt_smp.h"
#include "opt_xbox.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mman.h>
#include <sys/msgbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/sf_buf.h>
#include <sys/sx.h>
#include <sys/vmmeter.h>
#include <sys/sched.h>
#include <sys/sysctl.h>
#ifdef SMP
#include <sys/smp.h>
#else
#include <sys/cpuset.h>
#endif
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pager.h>
#include <vm/uma.h>
#include <machine/cpu.h>
#include <machine/cputypes.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/specialreg.h>
#ifdef SMP
#include <machine/smp.h>
#endif
#ifdef XBOX
#include <machine/xbox.h>
#endif
#include <xen/interface/xen.h>
#include <xen/hypervisor.h>
#include <machine/xen/hypercall.h>
#include <machine/xen/xenvar.h>
#include <machine/xen/xenfunc.h>
#if !defined(CPU_DISABLE_SSE) && defined(I686_CPU)
#define CPU_ENABLE_SSE
#endif
#ifndef PMAP_SHPGPERPROC
#define PMAP_SHPGPERPROC 200
#endif
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
#define DIAGNOSTIC
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
#if !defined(DIAGNOSTIC)
#ifdef __GNUC_GNU_INLINE__
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
#define PMAP_INLINE __attribute__((__gnu_inline__)) inline
#else
#define PMAP_INLINE extern inline
#endif
#else
#define PMAP_INLINE
#endif
#ifdef PV_STATS
#define PV_STAT(x) do { x ; } while (0)
#else
#define PV_STAT(x) do { } while (0)
#endif
/*
* Get PDEs and PTEs for user/kernel address space
*/
#define pmap_pde(m, v) (&((m)->pm_pdir[(vm_offset_t)(v) >> PDRSHIFT]))
#define pdir_pde(m, v) (m[(vm_offset_t)(v) >> PDRSHIFT])
#define pmap_pde_v(pte) ((*(int *)pte & PG_V) != 0)
#define pmap_pte_w(pte) ((*(int *)pte & PG_W) != 0)
#define pmap_pte_m(pte) ((*(int *)pte & PG_M) != 0)
#define pmap_pte_u(pte) ((*(int *)pte & PG_A) != 0)
#define pmap_pte_v(pte) ((*(int *)pte & PG_V) != 0)
#define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v)))
#define HAMFISTED_LOCKING
#ifdef HAMFISTED_LOCKING
static struct mtx createdelete_lock;
#endif
struct pmap kernel_pmap_store;
LIST_HEAD(pmaplist, pmap);
static struct pmaplist allpmaps;
static struct mtx allpmaps_lock;
vm_offset_t virtual_avail; /* VA of first avail page (after kernel bss) */
vm_offset_t virtual_end; /* VA of last avail page (end of kernel AS) */
int pgeflag = 0; /* PG_G or-in */
int pseflag = 0; /* PG_PS or-in */
int nkpt;
vm_offset_t kernel_vm_end;
extern u_int32_t KERNend;
#ifdef PAE
pt_entry_t pg_nx;
#endif
static SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD, 0, "VM/pmap parameters");
static int pat_works; /* Is page attribute table sane? */
/*
* This lock is defined as static in other pmap implementations. It cannot,
* however, be defined as static here, because it is (ab)used to serialize
* queued page table changes in other sources files.
*/
struct rwlock pvh_global_lock;
/*
* Data for the pv entry allocation mechanism
*/
static TAILQ_HEAD(pch, pv_chunk) pv_chunks = TAILQ_HEAD_INITIALIZER(pv_chunks);
static int pv_entry_count = 0, pv_entry_max = 0, pv_entry_high_water = 0;
static int shpgperproc = PMAP_SHPGPERPROC;
struct pv_chunk *pv_chunkbase; /* KVA block for pv_chunks */
int pv_maxchunks; /* How many chunks we have KVA for */
vm_offset_t pv_vafree; /* freelist stored in the PTE */
/*
* All those kernel PT submaps that BSD is so fond of
*/
struct sysmaps {
struct mtx lock;
pt_entry_t *CMAP1;
pt_entry_t *CMAP2;
caddr_t CADDR1;
caddr_t CADDR2;
};
static struct sysmaps sysmaps_pcpu[MAXCPU];
static pt_entry_t *CMAP3;
caddr_t ptvmmap = 0;
static caddr_t CADDR3;
struct msgbuf *msgbufp = 0;
/*
* Crashdump maps.
*/
static caddr_t crashdumpmap;
static pt_entry_t *PMAP1 = 0, *PMAP2;
static pt_entry_t *PADDR1 = 0, *PADDR2;
#ifdef SMP
static int PMAP1cpu;
static int PMAP1changedcpu;
SYSCTL_INT(_debug, OID_AUTO, PMAP1changedcpu, CTLFLAG_RD,
&PMAP1changedcpu, 0,
"Number of times pmap_pte_quick changed CPU with same PMAP1");
#endif
static int PMAP1changed;
SYSCTL_INT(_debug, OID_AUTO, PMAP1changed, CTLFLAG_RD,
&PMAP1changed, 0,
"Number of times pmap_pte_quick changed PMAP1");
static int PMAP1unchanged;
SYSCTL_INT(_debug, OID_AUTO, PMAP1unchanged, CTLFLAG_RD,
&PMAP1unchanged, 0,
"Number of times pmap_pte_quick didn't change PMAP1");
static struct mtx PMAP2mutex;
static void free_pv_chunk(struct pv_chunk *pc);
static void free_pv_entry(pmap_t pmap, pv_entry_t pv);
static pv_entry_t get_pv_entry(pmap_t pmap, boolean_t try);
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
static void pmap_pvh_free(struct md_page *pvh, pmap_t pmap, vm_offset_t va);
static pv_entry_t pmap_pvh_remove(struct md_page *pvh, pmap_t pmap,
vm_offset_t va);
static vm_page_t pmap_enter_quick_locked(multicall_entry_t **mcl, int *count, pmap_t pmap, vm_offset_t va,
vm_page_t m, vm_prot_t prot, vm_page_t mpte);
static void pmap_flush_page(vm_page_t m);
static void pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int mode);
static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t sva,
vm_page_t *free);
static void pmap_remove_page(struct pmap *pmap, vm_offset_t va,
vm_page_t *free);
static void pmap_remove_entry(struct pmap *pmap, vm_page_t m,
vm_offset_t va);
static boolean_t pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va,
vm_page_t m);
static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va, int flags);
static vm_page_t _pmap_allocpte(pmap_t pmap, u_int ptepindex, int flags);
static void _pmap_unwire_ptp(pmap_t pmap, vm_page_t m, vm_page_t *free);
static pt_entry_t *pmap_pte_quick(pmap_t pmap, vm_offset_t va);
static void pmap_pte_release(pt_entry_t *pte);
static int pmap_unuse_pt(pmap_t, vm_offset_t, vm_page_t *);
static boolean_t pmap_is_prefaultable_locked(pmap_t pmap, vm_offset_t addr);
2009-09-01 03:44:25 +00:00
static __inline void pagezero(void *page);
CTASSERT(1 << PDESHIFT == sizeof(pd_entry_t));
CTASSERT(1 << PTESHIFT == sizeof(pt_entry_t));
/*
* If you get an error here, then you set KVA_PAGES wrong! See the
* description of KVA_PAGES in sys/i386/include/pmap.h. It must be
* multiple of 4 for a normal kernel, or a multiple of 8 for a PAE.
*/
CTASSERT(KERNBASE % (1 << 24) == 0);
void
pd_set(struct pmap *pmap, int ptepindex, vm_paddr_t val, int type)
{
vm_paddr_t pdir_ma = vtomach(&pmap->pm_pdir[ptepindex]);
switch (type) {
case SH_PD_SET_VA:
#if 0
xen_queue_pt_update(shadow_pdir_ma,
xpmap_ptom(val & ~(PG_RW)));
#endif
xen_queue_pt_update(pdir_ma,
xpmap_ptom(val));
break;
case SH_PD_SET_VA_MA:
#if 0
xen_queue_pt_update(shadow_pdir_ma,
val & ~(PG_RW));
#endif
xen_queue_pt_update(pdir_ma, val);
break;
case SH_PD_SET_VA_CLEAR:
#if 0
xen_queue_pt_update(shadow_pdir_ma, 0);
#endif
xen_queue_pt_update(pdir_ma, 0);
break;
}
}
/*
* Bootstrap the system enough to run with virtual memory.
*
* On the i386 this is called after mapping has already been enabled
* and just syncs the pmap module with what has already been done.
* [We can't call it easily with mapping off since the kernel is not
* mapped with PA == VA, hence we would have to relocate every address
* from the linked base (virtual) address "KERNBASE" to the actual
* (physical) address starting relative to 0]
*/
void
pmap_bootstrap(vm_paddr_t firstaddr)
{
vm_offset_t va;
pt_entry_t *pte, *unused;
struct sysmaps *sysmaps;
int i;
/*
* Initialize the first available kernel virtual address. However,
* using "firstaddr" may waste a few pages of the kernel virtual
* address space, because locore may not have mapped every physical
* page that it allocated. Preferably, locore would provide a first
* unused virtual address in addition to "firstaddr".
*/
virtual_avail = (vm_offset_t) KERNBASE + firstaddr;
virtual_end = VM_MAX_KERNEL_ADDRESS;
/*
* Initialize the kernel pmap (which is statically allocated).
*/
PMAP_LOCK_INIT(kernel_pmap);
kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + (u_int)IdlePTD);
#ifdef PAE
kernel_pmap->pm_pdpt = (pdpt_entry_t *) (KERNBASE + (u_int)IdlePDPT);
#endif
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
CPU_FILL(&kernel_pmap->pm_active); /* don't allow deactivation */
TAILQ_INIT(&kernel_pmap->pm_pvchunk);
/*
* Initialize the global pv list lock.
*/
rw_init_flags(&pvh_global_lock, "pmap pv global", RW_RECURSE);
LIST_INIT(&allpmaps);
mtx_init(&allpmaps_lock, "allpmaps", NULL, MTX_SPIN);
mtx_lock_spin(&allpmaps_lock);
LIST_INSERT_HEAD(&allpmaps, kernel_pmap, pm_list);
mtx_unlock_spin(&allpmaps_lock);
if (nkpt == 0)
nkpt = NKPT;
/*
* Reserve some special page table entries/VA space for temporary
* mapping of pages.
*/
#define SYSMAP(c, p, v, n) \
v = (c)va; va += ((n)*PAGE_SIZE); p = pte; pte += (n);
va = virtual_avail;
pte = vtopte(va);
/*
* CMAP1/CMAP2 are used for zeroing and copying pages.
* CMAP3 is used for the idle process page zeroing.
*/
for (i = 0; i < MAXCPU; i++) {
sysmaps = &sysmaps_pcpu[i];
mtx_init(&sysmaps->lock, "SYSMAPS", NULL, MTX_DEF);
SYSMAP(caddr_t, sysmaps->CMAP1, sysmaps->CADDR1, 1)
SYSMAP(caddr_t, sysmaps->CMAP2, sysmaps->CADDR2, 1)
PT_SET_MA(sysmaps->CADDR1, 0);
PT_SET_MA(sysmaps->CADDR2, 0);
}
SYSMAP(caddr_t, CMAP3, CADDR3, 1)
PT_SET_MA(CADDR3, 0);
/*
* Crashdump maps.
*/
SYSMAP(caddr_t, unused, crashdumpmap, MAXDUMPPGS)
/*
* ptvmmap is used for reading arbitrary physical pages via /dev/mem.
*/
SYSMAP(caddr_t, unused, ptvmmap, 1)
/*
* msgbufp is used to map the system message buffer.
*/
SYSMAP(struct msgbuf *, unused, msgbufp, atop(round_page(msgbufsize)))
/*
* PADDR1 and PADDR2 are used by pmap_pte_quick() and pmap_pte(),
* respectively.
*/
SYSMAP(pt_entry_t *, PMAP1, PADDR1, 1)
SYSMAP(pt_entry_t *, PMAP2, PADDR2, 1)
mtx_init(&PMAP2mutex, "PMAP2", NULL, MTX_DEF);
virtual_avail = va;
/*
* Leave in place an identity mapping (virt == phys) for the low 1 MB
* physical memory region that is used by the ACPI wakeup code. This
* mapping must not have PG_G set.
*/
#ifndef XEN
/*
* leave here deliberately to show that this is not supported
*/
#ifdef XBOX
/* FIXME: This is gross, but needed for the XBOX. Since we are in such
* an early stadium, we cannot yet neatly map video memory ... :-(
* Better fixes are very welcome! */
if (!arch_i386_is_xbox)
#endif
for (i = 1; i < NKPT; i++)
PTD[i] = 0;
/* Initialize the PAT MSR if present. */
pmap_init_pat();
/* Turn on PG_G on kernel page(s) */
pmap_set_pg();
#endif
#ifdef HAMFISTED_LOCKING
mtx_init(&createdelete_lock, "pmap create/delete", NULL, MTX_DEF);
#endif
}
/*
* Setup the PAT MSR.
*/
void
pmap_init_pat(void)
{
uint64_t pat_msr;
/* Bail if this CPU doesn't implement PAT. */
if (!(cpu_feature & CPUID_PAT))
return;
if (cpu_vendor_id != CPU_VENDOR_INTEL ||
(CPUID_TO_FAMILY(cpu_id) == 6 && CPUID_TO_MODEL(cpu_id) >= 0xe)) {
/*
* Leave the indices 0-3 at the default of WB, WT, UC, and UC-.
* Program 4 and 5 as WP and WC.
* Leave 6 and 7 as UC and UC-.
*/
pat_msr = rdmsr(MSR_PAT);
pat_msr &= ~(PAT_MASK(4) | PAT_MASK(5));
pat_msr |= PAT_VALUE(4, PAT_WRITE_PROTECTED) |
PAT_VALUE(5, PAT_WRITE_COMBINING);
pat_works = 1;
} else {
/*
* Due to some Intel errata, we can only safely use the lower 4
* PAT entries. Thus, just replace PAT Index 2 with WC instead
* of UC-.
*
* Intel Pentium III Processor Specification Update
* Errata E.27 (Upper Four PAT Entries Not Usable With Mode B
* or Mode C Paging)
*
* Intel Pentium IV Processor Specification Update
* Errata N46 (PAT Index MSB May Be Calculated Incorrectly)
*/
pat_msr = rdmsr(MSR_PAT);
pat_msr &= ~PAT_MASK(2);
pat_msr |= PAT_VALUE(2, PAT_WRITE_COMBINING);
pat_works = 0;
}
wrmsr(MSR_PAT, pat_msr);
}
/*
* Initialize a vm_page's machine-dependent fields.
*/
void
pmap_page_init(vm_page_t m)
{
TAILQ_INIT(&m->md.pv_list);
Add support to the virtual memory system for configuring machine- dependent memory attributes: Rename vm_cache_mode_t to vm_memattr_t. The new name reflects the fact that there are machine-dependent memory attributes that have nothing to do with controlling the cache's behavior. Introduce vm_object_set_memattr() for setting the default memory attributes that will be given to an object's pages. Introduce and use pmap_page_{get,set}_memattr() for getting and setting a page's machine-dependent memory attributes. Add full support for these functions on amd64 and i386 and stubs for them on the other architectures. The function pmap_page_set_memattr() is also responsible for any other machine-dependent aspects of changing a page's memory attributes, such as flushing the cache or updating the direct map. The uses include kmem_alloc_contig(), vm_page_alloc(), and the device pager: kmem_alloc_contig() can now be used to allocate kernel memory with non-default memory attributes on amd64 and i386. vm_page_alloc() and the device pager will set the memory attributes for the real or fictitious page according to the object's default memory attributes. Update the various pmap functions on amd64 and i386 that map pages to incorporate each page's memory attributes in the mapping. Notes: (1) Inherent to this design are safety features that prevent the specification of inconsistent memory attributes by different mappings on amd64 and i386. In addition, the device pager provides a warning when a device driver creates a fictitious page with memory attributes that are inconsistent with the real page that the fictitious page is an alias for. (2) Storing the machine-dependent memory attributes for amd64 and i386 as a dedicated "int" in "struct md_page" represents a compromise between space efficiency and the ease of MFCing these changes to RELENG_7. In collaboration with: jhb Approved by: re (kib)
2009-07-12 23:31:20 +00:00
m->md.pat_mode = PAT_WRITE_BACK;
}
/*
* ABuse the pte nodes for unmapped kva to thread a kva freelist through.
* Requirements:
* - Must deal with pages in order to ensure that none of the PG_* bits
* are ever set, PG_V in particular.
* - Assumes we can write to ptes without pte_store() atomic ops, even
* on PAE systems. This should be ok.
* - Assumes nothing will ever test these addresses for 0 to indicate
* no mapping instead of correctly checking PG_V.
* - Assumes a vm_offset_t will fit in a pte (true for i386).
* Because PG_V is never set, there can be no mappings to invalidate.
*/
static int ptelist_count = 0;
static vm_offset_t
pmap_ptelist_alloc(vm_offset_t *head)
{
vm_offset_t va;
vm_offset_t *phead = (vm_offset_t *)*head;
if (ptelist_count == 0) {
printf("out of memory!!!!!!\n");
return (0); /* Out of memory */
}
ptelist_count--;
va = phead[ptelist_count];
return (va);
}
static void
pmap_ptelist_free(vm_offset_t *head, vm_offset_t va)
{
vm_offset_t *phead = (vm_offset_t *)*head;
phead[ptelist_count++] = va;
}
static void
pmap_ptelist_init(vm_offset_t *head, void *base, int npages)
{
int i, nstackpages;
vm_offset_t va;
vm_page_t m;
nstackpages = (npages + PAGE_SIZE/sizeof(vm_offset_t) - 1)/ (PAGE_SIZE/sizeof(vm_offset_t));
for (i = 0; i < nstackpages; i++) {
va = (vm_offset_t)base + i * PAGE_SIZE;
m = vm_page_alloc(NULL, i,
VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED |
VM_ALLOC_ZERO);
pmap_qenter(va, &m, 1);
}
*head = (vm_offset_t)base;
for (i = npages - 1; i >= nstackpages; i--) {
va = (vm_offset_t)base + i * PAGE_SIZE;
pmap_ptelist_free(head, va);
}
}
/*
* Initialize the pmap module.
* Called by vm_init, to initialize any structures that the pmap
* system needs to map virtual memory.
*/
void
pmap_init(void)
{
/*
* Initialize the address space (zone) for the pv entries. Set a
* high water mark so that the system can recover from excessive
* numbers of pv entries.
*/
TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
pv_entry_max = shpgperproc * maxproc + cnt.v_page_count;
TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max);
pv_entry_max = roundup(pv_entry_max, _NPCPV);
pv_entry_high_water = 9 * (pv_entry_max / 10);
pv_maxchunks = MAX(pv_entry_max / _NPCPV, maxproc);
pv_chunkbase = (struct pv_chunk *)kmem_alloc_nofault(kernel_map,
PAGE_SIZE * pv_maxchunks);
if (pv_chunkbase == NULL)
panic("pmap_init: not enough kvm for pv chunks");
pmap_ptelist_init(&pv_vafree, pv_chunkbase, pv_maxchunks);
}
SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_max, CTLFLAG_RD, &pv_entry_max, 0,
"Max number of PV entries");
SYSCTL_INT(_vm_pmap, OID_AUTO, shpgperproc, CTLFLAG_RD, &shpgperproc, 0,
"Page share factor per proc");
static SYSCTL_NODE(_vm_pmap, OID_AUTO, pde, CTLFLAG_RD, 0,
"2/4MB page mapping counters");
static u_long pmap_pde_mappings;
SYSCTL_ULONG(_vm_pmap_pde, OID_AUTO, mappings, CTLFLAG_RD,
&pmap_pde_mappings, 0, "2/4MB page mappings");
/***************************************************
* Low level helper routines.....
