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freebsd-skq/sys/i386/i386/pmap.c
Alan Cox aced26ce6e Make pte_load_store() an atomic operation in all cases, not just i386 PAE. 
Restructure pmap_enter() to prevent the loss of a page modified (PG_M) bit
in a race between processors.  (This restructuring assumes the newly atomic
pte_load_store() for correct operation.)

Reviewed by: tegge@
PR: i386/61852
2004-10-08 08:23:43 +00:00

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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.
*
* 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.
*
* In addition to hardware address maps, this
* module is called upon to provide software-use-only
* maps which may or may not be stored in the same
* form as hardware maps. These pseudo-maps are
* used to store intermediate results from copy
* operations to and from address spaces.
*
* 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_msgbuf.h"
#include "opt_kstack_pages.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.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/sx.h>
#include <sys/user.h>
#include <sys/vmmeter.h>
#include <sys/sched.h>
#include <sys/sysctl.h>
#ifdef SMP
#include <sys/smp.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/specialreg.h>
#ifdef SMP
#include <machine/smp.h>
#endif
#if !defined(CPU_ENABLE_SSE) && defined(I686_CPU)
#define CPU_ENABLE_SSE
#endif
#if defined(CPU_DISABLE_SSE)
#undef CPU_ENABLE_SSE
#endif
#ifndef PMAP_SHPGPERPROC
#define PMAP_SHPGPERPROC 200
#endif
#if defined(DIAGNOSTIC)
#define PMAP_DIAGNOSTIC
#endif
#define MINPV 2048
#if !defined(PMAP_DIAGNOSTIC)
#define PMAP_INLINE __inline
#else
#define PMAP_INLINE
#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_w(pte, v) ((v) ? atomic_set_int((u_int *)(pte), PG_W) : \
atomic_clear_int((u_int *)(pte), PG_W))
#define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v)))
struct pmap kernel_pmap_store;
LIST_HEAD(pmaplist, pmap);
static struct pmaplist allpmaps;
static struct mtx allpmaps_lock;
vm_paddr_t avail_end; /* PA of last available physical page */
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) */
static boolean_t pmap_initialized = FALSE; /* Has pmap_init completed? */
int pgeflag = 0; /* PG_G or-in */
int pseflag = 0; /* PG_PS or-in */
static int nkpt;
vm_offset_t kernel_vm_end;
extern u_int32_t KERNend;
#ifdef PAE
static uma_zone_t pdptzone;
#endif
/*
* Data for the pv entry allocation mechanism
*/
static uma_zone_t pvzone;
static struct vm_object pvzone_obj;
static int pv_entry_count = 0, pv_entry_max = 0, pv_entry_high_water = 0;
int pmap_pagedaemon_waken;
/*
* All those kernel PT submaps that BSD is so fond of
*/
pt_entry_t *CMAP1 = 0;
static pt_entry_t *CMAP2, *CMAP3;
caddr_t CADDR1 = 0, ptvmmap = 0;
static caddr_t CADDR2, CADDR3;
static struct mtx CMAPCADDR12_lock;
struct msgbuf *msgbufp = 0;
/*
* Crashdump maps.
*/
static caddr_t crashdumpmap;
#ifdef SMP
extern pt_entry_t *SMPpt;
#endif
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 PMAP_INLINE void free_pv_entry(pv_entry_t pv);
static pv_entry_t get_pv_entry(void);
static void pmap_clear_ptes(vm_page_t m, int bit);
static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t sva);
static void pmap_remove_page(struct pmap *pmap, vm_offset_t va);
static int pmap_remove_entry(struct pmap *pmap, vm_page_t m,
vm_offset_t va);
static void pmap_insert_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, unsigned ptepindex, int flags);
static int _pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m);
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);
static vm_offset_t pmap_kmem_choose(vm_offset_t addr);
#ifdef PAE
static void *pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait);
#endif
CTASSERT(1 << PDESHIFT == sizeof(pd_entry_t));
CTASSERT(1 << PTESHIFT == sizeof(pt_entry_t));
/*
* Move the kernel virtual free pointer to the next
* 4MB. This is used to help improve performance
* by using a large (4MB) page for much of the kernel
* (.text, .data, .bss)
*/
static vm_offset_t
pmap_kmem_choose(vm_offset_t addr)
{
vm_offset_t newaddr = addr;
#ifndef DISABLE_PSE
if (cpu_feature & CPUID_PSE)
newaddr = (addr + PDRMASK) & ~PDRMASK;
#endif
return newaddr;
}
/*
* 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(firstaddr, loadaddr)
vm_paddr_t firstaddr;
vm_paddr_t loadaddr;
{
vm_offset_t va;
pt_entry_t *pte, *unused;
int i;
/*
* XXX The calculation of virtual_avail is wrong. It's NKPT*PAGE_SIZE too
* large. It should instead be correctly calculated in locore.s and
* not based on 'first' (which is a physical address, not a virtual
* address, for the start of unused physical memory). The kernel
* page tables are NOT double mapped and thus should not be included
* in this calculation.
*/
virtual_avail = (vm_offset_t) KERNBASE + firstaddr;
virtual_avail = pmap_kmem_choose(virtual_avail);
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
kernel_pmap->pm_active = -1; /* don't allow deactivation */
TAILQ_INIT(&kernel_pmap->pm_pvlist);
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);
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.
*/
SYSMAP(caddr_t, CMAP1, CADDR1, 1)
SYSMAP(caddr_t, CMAP2, CADDR2, 1)
SYSMAP(caddr_t, CMAP3, CADDR3, 1)
*CMAP3 = 0;
mtx_init(&CMAPCADDR12_lock, "CMAPCADDR12", NULL, MTX_DEF);
/*
* 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(MSGBUF_SIZE)))
/*
* ptemap is used for pmap_pte_quick
*/
SYSMAP(pt_entry_t *, PMAP1, PADDR1, 1);
SYSMAP(pt_entry_t *, PMAP2, PADDR2, 1);
mtx_init(&PMAP2mutex, "PMAP2", NULL, MTX_DEF);
virtual_avail = va;
*CMAP1 = *CMAP2 = 0;
for (i = 0; i < NKPT; i++)
PTD[i] = 0;
/* Turn on PG_G on kernel page(s) */
pmap_set_pg();
}
/*
* Set PG_G on kernel pages. Only the BSP calls this when SMP is turned on.
*/
void
pmap_set_pg(void)
{
pd_entry_t pdir;
pt_entry_t *pte;
vm_offset_t va, endva;
int i;
if (pgeflag == 0)
return;
i = KERNLOAD/NBPDR;
endva = KERNBASE + KERNend;
if (pseflag) {
va = KERNBASE + KERNLOAD;
while (va < endva) {
pdir = kernel_pmap->pm_pdir[KPTDI+i];
pdir |= pgeflag;
kernel_pmap->pm_pdir[KPTDI+i] = PTD[KPTDI+i] = pdir;
invltlb(); /* Play it safe, invltlb() every time */
i++;
va += NBPDR;
}
} else {
va = (vm_offset_t)btext;
while (va < endva) {
pte = vtopte(va);
if (*pte)
*pte |= pgeflag;
invltlb(); /* Play it safe, invltlb() every time */
va += PAGE_SIZE;
}
}
}
#ifdef PAE
static MALLOC_DEFINE(M_PMAPPDPT, "pmap", "pmap pdpt");
static void *
pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
{
*flags = UMA_SLAB_PRIV;
return (contigmalloc(PAGE_SIZE, M_PMAPPDPT, 0, 0x0ULL, 0xffffffffULL,
1, 0));
}
#endif
/*
* Initialize the pmap module.
* Called by vm_init, to initialize any structures that the pmap
* system needs to map virtual memory.
* pmap_init has been enhanced to support in a fairly consistant
* way, discontiguous physical memory.
*/
void
pmap_init(void)
{
int i;
/*
* Allocate memory for random pmap data structures. Includes the
* pv_head_table.
*/
for(i = 0; i < vm_page_array_size; i++) {
vm_page_t m;
m = &vm_page_array[i];
TAILQ_INIT(&m->md.pv_list);
m->md.pv_list_count = 0;
}
/*
* init the pv free list
*/
pvzone = uma_zcreate("PV ENTRY", sizeof (struct pv_entry), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE);
uma_prealloc(pvzone, MINPV);
#ifdef PAE
pdptzone = uma_zcreate("PDPT", NPGPTD * sizeof(pdpt_entry_t), NULL,
NULL, NULL, NULL, (NPGPTD * sizeof(pdpt_entry_t)) - 1,
UMA_ZONE_VM | UMA_ZONE_NOFREE);
uma_zone_set_allocf(pdptzone, pmap_pdpt_allocf);
#endif
/*
* Now it is safe to enable pv_table recording.
*/
pmap_initialized = TRUE;
}
/*
* 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.
*/
void
pmap_init2()
{
int shpgperproc = PMAP_SHPGPERPROC;
TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
pv_entry_max = shpgperproc * maxproc + vm_page_array_size;
TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max);
pv_entry_high_water = 9 * (pv_entry_max / 10);
uma_zone_set_obj(pvzone, &pvzone_obj, pv_entry_max);
}
/***************************************************
* Low level helper routines.....
***************************************************/
#if defined(PMAP_DIAGNOSTIC)
/*
* This code checks for non-writeable/modified pages.
* This should be an invalid condition.
*/
static int
pmap_nw_modified(pt_entry_t ptea)
{
int pte;
pte = (int) ptea;
if ((pte & (PG_M|PG_RW)) == PG_M)
return 1;
else
return 0;
}
#endif
/*
* this routine defines the region(s) of memory that should
* not be tested for the modified bit.
*/
static PMAP_INLINE int
pmap_track_modified(vm_offset_t va)
{
if ((va < kmi.clean_sva) || (va >= kmi.clean_eva))
return 1;
else
return 0;
}
#ifdef I386_CPU
/*
* i386 only has "invalidate everything" and no SMP to worry about.
*/
PMAP_INLINE void
pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
{
if (pmap == kernel_pmap || pmap->pm_active)
invltlb();
}
PMAP_INLINE void
pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
if (pmap == kernel_pmap || pmap->pm_active)
invltlb();
}
PMAP_INLINE void
pmap_invalidate_all(pmap_t pmap)
{
if (pmap == kernel_pmap || pmap->pm_active)
invltlb();
}
#else /* !I386_CPU */
#ifdef SMP
/*
* For SMP, these functions have to use the IPI mechanism for coherence.
*/
void
pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
{
u_int cpumask;
u_int other_cpus;
if (smp_started) {
if (!(read_eflags() & PSL_I))
panic("%s: interrupts disabled", __func__);
mtx_lock_spin(&smp_ipi_mtx);
} else
critical_enter();
/*
* We need to disable interrupt preemption but MUST NOT have
* interrupts disabled here.
* XXX we may need to hold schedlock to get a coherent pm_active
* XXX critical sections disable interrupts again
*/
if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
invlpg(va);
smp_invlpg(va);
} else {
cpumask = PCPU_GET(cpumask);
other_cpus = PCPU_GET(other_cpus);
if (pmap->pm_active & cpumask)
invlpg(va);
if (pmap->pm_active & other_cpus)
smp_masked_invlpg(pmap->pm_active & other_cpus, va);
}
if (smp_started)
mtx_unlock_spin(&smp_ipi_mtx);
else
critical_exit();
}
void
pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
u_int cpumask;
u_int other_cpus;
vm_offset_t addr;
if (smp_started) {
if (!(read_eflags() & PSL_I))
panic("%s: interrupts disabled", __func__);
mtx_lock_spin(&smp_ipi_mtx);
} else
critical_enter();
/*
* We need to disable interrupt preemption but MUST NOT have
* interrupts disabled here.
* XXX we may need to hold schedlock to get a coherent pm_active
* XXX critical sections disable interrupts again
*/
if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
for (addr = sva; addr < eva; addr += PAGE_SIZE)
invlpg(addr);
smp_invlpg_range(sva, eva);
} else {
cpumask = PCPU_GET(cpumask);
other_cpus = PCPU_GET(other_cpus);
if (pmap->pm_active & cpumask)
for (addr = sva; addr < eva; addr += PAGE_SIZE)
invlpg(addr);
if (pmap->pm_active & other_cpus)
smp_masked_invlpg_range(pmap->pm_active & other_cpus,
sva, eva);
}
if (smp_started)
mtx_unlock_spin(&smp_ipi_mtx);
else
critical_exit();
}
void
pmap_invalidate_all(pmap_t pmap)
{
u_int cpumask;
u_int other_cpus;
if (smp_started) {
if (!(read_eflags() & PSL_I))
panic("%s: interrupts disabled", __func__);
mtx_lock_spin(&smp_ipi_mtx);
} else
critical_enter();
/*
* We need to disable interrupt preemption but MUST NOT have
* interrupts disabled here.