***************************************************/
/*
* Determine the appropriate bits to set in a PTE or PDE for a specified
* caching mode.
*/
int
pmap_cache_bits(int mode, boolean_t is_pde)
{
int pat_flag, pat_index, cache_bits;
/* The PAT bit is different for PTE's and PDE's. */
pat_flag = is_pde ? PG_PDE_PAT : PG_PTE_PAT;
/* If we don't support PAT, map extended modes to older ones. */
if (!(cpu_feature & CPUID_PAT)) {
switch (mode) {
case PAT_UNCACHEABLE:
case PAT_WRITE_THROUGH:
case PAT_WRITE_BACK:
break;
case PAT_UNCACHED:
case PAT_WRITE_COMBINING:
case PAT_WRITE_PROTECTED:
mode = PAT_UNCACHEABLE;
break;
}
}
/* Map the caching mode to a PAT index. */
if (pat_works) {
switch (mode) {
case PAT_UNCACHEABLE:
pat_index = 3;
break;
case PAT_WRITE_THROUGH:
pat_index = 1;
break;
case PAT_WRITE_BACK:
pat_index = 0;
break;
case PAT_UNCACHED:
pat_index = 2;
break;
case PAT_WRITE_COMBINING:
pat_index = 5;
break;
case PAT_WRITE_PROTECTED:
pat_index = 4;
break;
default:
panic("Unknown caching mode %d\n", mode);
}
} else {
switch (mode) {
case PAT_UNCACHED:
case PAT_UNCACHEABLE:
case PAT_WRITE_PROTECTED:
pat_index = 3;
break;
case PAT_WRITE_THROUGH:
pat_index = 1;
break;
case PAT_WRITE_BACK:
pat_index = 0;
break;
case PAT_WRITE_COMBINING:
pat_index = 2;
break;
default:
panic("Unknown caching mode %d\n", mode);
}
}
/* Map the 3-bit index value into the PAT, PCD, and PWT bits. */
cache_bits = 0;
if (pat_index & 0x4)
cache_bits |= pat_flag;
if (pat_index & 0x2)
cache_bits |= PG_NC_PCD;
if (pat_index & 0x1)
cache_bits |= PG_NC_PWT;
return (cache_bits);
}
#ifdef SMP
/*
* For SMP, these functions have to use the IPI mechanism for coherence.
*
* N.B.: Before calling any of the following TLB invalidation functions,
* the calling processor must ensure that all stores updating a non-
* kernel page table are globally performed. Otherwise, another
* processor could cache an old, pre-update entry without being
* invalidated. This can happen one of two ways: (1) The pmap becomes
* active on another processor after its pm_active field is checked by
* one of the following functions but before a store updating the page
* table is globally performed. (2) The pmap becomes active on another
* processor before its pm_active field is checked but due to
* speculative loads one of the following functions stills reads the
* pmap as inactive on the other processor.
*
* The kernel page table is exempt because its pm_active field is
* immutable. The kernel page table is always active on every
* processor.
*/
void
pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
{
cpuset_t other_cpus;
u_int cpuid;
CTR2(KTR_PMAP, "pmap_invalidate_page: pmap=%p va=0x%x",
pmap, va);
sched_pin();
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
if (pmap == kernel_pmap || !CPU_CMP(&pmap->pm_active, &all_cpus)) {
invlpg(va);
smp_invlpg(va);
} else {
cpuid = PCPU_GET(cpuid);
other_cpus = all_cpus;
CPU_CLR(cpuid, &other_cpus);
if (CPU_ISSET(cpuid, &pmap->pm_active))
invlpg(va);
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
CPU_AND(&other_cpus, &pmap->pm_active);
if (!CPU_EMPTY(&other_cpus))
smp_masked_invlpg(other_cpus, va);
}
sched_unpin();
PT_UPDATES_FLUSH();
}
void
pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
cpuset_t other_cpus;
vm_offset_t addr;
u_int cpuid;
CTR3(KTR_PMAP, "pmap_invalidate_page: pmap=%p eva=0x%x sva=0x%x",
pmap, sva, eva);
sched_pin();
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
if (pmap == kernel_pmap || !CPU_CMP(&pmap->pm_active, &all_cpus)) {
for (addr = sva; addr < eva; addr += PAGE_SIZE)
invlpg(addr);
smp_invlpg_range(sva, eva);
} else {
cpuid = PCPU_GET(cpuid);
other_cpus = all_cpus;
CPU_CLR(cpuid, &other_cpus);
if (CPU_ISSET(cpuid, &pmap->pm_active))
for (addr = sva; addr < eva; addr += PAGE_SIZE)
invlpg(addr);
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
CPU_AND(&other_cpus, &pmap->pm_active);
if (!CPU_EMPTY(&other_cpus))
smp_masked_invlpg_range(other_cpus, sva, eva);
}
sched_unpin();
PT_UPDATES_FLUSH();
}
void
pmap_invalidate_all(pmap_t pmap)
{
cpuset_t other_cpus;
u_int cpuid;
CTR1(KTR_PMAP, "pmap_invalidate_page: pmap=%p", pmap);
sched_pin();
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
if (pmap == kernel_pmap || !CPU_CMP(&pmap->pm_active, &all_cpus)) {
invltlb();
smp_invltlb();
} else {
cpuid = PCPU_GET(cpuid);
other_cpus = all_cpus;
CPU_CLR(cpuid, &other_cpus);
if (CPU_ISSET(cpuid, &pmap->pm_active))
invltlb();
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
CPU_AND(&other_cpus, &pmap->pm_active);
if (!CPU_EMPTY(&other_cpus))
smp_masked_invltlb(other_cpus);
}
sched_unpin();
}
void
pmap_invalidate_cache(void)
{
sched_pin();
wbinvd();
smp_cache_flush();
sched_unpin();
}
#else /* !SMP */
/*
* Normal, non-SMP, 486+ invalidation functions.
* We inline these within pmap.c for speed.
*/
PMAP_INLINE void
pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
{
CTR2(KTR_PMAP, "pmap_invalidate_page: pmap=%p va=0x%x",
pmap, va);
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
if (pmap == kernel_pmap || !CPU_EMPTY(&pmap->pm_active))
invlpg(va);
PT_UPDATES_FLUSH();
}
PMAP_INLINE void
pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
vm_offset_t addr;
if (eva - sva > PAGE_SIZE)
CTR3(KTR_PMAP, "pmap_invalidate_range: pmap=%p sva=0x%x eva=0x%x",
pmap, sva, eva);
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
if (pmap == kernel_pmap || !CPU_EMPTY(&pmap->pm_active))
for (addr = sva; addr < eva; addr += PAGE_SIZE)
invlpg(addr);
PT_UPDATES_FLUSH();
}
PMAP_INLINE void
pmap_invalidate_all(pmap_t pmap)
{
CTR1(KTR_PMAP, "pmap_invalidate_all: pmap=%p", pmap);
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
if (pmap == kernel_pmap || !CPU_EMPTY(&pmap->pm_active))
invltlb();
}
PMAP_INLINE void
pmap_invalidate_cache(void)
{
wbinvd();
}
#endif /* !SMP */
#define PMAP_CLFLUSH_THRESHOLD (2 * 1024 * 1024)
void
pmap_invalidate_cache_range(vm_offset_t sva, vm_offset_t eva)
{
KASSERT((sva & PAGE_MASK) == 0,
("pmap_invalidate_cache_range: sva not page-aligned"));
KASSERT((eva & PAGE_MASK) == 0,
("pmap_invalidate_cache_range: eva not page-aligned"));
if (cpu_feature & CPUID_SS)
; /* If "Self Snoop" is supported, do nothing. */
else if ((cpu_feature & CPUID_CLFSH) != 0 &&
eva - sva < PMAP_CLFLUSH_THRESHOLD) {
/*
* Otherwise, do per-cache line flush. Use the mfence
* instruction to insure that previous stores are
* included in the write-back. The processor
* propagates flush to other processors in the cache
* coherence domain.
*/
mfence();
for (; sva < eva; sva += cpu_clflush_line_size)
clflush(sva);
mfence();
} else {
/*
* No targeted cache flush methods are supported by CPU,
* or the supplied range is bigger than 2MB.
* Globally invalidate cache.
*/
pmap_invalidate_cache();
}
}
void
pmap_invalidate_cache_pages(vm_page_t *pages, int count)
{
int i;
if (count >= PMAP_CLFLUSH_THRESHOLD / PAGE_SIZE ||
(cpu_feature & CPUID_CLFSH) == 0) {
pmap_invalidate_cache();
} else {
for (i = 0; i < count; i++)
pmap_flush_page(pages[i]);
}
}
/*
* Are we current address space or kernel? N.B. We return FALSE when
* a pmap's page table is in use because a kernel thread is borrowing
* it. The borrowed page table can change spontaneously, making any
* dependence on its continued use subject to a race condition.
*/
static __inline int
pmap_is_current(pmap_t pmap)
{
return (pmap == kernel_pmap ||
(pmap == vmspace_pmap(curthread->td_proc->p_vmspace) &&
(pmap->pm_pdir[PTDPTDI] & PG_FRAME) == (PTDpde[0] & PG_FRAME)));
}
/*
* If the given pmap is not the current or kernel pmap, the returned pte must
* be released by passing it to pmap_pte_release().
*/
pt_entry_t *
pmap_pte(pmap_t pmap, vm_offset_t va)
{
pd_entry_t newpf;
pd_entry_t *pde;
pde = pmap_pde(pmap, va);
if (*pde & PG_PS)
return (pde);
if (*pde != 0) {
/* are we current address space or kernel? */
if (pmap_is_current(pmap))
return (vtopte(va));
mtx_lock(&PMAP2mutex);
newpf = *pde & PG_FRAME;
if ((*PMAP2 & PG_FRAME) != newpf) {
PT_SET_MA(PADDR2, newpf | PG_V | PG_A | PG_M);
CTR3(KTR_PMAP, "pmap_pte: pmap=%p va=0x%x newpte=0x%08x",
pmap, va, (*PMAP2 & 0xffffffff));
}
return (PADDR2 + (i386_btop(va) & (NPTEPG - 1)));
}
return (NULL);
}
/*
* Releases a pte that was obtained from pmap_pte(). Be prepared for the pte
* being NULL.
*/
static __inline void
pmap_pte_release(pt_entry_t *pte)
{
if ((pt_entry_t *)((vm_offset_t)pte & ~PAGE_MASK) == PADDR2) {
CTR1(KTR_PMAP, "pmap_pte_release: pte=0x%jx",
*PMAP2);
rw_wlock(&pvh_global_lock);
PT_SET_VA(PMAP2, 0, TRUE);
rw_wunlock(&pvh_global_lock);
mtx_unlock(&PMAP2mutex);
}
}
static __inline void
invlcaddr(void *caddr)
{
invlpg((u_int)caddr);
PT_UPDATES_FLUSH();
}
/*
* Super fast pmap_pte routine best used when scanning
* the pv lists. This eliminates many coarse-grained
* invltlb calls. Note that many of the pv list
* scans are across different pmaps. It is very wasteful
* to do an entire invltlb for checking a single mapping.
*
* If the given pmap is not the current pmap, pvh_global_lock
* must be held and curthread pinned to a CPU.
*/
static pt_entry_t *
pmap_pte_quick(pmap_t pmap, vm_offset_t va)
{
pd_entry_t newpf;
pd_entry_t *pde;
pde = pmap_pde(pmap, va);
if (*pde & PG_PS)
return (pde);
if (*pde != 0) {
/* are we current address space or kernel? */
if (pmap_is_current(pmap))
return (vtopte(va));
rw_assert(&pvh_global_lock, RA_WLOCKED);
KASSERT(curthread->td_pinned > 0, ("curthread not pinned"));
newpf = *pde & PG_FRAME;
if ((*PMAP1 & PG_FRAME) != newpf) {
PT_SET_MA(PADDR1, newpf | PG_V | PG_A | PG_M);
CTR3(KTR_PMAP, "pmap_pte_quick: pmap=%p va=0x%x newpte=0x%08x",
pmap, va, (u_long)*PMAP1);
#ifdef SMP
PMAP1cpu = PCPU_GET(cpuid);
#endif
PMAP1changed++;
} else
#ifdef SMP
if (PMAP1cpu != PCPU_GET(cpuid)) {
PMAP1cpu = PCPU_GET(cpuid);
invlcaddr(PADDR1);
PMAP1changedcpu++;
} else
#endif
PMAP1unchanged++;
return (PADDR1 + (i386_btop(va) & (NPTEPG - 1)));
}
return (0);
}
/*
* Routine: pmap_extract
* Function:
* Extract the physical page address associated
* with the given map/virtual_address pair.
*/
vm_paddr_t
pmap_extract(pmap_t pmap, vm_offset_t va)
{
vm_paddr_t rtval;
pt_entry_t *pte;
pd_entry_t pde;
pt_entry_t pteval;
rtval = 0;
PMAP_LOCK(pmap);
pde = pmap->pm_pdir[va >> PDRSHIFT];
if (pde != 0) {
if ((pde & PG_PS) != 0) {
rtval = xpmap_mtop(pde & PG_PS_FRAME) | (va & PDRMASK);
PMAP_UNLOCK(pmap);
return rtval;
}
pte = pmap_pte(pmap, va);
pteval = *pte ? xpmap_mtop(*pte) : 0;
rtval = (pteval & PG_FRAME) | (va & PAGE_MASK);
pmap_pte_release(pte);
}
PMAP_UNLOCK(pmap);
return (rtval);
}
/*
* Routine: pmap_extract_ma
* Function:
* Like pmap_extract, but returns machine address
*/
vm_paddr_t
pmap_extract_ma(pmap_t pmap, vm_offset_t va)
{
vm_paddr_t rtval;
pt_entry_t *pte;
pd_entry_t pde;
rtval = 0;
PMAP_LOCK(pmap);
pde = pmap->pm_pdir[va >> PDRSHIFT];
if (pde != 0) {
if ((pde & PG_PS) != 0) {
rtval = (pde & ~PDRMASK) | (va & PDRMASK);
PMAP_UNLOCK(pmap);
return rtval;
}
pte = pmap_pte(pmap, va);
rtval = (*pte & PG_FRAME) | (va & PAGE_MASK);
pmap_pte_release(pte);
}
PMAP_UNLOCK(pmap);
return (rtval);
}
/*
* Routine: pmap_extract_and_hold
* Function:
* Atomically extract and hold the physical page
* with the given pmap and virtual address pair
* if that mapping permits the given protection.
*/
vm_page_t
pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot)
{
pd_entry_t pde;
pt_entry_t pte, *ptep;
vm_page_t m;
vm_paddr_t pa;
pa = 0;
m = NULL;
PMAP_LOCK(pmap);
retry:
pde = PT_GET(pmap_pde(pmap, va));
if (pde != 0) {
if (pde & PG_PS) {
if ((pde & PG_RW) || (prot & VM_PROT_WRITE) == 0) {
if (vm_page_pa_tryrelock(pmap, (pde &
PG_PS_FRAME) | (va & PDRMASK), &pa))
goto retry;
m = PHYS_TO_VM_PAGE((pde & PG_PS_FRAME) |
(va & PDRMASK));
vm_page_hold(m);
}
} else {
ptep = pmap_pte(pmap, va);
pte = PT_GET(ptep);
pmap_pte_release(ptep);
if (pte != 0 &&
((pte & PG_RW) || (prot & VM_PROT_WRITE) == 0)) {
if (vm_page_pa_tryrelock(pmap, pte & PG_FRAME,
&pa))
goto retry;
m = PHYS_TO_VM_PAGE(pte & PG_FRAME);
vm_page_hold(m);
}
}
}
PA_UNLOCK_COND(pa);
PMAP_UNLOCK(pmap);
return (m);
}
/***************************************************
* Low level mapping routines.....
***************************************************/
/*
* Add a wired page to the kva.
* Note: not SMP coherent.
*
* This function may be used before pmap_bootstrap() is called.
*/
void
pmap_kenter(vm_offset_t va, vm_paddr_t pa)
{
PT_SET_MA(va, xpmap_ptom(pa)| PG_RW | PG_V | pgeflag);
}
void
pmap_kenter_ma(vm_offset_t va, vm_paddr_t ma)
{
pt_entry_t *pte;
pte = vtopte(va);
pte_store_ma(pte, ma | PG_RW | PG_V | pgeflag);
}
static __inline void
pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int mode)
{
PT_SET_MA(va, pa | PG_RW | PG_V | pgeflag | pmap_cache_bits(mode, 0));
}
/*
* Remove a page from the kernel pagetables.
* Note: not SMP coherent.
*
* This function may be used before pmap_bootstrap() is called.
*/
PMAP_INLINE void
pmap_kremove(vm_offset_t va)
{
pt_entry_t *pte;
pte = vtopte(va);
PT_CLEAR_VA(pte, FALSE);
}
/*
* Used to map a range of physical addresses into kernel
* virtual address space.
*
* The value passed in '*virt' is a suggested virtual address for
* the mapping. Architectures which can support a direct-mapped
* physical to virtual region can return the appropriate address
* within that region, leaving '*virt' unchanged. Other
* architectures should map the pages starting at '*virt' and
* update '*virt' with the first usable address after the mapped
* region.
*/
vm_offset_t
pmap_map(vm_offset_t *virt, vm_paddr_t start, vm_paddr_t end, int prot)
{
vm_offset_t va, sva;
va = sva = *virt;
CTR4(KTR_PMAP, "pmap_map: va=0x%x start=0x%jx end=0x%jx prot=0x%x",
va, start, end, prot);
while (start < end) {
pmap_kenter(va, start);
va += PAGE_SIZE;
start += PAGE_SIZE;
}
pmap_invalidate_range(kernel_pmap, sva, va);
*virt = va;
return (sva);
}
/*
* Add a list of wired pages to the kva
* this routine is only used for temporary
* kernel mappings that do not need to have
* page modification or references recorded.
* Note that old mappings are simply written
* over. The page *must* be wired.
* Note: SMP coherent. Uses a ranged shootdown IPI.
*/
void
pmap_qenter(vm_offset_t sva, vm_page_t *ma, int count)
{
pt_entry_t *endpte, *pte;
vm_paddr_t pa;
vm_offset_t va = sva;
int mclcount = 0;
multicall_entry_t mcl[16];
multicall_entry_t *mclp = mcl;
int error;
CTR2(KTR_PMAP, "pmap_qenter:sva=0x%x count=%d", va, count);
pte = vtopte(sva);
endpte = pte + count;
while (pte < endpte) {
pa = VM_PAGE_TO_MACH(*ma) | pgeflag | PG_RW | PG_V | PG_M | PG_A;
mclp->op = __HYPERVISOR_update_va_mapping;
mclp->args[0] = va;
mclp->args[1] = (uint32_t)(pa & 0xffffffff);
mclp->args[2] = (uint32_t)(pa >> 32);
mclp->args[3] = (*pte & PG_V) ? UVMF_INVLPG|UVMF_ALL : 0;
va += PAGE_SIZE;
pte++;
ma++;
mclp++;
mclcount++;
if (mclcount == 16) {
error = HYPERVISOR_multicall(mcl, mclcount);
mclp = mcl;
mclcount = 0;
KASSERT(error == 0, ("bad multicall %d", error));
}
}
if (mclcount) {
error = HYPERVISOR_multicall(mcl, mclcount);
KASSERT(error == 0, ("bad multicall %d", error));
}
#ifdef INVARIANTS
for (pte = vtopte(sva), mclcount = 0; mclcount < count; mclcount++, pte++)
KASSERT(*pte, ("pte not set for va=0x%x", sva + mclcount*PAGE_SIZE));
#endif
}
/*
* This routine tears out page mappings from the
* kernel -- it is meant only for temporary mappings.