* XXX we may need to hold schedlock to get a coherent pm_active
* XXX critical sections disable interrupts again
*/
if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
invltlb();
smp_invltlb();
} else {
cpumask = PCPU_GET(cpumask);
other_cpus = PCPU_GET(other_cpus);
if (pmap->pm_active & cpumask)
invltlb();
if (pmap->pm_active & other_cpus)
smp_masked_invltlb(pmap->pm_active & other_cpus);
}
if (smp_started)
mtx_unlock_spin(&smp_ipi_mtx);
else
critical_exit();
}
#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)
{
if (pmap == kernel_pmap || pmap->pm_active)
invlpg(va);
}
PMAP_INLINE void
pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
vm_offset_t addr;
if (pmap == kernel_pmap || pmap->pm_active)
for (addr = sva; addr < eva; addr += PAGE_SIZE)
invlpg(addr);
}
PMAP_INLINE void
pmap_invalidate_all(pmap_t pmap)
{
if (pmap == kernel_pmap || pmap->pm_active)
invltlb();
}
#endif /* !SMP */
#endif /* !I386_CPU */
/*
* 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) {
*PMAP2 = newpf | PG_RW | PG_V | PG_A | PG_M;
pmap_invalidate_page(kernel_pmap, (vm_offset_t)PADDR2);
}
return (PADDR2 + (i386_btop(va) & (NPTEPG - 1)));
}
return (0);
}
/*
* 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)
mtx_unlock(&PMAP2mutex);
}
static __inline void
invlcaddr(void *caddr)
{
#ifdef I386_CPU
invltlb();
#else
invlpg((u_int)caddr);
#endif
}
/*
* 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, vm_page_queue_mtx
* 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));
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
KASSERT(curthread->td_pinned > 0, ("curthread not pinned"));
newpf = *pde & PG_FRAME;
if ((*PMAP1 & PG_FRAME) != newpf) {
*PMAP1 = newpf | PG_RW | PG_V | PG_A | PG_M;
#ifdef SMP
PMAP1cpu = PCPU_GET(cpuid);
#endif
invlcaddr(PADDR1);
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;
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;
vm_page_t m;
m = NULL;
vm_page_lock_queues();
PMAP_LOCK(pmap);
pde = *pmap_pde(pmap, va);
if (pde != 0) {
if (pde & PG_PS) {
if ((pde & PG_RW) || (prot & VM_PROT_WRITE) == 0) {
m = PHYS_TO_VM_PAGE((pde & ~PDRMASK) |
(va & PDRMASK));
vm_page_hold(m);
}
} else {
sched_pin();
pte = *pmap_pte_quick(pmap, va);
if (pte != 0 &&
((pte & PG_RW) || (prot & VM_PROT_WRITE) == 0)) {
m = PHYS_TO_VM_PAGE(pte & PG_FRAME);
vm_page_hold(m);
}
sched_unpin();
}
}
vm_page_unlock_queues();
PMAP_UNLOCK(pmap);
return (m);
}
/***************************************************
* Low level mapping routines.....
***************************************************/
/*
* Add a wired page to the kva.
* Note: not SMP coherent.
*/
PMAP_INLINE void
pmap_kenter(vm_offset_t va, vm_paddr_t pa)
{
pt_entry_t *pte;
pte = vtopte(va);
pte_store(pte, pa | PG_RW | PG_V | pgeflag);
}
/*
* Remove a page from the kernel pagetables.
* Note: not SMP coherent.
*/
PMAP_INLINE void
pmap_kremove(vm_offset_t va)
{
pt_entry_t *pte;
pte = vtopte(va);
pte_clear(pte);
}
/*
* 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;
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 *m, int count)
{
vm_offset_t va;
va = sva;
while (count-- > 0) {
pmap_kenter(va, VM_PAGE_TO_PHYS(*m));
va += PAGE_SIZE;
m++;
}
pmap_invalidate_range(kernel_pmap, sva, va);
}
/*
* 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;
va = sva;
while (count-- > 0) {
pmap_kremove(va);
va += PAGE_SIZE;
}
pmap_invalidate_range(kernel_pmap, sva, va);
}
/***************************************************
* Page table page management routines.....
***************************************************/
/*
* This routine unholds page table pages, and if the hold count
* drops to zero, then it decrements the wire count.
*/
static PMAP_INLINE int
pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
{
--m->wire_count;
if (m->wire_count == 0)
return _pmap_unwire_pte_hold(pmap, m);
else
return 0;
}
static int
_pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
{
vm_offset_t pteva;
/*
* unmap the page table page
*/
pmap->pm_pdir[m->pindex] = 0;
--pmap->pm_stats.resident_count;
/*
* Do an invltlb to make the invalidated mapping
* take effect immediately.
*/
pteva = VM_MAXUSER_ADDRESS + i386_ptob(m->pindex);
pmap_invalidate_page(pmap, pteva);
vm_page_free_zero(m);
atomic_subtract_int(&cnt.v_wire_count, 1);
return 1;
}
/*
* 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)
{
pd_entry_t ptepde;
vm_page_t mpte;
if (va >= VM_MAXUSER_ADDRESS)
return 0;
ptepde = *pmap_pde(pmap, va);
mpte = PHYS_TO_VM_PAGE(ptepde & PG_FRAME);
return pmap_unwire_pte_hold(pmap, mpte);
}
void
pmap_pinit0(pmap)
struct pmap *pmap;
{
PMAP_LOCK_INIT(pmap);
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
pmap->pm_active = 0;
PCPU_SET(curpmap, pmap);
TAILQ_INIT(&pmap->pm_pvlist);
bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
mtx_lock_spin(&allpmaps_lock);
LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
mtx_unlock_spin(&allpmaps_lock);
}
/*
* Initialize a preallocated and zeroed pmap structure,
* such as one in a vmspace structure.
*/
void
pmap_pinit(pmap)
register struct pmap *pmap;
{
vm_page_t m, ptdpg[NPGPTD];
vm_paddr_t pa;
static int color;
int i;
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);
#ifdef PAE
pmap->pm_pdpt = uma_zalloc(pdptzone, M_WAITOK | M_ZERO);
KASSERT(((vm_offset_t)pmap->pm_pdpt &
((NPGPTD * sizeof(pdpt_entry_t)) - 1)) == 0,
("pmap_pinit: pdpt misaligned"));
KASSERT(pmap_kextract((vm_offset_t)pmap->pm_pdpt) < (4ULL<<30),
("pmap_pinit: pdpt above 4g"));
#endif
}
/*
* allocate the page directory page(s)
*/
for (i = 0; i < NPGPTD;) {
m = vm_page_alloc(NULL, color++,
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)
bzero(pmap->pm_pdir + (i * NPDEPG), PAGE_SIZE);
}
mtx_lock_spin(&allpmaps_lock);
LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
mtx_unlock_spin(&allpmaps_lock);
/* Wire in kernel global address entries. */
/* XXX copies current process, does not fill in MPPTDI */
bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * sizeof(pd_entry_t));
#ifdef SMP
pmap->pm_pdir[MPPTDI] = PTD[MPPTDI];
#endif
/* install self-referential address mapping entry(s) */
for (i = 0; i < NPGPTD; i++) {
pa = VM_PAGE_TO_PHYS(ptdpg[i]);
pmap->pm_pdir[PTDPTDI + i] = pa | PG_V | PG_RW | PG_A | PG_M;
#ifdef PAE
pmap->pm_pdpt[i] = pa | PG_V;
#endif
}
pmap->pm_active = 0;
TAILQ_INIT(&pmap->pm_pvlist);
bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
}
/*
* this routine is called if the page table page is not
* mapped correctly.
*/
static vm_page_t
_pmap_allocpte(pmap_t pmap, unsigned ptepindex, int flags)
{
vm_paddr_t ptepa;
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);
vm_page_unlock_queues();
VM_WAIT;
vm_page_lock_queues();
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++;
ptepa = VM_PAGE_TO_PHYS(m);
pmap->pm_pdir[ptepindex] =
(pd_entry_t) (ptepa | PG_U | PG_RW | PG_V | PG_A | PG_M);
return m;
}
static vm_page_t
pmap_allocpte(pmap_t pmap, vm_offset_t va, int flags)
{
unsigned ptepindex;
pd_entry_t ptepa;
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
*/
ptepa = pmap->pm_pdir[ptepindex];
/*
* This supports switching from a 4MB page to a
* normal 4K page.