* Note: SMP coherent. Uses a ranged shootdown IPI.
*/
void
pmap_qremove(vm_offset_t sva, int count)
{
vm_offset_t va;
CTR2(KTR_PMAP, "pmap_qremove: sva=0x%x count=%d", sva, count);
va = sva;
rw_wlock(&pvh_global_lock);
critical_enter();
while (count-- > 0) {
pmap_kremove(va);
va += PAGE_SIZE;
}
PT_UPDATES_FLUSH();
pmap_invalidate_range(kernel_pmap, sva, va);
critical_exit();
rw_wunlock(&pvh_global_lock);
}
/***************************************************
* Page table page management routines.....
***************************************************/
static __inline void
pmap_free_zero_pages(vm_page_t free)
{
vm_page_t m;
while (free != NULL) {
m = free;
Sync back vmcontention branch into HEAD: Replace the per-object resident and cached pages splay tree with a path-compressed multi-digit radix trie. Along with this, switch also the x86-specific handling of idle page tables to using the radix trie. This change is supposed to do the following: - Allowing the acquisition of read locking for lookup operations of the resident/cached pages collections as the per-vm_page_t splay iterators are now removed. - Increase the scalability of the operations on the page collections. The radix trie does rely on the consumers locking to ensure atomicity of its operations. In order to avoid deadlocks the bisection nodes are pre-allocated in the UMA zone. This can be done safely because the algorithm needs at maximum one new node per insert which means the maximum number of the desired nodes is the number of available physical frames themselves. However, not all the times a new bisection node is really needed. The radix trie implements path-compression because UFS indirect blocks can lead to several objects with a very sparse trie, increasing the number of levels to usually scan. It also helps in the nodes pre-fetching by introducing the single node per-insert property. This code is not generalized (yet) because of the possible loss of performance by having much of the sizes in play configurable. However, efforts to make this code more general and then reusable in further different consumers might be really done. The only KPI change is the removal of the function vm_page_splay() which is now reaped. The only KBI change, instead, is the removal of the left/right iterators from struct vm_page, which are now reaped. Further technical notes broken into mealpieces can be retrieved from the svn branch: http://svn.freebsd.org/base/user/attilio/vmcontention/ Sponsored by: EMC / Isilon storage division In collaboration with: alc, jeff Tested by: flo, pho, jhb, davide Tested by: ian (arm) Tested by: andreast (powerpc)
2013-03-18 00:25:02 +00:00
free = (void *)m->object;
m->object = NULL;
vm_page_free_zero(m);
}
}
/*
* Decrements a page table page's wire count, which is used to record the
* number of valid page table entries within the page. If the wire count
* drops to zero, then the page table page is unmapped. Returns TRUE if the
* page table page was unmapped and FALSE otherwise.
*/
static inline boolean_t
pmap_unwire_ptp(pmap_t pmap, vm_page_t m, vm_page_t *free)
{
--m->wire_count;
if (m->wire_count == 0) {
_pmap_unwire_ptp(pmap, m, free);
return (TRUE);
} else
return (FALSE);
}
static void
_pmap_unwire_ptp(pmap_t pmap, vm_page_t m, vm_page_t *free)
{
vm_offset_t pteva;
PT_UPDATES_FLUSH();
/*
* unmap the page table page
*/
xen_pt_unpin(pmap->pm_pdir[m->pindex]);
/*
* page *might* contain residual mapping :-/
*/
PD_CLEAR_VA(pmap, m->pindex, TRUE);
pmap_zero_page(m);
--pmap->pm_stats.resident_count;
/*
* This is a release store so that the ordinary store unmapping
* the page table page is globally performed before TLB shoot-
* down is begun.
*/
atomic_subtract_rel_int(&cnt.v_wire_count, 1);
/*
* Do an invltlb to make the invalidated mapping
* take effect immediately.
*/
pteva = VM_MAXUSER_ADDRESS + i386_ptob(m->pindex);
pmap_invalidate_page(pmap, pteva);
/*
* Put page on a list so that it is released after
* *ALL* TLB shootdown is done
*/
Sync back vmcontention branch into HEAD: Replace the per-object resident and cached pages splay tree with a path-compressed multi-digit radix trie. Along with this, switch also the x86-specific handling of idle page tables to using the radix trie. This change is supposed to do the following: - Allowing the acquisition of read locking for lookup operations of the resident/cached pages collections as the per-vm_page_t splay iterators are now removed. - Increase the scalability of the operations on the page collections. The radix trie does rely on the consumers locking to ensure atomicity of its operations. In order to avoid deadlocks the bisection nodes are pre-allocated in the UMA zone. This can be done safely because the algorithm needs at maximum one new node per insert which means the maximum number of the desired nodes is the number of available physical frames themselves. However, not all the times a new bisection node is really needed. The radix trie implements path-compression because UFS indirect blocks can lead to several objects with a very sparse trie, increasing the number of levels to usually scan. It also helps in the nodes pre-fetching by introducing the single node per-insert property. This code is not generalized (yet) because of the possible loss of performance by having much of the sizes in play configurable. However, efforts to make this code more general and then reusable in further different consumers might be really done. The only KPI change is the removal of the function vm_page_splay() which is now reaped. The only KBI change, instead, is the removal of the left/right iterators from struct vm_page, which are now reaped. Further technical notes broken into mealpieces can be retrieved from the svn branch: http://svn.freebsd.org/base/user/attilio/vmcontention/ Sponsored by: EMC / Isilon storage division In collaboration with: alc, jeff Tested by: flo, pho, jhb, davide Tested by: ian (arm) Tested by: andreast (powerpc)
2013-03-18 00:25:02 +00:00
m->object = (void *)*free;
*free = m;
}
/*
* After removing a page table entry, this routine is used to
* conditionally free the page, and manage the hold/wire counts.
*/
static int
pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t *free)
{
pd_entry_t ptepde;
vm_page_t mpte;
if (va >= VM_MAXUSER_ADDRESS)
return (0);
ptepde = PT_GET(pmap_pde(pmap, va));
mpte = PHYS_TO_VM_PAGE(ptepde & PG_FRAME);
return (pmap_unwire_ptp(pmap, mpte, free));
}
/*
* Initialize the pmap for the swapper process.
*/
void
pmap_pinit0(pmap_t pmap)
{
PMAP_LOCK_INIT(pmap);
/*
* Since the page table directory is shared with the kernel pmap,
* which is already included in the list "allpmaps", this pmap does
* not need to be inserted into that list.
*/
pmap->pm_pdir = (pd_entry_t *)(KERNBASE + (vm_offset_t)IdlePTD);
#ifdef PAE
pmap->pm_pdpt = (pdpt_entry_t *)(KERNBASE + (vm_offset_t)IdlePDPT);
#endif
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
CPU_ZERO(&pmap->pm_active);
PCPU_SET(curpmap, pmap);
TAILQ_INIT(&pmap->pm_pvchunk);
bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
}
/*
* Initialize a preallocated and zeroed pmap structure,
* such as one in a vmspace structure.
*/
int
pmap_pinit(pmap_t pmap)
{
vm_page_t m, ptdpg[NPGPTD + 1];
int npgptd = NPGPTD + 1;
int i;
#ifdef HAMFISTED_LOCKING
mtx_lock(&createdelete_lock);
#endif
PMAP_LOCK_INIT(pmap);
/*
* No need to allocate page table space yet but we do need a valid
* page directory table.
*/
if (pmap->pm_pdir == NULL) {
pmap->pm_pdir = (pd_entry_t *)kmem_alloc_nofault(kernel_map,
NBPTD);
if (pmap->pm_pdir == NULL) {
PMAP_LOCK_DESTROY(pmap);
#ifdef HAMFISTED_LOCKING
mtx_unlock(&createdelete_lock);
#endif
return (0);
}
#ifdef PAE
pmap->pm_pdpt = (pd_entry_t *)kmem_alloc_nofault(kernel_map, 1);
#endif
}
/*
* allocate the page directory page(s)
*/
for (i = 0; i < npgptd;) {
m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ |
VM_ALLOC_WIRED | VM_ALLOC_ZERO);
if (m == NULL)
VM_WAIT;
else {
ptdpg[i++] = m;
}
}
pmap_qenter((vm_offset_t)pmap->pm_pdir, ptdpg, NPGPTD);
for (i = 0; i < NPGPTD; i++)
if ((ptdpg[i]->flags & PG_ZERO) == 0)
pagezero(pmap->pm_pdir + (i * NPDEPG));
mtx_lock_spin(&allpmaps_lock);
LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
/* Copy the kernel page table directory entries. */
bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * sizeof(pd_entry_t));
mtx_unlock_spin(&allpmaps_lock);
#ifdef PAE
pmap_qenter((vm_offset_t)pmap->pm_pdpt, &ptdpg[NPGPTD], 1);
if ((ptdpg[NPGPTD]->flags & PG_ZERO) == 0)
bzero(pmap->pm_pdpt, PAGE_SIZE);
for (i = 0; i < NPGPTD; i++) {
vm_paddr_t ma;
ma = VM_PAGE_TO_MACH(ptdpg[i]);
pmap->pm_pdpt[i] = ma | PG_V;
}
#endif
for (i = 0; i < NPGPTD; i++) {
pt_entry_t *pd;
vm_paddr_t ma;
ma = VM_PAGE_TO_MACH(ptdpg[i]);
pd = pmap->pm_pdir + (i * NPDEPG);
PT_SET_MA(pd, *vtopte((vm_offset_t)pd) & ~(PG_M|PG_A|PG_U|PG_RW));
#if 0
xen_pgd_pin(ma);
#endif
}
#ifdef PAE
PT_SET_MA(pmap->pm_pdpt, *vtopte((vm_offset_t)pmap->pm_pdpt) & ~PG_RW);
#endif
rw_wlock(&pvh_global_lock);
xen_flush_queue();
xen_pgdpt_pin(VM_PAGE_TO_MACH(ptdpg[NPGPTD]));
for (i = 0; i < NPGPTD; i++) {
vm_paddr_t ma = VM_PAGE_TO_MACH(ptdpg[i]);
PT_SET_VA_MA(&pmap->pm_pdir[PTDPTDI + i], ma | PG_V | PG_A, FALSE);
}
xen_flush_queue();
rw_wunlock(&pvh_global_lock);
Commit the support for removing cpumask_t and replacing it directly with cpuset_t objects. That is going to offer the underlying support for a simple bump of MAXCPU and then support for number of cpus > 32 (as it is today). Right now, cpumask_t is an int, 32 bits on all our supported architecture. cpumask_t on the other side is implemented as an array of longs, and easilly extendible by definition. The architectures touched by this commit are the following: - amd64 - i386 - pc98 - arm - ia64 - XEN while the others are still missing. Userland is believed to be fully converted with the changes contained here. Some technical notes: - This commit may be considered an ABI nop for all the architectures different from amd64 and ia64 (and sparc64 in the future) - per-cpu members, which are now converted to cpuset_t, needs to be accessed avoiding migration, because the size of cpuset_t should be considered unknown - size of cpuset_t objects is different from kernel and userland (this is primirally done in order to leave some more space in userland to cope with KBI extensions). If you need to access kernel cpuset_t from the userland please refer to example in this patch on how to do that correctly (kgdb may be a good source, for example). - Support for other architectures is going to be added soon - Only MAXCPU for amd64 is bumped now The patch has been tested by sbruno and Nicholas Esborn on opteron 4 x 12 pack CPUs. More testing on big SMP is expected to came soon. pluknet tested the patch with his 8-ways on both amd64 and i386. Tested by: pluknet, sbruno, gianni, Nicholas Esborn Reviewed by: jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
CPU_ZERO(&pmap->pm_active);
TAILQ_INIT(&pmap->pm_pvchunk);
bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
#ifdef HAMFISTED_LOCKING
mtx_unlock(&createdelete_lock);
#endif
return (1);
}
/*
* this routine is called if the page table page is not
* mapped correctly.
*/
static vm_page_t
_pmap_allocpte(pmap_t pmap, u_int ptepindex, int flags)
{
vm_paddr_t ptema;
vm_page_t m;
KASSERT((flags & (M_NOWAIT | M_WAITOK)) == M_NOWAIT ||
(flags & (M_NOWAIT | M_WAITOK)) == M_WAITOK,
("_pmap_allocpte: flags is neither M_NOWAIT nor M_WAITOK"));
/*
* Allocate a page table page.
*/
if ((m = vm_page_alloc(NULL, ptepindex, VM_ALLOC_NOOBJ |
VM_ALLOC_WIRED | VM_ALLOC_ZERO)) == NULL) {
if (flags & M_WAITOK) {
PMAP_UNLOCK(pmap);
rw_wunlock(&pvh_global_lock);
VM_WAIT;
rw_wlock(&pvh_global_lock);
PMAP_LOCK(pmap);
}
/*
* Indicate the need to retry. While waiting, the page table
* page may have been allocated.
*/
return (NULL);
}
if ((m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
/*
* Map the pagetable page into the process address space, if
* it isn't already there.
*/
pmap->pm_stats.resident_count++;
ptema = VM_PAGE_TO_MACH(m);
xen_pt_pin(ptema);
PT_SET_VA_MA(&pmap->pm_pdir[ptepindex],
(ptema | PG_U | PG_RW | PG_V | PG_A | PG_M), TRUE);
KASSERT(pmap->pm_pdir[ptepindex],
("_pmap_allocpte: ptepindex=%d did not get mapped", ptepindex));
return (m);
}
static vm_page_t
pmap_allocpte(pmap_t pmap, vm_offset_t va, int flags)
{
u_int ptepindex;
pd_entry_t ptema;
vm_page_t m;
KASSERT((flags & (M_NOWAIT | M_WAITOK)) == M_NOWAIT ||
(flags & (M_NOWAIT | M_WAITOK)) == M_WAITOK,
("pmap_allocpte: flags is neither M_NOWAIT nor M_WAITOK"));
/*
* Calculate pagetable page index
*/
ptepindex = va >> PDRSHIFT;
retry:
/*
* Get the page directory entry
*/
ptema = pmap->pm_pdir[ptepindex];
/*
* This supports switching from a 4MB page to a
* normal 4K page.
*/
if (ptema & PG_PS) {
/*
* XXX
*/
pmap->pm_pdir[ptepindex] = 0;
ptema = 0;
pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
pmap_invalidate_all(kernel_pmap);
}
/*
* If the page table page is mapped, we just increment the
* hold count, and activate it.
*/
if (ptema & PG_V) {
m = PHYS_TO_VM_PAGE(xpmap_mtop(ptema) & PG_FRAME);
m->wire_count++;
} else {
/*
* Here if the pte page isn't mapped, or if it has
* been deallocated.
*/
CTR3(KTR_PMAP, "pmap_allocpte: pmap=%p va=0x%08x flags=0x%x",
pmap, va, flags);
m = _pmap_allocpte(pmap, ptepindex, flags);
if (m == NULL && (flags & M_WAITOK))
goto retry;
KASSERT(pmap->pm_pdir[ptepindex], ("ptepindex=%d did not get mapped", ptepindex));
}
return (m);
}
/***************************************************
* Pmap allocation/deallocation routines.
***************************************************/
#ifdef SMP
/*
* Deal with a SMP shootdown of other users of the pmap that we are
* trying to dispose of. This can be a bit hairy.
*/
static cpuset_t *lazymask;
static u_int lazyptd;
static volatile u_int lazywait;
void pmap_lazyfix_action(void);
void
pmap_lazyfix_action(void)
{
#ifdef COUNT_IPIS
(*ipi_lazypmap_counts[PCPU_GET(cpuid)])++;
#endif
if (rcr3() == lazyptd)
load_cr3(PCPU_GET(curpcb)->pcb_cr3);
CPU_CLR_ATOMIC(PCPU_GET(cpuid), lazymask);
atomic_store_rel_int(&lazywait, 1);
}
static void
pmap_lazyfix_self(u_int cpuid)
{
if (rcr3() == lazyptd)
load_cr3(PCPU_GET(curpcb)->pcb_cr3);
CPU_CLR_ATOMIC(cpuid, lazymask);
}
static void
pmap_lazyfix(pmap_t pmap)
{
cpuset_t mymask, mask;
u_int cpuid, spins;
int lsb;
mask = pmap->pm_active;
while (!CPU_EMPTY(&mask)) {
spins = 50000000;
/* Find least significant set bit. */
lsb = cpusetobj_ffs(&mask);
MPASS(lsb != 0);
lsb--;
CPU_SETOF(lsb, &mask);
mtx_lock_spin(&smp_ipi_mtx);
#ifdef PAE
lazyptd = vtophys(pmap->pm_pdpt);
#else
lazyptd = vtophys(pmap->pm_pdir);
#endif
cpuid = PCPU_GET(cpuid);
/* Use a cpuset just for having an easy check. */
CPU_SETOF(cpuid, &mymask);
if (!CPU_CMP(&mask, &mymask)) {
lazymask = &pmap->pm_active;
pmap_lazyfix_self(cpuid);
} else {
atomic_store_rel_int((u_int *)&lazymask,
(u_int)&pmap->pm_active);
atomic_store_rel_int(&lazywait, 0);
ipi_selected(mask, IPI_LAZYPMAP);
while (lazywait == 0) {
ia32_pause();
if (--spins == 0)
break;
}
}
mtx_unlock_spin(&smp_ipi_mtx);
if (spins == 0)
printf("pmap_lazyfix: spun for 50000000\n");
mask = pmap->pm_active;
}
}
#else /* SMP */
/*
* Cleaning up on uniprocessor is easy. For various reasons, we're
* unlikely to have to even execute this code, including the fact
* that the cleanup is deferred until the parent does a wait(2), which
* means that another userland process has run.
*/
static void
pmap_lazyfix(pmap_t pmap)
{
u_int cr3;
cr3 = vtophys(pmap->pm_pdir);
if (cr3 == rcr3()) {
load_cr3(PCPU_GET(curpcb)->pcb_cr3);
CPU_CLR(PCPU_GET(cpuid), &pmap->pm_active);
}
}
#endif /* SMP */
/*
* Release any resources held by the given physical map.
* Called when a pmap initialized by pmap_pinit is being released.
* Should only be called if the map contains no valid mappings.
*/
void
pmap_release(pmap_t pmap)
{
vm_page_t m, ptdpg[2*NPGPTD+1];
vm_paddr_t ma;
int i;
#ifdef PAE
int npgptd = NPGPTD + 1;
#else
int npgptd = NPGPTD;
#endif
KASSERT(pmap->pm_stats.resident_count == 0,
("pmap_release: pmap resident count %ld != 0",
pmap->pm_stats.resident_count));
PT_UPDATES_FLUSH();
#ifdef HAMFISTED_LOCKING
mtx_lock(&createdelete_lock);
#endif
pmap_lazyfix(pmap);
mtx_lock_spin(&allpmaps_lock);
LIST_REMOVE(pmap, pm_list);
mtx_unlock_spin(&allpmaps_lock);
for (i = 0; i < NPGPTD; i++)
ptdpg[i] = PHYS_TO_VM_PAGE(vtophys(pmap->pm_pdir + (i*NPDEPG)) & PG_FRAME);
pmap_qremove((vm_offset_t)pmap->pm_pdir, NPGPTD);
#ifdef PAE
ptdpg[NPGPTD] = PHYS_TO_VM_PAGE(vtophys(pmap->pm_pdpt));
#endif
for (i = 0; i < npgptd; i++) {
m = ptdpg[i];
ma = VM_PAGE_TO_MACH(m);
/* unpinning L1 and L2 treated the same */
#if 0
xen_pgd_unpin(ma);
#else
if (i == NPGPTD)
xen_pgd_unpin(ma);
#endif
#ifdef PAE
if (i < NPGPTD)
KASSERT(VM_PAGE_TO_MACH(m) == (pmap->pm_pdpt[i] & PG_FRAME),
("pmap_release: got wrong ptd page"));
#endif
m->wire_count--;
atomic_subtract_int(&cnt.v_wire_count, 1);
vm_page_free(m);
}
#ifdef PAE
pmap_qremove((vm_offset_t)pmap->pm_pdpt, 1);
#endif
PMAP_LOCK_DESTROY(pmap);
#ifdef HAMFISTED_LOCKING
mtx_unlock(&createdelete_lock);
#endif
}
static int
kvm_size(SYSCTL_HANDLER_ARGS)
{
unsigned long ksize = VM_MAX_KERNEL_ADDRESS - KERNBASE;
return (sysctl_handle_long(oidp, &ksize, 0, req));
}
SYSCTL_PROC(_vm, OID_AUTO, kvm_size, CTLTYPE_LONG|CTLFLAG_RD,
0, 0, kvm_size, "IU", "Size of KVM");
static int
kvm_free(SYSCTL_HANDLER_ARGS)
{
unsigned long kfree = VM_MAX_KERNEL_ADDRESS - kernel_vm_end;
return (sysctl_handle_long(oidp, &kfree, 0, req));
}
SYSCTL_PROC(_vm, OID_AUTO, kvm_free, CTLTYPE_LONG|CTLFLAG_RD,
0, 0, kvm_free, "IU", "Amount of KVM free");
/*
* grow the number of kernel page table entries, if needed
*/
void
pmap_growkernel(vm_offset_t addr)
{
struct pmap *pmap;
vm_paddr_t ptppaddr;
vm_page_t nkpg;
pd_entry_t newpdir;
mtx_assert(&kernel_map->system_mtx, MA_OWNED);
if (kernel_vm_end == 0) {
kernel_vm_end = KERNBASE;
nkpt = 0;
while (pdir_pde(PTD, kernel_vm_end)) {
kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
nkpt++;
if (kernel_vm_end - 1 >= kernel_map->max_offset) {
kernel_vm_end = kernel_map->max_offset;
break;
}
}
}
addr = roundup2(addr, NBPDR);
if (addr - 1 >= kernel_map->max_offset)
addr = kernel_map->max_offset;
while (kernel_vm_end < addr) {
if (pdir_pde(PTD, kernel_vm_end)) {
kernel_vm_end = (kernel_vm_end + NBPDR) & ~PDRMASK;
if (kernel_vm_end - 1 >= kernel_map->max_offset) {
kernel_vm_end = kernel_map->max_offset;
break;
}
continue;
}
nkpg = vm_page_alloc(NULL, kernel_vm_end >> PDRSHIFT,
VM_ALLOC_INTERRUPT | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED |
VM_ALLOC_ZERO);
if (nkpg == NULL)
panic("pmap_growkernel: no memory to grow kernel");
nkpt++;
if ((nkpg->flags & PG_ZERO) == 0)
pmap_zero_page(nkpg);
ptppaddr = VM_PAGE_TO_PHYS(nkpg);
newpdir = (pd_entry_t) (ptppaddr | PG_V | PG_RW | PG_A | PG_M);
rw_wlock(&pvh_global_lock);
PD_SET_VA(kernel_pmap, (kernel_vm_end >> PDRSHIFT), newpdir, TRUE);
mtx_lock_spin(&allpmaps_lock);
LIST_FOREACH(pmap, &allpmaps, pm_list)
PD_SET_VA(pmap, (kernel_vm_end >> PDRSHIFT), newpdir, TRUE);
mtx_unlock_spin(&allpmaps_lock);
rw_wunlock(&pvh_global_lock);
kernel_vm_end = (kernel_vm_end + NBPDR) & ~PDRMASK;
if (kernel_vm_end - 1 >= kernel_map->max_offset) {
kernel_vm_end = kernel_map->max_offset;
break;
}
}
}
/***************************************************
* page management routines.
***************************************************/
CTASSERT(sizeof(struct pv_chunk) == PAGE_SIZE);
CTASSERT(_NPCM == 11);
CTASSERT(_NPCPV == 336);
static __inline struct pv_chunk *
pv_to_chunk(pv_entry_t pv)
{
return ((struct pv_chunk *)((uintptr_t)pv & ~(uintptr_t)PAGE_MASK));
}
#define PV_PMAP(pv) (pv_to_chunk(pv)->pc_pmap)
#define PC_FREE0_9 0xfffffffful /* Free values for index 0 through 9 */
#define PC_FREE10 0x0000fffful /* Free values for index 10 */
static const uint32_t pc_freemask[_NPCM] = {
PC_FREE0_9, PC_FREE0_9, PC_FREE0_9,
PC_FREE0_9, PC_FREE0_9, PC_FREE0_9,
PC_FREE0_9, PC_FREE0_9, PC_FREE0_9,
PC_FREE0_9, PC_FREE10
};
SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_count, CTLFLAG_RD, &pv_entry_count, 0,
"Current number of pv entries");
#ifdef PV_STATS
static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail;
SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_count, CTLFLAG_RD, &pc_chunk_count, 0,
"Current number of pv entry chunks");
SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_allocs, CTLFLAG_RD, &pc_chunk_allocs, 0,
"Current number of pv entry chunks allocated");
SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_frees, CTLFLAG_RD, &pc_chunk_frees, 0,
"Current number of pv entry chunks frees");
SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_tryfail, CTLFLAG_RD, &pc_chunk_tryfail, 0,
"Number of times tried to get a chunk page but failed.");
static long pv_entry_frees, pv_entry_allocs;
static int pv_entry_spare;
SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_frees, CTLFLAG_RD, &pv_entry_frees, 0,
"Current number of pv entry frees");
SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_allocs, CTLFLAG_RD, &pv_entry_allocs, 0,
"Current number of pv entry allocs");
SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_spare, CTLFLAG_RD, &pv_entry_spare, 0,
"Current number of spare pv entries");
#endif
/*
* We are in a serious low memory condition. Resort to
* drastic measures to free some pages so we can allocate
* another pv entry chunk.
*/
static vm_page_t
pmap_pv_reclaim(pmap_t locked_pmap)
{
struct pch newtail;
struct pv_chunk *pc;
pmap_t pmap;
pt_entry_t *pte, tpte;
pv_entry_t pv;
vm_offset_t va;
vm_page_t free, m, m_pc;
uint32_t inuse;
int bit, field, freed;
PMAP_LOCK_ASSERT(locked_pmap, MA_OWNED);
pmap = NULL;
free = m_pc = NULL;
TAILQ_INIT(&newtail);
while ((pc = TAILQ_FIRST(&pv_chunks)) != NULL && (pv_vafree == 0 ||
free == NULL)) {
TAILQ_REMOVE(&pv_chunks, pc, pc_lru);
if (pmap != pc->pc_pmap) {
if (pmap != NULL) {
pmap_invalidate_all(pmap);
if (pmap != locked_pmap)
PMAP_UNLOCK(pmap);
}
pmap = pc->pc_pmap;
/* Avoid deadlock and lock recursion. */
if (pmap > locked_pmap)
PMAP_LOCK(pmap);
else if (pmap != locked_pmap && !PMAP_TRYLOCK(pmap)) {
pmap = NULL;
TAILQ_INSERT_TAIL(&newtail, pc, pc_lru);
continue;
}
}
/*
* Destroy every non-wired, 4 KB page mapping in the chunk.
*/
freed = 0;
for (field = 0; field < _NPCM; field++) {
for (inuse = ~pc->pc_map[field] & pc_freemask[field];
inuse != 0; inuse &= ~(1UL << bit)) {
bit = bsfl(inuse);
pv = &pc->pc_pventry[field * 32 + bit];
va = pv->pv_va;
pte = pmap_pte(pmap, va);
tpte = *pte;
if ((tpte & PG_W) == 0)
tpte = pte_load_clear(pte);
pmap_pte_release(pte);
if ((tpte & PG_W) != 0)
continue;
KASSERT(tpte != 0,
("pmap_pv_reclaim: pmap %p va %x zero pte",
pmap, va));
if ((tpte & PG_G) != 0)
pmap_invalidate_page(pmap, va);
m = PHYS_TO_VM_PAGE(tpte & PG_FRAME);
if ((tpte & (PG_M | PG_RW)) == (PG_M | PG_RW))
vm_page_dirty(m);
if ((tpte & PG_A) != 0)
vm_page_aflag_set(m, PGA_REFERENCED);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_next);
if (TAILQ_EMPTY(&m->md.pv_list))
vm_page_aflag_clear(m, PGA_WRITEABLE);
pc->pc_map[field] |= 1UL << bit;
pmap_unuse_pt(pmap, va, &free);
freed++;
}
}
if (freed == 0) {
TAILQ_INSERT_TAIL(&newtail, pc, pc_lru);
continue;
}
/* Every freed mapping is for a 4 KB page. */
pmap->pm_stats.resident_count -= freed;
PV_STAT(pv_entry_frees += freed);
PV_STAT(pv_entry_spare += freed);
pv_entry_count -= freed;
TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
for (field = 0; field < _NPCM; field++)
if (pc->pc_map[field] != pc_freemask[field]) {
TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc,
pc_list);
TAILQ_INSERT_TAIL(&newtail, pc, pc_lru);
/*
* One freed pv entry in locked_pmap is
* sufficient.
*/
if (pmap == locked_pmap)
goto out;
break;
}
if (field == _NPCM) {
PV_STAT(pv_entry_spare -= _NPCPV);
PV_STAT(pc_chunk_count--);
PV_STAT(pc_chunk_frees++);
/* Entire chunk is free; return it. */
m_pc = PHYS_TO_VM_PAGE(pmap_kextract((vm_offset_t)pc));
pmap_qremove((vm_offset_t)pc, 1);
pmap_ptelist_free(&pv_vafree, (vm_offset_t)pc);
break;
}
}
out:
TAILQ_CONCAT(&pv_chunks, &newtail, pc_lru);
if (pmap != NULL) {
pmap_invalidate_all(pmap);
if (pmap != locked_pmap)
PMAP_UNLOCK(pmap);
}
if (m_pc == NULL && pv_vafree != 0 && free != NULL) {
m_pc = free;
Sync back vmcontention branch into HEAD: Replace the per-object resident and cached pages splay tree with a path-compressed multi-digit radix trie. Along with this, switch also the x86-specific handling of idle page tables to using the radix trie. This change is supposed to do the following: - Allowing the acquisition of read locking for lookup operations of the resident/cached pages collections as the per-vm_page_t splay iterators are now removed. - Increase the scalability of the operations on the page collections. The radix trie does rely on the consumers locking to ensure atomicity of its operations. In order to avoid deadlocks the bisection nodes are pre-allocated in the UMA zone. This can be done safely because the algorithm needs at maximum one new node per insert which means the maximum number of the desired nodes is the number of available physical frames themselves. However, not all the times a new bisection node is really needed. The radix trie implements path-compression because UFS indirect blocks can lead to several objects with a very sparse trie, increasing the number of levels to usually scan. It also helps in the nodes pre-fetching by introducing the single node per-insert property. This code is not generalized (yet) because of the possible loss of performance by having much of the sizes in play configurable. However, efforts to make this code more general and then reusable in further different consumers might be really done. The only KPI change is the removal of the function vm_page_splay() which is now reaped. The only KBI change, instead, is the removal of the left/right iterators from struct vm_page, which are now reaped. Further technical notes broken into mealpieces can be retrieved from the svn branch: http://svn.freebsd.org/base/user/attilio/vmcontention/ Sponsored by: EMC / Isilon storage division In collaboration with: alc, jeff Tested by: flo, pho, jhb, davide Tested by: ian (arm) Tested by: andreast (powerpc)
2013-03-18 00:25:02 +00:00
free = (void *)m_pc->object;
/* Recycle a freed page table page. */
m_pc->wire_count = 1;
atomic_add_int(&cnt.v_wire_count, 1);
}
pmap_free_zero_pages(free);
return (m_pc);
}
/*
* free the pv_entry back to the free list
*/
static void
free_pv_entry(pmap_t pmap, pv_entry_t pv)
{
struct pv_chunk *pc;
int idx, field, bit;
rw_assert(&pvh_global_lock, RA_WLOCKED);
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
PV_STAT(pv_entry_frees++);
PV_STAT(pv_entry_spare++);
pv_entry_count--;
pc = pv_to_chunk(pv);
idx = pv - &pc->pc_pventry[0];
field = idx / 32;
bit = idx % 32;
pc->pc_map[field] |= 1ul << bit;
for (idx = 0; idx < _NPCM; idx++)
if (pc->pc_map[idx] != pc_freemask[idx]) {
/*
* 98% of the time, pc is already at the head of the
* list. If it isn't already, move it to the head.
*/
if (__predict_false(TAILQ_FIRST(&pmap->pm_pvchunk) !=
pc)) {
TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc,
pc_list);
}
return;
}
TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
free_pv_chunk(pc);
}
static void
free_pv_chunk(struct pv_chunk *pc)
{
vm_page_t m;
TAILQ_REMOVE(&pv_chunks, pc, pc_lru);
PV_STAT(pv_entry_spare -= _NPCPV);
PV_STAT(pc_chunk_count--);
PV_STAT(pc_chunk_frees++);
/* entire chunk is free, return it */
m = PHYS_TO_VM_PAGE(pmap_kextract((vm_offset_t)pc));
pmap_qremove((vm_offset_t)pc, 1);
vm_page_unwire(m, 0);
vm_page_free(m);
pmap_ptelist_free(&pv_vafree, (vm_offset_t)pc);
}
/*
* get a new pv_entry, allocating a block from the system
* when needed.
*/
static pv_entry_t
get_pv_entry(pmap_t pmap, boolean_t try)
{
static const struct timeval printinterval = { 60, 0 };
static struct timeval lastprint;
int bit, field;
pv_entry_t pv;
struct pv_chunk *pc;
vm_page_t m;
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
rw_assert(&pvh_global_lock, RA_WLOCKED);
PV_STAT(pv_entry_allocs++);
pv_entry_count++;
if (pv_entry_count > pv_entry_high_water)
if (ratecheck(&lastprint, &printinterval))
printf("Approaching the limit on PV entries, consider "
"increasing either the vm.pmap.shpgperproc or the "
"vm.pmap.pv_entry_max tunable.\n");
retry:
pc = TAILQ_FIRST(&pmap->pm_pvchunk);
if (pc != NULL) {
for (field = 0; field < _NPCM; field++) {
if (pc->pc_map[field]) {
bit = bsfl(pc->pc_map[field]);
break;
}
}
if (field < _NPCM) {
pv = &pc->pc_pventry[field * 32 + bit];
pc->pc_map[field] &= ~(1ul << bit);
/* If this was the last item, move it to tail */
for (field = 0; field < _NPCM; field++)
if (pc->pc_map[field] != 0) {
PV_STAT(pv_entry_spare--);
return (pv); /* not full, return */
}
TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list);
PV_STAT(pv_entry_spare--);
return (pv);
}
}
/*
* Access to the ptelist "pv_vafree" is synchronized by the page
* queues lock. If "pv_vafree" is currently non-empty, it will
* remain non-empty until pmap_ptelist_alloc() completes.
*/
if (pv_vafree == 0 || (m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) {
if (try) {
pv_entry_count--;
PV_STAT(pc_chunk_tryfail++);
return (NULL);
}
m = pmap_pv_reclaim(pmap);
if (m == NULL)
goto retry;
}
PV_STAT(pc_chunk_count++);
PV_STAT(pc_chunk_allocs++);
pc = (struct pv_chunk *)pmap_ptelist_alloc(&pv_vafree);
pmap_qenter((vm_offset_t)pc, &m, 1);
if ((m->flags & PG_ZERO) == 0)
pagezero(pc);
pc->pc_pmap = pmap;
pc->pc_map[0] = pc_freemask[0] & ~1ul; /* preallocated bit 0 */
for (field = 1; field < _NPCM; field++)
pc->pc_map[field] = pc_freemask[field];
TAILQ_INSERT_TAIL(&pv_chunks, pc, pc_lru);
pv = &pc->pc_pventry[0];
TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list);
PV_STAT(pv_entry_spare += _NPCPV - 1);
return (pv);
}
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
static __inline pv_entry_t
pmap_pvh_remove(struct md_page *pvh, pmap_t pmap, vm_offset_t va)
{
pv_entry_t pv;
rw_assert(&pvh_global_lock, RA_WLOCKED);
TAILQ_FOREACH(pv, &pvh->pv_list, pv_next) {
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
if (pmap == PV_PMAP(pv) && va == pv->pv_va) {
TAILQ_REMOVE(&pvh->pv_list, pv, pv_next);
break;
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
}
}
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
return (pv);
}
static void
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
pmap_pvh_free(struct md_page *pvh, pmap_t pmap, vm_offset_t va)
{
pv_entry_t pv;
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
pv = pmap_pvh_remove(pvh, pmap, va);
KASSERT(pv != NULL, ("pmap_pvh_free: pv not found"));
free_pv_entry(pmap, pv);
}
static void
pmap_remove_entry(pmap_t pmap, vm_page_t m, vm_offset_t va)
{
rw_assert(&pvh_global_lock, RA_WLOCKED);
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
pmap_pvh_free(&m->md, pmap, va);
if (TAILQ_EMPTY(&m->md.pv_list))
vm_page_aflag_clear(m, PGA_WRITEABLE);
}
/*
* Conditionally create a pv entry.
*/
static boolean_t
pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
{
pv_entry_t pv;
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
rw_assert(&pvh_global_lock, RA_WLOCKED);
if (pv_entry_count < pv_entry_high_water &&
(pv = get_pv_entry(pmap, TRUE)) != NULL) {
pv->pv_va = va;
TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next);
return (TRUE);
} else
return (FALSE);
}
/*
* pmap_remove_pte: do the things to unmap a page in a process
*/
static int
pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va, vm_page_t *free)
{
pt_entry_t oldpte;
vm_page_t m;
CTR3(KTR_PMAP, "pmap_remove_pte: pmap=%p *ptq=0x%x va=0x%x",
pmap, (u_long)*ptq, va);
rw_assert(&pvh_global_lock, RA_WLOCKED);
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
oldpte = *ptq;
PT_SET_VA_MA(ptq, 0, TRUE);
KASSERT(oldpte != 0,
("pmap_remove_pte: pmap %p va %x zero pte", pmap, va));
if (oldpte & PG_W)
pmap->pm_stats.wired_count -= 1;
/*
* Machines that don't support invlpg, also don't support
* PG_G.