*/
if (ptepa & PG_PS) {
pmap->pm_pdir[ptepindex] = 0;
ptepa = 0;
pmap_invalidate_all(kernel_pmap);
}
/*
* If the page table page is mapped, we just increment the
* hold count, and activate it.
*/
if (ptepa) {
m = PHYS_TO_VM_PAGE(ptepa);
m->wire_count++;
} else {
/*
* Here if the pte page isn't mapped, or if it has
* been deallocated.
*/
m = _pmap_allocpte(pmap, ptepindex, flags);
if (m == NULL && (flags & M_WAITOK))
goto retry;
}
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 u_int *lazymask;
static u_int lazyptd;
static volatile u_int lazywait;
void pmap_lazyfix_action(void);
void
pmap_lazyfix_action(void)
{
u_int mymask = PCPU_GET(cpumask);
if (rcr3() == lazyptd)
load_cr3(PCPU_GET(curpcb)->pcb_cr3);
atomic_clear_int(lazymask, mymask);
atomic_store_rel_int(&lazywait, 1);
}
static void
pmap_lazyfix_self(u_int mymask)
{
if (rcr3() == lazyptd)
load_cr3(PCPU_GET(curpcb)->pcb_cr3);
atomic_clear_int(lazymask, mymask);
}
static void
pmap_lazyfix(pmap_t pmap)
{
u_int mymask = PCPU_GET(cpumask);
u_int mask;
register u_int spins;
while ((mask = pmap->pm_active) != 0) {
spins = 50000000;
mask = mask & -mask; /* Find least significant set bit */
mtx_lock_spin(&smp_ipi_mtx);
#ifdef PAE
lazyptd = vtophys(pmap->pm_pdpt);
#else
lazyptd = vtophys(pmap->pm_pdir);
#endif
if (mask == mymask) {
lazymask = &pmap->pm_active;
pmap_lazyfix_self(mymask);
} 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");
}
}
#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);
pmap->pm_active &= ~(PCPU_GET(cpumask));
}
}
#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[NPGPTD];
int i;
KASSERT(pmap->pm_stats.resident_count == 0,
("pmap_release: pmap resident count %ld != 0",
pmap->pm_stats.resident_count));
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(pmap->pm_pdir[PTDPTDI + i]);
bzero(pmap->pm_pdir + PTDPTDI, (nkpt + NPGPTD) *
sizeof(*pmap->pm_pdir));
#ifdef SMP
pmap->pm_pdir[MPPTDI] = 0;
#endif
pmap_qremove((vm_offset_t)pmap->pm_pdir, NPGPTD);
vm_page_lock_queues();
for (i = 0; i < NPGPTD; i++) {
m = ptdpg[i];
#ifdef PAE
KASSERT(VM_PAGE_TO_PHYS(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_zero(m);
}
vm_page_unlock_queues();
PMAP_LOCK_DESTROY(pmap);
}
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;
pt_entry_t *pde;
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++;
}
}
addr = roundup2(addr, PAGE_SIZE * NPTEPG);
while (kernel_vm_end < addr) {
if (pdir_pde(PTD, kernel_vm_end)) {
kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
continue;
}
/*
* This index is bogus, but out of the way
*/
nkpg = vm_page_alloc(NULL, nkpt,
VM_ALLOC_NOOBJ | VM_ALLOC_SYSTEM | VM_ALLOC_WIRED);
if (!nkpg)
panic("pmap_growkernel: no memory to grow kernel");
nkpt++;
pmap_zero_page(nkpg);
ptppaddr = VM_PAGE_TO_PHYS(nkpg);
newpdir = (pd_entry_t) (ptppaddr | PG_V | PG_RW | PG_A | PG_M);
pdir_pde(PTD, kernel_vm_end) = newpdir;
mtx_lock_spin(&allpmaps_lock);
LIST_FOREACH(pmap, &allpmaps, pm_list) {
pde = pmap_pde(pmap, kernel_vm_end);
pde_store(pde, newpdir);
}
mtx_unlock_spin(&allpmaps_lock);
kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
}
}
/***************************************************
* page management routines.
***************************************************/
/*
* free the pv_entry back to the free list
*/
static PMAP_INLINE void
free_pv_entry(pv_entry_t pv)
{
pv_entry_count--;
uma_zfree(pvzone, pv);
}
/*
* get a new pv_entry, allocating a block from the system
* when needed.
* the memory allocation is performed bypassing the malloc code
* because of the possibility of allocations at interrupt time.
*/
static pv_entry_t
get_pv_entry(void)
{
pv_entry_count++;
if (pv_entry_high_water &&
(pv_entry_count > pv_entry_high_water) &&
(pmap_pagedaemon_waken == 0)) {
pmap_pagedaemon_waken = 1;
wakeup (&vm_pages_needed);
}
return uma_zalloc(pvzone, M_NOWAIT);
}
static int
pmap_remove_entry(pmap_t pmap, vm_page_t m, vm_offset_t va)
{
pv_entry_t pv;
int rtval;
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
if (m->md.pv_list_count < pmap->pm_stats.resident_count) {
TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
if (pmap == pv->pv_pmap && va == pv->pv_va)
break;
}
} else {
TAILQ_FOREACH(pv, &pmap->pm_pvlist, pv_plist) {
if (va == pv->pv_va)
break;
}
}
rtval = 0;
if (pv) {
rtval = pmap_unuse_pt(pmap, va);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
m->md.pv_list_count--;
if (TAILQ_FIRST(&m->md.pv_list) == NULL)
vm_page_flag_clear(m, PG_WRITEABLE);
TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
free_pv_entry(pv);
}
return rtval;
}
/*
* Create a pv entry for page at pa for
* (pmap, va).
*/
static void
pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
{
pv_entry_t pv;
pv = get_pv_entry();
pv->pv_va = va;
pv->pv_pmap = pmap;
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist);
TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
m->md.pv_list_count++;
}
/*
* 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)
{
pt_entry_t oldpte;
vm_page_t m;
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
oldpte = pte_load_clear(ptq);
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(oldpte);
if (oldpte & PG_M) {
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified((pt_entry_t) oldpte)) {
printf(
"pmap_remove: modified page not writable: va: 0x%x, pte: 0x%x\n",
va, oldpte);
}
#endif
if (pmap_track_modified(va))
vm_page_dirty(m);
}
if (oldpte & PG_A)
vm_page_flag_set(m, PG_REFERENCED);
return pmap_remove_entry(pmap, m, va);
} else {
return pmap_unuse_pt(pmap, va);
}
}
/*
* Remove a single page from a process address space
*/
static void
pmap_remove_page(pmap_t pmap, vm_offset_t va)
{
pt_entry_t *pte;
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
KASSERT(curthread->td_pinned > 0, ("curthread not pinned"));
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
if ((pte = pmap_pte_quick(pmap, va)) == NULL || *pte == 0)
return;
pmap_remove_pte(pmap, pte, va);
pmap_invalidate_page(pmap, va);
}
/*
* 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;
int anyvalid;
/*
* Perform an unsynchronized read. This is, however, safe.