*/
if (oldpte & PG_G)
pmap_invalidate_page(kernel_pmap, va);
pmap->pm_stats.resident_count -= 1;
if (oldpte & PG_MANAGED) {
m = PHYS_TO_VM_PAGE(xpmap_mtop(oldpte) & PG_FRAME);
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
if ((oldpte & (PG_M | PG_RW)) == (PG_M | PG_RW))
vm_page_dirty(m);
if (oldpte & PG_A)
vm_page_aflag_set(m, PGA_REFERENCED);
pmap_remove_entry(pmap, m, va);
}
return (pmap_unuse_pt(pmap, va, free));
}
/*
* Remove a single page from a process address space
*/
static void
pmap_remove_page(pmap_t pmap, vm_offset_t va, vm_page_t *free)
{
pt_entry_t *pte;
CTR2(KTR_PMAP, "pmap_remove_page: pmap=%p va=0x%x",
pmap, va);
rw_assert(&pvh_global_lock, RA_WLOCKED);
KASSERT(curthread->td_pinned > 0, ("curthread not pinned"));
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
if ((pte = pmap_pte_quick(pmap, va)) == NULL || (*pte & PG_V) == 0)
return;
pmap_remove_pte(pmap, pte, va, free);
pmap_invalidate_page(pmap, va);
if (*PMAP1)
PT_SET_MA(PADDR1, 0);
}
/*
* Remove the given range of addresses from the specified map.
*
* It is assumed that the start and end are properly
* rounded to the page size.
*/
void
pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
vm_offset_t pdnxt;
pd_entry_t ptpaddr;
pt_entry_t *pte;
vm_page_t free = NULL;
int anyvalid;
CTR3(KTR_PMAP, "pmap_remove: pmap=%p sva=0x%x eva=0x%x",
pmap, sva, eva);
/*
* Perform an unsynchronized read. This is, however, safe.
*/
if (pmap->pm_stats.resident_count == 0)
return;
anyvalid = 0;
rw_wlock(&pvh_global_lock);
sched_pin();
PMAP_LOCK(pmap);
/*
* special handling of removing one page. a very
* common operation and easy to short circuit some
* code.
*/
if ((sva + PAGE_SIZE == eva) &&
((pmap->pm_pdir[(sva >> PDRSHIFT)] & PG_PS) == 0)) {
pmap_remove_page(pmap, sva, &free);
goto out;
}
for (; sva < eva; sva = pdnxt) {
u_int pdirindex;
/*
* Calculate index for next page table.
*/
pdnxt = (sva + NBPDR) & ~PDRMASK;
if (pdnxt < sva)
pdnxt = eva;
if (pmap->pm_stats.resident_count == 0)
break;
pdirindex = sva >> PDRSHIFT;
ptpaddr = pmap->pm_pdir[pdirindex];
/*
* Weed out invalid mappings. Note: we assume that the page
* directory table is always allocated, and in kernel virtual.
*/
if (ptpaddr == 0)
continue;
/*
* Check for large page.
*/
if ((ptpaddr & PG_PS) != 0) {
PD_CLEAR_VA(pmap, pdirindex, TRUE);
pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
anyvalid = 1;
continue;
}
/*
* Limit our scan to either the end of the va represented
* by the current page table page, or to the end of the
* range being removed.
*/
if (pdnxt > eva)
pdnxt = eva;
for (pte = pmap_pte_quick(pmap, sva); sva != pdnxt; pte++,
sva += PAGE_SIZE) {
if ((*pte & PG_V) == 0)
continue;
/*
* The TLB entry for a PG_G mapping is invalidated
* by pmap_remove_pte().
*/
if ((*pte & PG_G) == 0)
anyvalid = 1;
if (pmap_remove_pte(pmap, pte, sva, &free))
break;
}
}
PT_UPDATES_FLUSH();
if (*PMAP1)
PT_SET_VA_MA(PMAP1, 0, TRUE);
out:
if (anyvalid)
pmap_invalidate_all(pmap);
sched_unpin();
rw_wunlock(&pvh_global_lock);
PMAP_UNLOCK(pmap);
pmap_free_zero_pages(free);
}
/*
* Routine: pmap_remove_all
* Function:
* Removes this physical page from
* all physical maps in which it resides.
* Reflects back modify bits to the pager.
*
* Notes:
* Original versions of this routine were very
* inefficient because they iteratively called
* pmap_remove (slow...)
*/
void
pmap_remove_all(vm_page_t m)
{
pv_entry_t pv;
pmap_t pmap;
pt_entry_t *pte, tpte;
vm_page_t free;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
("pmap_remove_all: page %p is not managed", m));
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
free = NULL;
rw_wlock(&pvh_global_lock);
sched_pin();
while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
pmap = PV_PMAP(pv);
PMAP_LOCK(pmap);
pmap->pm_stats.resident_count--;
pte = pmap_pte_quick(pmap, pv->pv_va);
tpte = *pte;
PT_SET_VA_MA(pte, 0, TRUE);
KASSERT(tpte != 0, ("pmap_remove_all: pmap %p va %x zero pte",
pmap, pv->pv_va));
if (tpte & PG_W)
pmap->pm_stats.wired_count--;
if (tpte & PG_A)
vm_page_aflag_set(m, PGA_REFERENCED);
/*
* Update the vm_page_t clean and reference bits.
*/
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
if ((tpte & (PG_M | PG_RW)) == (PG_M | PG_RW))
vm_page_dirty(m);
pmap_unuse_pt(pmap, pv->pv_va, &free);
pmap_invalidate_page(pmap, pv->pv_va);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_next);
free_pv_entry(pmap, pv);
PMAP_UNLOCK(pmap);
}
vm_page_aflag_clear(m, PGA_WRITEABLE);
PT_UPDATES_FLUSH();
if (*PMAP1)
PT_SET_MA(PADDR1, 0);
sched_unpin();
rw_wunlock(&pvh_global_lock);
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
pmap_free_zero_pages(free);
}
/*
* Set the physical protection on the
* specified range of this map as requested.
*/
void
pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
{
vm_offset_t pdnxt;
pd_entry_t ptpaddr;
pt_entry_t *pte;
int anychanged;
CTR4(KTR_PMAP, "pmap_protect: pmap=%p sva=0x%x eva=0x%x prot=0x%x",
pmap, sva, eva, prot);
if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
pmap_remove(pmap, sva, eva);
return;
}
#ifdef PAE
if ((prot & (VM_PROT_WRITE|VM_PROT_EXECUTE)) ==
(VM_PROT_WRITE|VM_PROT_EXECUTE))
return;
#else
if (prot & VM_PROT_WRITE)
return;
#endif
anychanged = 0;
rw_wlock(&pvh_global_lock);
sched_pin();
PMAP_LOCK(pmap);
for (; sva < eva; sva = pdnxt) {
pt_entry_t obits, pbits;
u_int pdirindex;
pdnxt = (sva + NBPDR) & ~PDRMASK;
if (pdnxt < sva)
pdnxt = eva;
pdirindex = sva >> PDRSHIFT;
ptpaddr = pmap->pm_pdir[pdirindex];
/*
* Weed out invalid mappings. Note: we assume that the page
* directory table is always allocated, and in kernel virtual.
*/
if (ptpaddr == 0)
continue;
/*
* Check for large page.
*/
if ((ptpaddr & PG_PS) != 0) {
if ((prot & VM_PROT_WRITE) == 0)
pmap->pm_pdir[pdirindex] &= ~(PG_M|PG_RW);
#ifdef PAE
if ((prot & VM_PROT_EXECUTE) == 0)
pmap->pm_pdir[pdirindex] |= pg_nx;
#endif
anychanged = 1;
continue;
}
if (pdnxt > eva)
pdnxt = eva;
for (pte = pmap_pte_quick(pmap, sva); sva != pdnxt; pte++,
sva += PAGE_SIZE) {
vm_page_t m;
retry:
/*
* Regardless of whether a pte is 32 or 64 bits in
* size, PG_RW, PG_A, and PG_M are among the least
* significant 32 bits.
*/
obits = pbits = *pte;
if ((pbits & PG_V) == 0)
continue;
if ((prot & VM_PROT_WRITE) == 0) {
if ((pbits & (PG_MANAGED | PG_M | PG_RW)) ==
(PG_MANAGED | PG_M | PG_RW)) {
m = PHYS_TO_VM_PAGE(xpmap_mtop(pbits) &
PG_FRAME);
vm_page_dirty(m);
}
pbits &= ~(PG_RW | PG_M);
}
#ifdef PAE
if ((prot & VM_PROT_EXECUTE) == 0)
pbits |= pg_nx;
#endif
if (pbits != obits) {
obits = *pte;
PT_SET_VA_MA(pte, pbits, TRUE);
if (*pte != pbits)
goto retry;
if (obits & PG_G)
pmap_invalidate_page(pmap, sva);
else
anychanged = 1;
}
}
}
PT_UPDATES_FLUSH();
if (*PMAP1)
PT_SET_VA_MA(PMAP1, 0, TRUE);
if (anychanged)
pmap_invalidate_all(pmap);
sched_unpin();
rw_wunlock(&pvh_global_lock);
PMAP_UNLOCK(pmap);
}
/*
* Insert the given physical page (p) at
* the specified virtual address (v) in the
* target physical map with the protection requested.
*
* If specified, the page will be wired down, meaning
* that the related pte can not be reclaimed.
*
* NB: This is the only routine which MAY NOT lazy-evaluate
* or lose information. That is, this routine must actually
* insert this page into the given map NOW.
*/
void
pmap_enter(pmap_t pmap, vm_offset_t va, vm_prot_t access, vm_page_t m,
vm_prot_t prot, boolean_t wired)
{
pd_entry_t *pde;
pt_entry_t *pte;
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
pt_entry_t newpte, origpte;
pv_entry_t pv;
vm_paddr_t opa, pa;
vm_page_t mpte, om;
boolean_t invlva;
CTR6(KTR_PMAP, "pmap_enter: pmap=%08p va=0x%08x access=0x%x ma=0x%08x prot=0x%x wired=%d",
pmap, va, access, VM_PAGE_TO_MACH(m), prot, wired);
va = trunc_page(va);
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
KASSERT(va <= VM_MAX_KERNEL_ADDRESS, ("pmap_enter: toobig"));
KASSERT(va < UPT_MIN_ADDRESS || va >= UPT_MAX_ADDRESS,
("pmap_enter: invalid to pmap_enter page table pages (va: 0x%x)",
va));
if ((m->oflags & (VPO_UNMANAGED | VPO_BUSY)) == 0)
Switch the vm_object mutex to be a rwlock. This will enable in the future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
2013-03-09 02:32:23 +00:00
VM_OBJECT_ASSERT_WLOCKED(m->object);
mpte = NULL;
rw_wlock(&pvh_global_lock);
PMAP_LOCK(pmap);
sched_pin();
/*
* In the case that a page table page is not
* resident, we are creating it here.
*/
if (va < VM_MAXUSER_ADDRESS) {
mpte = pmap_allocpte(pmap, va, M_WAITOK);
}
pde = pmap_pde(pmap, va);
if ((*pde & PG_PS) != 0)
panic("pmap_enter: attempted pmap_enter on 4MB page");
pte = pmap_pte_quick(pmap, va);
/*
* Page Directory table entry not valid, we need a new PT page
*/
if (pte == NULL) {
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
panic("pmap_enter: invalid page directory pdir=%#jx, va=%#x",
(uintmax_t)pmap->pm_pdir[va >> PDRSHIFT], va);
}
pa = VM_PAGE_TO_PHYS(m);
om = NULL;
opa = origpte = 0;
#if 0
KASSERT((*pte & PG_V) || (*pte == 0), ("address set but not valid pte=%p *pte=0x%016jx",
pte, *pte));
#endif
origpte = *pte;
if (origpte)
origpte = xpmap_mtop(origpte);
opa = origpte & PG_FRAME;
/*
* Mapping has not changed, must be protection or wiring change.
*/
if (origpte && (opa == pa)) {
/*
* Wiring change, just update stats. We don't worry about
* wiring PT pages as they remain resident as long as there
* are valid mappings in them. Hence, if a user page is wired,
* the PT page will be also.
*/
if (wired && ((origpte & PG_W) == 0))
pmap->pm_stats.wired_count++;
else if (!wired && (origpte & PG_W))
pmap->pm_stats.wired_count--;
/*
* Remove extra pte reference
*/
if (mpte)
mpte->wire_count--;
if (origpte & PG_MANAGED) {
om = m;
pa |= PG_MANAGED;
}
goto validate;
}
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
pv = NULL;
/*
* Mapping has changed, invalidate old range and fall through to
* handle validating new mapping.
*/
if (opa) {
if (origpte & PG_W)
pmap->pm_stats.wired_count--;
if (origpte & PG_MANAGED) {
om = PHYS_TO_VM_PAGE(opa);
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
pv = pmap_pvh_remove(&om->md, pmap, va);
} else if (va < VM_MAXUSER_ADDRESS)
printf("va=0x%x is unmanaged :-( \n", va);
if (mpte != NULL) {
mpte->wire_count--;
KASSERT(mpte->wire_count > 0,
("pmap_enter: missing reference to page table page,"
" va: 0x%x", va));
}
} else
pmap->pm_stats.resident_count++;
/*
* Enter on the PV list if part of our managed memory.
*/
if ((m->oflags & VPO_UNMANAGED) == 0) {
KASSERT(va < kmi.clean_sva || va >= kmi.clean_eva,
("pmap_enter: managed mapping within the clean submap"));
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
if (pv == NULL)
pv = get_pv_entry(pmap, FALSE);
pv->pv_va = va;
TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next);
pa |= PG_MANAGED;
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
} else if (pv != NULL)
free_pv_entry(pmap, pv);
/*
* Increment counters
*/
if (wired)
pmap->pm_stats.wired_count++;
validate:
/*
* Now validate mapping with desired protection/wiring.
*/
newpte = (pt_entry_t)(pa | PG_V);
if ((prot & VM_PROT_WRITE) != 0) {
newpte |= PG_RW;
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
if ((newpte & PG_MANAGED) != 0)
vm_page_aflag_set(m, PGA_WRITEABLE);
}
#ifdef PAE
if ((prot & VM_PROT_EXECUTE) == 0)
newpte |= pg_nx;
#endif
if (wired)
newpte |= PG_W;
if (va < VM_MAXUSER_ADDRESS)
newpte |= PG_U;
if (pmap == kernel_pmap)
newpte |= pgeflag;
critical_enter();
/*
* if the mapping or permission bits are different, we need
* to update the pte.
*/
if ((origpte & ~(PG_M|PG_A)) != newpte) {
if (origpte) {
invlva = FALSE;
origpte = *pte;
PT_SET_VA(pte, newpte | PG_A, FALSE);
if (origpte & PG_A) {
if (origpte & PG_MANAGED)
vm_page_aflag_set(om, PGA_REFERENCED);
if (opa != VM_PAGE_TO_PHYS(m))
invlva = TRUE;
#ifdef PAE
if ((origpte & PG_NX) == 0 &&
(newpte & PG_NX) != 0)
invlva = TRUE;
#endif
}
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
if ((origpte & (PG_M | PG_RW)) == (PG_M | PG_RW)) {
if ((origpte & PG_MANAGED) != 0)
vm_page_dirty(om);
if ((prot & VM_PROT_WRITE) == 0)
invlva = TRUE;
}
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
if ((origpte & PG_MANAGED) != 0 &&
TAILQ_EMPTY(&om->md.pv_list))
vm_page_aflag_clear(om, PGA_WRITEABLE);
if (invlva)
pmap_invalidate_page(pmap, va);
} else{
PT_SET_VA(pte, newpte | PG_A, FALSE);
}
}
PT_UPDATES_FLUSH();
critical_exit();
if (*PMAP1)
PT_SET_VA_MA(PMAP1, 0, TRUE);
sched_unpin();
rw_wunlock(&pvh_global_lock);
PMAP_UNLOCK(pmap);
}
/*
* Maps a sequence of resident pages belonging to the same object.
* The sequence begins with the given page m_start. This page is
* mapped at the given virtual address start. Each subsequent page is
* mapped at a virtual address that is offset from start by the same
* amount as the page is offset from m_start within the object. The
* last page in the sequence is the page with the largest offset from
* m_start that can be mapped at a virtual address less than the given
* virtual address end. Not every virtual page between start and end
* is mapped; only those for which a resident page exists with the
* corresponding offset from m_start are mapped.
*/
void
pmap_enter_object(pmap_t pmap, vm_offset_t start, vm_offset_t end,
vm_page_t m_start, vm_prot_t prot)
{
vm_page_t m, mpte;
vm_pindex_t diff, psize;
multicall_entry_t mcl[16];
multicall_entry_t *mclp = mcl;
int error, count = 0;
VM_OBJECT_ASSERT_LOCKED(m_start->object);
psize = atop(end - start);
mpte = NULL;
m = m_start;
rw_wlock(&pvh_global_lock);
PMAP_LOCK(pmap);
while (m != NULL && (diff = m->pindex - m_start->pindex) < psize) {
mpte = pmap_enter_quick_locked(&mclp, &count, pmap, start + ptoa(diff), m,
prot, mpte);
m = TAILQ_NEXT(m, listq);
if (count == 16) {
error = HYPERVISOR_multicall(mcl, count);
KASSERT(error == 0, ("bad multicall %d", error));
mclp = mcl;
count = 0;
}
}
if (count) {
error = HYPERVISOR_multicall(mcl, count);
KASSERT(error == 0, ("bad multicall %d", error));
}
rw_wunlock(&pvh_global_lock);
PMAP_UNLOCK(pmap);
}
/*
* this code makes some *MAJOR* assumptions:
* 1. Current pmap & pmap exists.
* 2. Not wired.
* 3. Read access.
* 4. No page table pages.
* but is *MUCH* faster than pmap_enter...
*/
void
pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot)
{
multicall_entry_t mcl, *mclp;
int count = 0;
mclp = &mcl;
CTR4(KTR_PMAP, "pmap_enter_quick: pmap=%p va=0x%x m=%p prot=0x%x",
pmap, va, m, prot);
rw_wlock(&pvh_global_lock);
PMAP_LOCK(pmap);
(void)pmap_enter_quick_locked(&mclp, &count, pmap, va, m, prot, NULL);
if (count)
HYPERVISOR_multicall(&mcl, count);
rw_wunlock(&pvh_global_lock);
PMAP_UNLOCK(pmap);
}
#ifdef notyet
void
pmap_enter_quick_range(pmap_t pmap, vm_offset_t *addrs, vm_page_t *pages, vm_prot_t *prots, int count)
{
int i, error, index = 0;
multicall_entry_t mcl[16];
multicall_entry_t *mclp = mcl;
PMAP_LOCK(pmap);
for (i = 0; i < count; i++, addrs++, pages++, prots++) {
if (!pmap_is_prefaultable_locked(pmap, *addrs))
continue;
(void) pmap_enter_quick_locked(&mclp, &index, pmap, *addrs, *pages, *prots, NULL);
if (index == 16) {
error = HYPERVISOR_multicall(mcl, index);
mclp = mcl;
index = 0;
KASSERT(error == 0, ("bad multicall %d", error));
}
}
if (index) {
error = HYPERVISOR_multicall(mcl, index);
KASSERT(error == 0, ("bad multicall %d", error));
}
PMAP_UNLOCK(pmap);
}
#endif
static vm_page_t
pmap_enter_quick_locked(multicall_entry_t **mclpp, int *count, pmap_t pmap, vm_offset_t va, vm_page_t m,
vm_prot_t prot, vm_page_t mpte)
{
pt_entry_t *pte;
vm_paddr_t pa;
vm_page_t free;
multicall_entry_t *mcl = *mclpp;
KASSERT(va < kmi.clean_sva || va >= kmi.clean_eva ||
(m->oflags & VPO_UNMANAGED) != 0,
("pmap_enter_quick_locked: managed mapping within the clean submap"));
rw_assert(&pvh_global_lock, RA_WLOCKED);
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
/*
* In the case that a page table page is not
* resident, we are creating it here.
*/
if (va < VM_MAXUSER_ADDRESS) {
u_int ptepindex;
pd_entry_t ptema;
/*
* Calculate pagetable page index
*/
ptepindex = va >> PDRSHIFT;
if (mpte && (mpte->pindex == ptepindex)) {
mpte->wire_count++;
} else {
/*
* Get the page directory entry
*/
ptema = pmap->pm_pdir[ptepindex];
/*
* If the page table page is mapped, we just increment
* the hold count, and activate it.
*/
if (ptema & PG_V) {
if (ptema & PG_PS)
panic("pmap_enter_quick: unexpected mapping into 4MB page");
mpte = PHYS_TO_VM_PAGE(xpmap_mtop(ptema) & PG_FRAME);
mpte->wire_count++;
} else {
mpte = _pmap_allocpte(pmap, ptepindex,
M_NOWAIT);
if (mpte == NULL)
return (mpte);
}
}
} else {
mpte = NULL;
}
/*
* This call to vtopte makes the assumption that we are
* entering the page into the current pmap. In order to support
* quick entry into any pmap, one would likely use pmap_pte_quick.
* But that isn't as quick as vtopte.
*/
KASSERT(pmap_is_current(pmap), ("entering pages in non-current pmap"));
pte = vtopte(va);
if (*pte & PG_V) {
if (mpte != NULL) {
mpte->wire_count--;
mpte = NULL;
}
return (mpte);
}
/*
* Enter on the PV list if part of our managed memory.
*/
if ((m->oflags & VPO_UNMANAGED) == 0 &&
!pmap_try_insert_pv_entry(pmap, va, m)) {
if (mpte != NULL) {
free = NULL;
if (pmap_unwire_ptp(pmap, mpte, &free)) {
pmap_invalidate_page(pmap, va);
pmap_free_zero_pages(free);
}
mpte = NULL;
}
return (mpte);
}
/*
* Increment counters
*/
pmap->pm_stats.resident_count++;
pa = VM_PAGE_TO_PHYS(m);
#ifdef PAE
if ((prot & VM_PROT_EXECUTE) == 0)
pa |= pg_nx;
#endif
#if 0
/*
* Now validate mapping with RO protection
*/
if ((m->oflags & VPO_UNMANAGED) != 0)
pte_store(pte, pa | PG_V | PG_U);
else
pte_store(pte, pa | PG_V | PG_U | PG_MANAGED);
#else
/*
* Now validate mapping with RO protection
*/
if ((m->oflags & VPO_UNMANAGED) != 0)
pa = xpmap_ptom(pa | PG_V | PG_U);
else
pa = xpmap_ptom(pa | PG_V | PG_U | PG_MANAGED);
mcl->op = __HYPERVISOR_update_va_mapping;
mcl->args[0] = va;
mcl->args[1] = (uint32_t)(pa & 0xffffffff);
mcl->args[2] = (uint32_t)(pa >> 32);
mcl->args[3] = 0;
*mclpp = mcl + 1;
*count = *count + 1;
#endif
return (mpte);
}
/*
* Make a temporary mapping for a physical address. This is only intended
* to be used for panic dumps.
*/
void *
pmap_kenter_temporary(vm_paddr_t pa, int i)
{
vm_offset_t va;
vm_paddr_t ma = xpmap_ptom(pa);
va = (vm_offset_t)crashdumpmap + (i * PAGE_SIZE);
PT_SET_MA(va, (ma & ~PAGE_MASK) | PG_V | pgeflag);
invlpg(va);
return ((void *)crashdumpmap);
}
/*
* This code maps large physical mmap regions into the
* processor address space. Note that some shortcuts
* are taken, but the code works.
*/
void
pmap_object_init_pt(pmap_t pmap, vm_offset_t addr, vm_object_t object,
vm_pindex_t pindex, vm_size_t size)
{
pd_entry_t *pde;
vm_paddr_t pa, ptepa;
vm_page_t p;
int pat_mode;
Switch the vm_object mutex to be a rwlock. This will enable in the future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
2013-03-09 02:32:23 +00:00
VM_OBJECT_ASSERT_WLOCKED(object);
KASSERT(object->type == OBJT_DEVICE || object->type == OBJT_SG,
("pmap_object_init_pt: non-device object"));
if (pseflag &&
(addr & (NBPDR - 1)) == 0 && (size & (NBPDR - 1)) == 0) {
if (!vm_object_populate(object, pindex, pindex + atop(size)))
return;
p = vm_page_lookup(object, pindex);
KASSERT(p->valid == VM_PAGE_BITS_ALL,
("pmap_object_init_pt: invalid page %p", p));
pat_mode = p->md.pat_mode;
/*
* Abort the mapping if the first page is not physically
* aligned to a 2/4MB page boundary.
*/
ptepa = VM_PAGE_TO_PHYS(p);
if (ptepa & (NBPDR - 1))
return;
/*
* Skip the first page. Abort the mapping if the rest of
* the pages are not physically contiguous or have differing
* memory attributes.
*/
p = TAILQ_NEXT(p, listq);
for (pa = ptepa + PAGE_SIZE; pa < ptepa + size;
pa += PAGE_SIZE) {
KASSERT(p->valid == VM_PAGE_BITS_ALL,
("pmap_object_init_pt: invalid page %p", p));
if (pa != VM_PAGE_TO_PHYS(p) ||
pat_mode != p->md.pat_mode)
return;
p = TAILQ_NEXT(p, listq);
}
/*
* Map using 2/4MB pages. Since "ptepa" is 2/4M aligned and
* "size" is a multiple of 2/4M, adding the PAT setting to
* "pa" will not affect the termination of this loop.
*/
PMAP_LOCK(pmap);
for (pa = ptepa | pmap_cache_bits(pat_mode, 1); pa < ptepa +
size; pa += NBPDR) {
pde = pmap_pde(pmap, addr);
if (*pde == 0) {
pde_store(pde, pa | PG_PS | PG_M | PG_A |
PG_U | PG_RW | PG_V);
pmap->pm_stats.resident_count += NBPDR /
PAGE_SIZE;
pmap_pde_mappings++;
}
/* Else continue on if the PDE is already valid. */
addr += NBPDR;
}
PMAP_UNLOCK(pmap);
}
}
/*
* Routine: pmap_change_wiring
* Function: Change the wiring attribute for a map/virtual-address
* pair.
* In/out conditions:
* The mapping must already exist in the pmap.
*/
void
pmap_change_wiring(pmap_t pmap, vm_offset_t va, boolean_t wired)
{
pt_entry_t *pte;
rw_wlock(&pvh_global_lock);
PMAP_LOCK(pmap);
pte = pmap_pte(pmap, va);
if (wired && !pmap_pte_w(pte)) {
PT_SET_VA_MA((pte), *(pte) | PG_W, TRUE);
pmap->pm_stats.wired_count++;
} else if (!wired && pmap_pte_w(pte)) {
PT_SET_VA_MA((pte), *(pte) & ~PG_W, TRUE);
pmap->pm_stats.wired_count--;
}
/*
* Wiring is not a hardware characteristic so there is no need to
* invalidate TLB.
*/
pmap_pte_release(pte);
PMAP_UNLOCK(pmap);
rw_wunlock(&pvh_global_lock);
}
/*
* Copy the range specified by src_addr/len
* from the source map to the range dst_addr/len
* in the destination map.
*
* This routine is only advisory and need not do anything.
*/
void
pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len,
vm_offset_t src_addr)
{
vm_page_t free;
vm_offset_t addr;
vm_offset_t end_addr = src_addr + len;
vm_offset_t pdnxt;
if (dst_addr != src_addr)
return;
if (!pmap_is_current(src_pmap)) {
CTR2(KTR_PMAP,
"pmap_copy, skipping: pdir[PTDPTDI]=0x%jx PTDpde[0]=0x%jx",
(src_pmap->pm_pdir[PTDPTDI] & PG_FRAME), (PTDpde[0] & PG_FRAME));
return;
}
CTR5(KTR_PMAP, "pmap_copy: dst_pmap=%p src_pmap=%p dst_addr=0x%x len=%d src_addr=0x%x",
dst_pmap, src_pmap, dst_addr, len, src_addr);
#ifdef HAMFISTED_LOCKING
mtx_lock(&createdelete_lock);
#endif
rw_wlock(&pvh_global_lock);
if (dst_pmap < src_pmap) {
PMAP_LOCK(dst_pmap);
PMAP_LOCK(src_pmap);
} else {
PMAP_LOCK(src_pmap);
PMAP_LOCK(dst_pmap);
}
sched_pin();
for (addr = src_addr; addr < end_addr; addr = pdnxt) {
pt_entry_t *src_pte, *dst_pte;
vm_page_t dstmpte, srcmpte;
pd_entry_t srcptepaddr;
u_int ptepindex;
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
KASSERT(addr < UPT_MIN_ADDRESS,
("pmap_copy: invalid to pmap_copy page tables"));
pdnxt = (addr + NBPDR) & ~PDRMASK;
if (pdnxt < addr)
pdnxt = end_addr;
ptepindex = addr >> PDRSHIFT;
srcptepaddr = PT_GET(&src_pmap->pm_pdir[ptepindex]);
if (srcptepaddr == 0)
continue;
if (srcptepaddr & PG_PS) {
if (dst_pmap->pm_pdir[ptepindex] == 0) {
PD_SET_VA(dst_pmap, ptepindex, srcptepaddr & ~PG_W, TRUE);
dst_pmap->pm_stats.resident_count +=
NBPDR / PAGE_SIZE;
}
continue;
}
srcmpte = PHYS_TO_VM_PAGE(srcptepaddr & PG_FRAME);
Merge various changes from i386/i386/pmap.c: The remaining, unmerged portions of r175404 Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel option DIAGNOSTIC still disables inlining of certain pmap functions.) Eliminate dead code from pmap_enter(). This code implemented an assertion. On i386, an equivalent check is already implemented. However, on amd64, a small change is required to implement an equivalent check. Eliminate \n from a nearby panic string. Use KASSERT() to reimplement pmap_copy()'s two assertions. Merge portions of r177659 To date, we have assumed that the TLB will only set the PG_M bit in a PTE if that PTE has the PG_RW bit set. However, this assumption does not hold on recent processors from Intel. For example, consider a PTE that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE is cached in the TLB and later the PG_RW bit is cleared in the PTE, but the corresponding TLB entry is not (yet) invalidated. Historically, upon a write access using this (stale) TLB entry, the TLB would observe that the PG_RW bit had been cleared and initiate a page fault, aborting the setting of the PG_M bit in the PTE. Now, however, P4- and Core2-family processors will set the PG_M bit before observing that the PG_RW bit is clear and initiating a page fault. In other words, the write does not occur but the PG_M bit is still set. The real impact of this difference is not that great. Specifically, we should no longer assert that any PTE with the PG_M bit set must also have the PG_RW bit set, and we should ignore the state of the PG_M bit unless the PG_RW bit is set. r208609 Defer freeing any page table pages in pmap_remove_all() until after the page queues lock is released. This may reduce the amount of time that the page queues lock is held by pmap_remove_all(). r208645 When I pushed down the page queues lock into pmap_is_modified(), I created an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified() could return FALSE without acquiring the page queues lock because the page is not (currently) writeable, and the caller to pmap_is_modified() might believe that the page's dirty field is clear because it has not seen the effect of the vm_page_dirty() call. When I pushed down the page queues lock into pmap_is_modified(), I overlooked one place where this ordering dependence is violated: pmap_enter(). In a rare situation pmap_enter() can be called to replace a dirty mapping to one page with a mapping to another page. (I say rare because replacements generally occur as a result of a copy-on-write fault, and so the old page is not dirty.) This change delays clearing PG_WRITEABLE until after vm_page_dirty() has been called. Fixing the ordering dependency also makes it easy to introduce a small optimization: When pmap_enter() used to replace a mapping to one page with a mapping to another page, it freed the pv entry for the first mapping and later called the pv entry allocator for the new mapping. Now, pmap_enter() attempts to recycle the old pv entry, saving two calls to the pv entry allocator. There is no point in setting PG_WRITEABLE on unmanaged pages, so don't. Update a comment to reflect this. Tidy up the variable declarations at the start of pmap_enter().
2010-05-30 04:44:32 +00:00
KASSERT(srcmpte->wire_count > 0,
("pmap_copy: source page table page is unused"));
if (pdnxt > end_addr)
pdnxt = end_addr;
src_pte = vtopte(addr);
while (addr < pdnxt) {
pt_entry_t ptetemp;
ptetemp = *src_pte;
/*
* we only virtual copy managed pages
*/
if ((ptetemp & PG_MANAGED) != 0) {
dstmpte = pmap_allocpte(dst_pmap, addr,
M_NOWAIT);
if (dstmpte == NULL)
goto out;
dst_pte = pmap_pte_quick(dst_pmap, addr);
if (*dst_pte == 0 &&
pmap_try_insert_pv_entry(dst_pmap, addr,
PHYS_TO_VM_PAGE(xpmap_mtop(ptetemp) & PG_FRAME))) {
/*
* Clear the wired, modified, and
* accessed (referenced) bits
* during the copy.
*/
KASSERT(ptetemp != 0, ("src_pte not set"));
PT_SET_VA_MA(dst_pte, ptetemp & ~(PG_W | PG_M | PG_A), TRUE /* XXX debug */);
KASSERT(*dst_pte == (ptetemp & ~(PG_W | PG_M | PG_A)),
("no pmap copy expected: 0x%jx saw: 0x%jx",
ptetemp & ~(PG_W | PG_M | PG_A), *dst_pte));
dst_pmap->pm_stats.resident_count++;
} else {
free = NULL;
if (pmap_unwire_ptp(dst_pmap, dstmpte,
&free)) {
pmap_invalidate_page(dst_pmap,
addr);
pmap_free_zero_pages(free);
}
goto out;
}
if (dstmpte->wire_count >= srcmpte->wire_count)
break;
}
addr += PAGE_SIZE;
src_pte++;
}
}
out:
PT_UPDATES_FLUSH();
sched_unpin();
rw_wunlock(&pvh_global_lock);
PMAP_UNLOCK(src_pmap);
PMAP_UNLOCK(dst_pmap);
#ifdef HAMFISTED_LOCKING
mtx_unlock(&createdelete_lock);
#endif
}
static __inline void
pagezero(void *page)
{
#if defined(I686_CPU)
if (cpu_class == CPUCLASS_686) {
#if defined(CPU_ENABLE_SSE)
if (cpu_feature & CPUID_SSE2)
sse2_pagezero(page);
else
#endif
i686_pagezero(page);
} else
#endif
bzero(page, PAGE_SIZE);
}
/*
* pmap_zero_page zeros the specified hardware page by mapping
* the page into KVM and using bzero to clear its contents.
*/
void
pmap_zero_page(vm_page_t m)
{
struct sysmaps *sysmaps;
sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
mtx_lock(&sysmaps->lock);
if (*sysmaps->CMAP2)
panic("pmap_zero_page: CMAP2 busy");
sched_pin();
PT_SET_MA(sysmaps->CADDR2, PG_V | PG_RW | VM_PAGE_TO_MACH(m) | PG_A | PG_M);
pagezero(sysmaps->CADDR2);
PT_SET_MA(sysmaps->CADDR2, 0);
sched_unpin();
mtx_unlock(&sysmaps->lock);
}
/*
* pmap_zero_page_area zeros the specified hardware page by mapping
* the page into KVM and using bzero to clear its contents.
*
* off and size may not cover an area beyond a single hardware page.
*/
void
pmap_zero_page_area(vm_page_t m, int off, int size)
{
struct sysmaps *sysmaps;
sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
mtx_lock(&sysmaps->lock);
if (*sysmaps->CMAP2)
panic("pmap_zero_page_area: CMAP2 busy");
sched_pin();
PT_SET_MA(sysmaps->CADDR2, PG_V | PG_RW | VM_PAGE_TO_MACH(m) | PG_A | PG_M);
if (off == 0 && size == PAGE_SIZE)
pagezero(sysmaps->CADDR2);
else
bzero((char *)sysmaps->CADDR2 + off, size);
PT_SET_MA(sysmaps->CADDR2, 0);
sched_unpin();
mtx_unlock(&sysmaps->lock);
}
/*
* pmap_zero_page_idle zeros the specified hardware page by mapping
* the page into KVM and using bzero to clear its contents. This
* is intended to be called from the vm_pagezero process only and
* outside of Giant.
*/
void
pmap_zero_page_idle(vm_page_t m)
{
if (*CMAP3)
panic("pmap_zero_page_idle: CMAP3 busy");
sched_pin();
PT_SET_MA(CADDR3, PG_V | PG_RW | VM_PAGE_TO_MACH(m) | PG_A | PG_M);
pagezero(CADDR3);
PT_SET_MA(CADDR3, 0);
sched_unpin();
}
/*
* pmap_copy_page copies the specified (machine independent)
* page by mapping the page into virtual memory and using
* bcopy to copy the page, one machine dependent page at a
* time.
*/
void
pmap_copy_page(vm_page_t src, vm_page_t dst)
{
struct sysmaps *sysmaps;
sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
mtx_lock(&sysmaps->lock);
if (*sysmaps->CMAP1)
panic("pmap_copy_page: CMAP1 busy");
if (*sysmaps->CMAP2)
panic("pmap_copy_page: CMAP2 busy");
sched_pin();
PT_SET_MA(sysmaps->CADDR1, PG_V | VM_PAGE_TO_MACH(src) | PG_A);
PT_SET_MA(sysmaps->CADDR2, PG_V | PG_RW | VM_PAGE_TO_MACH(dst) | PG_A | PG_M);
bcopy(sysmaps->CADDR1, sysmaps->CADDR2, PAGE_SIZE);
PT_SET_MA(sysmaps->CADDR1, 0);
PT_SET_MA(sysmaps->CADDR2, 0);
sched_unpin();
mtx_unlock(&sysmaps->lock);
}
Implement the concept of the unmapped VMIO buffers, i.e. buffers which do not map the b_pages pages into buffer_map KVA. The use of the unmapped buffers eliminate the need to perform TLB shootdown for mapping on the buffer creation and reuse, greatly reducing the amount of IPIs for shootdown on big-SMP machines and eliminating up to 25-30% of the system time on i/o intensive workloads. The unmapped buffer should be explicitely requested by the GB_UNMAPPED flag by the consumer. For unmapped buffer, no KVA reservation is performed at all. The consumer might request unmapped buffer which does have a KVA reserve, to manually map it without recursing into buffer cache and blocking, with the GB_KVAALLOC flag. When the mapped buffer is requested and unmapped buffer already exists, the cache performs an upgrade, possibly reusing the KVA reservation. Unmapped buffer is translated into unmapped bio in g_vfs_strategy(). Unmapped bio carry a pointer to the vm_page_t array, offset and length instead of the data pointer. The provider which processes the bio should explicitely specify a readiness to accept unmapped bio, otherwise g_down geom thread performs the transient upgrade of the bio request by mapping the pages into the new bio_transient_map KVA submap. The bio_transient_map submap claims up to 10% of the buffer map, and the total buffer_map + bio_transient_map KVA usage stays the same. Still, it could be manually tuned by kern.bio_transient_maxcnt tunable, in the units of the transient mappings. Eventually, the bio_transient_map could be removed after all geom classes and drivers can accept unmapped i/o requests. Unmapped support can be turned off by the vfs.unmapped_buf_allowed tunable, disabling which makes the buffer (or cluster) creation requests to ignore GB_UNMAPPED and GB_KVAALLOC flags. Unmapped buffers are only enabled by default on the architectures where pmap_copy_page() was implemented and tested. In the rework, filesystem metadata is not the subject to maxbufspace limit anymore. Since the metadata buffers are always mapped, the buffers still have to fit into the buffer map, which provides a reasonable (but practically unreachable) upper bound on it. The non-metadata buffer allocations, both mapped and unmapped, is accounted against maxbufspace, as before. Effectively, this means that the maxbufspace is forced on mapped and unmapped buffers separately. The pre-patch bufspace limiting code did not worked, because buffer_map fragmentation does not allow the limit to be reached. By Jeff Roberson request, the getnewbuf() function was split into smaller single-purpose functions. Sponsored by: The FreeBSD Foundation Discussed with: jeff (previous version) Tested by: pho, scottl (previous version), jhb, bf MFC after: 2 weeks
2013-03-19 14:13:12 +00:00
int unmapped_buf_allowed = 1;
void
pmap_copy_pages(vm_page_t ma[], vm_offset_t a_offset, vm_page_t mb[],
vm_offset_t b_offset, int xfersize)
{
struct sysmaps *sysmaps;
vm_page_t a_pg, b_pg;
char *a_cp, *b_cp;
vm_offset_t a_pg_offset, b_pg_offset;
int cnt;
sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
mtx_lock(&sysmaps->lock);
if (*sysmaps->CMAP1 != 0)
panic("pmap_copy_pages: CMAP1 busy");
if (*sysmaps->CMAP2 != 0)
panic("pmap_copy_pages: CMAP2 busy");
sched_pin();
while (xfersize > 0) {
a_pg = ma[a_offset >> PAGE_SHIFT];
a_pg_offset = a_offset & PAGE_MASK;
cnt = min(xfersize, PAGE_SIZE - a_pg_offset);
b_pg = mb[b_offset >> PAGE_SHIFT];
b_pg_offset = b_offset & PAGE_MASK;
cnt = min(cnt, PAGE_SIZE - b_pg_offset);
PT_SET_MA(sysmaps->CADDR1, PG_V | VM_PAGE_TO_MACH(a_pg) | PG_A);
PT_SET_MA(sysmaps->CADDR2, PG_V | PG_RW |
VM_PAGE_TO_MACH(b_pg) | PG_A | PG_M);
a_cp = sysmaps->CADDR1 + a_pg_offset;
b_cp = sysmaps->CADDR2 + b_pg_offset;
bcopy(a_cp, b_cp, cnt);
a_offset += cnt;
b_offset += cnt;
xfersize -= cnt;
}
PT_SET_MA(sysmaps->CADDR1, 0);
PT_SET_MA(sysmaps->CADDR2, 0);
sched_unpin();
mtx_unlock(&sysmaps->lock);
}
/*
* Returns true if the pmap's pv is one of the first
* 16 pvs linked to from this page. This count may
* be changed upwards or downwards in the future; it
* is only necessary that true be returned for a small
* subset of pmaps for proper page aging.