*/
if (pmap->pm_stats.resident_count == 0)
return;
anyvalid = 0;
vm_page_lock_queues();
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);
goto out;
}
for (; sva < eva; sva = pdnxt) {
unsigned pdirindex;
/*
* Calculate index for next page table.
*/
pdnxt = (sva + NBPDR) & ~PDRMASK;
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) {
pmap->pm_pdir[pdirindex] = 0;
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 (; sva != pdnxt; sva += PAGE_SIZE) {
if ((pte = pmap_pte_quick(pmap, sva)) == NULL ||
*pte == 0)
continue;
anyvalid = 1;
if (pmap_remove_pte(pmap, pte, sva))
break;
}
}
out:
sched_unpin();
vm_page_unlock_queues();
if (anyvalid)
pmap_invalidate_all(pmap);
PMAP_UNLOCK(pmap);
}
/*
* 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)
{
register pv_entry_t pv;
pt_entry_t *pte, tpte;
#if defined(PMAP_DIAGNOSTIC)
/*
* XXX This makes pmap_remove_all() illegal for non-managed pages!
*/
if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) {
panic("pmap_remove_all: illegal for unmanaged page, va: 0x%x",
VM_PAGE_TO_PHYS(m));
}
#endif
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
sched_pin();
while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
PMAP_LOCK(pv->pv_pmap);
pv->pv_pmap->pm_stats.resident_count--;
pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
tpte = pte_load_clear(pte);
if (tpte & PG_W)
pv->pv_pmap->pm_stats.wired_count--;
if (tpte & PG_A)
vm_page_flag_set(m, PG_REFERENCED);
/*
* Update the vm_page_t clean and reference bits.
*/
if (tpte & PG_M) {
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified((pt_entry_t) tpte)) {
printf(
"pmap_remove_all: modified page not writable: va: 0x%x, pte: 0x%x\n",
pv->pv_va, tpte);
}
#endif
if (pmap_track_modified(pv->pv_va))
vm_page_dirty(m);
}
pmap_invalidate_page(pv->pv_pmap, pv->pv_va);
TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
m->md.pv_list_count--;
pmap_unuse_pt(pv->pv_pmap, pv->pv_va);
PMAP_UNLOCK(pv->pv_pmap);
free_pv_entry(pv);
}
vm_page_flag_clear(m, PG_WRITEABLE);
sched_unpin();
}
/*
* 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;
int anychanged;
if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
pmap_remove(pmap, sva, eva);
return;
}
if (prot & VM_PROT_WRITE)
return;
anychanged = 0;
vm_page_lock_queues();
sched_pin();
PMAP_LOCK(pmap);
for (; sva < eva; sva = pdnxt) {
unsigned obits, pbits, pdirindex;
pdnxt = (sva + NBPDR) & ~PDRMASK;
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) {
pmap->pm_pdir[pdirindex] &= ~(PG_M|PG_RW);
pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
anychanged = 1;
continue;
}
if (pdnxt > eva)
pdnxt = eva;
for (; sva != pdnxt; sva += PAGE_SIZE) {
pt_entry_t *pte;
vm_page_t m;
if ((pte = pmap_pte_quick(pmap, sva)) == NULL)
continue;
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 = *(u_int *)pte;
if (pbits & PG_MANAGED) {
m = NULL;
if (pbits & PG_A) {
m = PHYS_TO_VM_PAGE(pbits);
vm_page_flag_set(m, PG_REFERENCED);
pbits &= ~PG_A;
}
if ((pbits & PG_M) != 0 &&
pmap_track_modified(sva)) {
if (m == NULL)
m = PHYS_TO_VM_PAGE(pbits);
vm_page_dirty(m);
}
}
pbits &= ~(PG_RW | PG_M);
if (pbits != obits) {
if (!atomic_cmpset_int((u_int *)pte, obits,
pbits))
goto retry;
anychanged = 1;
}
}
}
sched_unpin();
vm_page_unlock_queues();
if (anychanged)
pmap_invalidate_all(pmap);
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_page_t m, vm_prot_t prot,
boolean_t wired)
{
vm_paddr_t pa;
register pt_entry_t *pte;
vm_paddr_t opa;
pt_entry_t origpte, newpte;
vm_page_t mpte, om;
va &= PG_FRAME;
#ifdef PMAP_DIAGNOSTIC
if (va > VM_MAX_KERNEL_ADDRESS)
panic("pmap_enter: toobig");
if ((va >= UPT_MIN_ADDRESS) && (va < UPT_MAX_ADDRESS))
panic("pmap_enter: invalid to pmap_enter page table pages (va: 0x%x)", va);
#endif
mpte = NULL;
vm_page_lock_queues();
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);
}
#if 0 && defined(PMAP_DIAGNOSTIC)
else {
pd_entry_t *pdeaddr = pmap_pde(pmap, va);
origpte = *pdeaddr;
if ((origpte & PG_V) == 0) {
panic("pmap_enter: invalid kernel page table page, pdir=%p, pde=%p, va=%p\n",
pmap->pm_pdir[PTDPTDI], origpte, va);
}
}
#endif
pte = pmap_pte_quick(pmap, va);
/*
* Page Directory table entry not valid, we need a new PT page
*/
if (pte == NULL) {
panic("pmap_enter: invalid page directory pdir=%#jx, va=%#x\n",
(uintmax_t)pmap->pm_pdir[PTDPTDI], va);
}
pa = VM_PAGE_TO_PHYS(m);
om = NULL;
origpte = *pte;
opa = origpte & PG_FRAME;
if (origpte & PG_PS) {
/*
* Yes, I know this will truncate upper address bits for PAE,
* but I'm actually more interested in the lower bits
*/
printf("pmap_enter: va %p, pte %p, origpte %p\n",
(void *)va, (void *)pte, (void *)(uintptr_t)origpte);
panic("pmap_enter: attempted pmap_enter on 4MB page");
}
/*
* 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--;
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified((pt_entry_t) origpte)) {
printf(
"pmap_enter: modified page not writable: va: 0x%x, pte: 0x%x\n",
va, origpte);
}
#endif
/*
* Remove extra pte reference
*/
if (mpte)
mpte->wire_count--;
/*
* We might be turning off write access to the page,
* so we go ahead and sense modify status.
*/
if (origpte & PG_MANAGED) {
om = m;
pa |= PG_MANAGED;
}
goto validate;
}
/*
* Mapping has changed, invalidate old range and fall through to
* handle validating new mapping.
*/
if (opa) {
int err;
if (origpte & PG_W)
pmap->pm_stats.wired_count--;
if (origpte & PG_MANAGED) {
om = PHYS_TO_VM_PAGE(opa);
err = pmap_remove_entry(pmap, om, va);
} else
err = pmap_unuse_pt(pmap, va);
if (err)
panic("pmap_enter: pte vanished, va: 0x%x", va);
} else
pmap->pm_stats.resident_count++;
/*
* Enter on the PV list if part of our managed memory. Note that we
* raise IPL while manipulating pv_table since pmap_enter can be
* called at interrupt time.
*/
if (pmap_initialized &&
(m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) {
pmap_insert_entry(pmap, va, m);
pa |= PG_MANAGED;
}
/*
* 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;
if (wired)
newpte |= PG_W;
if (va < VM_MAXUSER_ADDRESS)
newpte |= PG_U;
if (pmap == kernel_pmap)
newpte |= pgeflag;
/*
* if the mapping or permission bits are different, we need
* to update the pte.
*/
if ((origpte & ~(PG_M|PG_A)) != newpte) {
if (origpte & PG_MANAGED) {
origpte = pte_load_store(pte, newpte | PG_A);
if ((origpte & PG_M) && pmap_track_modified(va))
vm_page_dirty(om);
if (origpte & PG_A)
vm_page_flag_set(om, PG_REFERENCED);
} else
pte_store(pte, newpte | PG_A);
if (origpte) {
pmap_invalidate_page(pmap, va);
}
}
sched_unpin();
vm_page_unlock_queues();
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.
* 5. Tlbflush is deferred to calling procedure.
* 6. Page IS managed.
* but is *MUCH* faster than pmap_enter...
*/
vm_page_t
pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_page_t mpte)
{
pt_entry_t *pte;
vm_paddr_t pa;
vm_page_lock_queues();
PMAP_LOCK(pmap);
/*
* In the case that a page table page is not
* resident, we are creating it here.
*/
if (va < VM_MAXUSER_ADDRESS) {
unsigned ptepindex;
pd_entry_t ptepa;
/*
* Calculate pagetable page index
*/
ptepindex = va >> PDRSHIFT;
if (mpte && (mpte->pindex == ptepindex)) {
mpte->wire_count++;
} else {
retry:
/*
* Get the page directory entry
*/
ptepa = pmap->pm_pdir[ptepindex];
/*
* If the page table page is mapped, we just increment
* the hold count, and activate it.
*/
if (ptepa) {
if (ptepa & PG_PS)
panic("pmap_enter_quick: unexpected mapping into 4MB page");
mpte = PHYS_TO_VM_PAGE(ptepa);
mpte->wire_count++;
} else {
mpte = _pmap_allocpte(pmap, ptepindex,
M_WAITOK);
if (mpte == NULL)
goto retry;
}
}
} 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.
*/
pte = vtopte(va);
if (*pte) {
if (mpte != NULL) {
pmap_unwire_pte_hold(pmap, mpte);
mpte = NULL;
}
goto out;
}
/*
* Enter on the PV list if part of our managed memory. Note that we
* raise IPL while manipulating pv_table since pmap_enter can be
* called at interrupt time.
*/
if ((m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0)
pmap_insert_entry(pmap, va, m);
/*
* Increment counters
*/
pmap->pm_stats.resident_count++;
pa = VM_PAGE_TO_PHYS(m);
/*
* Now validate mapping with RO protection
*/
if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED))
pte_store(pte, pa | PG_V | PG_U);
else
pte_store(pte, pa | PG_V | PG_U | PG_MANAGED);
out:
vm_page_unlock_queues();
PMAP_UNLOCK(pmap);
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;
va = (vm_offset_t)crashdumpmap + (i * PAGE_SIZE);
pmap_kenter(va, pa);
#ifndef I386_CPU
invlpg(va);
#else
invltlb();
#endif
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)
{
vm_page_t p;
VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
KASSERT(object->type == OBJT_DEVICE,
("pmap_object_init_pt: non-device object"));
if (pseflag &&
((addr & (NBPDR - 1)) == 0) && ((size & (NBPDR - 1)) == 0)) {
int i;
vm_page_t m[1];
unsigned int ptepindex;
int npdes;
pd_entry_t ptepa;
PMAP_LOCK(pmap);
if (pmap->pm_pdir[ptepindex = (addr >> PDRSHIFT)])
goto out;
PMAP_UNLOCK(pmap);
retry:
p = vm_page_lookup(object, pindex);
if (p != NULL) {
vm_page_lock_queues();
if (vm_page_sleep_if_busy(p, FALSE, "init4p"))
goto retry;
} else {
p = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL);
if (p == NULL)
return;
m[0] = p;
if (vm_pager_get_pages(object, m, 1, 0) != VM_PAGER_OK) {
vm_page_lock_queues();
vm_page_free(p);
vm_page_unlock_queues();
return;
}
p = vm_page_lookup(object, pindex);
vm_page_lock_queues();
vm_page_wakeup(p);
}
vm_page_unlock_queues();
ptepa = VM_PAGE_TO_PHYS(p);
if (ptepa & (NBPDR - 1))
return;
p->valid = VM_PAGE_BITS_ALL;
PMAP_LOCK(pmap);
pmap->pm_stats.resident_count += size >> PAGE_SHIFT;
npdes = size >> PDRSHIFT;
for(i = 0; i < npdes; i++) {
pde_store(&pmap->pm_pdir[ptepindex],
ptepa | PG_U | PG_RW | PG_V | PG_PS);
ptepa += NBPDR;
ptepindex += 1;
}
pmap_invalidate_all(pmap);
out:
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, va, wired)
register pmap_t pmap;
vm_offset_t va;
boolean_t wired;
{
register pt_entry_t *pte;
PMAP_LOCK(pmap);
pte = pmap_pte(pmap, va);
if (wired && !pmap_pte_w(pte))
pmap->pm_stats.wired_count++;
else if (!wired && pmap_pte_w(pte))
pmap->pm_stats.wired_count--;
/*
* Wiring is not a hardware characteristic so there is no need to
* invalidate TLB.
*/
pmap_pte_set_w(pte, wired);
pmap_pte_release(pte);
PMAP_UNLOCK(pmap);
}
/*
* 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_offset_t addr;
vm_offset_t end_addr = src_addr + len;
vm_offset_t pdnxt;
vm_page_t m;
if (dst_addr != src_addr)
return;
if (!pmap_is_current(src_pmap))
return;
vm_page_lock_queues();
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;
unsigned ptepindex;
if (addr >= UPT_MIN_ADDRESS)
panic("pmap_copy: invalid to pmap_copy page tables");
/*
* Don't let optional prefaulting of pages make us go
* way below the low water mark of free pages or way
* above high water mark of used pv entries.
*/
if (cnt.v_free_count < cnt.v_free_reserved ||
pv_entry_count > pv_entry_high_water)
break;
pdnxt = (addr + NBPDR) & ~PDRMASK;
ptepindex = addr >> PDRSHIFT;
srcptepaddr = src_pmap->pm_pdir[ptepindex];
if (srcptepaddr == 0)
continue;
if (srcptepaddr & PG_PS) {
if (dst_pmap->pm_pdir[ptepindex] == 0) {
dst_pmap->pm_pdir[ptepindex] = srcptepaddr;
dst_pmap->pm_stats.resident_count +=
NBPDR / PAGE_SIZE;
}
continue;
}
srcmpte = PHYS_TO_VM_PAGE(srcptepaddr);
if (srcmpte->wire_count == 0)
panic("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) {
/*
* We have to check after allocpte for the
* pte still being around... allocpte can
* block.