*/
boolean_t
pmap_page_exists_quick(pmap_t pmap, vm_page_t m)
{
pv_entry_t pv;
int loops = 0;
Reduce the scope of the page queues lock and the number of PG_REFERENCED changes in vm_pageout_object_deactivate_pages(). Simplify this function's inner loop using TAILQ_FOREACH(), and shorten some of its overly long lines. Update a stale comment. Assert that PG_REFERENCED may be cleared only if the object containing the page is locked. Add a comment documenting this. Assert that a caller to vm_page_requeue() holds the page queues lock, and assert that the page is on a page queue. Push down the page queues lock into pmap_ts_referenced() and pmap_page_exists_quick(). (As of now, there are no longer any pmap functions that expect to be called with the page queues lock held.) Neither pmap_ts_referenced() nor pmap_page_exists_quick() should ever be passed an unmanaged page. Assert this rather than returning "0" and "FALSE" respectively. ARM: Simplify pmap_page_exists_quick() by switching to TAILQ_FOREACH(). Push down the page queues lock inside of pmap_clearbit(), simplifying pmap_clear_modify(), pmap_clear_reference(), and pmap_remove_write(). Additionally, this allows for avoiding the acquisition of the page queues lock in some cases. PowerPC/AIM: moea*_page_exits_quick() and moea*_page_wired_mappings() will never be called before pmap initialization is complete. Therefore, the check for moea_initialized can be eliminated. Push down the page queues lock inside of moea*_clear_bit(), simplifying moea*_clear_modify() and moea*_clear_reference(). The last parameter to moea*_clear_bit() is never used. Eliminate it. PowerPC/BookE: Simplify mmu_booke_page_exists_quick()'s control flow. Reviewed by: kib@
2010-06-10 16:56:35 +00:00
boolean_t rv;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
Reduce the scope of the page queues lock and the number of PG_REFERENCED changes in vm_pageout_object_deactivate_pages(). Simplify this function's inner loop using TAILQ_FOREACH(), and shorten some of its overly long lines. Update a stale comment. Assert that PG_REFERENCED may be cleared only if the object containing the page is locked. Add a comment documenting this. Assert that a caller to vm_page_requeue() holds the page queues lock, and assert that the page is on a page queue. Push down the page queues lock into pmap_ts_referenced() and pmap_page_exists_quick(). (As of now, there are no longer any pmap functions that expect to be called with the page queues lock held.) Neither pmap_ts_referenced() nor pmap_page_exists_quick() should ever be passed an unmanaged page. Assert this rather than returning "0" and "FALSE" respectively. ARM: Simplify pmap_page_exists_quick() by switching to TAILQ_FOREACH(). Push down the page queues lock inside of pmap_clearbit(), simplifying pmap_clear_modify(), pmap_clear_reference(), and pmap_remove_write(). Additionally, this allows for avoiding the acquisition of the page queues lock in some cases. PowerPC/AIM: moea*_page_exits_quick() and moea*_page_wired_mappings() will never be called before pmap initialization is complete. Therefore, the check for moea_initialized can be eliminated. Push down the page queues lock inside of moea*_clear_bit(), simplifying moea*_clear_modify() and moea*_clear_reference(). The last parameter to moea*_clear_bit() is never used. Eliminate it. PowerPC/BookE: Simplify mmu_booke_page_exists_quick()'s control flow. Reviewed by: kib@
2010-06-10 16:56:35 +00:00
("pmap_page_exists_quick: page %p is not managed", m));
rv = FALSE;
rw_wlock(&pvh_global_lock);
TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
if (PV_PMAP(pv) == pmap) {
Reduce the scope of the page queues lock and the number of PG_REFERENCED changes in vm_pageout_object_deactivate_pages(). Simplify this function's inner loop using TAILQ_FOREACH(), and shorten some of its overly long lines. Update a stale comment. Assert that PG_REFERENCED may be cleared only if the object containing the page is locked. Add a comment documenting this. Assert that a caller to vm_page_requeue() holds the page queues lock, and assert that the page is on a page queue. Push down the page queues lock into pmap_ts_referenced() and pmap_page_exists_quick(). (As of now, there are no longer any pmap functions that expect to be called with the page queues lock held.) Neither pmap_ts_referenced() nor pmap_page_exists_quick() should ever be passed an unmanaged page. Assert this rather than returning "0" and "FALSE" respectively. ARM: Simplify pmap_page_exists_quick() by switching to TAILQ_FOREACH(). Push down the page queues lock inside of pmap_clearbit(), simplifying pmap_clear_modify(), pmap_clear_reference(), and pmap_remove_write(). Additionally, this allows for avoiding the acquisition of the page queues lock in some cases. PowerPC/AIM: moea*_page_exits_quick() and moea*_page_wired_mappings() will never be called before pmap initialization is complete. Therefore, the check for moea_initialized can be eliminated. Push down the page queues lock inside of moea*_clear_bit(), simplifying moea*_clear_modify() and moea*_clear_reference(). The last parameter to moea*_clear_bit() is never used. Eliminate it. PowerPC/BookE: Simplify mmu_booke_page_exists_quick()'s control flow. Reviewed by: kib@
2010-06-10 16:56:35 +00:00
rv = TRUE;
break;
}
loops++;
if (loops >= 16)
break;
}
rw_wunlock(&pvh_global_lock);
Reduce the scope of the page queues lock and the number of PG_REFERENCED changes in vm_pageout_object_deactivate_pages(). Simplify this function's inner loop using TAILQ_FOREACH(), and shorten some of its overly long lines. Update a stale comment. Assert that PG_REFERENCED may be cleared only if the object containing the page is locked. Add a comment documenting this. Assert that a caller to vm_page_requeue() holds the page queues lock, and assert that the page is on a page queue. Push down the page queues lock into pmap_ts_referenced() and pmap_page_exists_quick(). (As of now, there are no longer any pmap functions that expect to be called with the page queues lock held.) Neither pmap_ts_referenced() nor pmap_page_exists_quick() should ever be passed an unmanaged page. Assert this rather than returning "0" and "FALSE" respectively. ARM: Simplify pmap_page_exists_quick() by switching to TAILQ_FOREACH(). Push down the page queues lock inside of pmap_clearbit(), simplifying pmap_clear_modify(), pmap_clear_reference(), and pmap_remove_write(). Additionally, this allows for avoiding the acquisition of the page queues lock in some cases. PowerPC/AIM: moea*_page_exits_quick() and moea*_page_wired_mappings() will never be called before pmap initialization is complete. Therefore, the check for moea_initialized can be eliminated. Push down the page queues lock inside of moea*_clear_bit(), simplifying moea*_clear_modify() and moea*_clear_reference(). The last parameter to moea*_clear_bit() is never used. Eliminate it. PowerPC/BookE: Simplify mmu_booke_page_exists_quick()'s control flow. Reviewed by: kib@
2010-06-10 16:56:35 +00:00
return (rv);
}
/*
* pmap_page_wired_mappings:
*
* Return the number of managed mappings to the given physical page
* that are wired.
*/
int
pmap_page_wired_mappings(vm_page_t m)
{
pv_entry_t pv;
pt_entry_t *pte;
pmap_t pmap;
int count;
count = 0;
if ((m->oflags & VPO_UNMANAGED) != 0)
return (count);
rw_wlock(&pvh_global_lock);
sched_pin();
TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
pmap = PV_PMAP(pv);
PMAP_LOCK(pmap);
pte = pmap_pte_quick(pmap, pv->pv_va);
if ((*pte & PG_W) != 0)
count++;
PMAP_UNLOCK(pmap);
}
sched_unpin();
rw_wunlock(&pvh_global_lock);
return (count);
}
/*
* Returns TRUE if the given page is mapped. Otherwise, returns FALSE.
*/
boolean_t
pmap_page_is_mapped(vm_page_t m)
{
if ((m->oflags & VPO_UNMANAGED) != 0)
return (FALSE);
return (!TAILQ_EMPTY(&m->md.pv_list));
}
/*
* Remove all pages from specified address space
* this aids process exit speeds. Also, this code
* is special cased for current process only, but
* can have the more generic (and slightly slower)
* mode enabled. This is much faster than pmap_remove
* in the case of running down an entire address space.
*/
void
pmap_remove_pages(pmap_t pmap)
{
pt_entry_t *pte, tpte;
vm_page_t m, free = NULL;
pv_entry_t pv;
struct pv_chunk *pc, *npc;
int field, idx;
int32_t bit;
uint32_t inuse, bitmask;
int allfree;
CTR1(KTR_PMAP, "pmap_remove_pages: pmap=%p", pmap);
if (pmap != vmspace_pmap(curthread->td_proc->p_vmspace)) {
printf("warning: pmap_remove_pages called with non-current pmap\n");
return;
}
rw_wlock(&pvh_global_lock);
KASSERT(pmap_is_current(pmap), ("removing pages from non-current pmap"));
PMAP_LOCK(pmap);
sched_pin();
TAILQ_FOREACH_SAFE(pc, &pmap->pm_pvchunk, pc_list, npc) {
KASSERT(pc->pc_pmap == pmap, ("Wrong pmap %p %p", pmap,
pc->pc_pmap));
allfree = 1;
for (field = 0; field < _NPCM; field++) {
inuse = ~pc->pc_map[field] & pc_freemask[field];
while (inuse != 0) {
bit = bsfl(inuse);
bitmask = 1UL << bit;
idx = field * 32 + bit;
pv = &pc->pc_pventry[idx];
inuse &= ~bitmask;
pte = vtopte(pv->pv_va);
tpte = *pte ? xpmap_mtop(*pte) : 0;
if (tpte == 0) {
printf(
"TPTE at %p IS ZERO @ VA %08x\n",
pte, pv->pv_va);
panic("bad pte");
}
/*
* We cannot remove wired pages from a process' mapping at this time
*/
if (tpte & PG_W) {
allfree = 0;
continue;
}
m = PHYS_TO_VM_PAGE(tpte & PG_FRAME);
KASSERT(m->phys_addr == (tpte & PG_FRAME),
("vm_page_t %p phys_addr mismatch %016jx %016jx",
m, (uintmax_t)m->phys_addr,
(uintmax_t)tpte));
KASSERT(m < &vm_page_array[vm_page_array_size],
("pmap_remove_pages: bad tpte %#jx",
(uintmax_t)tpte));
PT_CLEAR_VA(pte, FALSE);
/*
* Update the vm_page_t clean/reference bits.
*/
if (tpte & PG_M)
vm_page_dirty(m);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_next);
if (TAILQ_EMPTY(&m->md.pv_list))
vm_page_aflag_clear(m, PGA_WRITEABLE);
pmap_unuse_pt(pmap, pv->pv_va, &free);
/* Mark free */
PV_STAT(pv_entry_frees++);
PV_STAT(pv_entry_spare++);
pv_entry_count--;
pc->pc_map[field] |= bitmask;
pmap->pm_stats.resident_count--;
}
}
PT_UPDATES_FLUSH();
if (allfree) {
TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
free_pv_chunk(pc);
}
}
PT_UPDATES_FLUSH();
if (*PMAP1)
PT_SET_MA(PADDR1, 0);
sched_unpin();
pmap_invalidate_all(pmap);
rw_wunlock(&pvh_global_lock);
PMAP_UNLOCK(pmap);
pmap_free_zero_pages(free);
}
/*
* pmap_is_modified:
*
* Return whether or not the specified physical page was modified
* in any physical maps.
*/
boolean_t
pmap_is_modified(vm_page_t m)
{
pv_entry_t pv;
pt_entry_t *pte;
pmap_t pmap;
boolean_t rv;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
("pmap_is_modified: page %p is not managed", m));
rv = FALSE;
/*
* If the page is not VPO_BUSY, then PGA_WRITEABLE cannot be
* concurrently set while the object is locked. Thus, if PGA_WRITEABLE
* is clear, no PTEs can have PG_M set.
*/
Switch the vm_object mutex to be a rwlock. This will enable in the future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
2013-03-09 02:32:23 +00:00
VM_OBJECT_ASSERT_WLOCKED(m->object);
if ((m->oflags & VPO_BUSY) == 0 &&
(m->aflags & PGA_WRITEABLE) == 0)
return (rv);
rw_wlock(&pvh_global_lock);
sched_pin();
TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
pmap = PV_PMAP(pv);
PMAP_LOCK(pmap);
pte = pmap_pte_quick(pmap, pv->pv_va);
rv = (*pte & PG_M) != 0;
PMAP_UNLOCK(pmap);
if (rv)
break;
}
if (*PMAP1)
PT_SET_MA(PADDR1, 0);
sched_unpin();
rw_wunlock(&pvh_global_lock);
return (rv);
}
/*
* pmap_is_prefaultable:
*
* Return whether or not the specified virtual address is elgible
* for prefault.
*/
static boolean_t
pmap_is_prefaultable_locked(pmap_t pmap, vm_offset_t addr)
{
pt_entry_t *pte;
boolean_t rv = FALSE;
return (rv);
if (pmap_is_current(pmap) && *pmap_pde(pmap, addr)) {
pte = vtopte(addr);
rv = (*pte == 0);
}
return (rv);
}
boolean_t
pmap_is_prefaultable(pmap_t pmap, vm_offset_t addr)
{
boolean_t rv;
PMAP_LOCK(pmap);
rv = pmap_is_prefaultable_locked(pmap, addr);
PMAP_UNLOCK(pmap);
return (rv);
}
boolean_t
pmap_is_referenced(vm_page_t m)
{
pv_entry_t pv;
pt_entry_t *pte;
pmap_t pmap;
boolean_t rv;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
("pmap_is_referenced: page %p is not managed", m));
rv = FALSE;
rw_wlock(&pvh_global_lock);
sched_pin();
TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
pmap = PV_PMAP(pv);
PMAP_LOCK(pmap);
pte = pmap_pte_quick(pmap, pv->pv_va);
rv = (*pte & (PG_A | PG_V)) == (PG_A | PG_V);
PMAP_UNLOCK(pmap);
if (rv)
break;
}
if (*PMAP1)
PT_SET_MA(PADDR1, 0);
sched_unpin();
rw_wunlock(&pvh_global_lock);
return (rv);
}
void
pmap_map_readonly(pmap_t pmap, vm_offset_t va, int len)
{
int i, npages = round_page(len) >> PAGE_SHIFT;
for (i = 0; i < npages; i++) {
pt_entry_t *pte;
pte = pmap_pte(pmap, (vm_offset_t)(va + i*PAGE_SIZE));
rw_wlock(&pvh_global_lock);
pte_store(pte, xpmap_mtop(*pte & ~(PG_RW|PG_M)));
rw_wunlock(&pvh_global_lock);
PMAP_MARK_PRIV(xpmap_mtop(*pte));
pmap_pte_release(pte);
}
}
void
pmap_map_readwrite(pmap_t pmap, vm_offset_t va, int len)
{
int i, npages = round_page(len) >> PAGE_SHIFT;
for (i = 0; i < npages; i++) {
pt_entry_t *pte;
pte = pmap_pte(pmap, (vm_offset_t)(va + i*PAGE_SIZE));
PMAP_MARK_UNPRIV(xpmap_mtop(*pte));
rw_wlock(&pvh_global_lock);
pte_store(pte, xpmap_mtop(*pte) | (PG_RW|PG_M));
rw_wunlock(&pvh_global_lock);
pmap_pte_release(pte);
}
}
/*
* Clear the write and modified bits in each of the given page's mappings.
*/
void
pmap_remove_write(vm_page_t m)
{
pv_entry_t pv;
pmap_t pmap;
pt_entry_t oldpte, *pte;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
("pmap_remove_write: page %p is not managed", m));
/*
* If the page is not VPO_BUSY, then PGA_WRITEABLE cannot be set by
* another thread while the object is locked. Thus, if PGA_WRITEABLE
* is clear, no page table entries need updating.
*/
Switch the vm_object mutex to be a rwlock. This will enable in the future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
2013-03-09 02:32:23 +00:00
VM_OBJECT_ASSERT_WLOCKED(m->object);
if ((m->oflags & VPO_BUSY) == 0 &&
(m->aflags & PGA_WRITEABLE) == 0)
return;
rw_wlock(&pvh_global_lock);
sched_pin();
TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
pmap = PV_PMAP(pv);
PMAP_LOCK(pmap);
pte = pmap_pte_quick(pmap, pv->pv_va);
retry:
oldpte = *pte;
if ((oldpte & PG_RW) != 0) {
vm_paddr_t newpte = oldpte & ~(PG_RW | PG_M);
/*
* Regardless of whether a pte is 32 or 64 bits
* in size, PG_RW and PG_M are among the least
* significant 32 bits.
*/
PT_SET_VA_MA(pte, newpte, TRUE);
if (*pte != newpte)
goto retry;
if ((oldpte & PG_M) != 0)
vm_page_dirty(m);
pmap_invalidate_page(pmap, pv->pv_va);
}
PMAP_UNLOCK(pmap);
}
vm_page_aflag_clear(m, PGA_WRITEABLE);
PT_UPDATES_FLUSH();
if (*PMAP1)
PT_SET_MA(PADDR1, 0);
sched_unpin();
rw_wunlock(&pvh_global_lock);
}
/*
* pmap_ts_referenced:
*
* Return a count of reference bits for a page, clearing those bits.
* It is not necessary for every reference bit to be cleared, but it
* is necessary that 0 only be returned when there are truly no
* reference bits set.
*
* XXX: The exact number of bits to check and clear is a matter that
* should be tested and standardized at some point in the future for
* optimal aging of shared pages.
*/
int
pmap_ts_referenced(vm_page_t m)
{
pv_entry_t pv, pvf, pvn;
pmap_t pmap;
pt_entry_t *pte;
int rtval = 0;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
Reduce the scope of the page queues lock and the number of PG_REFERENCED changes in vm_pageout_object_deactivate_pages(). Simplify this function's inner loop using TAILQ_FOREACH(), and shorten some of its overly long lines. Update a stale comment. Assert that PG_REFERENCED may be cleared only if the object containing the page is locked. Add a comment documenting this. Assert that a caller to vm_page_requeue() holds the page queues lock, and assert that the page is on a page queue. Push down the page queues lock into pmap_ts_referenced() and pmap_page_exists_quick(). (As of now, there are no longer any pmap functions that expect to be called with the page queues lock held.) Neither pmap_ts_referenced() nor pmap_page_exists_quick() should ever be passed an unmanaged page. Assert this rather than returning "0" and "FALSE" respectively. ARM: Simplify pmap_page_exists_quick() by switching to TAILQ_FOREACH(). Push down the page queues lock inside of pmap_clearbit(), simplifying pmap_clear_modify(), pmap_clear_reference(), and pmap_remove_write(). Additionally, this allows for avoiding the acquisition of the page queues lock in some cases. PowerPC/AIM: moea*_page_exits_quick() and moea*_page_wired_mappings() will never be called before pmap initialization is complete. Therefore, the check for moea_initialized can be eliminated. Push down the page queues lock inside of moea*_clear_bit(), simplifying moea*_clear_modify() and moea*_clear_reference(). The last parameter to moea*_clear_bit() is never used. Eliminate it. PowerPC/BookE: Simplify mmu_booke_page_exists_quick()'s control flow. Reviewed by: kib@
2010-06-10 16:56:35 +00:00
("pmap_ts_referenced: page %p is not managed", m));
rw_wlock(&pvh_global_lock);
sched_pin();
if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
pvf = pv;
do {
pvn = TAILQ_NEXT(pv, pv_next);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_next);
TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next);
pmap = PV_PMAP(pv);
PMAP_LOCK(pmap);
pte = pmap_pte_quick(pmap, pv->pv_va);
if ((*pte & PG_A) != 0) {
PT_SET_VA_MA(pte, *pte & ~PG_A, FALSE);
pmap_invalidate_page(pmap, pv->pv_va);
rtval++;
if (rtval > 4)
pvn = NULL;
}
PMAP_UNLOCK(pmap);
} while ((pv = pvn) != NULL && pv != pvf);
}
PT_UPDATES_FLUSH();
if (*PMAP1)
PT_SET_MA(PADDR1, 0);
sched_unpin();
rw_wunlock(&pvh_global_lock);
return (rtval);
}
/*
* Clear the modify bits on the specified physical page.
*/
void
pmap_clear_modify(vm_page_t m)
{
pv_entry_t pv;
pmap_t pmap;
pt_entry_t *pte;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
("pmap_clear_modify: page %p is not managed", m));
Switch the vm_object mutex to be a rwlock. This will enable in the future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
2013-03-09 02:32:23 +00:00
VM_OBJECT_ASSERT_WLOCKED(m->object);
KASSERT((m->oflags & VPO_BUSY) == 0,
("pmap_clear_modify: page %p is busy", m));
/*
* If the page is not PGA_WRITEABLE, then no PTEs can have PG_M set.
* If the object containing the page is locked and the page is not
* VPO_BUSY, then PGA_WRITEABLE cannot be concurrently set.
*/
if ((m->aflags & PGA_WRITEABLE) == 0)
return;
rw_wlock(&pvh_global_lock);
sched_pin();
TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
pmap = PV_PMAP(pv);
PMAP_LOCK(pmap);
pte = pmap_pte_quick(pmap, pv->pv_va);
if ((*pte & (PG_M | PG_RW)) == (PG_M | PG_RW)) {
/*
* Regardless of whether a pte is 32 or 64 bits
* in size, PG_M is among the least significant
* 32 bits.
*/
PT_SET_VA_MA(pte, *pte & ~PG_M, FALSE);
pmap_invalidate_page(pmap, pv->pv_va);
}
PMAP_UNLOCK(pmap);
}
sched_unpin();
rw_wunlock(&pvh_global_lock);
}
/*
* pmap_clear_reference:
*
* Clear the reference bit on the specified physical page.
*/
void
pmap_clear_reference(vm_page_t m)
{
pv_entry_t pv;
pmap_t pmap;
pt_entry_t *pte;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
("pmap_clear_reference: page %p is not managed", m));
rw_wlock(&pvh_global_lock);
sched_pin();
TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
pmap = PV_PMAP(pv);
PMAP_LOCK(pmap);
pte = pmap_pte_quick(pmap, pv->pv_va);
if ((*pte & PG_A) != 0) {
/*
* Regardless of whether a pte is 32 or 64 bits
* in size, PG_A is among the least significant
* 32 bits.
*/
PT_SET_VA_MA(pte, *pte & ~PG_A, FALSE);
pmap_invalidate_page(pmap, pv->pv_va);
}
PMAP_UNLOCK(pmap);
}
sched_unpin();
rw_wunlock(&pvh_global_lock);
}
/*
* Miscellaneous support routines follow
*/
/*
* Map a set of physical memory pages into the kernel virtual
* address space. Return a pointer to where it is mapped. This
* routine is intended to be used for mapping device memory,
* NOT real memory.
*/
void *
pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode)
{
vm_offset_t va, offset;
vm_size_t tmpsize;
offset = pa & PAGE_MASK;
size = round_page(offset + size);
pa = pa & PG_FRAME;
if (pa < KERNLOAD && pa + size <= KERNLOAD)
va = KERNBASE + pa;
else
va = kmem_alloc_nofault(kernel_map, size);
if (!va)
panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
for (tmpsize = 0; tmpsize < size; tmpsize += PAGE_SIZE)
pmap_kenter_attr(va + tmpsize, pa + tmpsize, mode);
pmap_invalidate_range(kernel_pmap, va, va + tmpsize);
pmap_invalidate_cache_range(va, va + size);
return ((void *)(va + offset));
}
void *
pmap_mapdev(vm_paddr_t pa, vm_size_t size)
{
return (pmap_mapdev_attr(pa, size, PAT_UNCACHEABLE));
}
void *
pmap_mapbios(vm_paddr_t pa, vm_size_t size)
{
return (pmap_mapdev_attr(pa, size, PAT_WRITE_BACK));
}
void
pmap_unmapdev(vm_offset_t va, vm_size_t size)
{
vm_offset_t base, offset;
if (va >= KERNBASE && va + size <= KERNBASE + KERNLOAD)
return;
base = trunc_page(va);
offset = va & PAGE_MASK;
size = round_page(offset + size);
kmem_free(kernel_map, base, size);
}
/*
* Sets the memory attribute for the specified page.
*/
void
pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma)
{
m->md.pat_mode = ma;
if ((m->flags & PG_FICTITIOUS) != 0)
return;
/*
* If "m" is a normal page, flush it from the cache.
* See pmap_invalidate_cache_range().
*
* First, try to find an existing mapping of the page by sf
* buffer. sf_buf_invalidate_cache() modifies mapping and
* flushes the cache.
*/
if (sf_buf_invalidate_cache(m))
return;
/*
* If page is not mapped by sf buffer, but CPU does not
* support self snoop, map the page transient and do
* invalidation. In the worst case, whole cache is flushed by
* pmap_invalidate_cache_range().
*/
if ((cpu_feature & CPUID_SS) == 0)
pmap_flush_page(m);
}
static void
pmap_flush_page(vm_page_t m)
{
struct sysmaps *sysmaps;
vm_offset_t sva, eva;
if ((cpu_feature & CPUID_CLFSH) != 0) {
sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
mtx_lock(&sysmaps->lock);
if (*sysmaps->CMAP2)
panic("pmap_flush_page: CMAP2 busy");
sched_pin();
PT_SET_MA(sysmaps->CADDR2, PG_V | PG_RW |
VM_PAGE_TO_MACH(m) | PG_A | PG_M |
pmap_cache_bits(m->md.pat_mode, 0));
invlcaddr(sysmaps->CADDR2);
sva = (vm_offset_t)sysmaps->CADDR2;
eva = sva + PAGE_SIZE;
/*
* Use mfence despite the ordering implied by
* mtx_{un,}lock() because clflush is not guaranteed
* to be ordered by any other instruction.
*/
mfence();
for (; sva < eva; sva += cpu_clflush_line_size)
clflush(sva);
mfence();
PT_SET_MA(sysmaps->CADDR2, 0);
sched_unpin();
mtx_unlock(&sysmaps->lock);
} else
pmap_invalidate_cache();
}
/*
* Changes the specified virtual address range's memory type to that given by
* the parameter "mode". The specified virtual address range must be
* completely contained within either the kernel map.
*
* Returns zero if the change completed successfully, and either EINVAL or
* ENOMEM if the change failed. Specifically, EINVAL is returned if some part
* of the virtual address range was not mapped, and ENOMEM is returned if
* there was insufficient memory available to complete the change.
*/
int
pmap_change_attr(vm_offset_t va, vm_size_t size, int mode)
{
vm_offset_t base, offset, tmpva;
pt_entry_t *pte;
u_int opte, npte;
pd_entry_t *pde;
boolean_t changed;
base = trunc_page(va);
offset = va & PAGE_MASK;
size = round_page(offset + size);
/* Only supported on kernel virtual addresses. */
if (base <= VM_MAXUSER_ADDRESS)
return (EINVAL);
/* 4MB pages and pages that aren't mapped aren't supported. */
for (tmpva = base; tmpva < (base + size); tmpva += PAGE_SIZE) {
pde = pmap_pde(kernel_pmap, tmpva);
if (*pde & PG_PS)
return (EINVAL);
if ((*pde & PG_V) == 0)
return (EINVAL);
pte = vtopte(va);
if ((*pte & PG_V) == 0)
return (EINVAL);
}
changed = FALSE;
/*
* Ok, all the pages exist and are 4k, so run through them updating
* their cache mode.
*/
for (tmpva = base; size > 0; ) {
pte = vtopte(tmpva);
/*
* The cache mode bits are all in the low 32-bits of the
* PTE, so we can just spin on updating the low 32-bits.
*/
do {
opte = *(u_int *)pte;
npte = opte & ~(PG_PTE_PAT | PG_NC_PCD | PG_NC_PWT);
npte |= pmap_cache_bits(mode, 0);
PT_SET_VA_MA(pte, npte, TRUE);
} while (npte != opte && (*pte != npte));
if (npte != opte)
changed = TRUE;
tmpva += PAGE_SIZE;
size -= PAGE_SIZE;
}
/*
* Flush CPU caches to make sure any data isn't cached that
* shouldn't be, etc.
*/
if (changed) {
pmap_invalidate_range(kernel_pmap, base, tmpva);
pmap_invalidate_cache_range(base, tmpva);
}
return (0);
}
/*
* perform the pmap work for mincore
*/
int
pmap_mincore(pmap_t pmap, vm_offset_t addr, vm_paddr_t *locked_pa)
{
pt_entry_t *ptep, pte;
vm_paddr_t pa;
int val;
PMAP_LOCK(pmap);
retry:
ptep = pmap_pte(pmap, addr);
pte = (ptep != NULL) ? PT_GET(ptep) : 0;
pmap_pte_release(ptep);
val = 0;
if ((pte & PG_V) != 0) {
val |= MINCORE_INCORE;
if ((pte & (PG_M | PG_RW)) == (PG_M | PG_RW))
val |= MINCORE_MODIFIED | MINCORE_MODIFIED_OTHER;
if ((pte & PG_A) != 0)
val |= MINCORE_REFERENCED | MINCORE_REFERENCED_OTHER;
}
if ((val & (MINCORE_MODIFIED_OTHER | MINCORE_REFERENCED_OTHER)) !=
(MINCORE_MODIFIED_OTHER | MINCORE_REFERENCED_OTHER) &&
(pte & (PG_MANAGED | PG_V)) == (PG_MANAGED | PG_V)) {
pa = pte & PG_FRAME;
/* Ensure that "PHYS_TO_VM_PAGE(pa)->object" doesn't change. */
if (vm_page_pa_tryrelock(pmap, pa, locked_pa))
goto retry;
} else
PA_UNLOCK_COND(*locked_pa);
PMAP_UNLOCK(pmap);
return (val);
}
void
pmap_activate(struct thread *td)
{
pmap_t pmap, oldpmap;
u_int cpuid;
u_int32_t cr3;
critical_enter();
pmap = vmspace_pmap(td->td_proc->p_vmspace);
oldpmap = PCPU_GET(curpmap);
cpuid = PCPU_GET(cpuid);
#if defined(SMP)
CPU_CLR_ATOMIC(cpuid, &oldpmap->pm_active);
CPU_SET_ATOMIC(cpuid, &pmap->pm_active);
#else
CPU_CLR(cpuid, &oldpmap->pm_active);
CPU_SET(cpuid, &pmap->pm_active);
#endif
#ifdef PAE
cr3 = vtophys(pmap->pm_pdpt);
#else
cr3 = vtophys(pmap->pm_pdir);
#endif
/*
* pmap_activate is for the current thread on the current cpu
*/
td->td_pcb->pcb_cr3 = cr3;
PT_UPDATES_FLUSH();
load_cr3(cr3);
PCPU_SET(curpmap, pmap);
critical_exit();
}
void
pmap_sync_icache(pmap_t pm, vm_offset_t va, vm_size_t sz)
{
}
/*
* Increase the starting virtual address of the given mapping if a
* different alignment might result in more superpage mappings.
*/
void
pmap_align_superpage(vm_object_t object, vm_ooffset_t offset,
vm_offset_t *addr, vm_size_t size)
{
vm_offset_t superpage_offset;
if (size < NBPDR)
return;
if (object != NULL && (object->flags & OBJ_COLORED) != 0)
offset += ptoa(object->pg_color);
superpage_offset = offset & PDRMASK;
if (size - ((NBPDR - superpage_offset) & PDRMASK) < NBPDR ||
(*addr & PDRMASK) == superpage_offset)
return;
if ((*addr & PDRMASK) < superpage_offset)
*addr = (*addr & ~PDRMASK) + superpage_offset;
else
*addr = ((*addr + PDRMASK) & ~PDRMASK) + superpage_offset;
}
2009-04-01 17:06:28 +00:00
void
pmap_suspend()
{
pmap_t pmap;
int i, pdir, offset;
vm_paddr_t pdirma;
mmu_update_t mu[4];
/*
* We need to remove the recursive mapping structure from all
* our pmaps so that Xen doesn't get confused when it restores
* the page tables. The recursive map lives at page directory
* index PTDPTDI. We assume that the suspend code has stopped
* the other vcpus (if any).
*/
LIST_FOREACH(pmap, &allpmaps, pm_list) {
for (i = 0; i < 4; i++) {
/*
* Figure out which page directory (L2) page
* contains this bit of the recursive map and
* the offset within that page of the map
* entry
*/
pdir = (PTDPTDI + i) / NPDEPG;
offset = (PTDPTDI + i) % NPDEPG;
pdirma = pmap->pm_pdpt[pdir] & PG_FRAME;
mu[i].ptr = pdirma + offset * sizeof(pd_entry_t);
mu[i].val = 0;
}
HYPERVISOR_mmu_update(mu, 4, NULL, DOMID_SELF);
}
}
void
pmap_resume()
{
pmap_t pmap;
int i, pdir, offset;
vm_paddr_t pdirma;
mmu_update_t mu[4];
/*
* Restore the recursive map that we removed on suspend.
*/
LIST_FOREACH(pmap, &allpmaps, pm_list) {
for (i = 0; i < 4; i++) {
/*
* Figure out which page directory (L2) page
* contains this bit of the recursive map and
* the offset within that page of the map
* entry
*/
pdir = (PTDPTDI + i) / NPDEPG;
offset = (PTDPTDI + i) % NPDEPG;
pdirma = pmap->pm_pdpt[pdir] & PG_FRAME;
mu[i].ptr = pdirma + offset * sizeof(pd_entry_t);
mu[i].val = (pmap->pm_pdpt[i] & PG_FRAME) | PG_V;
}
HYPERVISOR_mmu_update(mu, 4, NULL, DOMID_SELF);
}
}
#if defined(PMAP_DEBUG)
pmap_pid_dump(int pid)
{
pmap_t pmap;
struct proc *p;
int npte = 0;
int index;
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
if (p->p_pid != pid)
continue;
if (p->p_vmspace) {
int i,j;
index = 0;
pmap = vmspace_pmap(p->p_vmspace);
for (i = 0; i < NPDEPTD; i++) {
pd_entry_t *pde;
pt_entry_t *pte;
vm_offset_t base = i << PDRSHIFT;
pde = &pmap->pm_pdir[i];
if (pde && pmap_pde_v(pde)) {
for (j = 0; j < NPTEPG; j++) {
vm_offset_t va = base + (j << PAGE_SHIFT);
if (va >= (vm_offset_t) VM_MIN_KERNEL_ADDRESS) {
if (index) {
index = 0;
printf("\n");
}
sx_sunlock(&allproc_lock);
return (npte);
}
pte = pmap_pte(pmap, va);
if (pte && pmap_pte_v(pte)) {
pt_entry_t pa;
vm_page_t m;
pa = PT_GET(pte);
m = PHYS_TO_VM_PAGE(pa & PG_FRAME);
printf("va: 0x%x, pt: 0x%x, h: %d, w: %d, f: 0x%x",
va, pa, m->hold_count, m->wire_count, m->flags);
npte++;
index++;
if (index >= 2) {
index = 0;
printf("\n");
} else {
printf(" ");
}
}
}
}
}
}
}
sx_sunlock(&allproc_lock);
return (npte);
}
#endif
#if defined(DEBUG)
static void pads(pmap_t pm);
void pmap_pvdump(vm_paddr_t pa);
/* print address space of pmap*/
static void
pads(pmap_t pm)
{
int i, j;
vm_paddr_t va;
pt_entry_t *ptep;
if (pm == kernel_pmap)
return;
for (i = 0; i < NPDEPTD; i++)
if (pm->pm_pdir[i])
for (j = 0; j < NPTEPG; j++) {
va = (i << PDRSHIFT) + (j << PAGE_SHIFT);
if (pm == kernel_pmap && va < KERNBASE)
continue;
if (pm != kernel_pmap && va > UPT_MAX_ADDRESS)
continue;
ptep = pmap_pte(pm, va);
if (pmap_pte_v(ptep))
printf("%x:%x ", va, *ptep);
};
}
void
pmap_pvdump(vm_paddr_t pa)
{
pv_entry_t pv;
pmap_t pmap;
vm_page_t m;
printf("pa %x", pa);
m = PHYS_TO_VM_PAGE(pa);
TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
pmap = PV_PMAP(pv);
printf(" -> pmap %p, va %x", (void *)pmap, pv->pv_va);
pads(pmap);
}
printf(" ");
}
#endif