*/
dstmpte = pmap_allocpte(dst_pmap, addr,
M_NOWAIT);
if (dstmpte == NULL)
break;
dst_pte = pmap_pte_quick(dst_pmap, addr);
if (*dst_pte == 0) {
/*
* Clear the modified and
* accessed (referenced) bits
* during the copy.
*/
m = PHYS_TO_VM_PAGE(ptetemp);
*dst_pte = ptetemp & ~(PG_M | PG_A);
dst_pmap->pm_stats.resident_count++;
pmap_insert_entry(dst_pmap, addr, m);
} else
pmap_unwire_pte_hold(dst_pmap, dstmpte);
if (dstmpte->wire_count >= srcmpte->wire_count)
break;
}
addr += PAGE_SIZE;
src_pte++;
}
}
sched_unpin();
vm_page_unlock_queues();
PMAP_UNLOCK(src_pmap);
PMAP_UNLOCK(dst_pmap);
}
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)
{
mtx_lock(&CMAPCADDR12_lock);
if (*CMAP2)
panic("pmap_zero_page: CMAP2 busy");
sched_pin();
*CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M;
invlcaddr(CADDR2);
pagezero(CADDR2);
*CMAP2 = 0;
sched_unpin();
mtx_unlock(&CMAPCADDR12_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)
{
mtx_lock(&CMAPCADDR12_lock);
if (*CMAP2)
panic("pmap_zero_page: CMAP2 busy");
sched_pin();
*CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M;
invlcaddr(CADDR2);
if (off == 0 && size == PAGE_SIZE)
pagezero(CADDR2);
else
bzero((char *)CADDR2 + off, size);
*CMAP2 = 0;
sched_unpin();
mtx_unlock(&CMAPCADDR12_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: CMAP3 busy");
sched_pin();
*CMAP3 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M;
invlcaddr(CADDR3);
pagezero(CADDR3);
*CMAP3 = 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)
{
mtx_lock(&CMAPCADDR12_lock);
if (*CMAP1)
panic("pmap_copy_page: CMAP1 busy");
if (*CMAP2)
panic("pmap_copy_page: CMAP2 busy");
sched_pin();
#ifdef I386_CPU
invltlb();
#else
invlpg((u_int)CADDR1);
invlpg((u_int)CADDR2);
#endif
*CMAP1 = PG_V | VM_PAGE_TO_PHYS(src) | PG_A;
*CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(dst) | PG_A | PG_M;
bcopy(CADDR1, CADDR2, PAGE_SIZE);
*CMAP1 = 0;
*CMAP2 = 0;
sched_unpin();
mtx_unlock(&CMAPCADDR12_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, m)
pmap_t pmap;
vm_page_t m;
{
pv_entry_t pv;
int loops = 0;
if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
return FALSE;
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
if (pv->pv_pmap == pmap) {
return TRUE;
}
loops++;
if (loops >= 16)
break;
}
return (FALSE);
}
#define PMAP_REMOVE_PAGES_CURPROC_ONLY
/*
* 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, sva, eva)
pmap_t pmap;
vm_offset_t sva, eva;
{
pt_entry_t *pte, tpte;
vm_page_t m;
pv_entry_t pv, npv;
#ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY
if (pmap != vmspace_pmap(curthread->td_proc->p_vmspace)) {
printf("warning: pmap_remove_pages called with non-current pmap\n");
return;
}
#endif
vm_page_lock_queues();
PMAP_LOCK(pmap);
sched_pin();
for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv; pv = npv) {
if (pv->pv_va >= eva || pv->pv_va < sva) {
npv = TAILQ_NEXT(pv, pv_plist);
continue;
}
#ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY
pte = vtopte(pv->pv_va);
#else
pte = pmap_pte_quick(pmap, pv->pv_va);
#endif
tpte = *pte;
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) {
npv = TAILQ_NEXT(pv, pv_plist);
continue;
}
m = PHYS_TO_VM_PAGE(tpte);
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));
pmap->pm_stats.resident_count--;
pte_clear(pte);
/*
* Update the vm_page_t clean and reference bits.
*/
if (tpte & PG_M) {
vm_page_dirty(m);
}
npv = TAILQ_NEXT(pv, pv_plist);
TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
m->md.pv_list_count--;
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
if (TAILQ_EMPTY(&m->md.pv_list))
vm_page_flag_clear(m, PG_WRITEABLE);
pmap_unuse_pt(pmap, pv->pv_va);
free_pv_entry(pv);
}
sched_unpin();
pmap_invalidate_all(pmap);
PMAP_UNLOCK(pmap);
vm_page_unlock_queues();
}
/*
* 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;
boolean_t rv;
rv = FALSE;
if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
return (rv);
sched_pin();
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
/*
* if the bit being tested is the modified bit, then
* mark clean_map and ptes as never
* modified.
*/
if (!pmap_track_modified(pv->pv_va))
continue;
#if defined(PMAP_DIAGNOSTIC)
if (!pv->pv_pmap) {
printf("Null pmap (tb) at va: 0x%x\n", pv->pv_va);
continue;
}
#endif
PMAP_LOCK(pv->pv_pmap);
pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
rv = (*pte & PG_M) != 0;
PMAP_UNLOCK(pv->pv_pmap);
if (rv)
break;
}
sched_unpin();
return (rv);
}
/*
* pmap_is_prefaultable:
*
* Return whether or not the specified virtual address is elgible
* for prefault.
*/
boolean_t
pmap_is_prefaultable(pmap_t pmap, vm_offset_t addr)
{
pt_entry_t *pte;
boolean_t rv;
rv = FALSE;
PMAP_LOCK(pmap);
if (*pmap_pde(pmap, addr)) {
pte = vtopte(addr);
rv = *pte == 0;
}
PMAP_UNLOCK(pmap);
return (rv);
}
/*
* Clear the given bit in each of the given page's ptes. The bit is
* expressed as a 32-bit mask. Consequently, if the pte is 64 bits in
* size, only a bit within the least significant 32 can be cleared.
*/
static __inline void
pmap_clear_ptes(vm_page_t m, int bit)
{
register pv_entry_t pv;
pt_entry_t pbits, *pte;
if (!pmap_initialized || (m->flags & PG_FICTITIOUS) ||
(bit == PG_RW && (m->flags & PG_WRITEABLE) == 0))
return;
sched_pin();
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
/*
* Loop over all current mappings setting/clearing as appropos If
* setting RO do we need to clear the VAC?
*/
TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
/*
* don't write protect pager mappings
*/
if (bit == PG_RW) {
if (!pmap_track_modified(pv->pv_va))
continue;
}
#if defined(PMAP_DIAGNOSTIC)
if (!pv->pv_pmap) {
printf("Null pmap (cb) at va: 0x%x\n", pv->pv_va);
continue;
}
#endif
PMAP_LOCK(pv->pv_pmap);
pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
retry:
pbits = *pte;
if (pbits & bit) {
if (bit == PG_RW) {
/*
* Regardless of whether a pte is 32 or 64 bits
* in size, PG_RW and PG_M are among the least
* significant 32 bits.
*/
if (!atomic_cmpset_int((u_int *)pte, pbits,
pbits & ~(PG_RW | PG_M)))
goto retry;
if (pbits & PG_M) {
vm_page_dirty(m);
}
} else {
atomic_clear_int((u_int *)pte, bit);
}
pmap_invalidate_page(pv->pv_pmap, pv->pv_va);
}
PMAP_UNLOCK(pv->pv_pmap);
}
if (bit == PG_RW)
vm_page_flag_clear(m, PG_WRITEABLE);
sched_unpin();
}
/*
* pmap_page_protect:
*
* Lower the permission for all mappings to a given page.
*/
void
pmap_page_protect(vm_page_t m, vm_prot_t prot)
{
if ((prot & VM_PROT_WRITE) == 0) {
if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) {
pmap_clear_ptes(m, PG_RW);
} else {
pmap_remove_all(m);
}
}
}
/*
* 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)
{
register pv_entry_t pv, pvf, pvn;
pt_entry_t *pte;
pt_entry_t v;
int rtval = 0;
if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
return (rtval);
sched_pin();
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
pvf = pv;
do {
pvn = TAILQ_NEXT(pv, pv_list);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
if (!pmap_track_modified(pv->pv_va))
continue;
PMAP_LOCK(pv->pv_pmap);
pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
if (pte && ((v = pte_load(pte)) & PG_A) != 0) {
atomic_clear_int((u_int *)pte, PG_A);
pmap_invalidate_page(pv->pv_pmap, pv->pv_va);
rtval++;
if (rtval > 4) {
PMAP_UNLOCK(pv->pv_pmap);
break;
}
}
PMAP_UNLOCK(pv->pv_pmap);
} while ((pv = pvn) != NULL && pv != pvf);
}
sched_unpin();
return (rtval);
}
/*
* Clear the modify bits on the specified physical page.
*/
void
pmap_clear_modify(vm_page_t m)
{
pmap_clear_ptes(m, PG_M);
}
/*
* pmap_clear_reference:
*
* Clear the reference bit on the specified physical page.
*/
void
pmap_clear_reference(vm_page_t m)
{
pmap_clear_ptes(m, PG_A);
}
/*
* 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(pa, size)
vm_paddr_t pa;
vm_size_t size;
{
vm_offset_t va, tmpva, offset;
offset = pa & PAGE_MASK;
size = roundup(offset + size, PAGE_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 (tmpva = va; size > 0; ) {
pmap_kenter(tmpva, pa);
size -= PAGE_SIZE;
tmpva += PAGE_SIZE;
pa += PAGE_SIZE;
}
pmap_invalidate_range(kernel_pmap, va, tmpva);
return ((void *)(va + offset));
}
void
pmap_unmapdev(va, size)
vm_offset_t va;
vm_size_t size;
{
vm_offset_t base, offset, tmpva;
if (va >= KERNBASE && va + size <= KERNBASE + KERNLOAD)
return;
base = va & PG_FRAME;
offset = va & PAGE_MASK;
size = roundup(offset + size, PAGE_SIZE);
for (tmpva = base; tmpva < (base + size); tmpva += PAGE_SIZE)
pmap_kremove(tmpva);
pmap_invalidate_range(kernel_pmap, va, tmpva);
kmem_free(kernel_map, base, size);
}
/*
* perform the pmap work for mincore
*/
int
pmap_mincore(pmap, addr)
pmap_t pmap;
vm_offset_t addr;
{
pt_entry_t *ptep, pte;
vm_page_t m;
int val = 0;
PMAP_LOCK(pmap);
ptep = pmap_pte(pmap, addr);
pte = (ptep != NULL) ? *ptep : 0;
pmap_pte_release(ptep);
PMAP_UNLOCK(pmap);
if (pte != 0) {
vm_paddr_t pa;
val = MINCORE_INCORE;
if ((pte & PG_MANAGED) == 0)
return val;
pa = pte & PG_FRAME;
m = PHYS_TO_VM_PAGE(pa);
/*
* Modified by us
*/
if (pte & PG_M)
val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER;
else {
/*
* Modified by someone else
*/
vm_page_lock_queues();
if (m->dirty || pmap_is_modified(m))
val |= MINCORE_MODIFIED_OTHER;
vm_page_unlock_queues();
}
/*
* Referenced by us
*/
if (pte & PG_A)
val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER;
else {
/*
* Referenced by someone else
*/
vm_page_lock_queues();
if ((m->flags & PG_REFERENCED) ||
pmap_ts_referenced(m)) {
val |= MINCORE_REFERENCED_OTHER;
vm_page_flag_set(m, PG_REFERENCED);
}
vm_page_unlock_queues();
}
}
return val;
}
void
pmap_activate(struct thread *td)
{
struct proc *p = td->td_proc;
pmap_t pmap, oldpmap;
u_int32_t cr3;
critical_enter();
pmap = vmspace_pmap(td->td_proc->p_vmspace);
oldpmap = PCPU_GET(curpmap);
#if defined(SMP)
atomic_clear_int(&oldpmap->pm_active, PCPU_GET(cpumask));
atomic_set_int(&pmap->pm_active, PCPU_GET(cpumask));
#else
oldpmap->pm_active &= ~1;
pmap->pm_active |= 1;
#endif
#ifdef PAE
cr3 = vtophys(pmap->pm_pdpt);
#else
cr3 = vtophys(pmap->pm_pdir);
#endif
/* XXXKSE this is wrong.
* pmap_activate is for the current thread on the current cpu
*/
if (p->p_flag & P_SA) {
/* Make sure all other cr3 entries are updated. */
/* what if they are running? XXXKSE (maybe abort them) */
FOREACH_THREAD_IN_PROC(p, td) {
td->td_pcb->pcb_cr3 = cr3;
}
} else {
td->td_pcb->pcb_cr3 = cr3;
}
load_cr3(cr3);
PCPU_SET(curpmap, pmap);
critical_exit();
}
vm_offset_t
pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size)
{
if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) {
return addr;
}
addr = (addr + PDRMASK) & ~PDRMASK;
return addr;
}
#if defined(PMAP_DEBUG)
pmap_pid_dump(int pid)
{
pmap_t pmap;
struct proc *p;
int npte = 0;
int index;
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list) {
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 = *pte;
m = PHYS_TO_VM_PAGE(pa);
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_offset_t pa);
/* print address space of pmap*/
static void
pads(pm)
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(pa)
vm_paddr_t pa;
{
pv_entry_t pv;
vm_page_t m;
printf("pa %x", pa);
m = PHYS_TO_VM_PAGE(pa);
TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
printf(" -> pmap %p, va %x", (void *)pv->pv_pmap, pv->pv_va);
pads(pv->pv_pmap);
}
printf(" ");
}
#endif
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