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freebsd-dev/sys/pc98/i386/pmap.c
Satoshi Asami 92b4f2e0df Update to current state of PC98 world. 
Submitted by:	The FreeBSD(98) development team
1996-07-23 07:46:59 +00:00

2676 lines
58 KiB
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.
*
* 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
* $Id: pmap.c,v 1.1.1.1 1996/06/14 10:04:41 asami Exp $
*/
/*
* 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/msgbuf.h>
#include <sys/queue.h>
#include <sys/vmmeter.h>
#include <sys/mman.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <vm/lock.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 <machine/pcb.h>
#include <machine/cputypes.h>
#include <machine/md_var.h>
#define PMAP_KEEP_PDIRS
#if defined(DIAGNOSTIC)
#define PMAP_DIAGNOSTIC
#endif
static void init_pv_entries __P((int));
/*
* 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)?(*(int *)pte |= PG_W):(*(int *)pte &= ~PG_W))
#define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v)))
/*
* Given a map and a machine independent protection code,
* convert to a vax protection code.
*/
#define pte_prot(m, p) (protection_codes[p])
static int protection_codes[8];
static struct pmap kernel_pmap_store;
pmap_t kernel_pmap;
vm_offset_t avail_start; /* PA of first available physical page */
vm_offset_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? */
static vm_offset_t vm_first_phys;
static int nkpt;
static vm_page_t nkpg;
vm_offset_t kernel_vm_end;
extern vm_offset_t clean_sva, clean_eva;
extern int cpu_class;
#if defined(I386_CPU) || defined(CYRIX_486DLC)
extern int cpu;
#endif
#define PV_FREELIST_MIN ((PAGE_SIZE / sizeof (struct pv_entry)) / 2)
/*
* Data for the pv entry allocation mechanism
*/
static int pv_freelistcnt;
static pv_entry_t pv_freelist;
static vm_offset_t pvva;
static int npvvapg;
/*
* All those kernel PT submaps that BSD is so fond of
*/
pt_entry_t *CMAP1;
static pt_entry_t *CMAP2, *ptmmap;
static pv_entry_t *pv_table;
caddr_t CADDR1, ptvmmap;
static caddr_t CADDR2;
static pt_entry_t *msgbufmap;
struct msgbuf *msgbufp;
pt_entry_t *PMAP1;
unsigned *PADDR1;
static void free_pv_entry __P((pv_entry_t pv));
static __inline unsigned * get_ptbase __P((pmap_t pmap));
static pv_entry_t get_pv_entry __P((void));
static void i386_protection_init __P((void));
static void pmap_alloc_pv_entry __P((void));
static void pmap_changebit __P((vm_offset_t pa, int bit, boolean_t setem));
static int pmap_is_managed __P((vm_offset_t pa));
static void pmap_remove_all __P((vm_offset_t pa));
static void pmap_enter_quick __P((pmap_t pmap, vm_offset_t va,
vm_offset_t pa));
static int pmap_remove_pte __P((struct pmap *pmap, unsigned *ptq,
vm_offset_t sva));
static void pmap_remove_page __P((struct pmap *pmap, vm_offset_t va));
static __inline int pmap_remove_entry __P((struct pmap *pmap, pv_entry_t *pv,
vm_offset_t va));
static boolean_t pmap_testbit __P((vm_offset_t pa, int bit));
static __inline void pmap_insert_entry __P((pmap_t pmap, vm_offset_t va,
vm_page_t mpte, vm_offset_t pa));
static __inline vm_page_t pmap_allocpte __P((pmap_t pmap, vm_offset_t va));
static __inline int pmap_release_free_page __P((pmap_t pmap, vm_page_t p));
static vm_page_t _pmap_allocpte __P((pmap_t pmap, int ptepindex));
#define VATRACK 4
#define PDSTACKMAX 16
static vm_offset_t pdstack[PDSTACKMAX];
static int pdstackptr;
/*
* 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_offset_t firstaddr;
vm_offset_t loadaddr;
{
vm_offset_t va;
pt_entry_t *pte;
avail_start = firstaddr;
/*
* 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_end = VM_MAX_KERNEL_ADDRESS;
/*
* Initialize protection array.
*/
i386_protection_init();
/*
* The kernel's pmap is statically allocated so we don't have to use
* pmap_create, which is unlikely to work correctly at this part of
* the boot sequence (XXX and which no longer exists).
*/
kernel_pmap = &kernel_pmap_store;
kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + IdlePTD);
kernel_pmap->pm_count = 1;
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 = (pt_entry_t *) pmap_pte(kernel_pmap, va);
/*
* CMAP1/CMAP2 are used for zeroing and copying pages.
*/
SYSMAP(caddr_t, CMAP1, CADDR1, 1)
SYSMAP(caddr_t, CMAP2, CADDR2, 1)
/*
* ptmmap is used for reading arbitrary physical pages via /dev/mem.
*/
SYSMAP(caddr_t, ptmmap, ptvmmap, 1)
/*
* msgbufmap is used to map the system message buffer.
*/
SYSMAP(struct msgbuf *, msgbufmap, msgbufp, 1)
/*
* ptemap is used for pmap_pte_quick
*/
SYSMAP(unsigned *, PMAP1, PADDR1, 1);
virtual_avail = va;
*(int *) CMAP1 = *(int *) CMAP2 = *(int *) PTD = 0;
pmap_update();
}
/*
* 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(phys_start, phys_end)
vm_offset_t phys_start, phys_end;
{
vm_offset_t addr;
vm_size_t npg, s;
int i;
/*
* calculate the number of pv_entries needed
*/
vm_first_phys = phys_avail[0];
for (i = 0; phys_avail[i + 1]; i += 2);
npg = (phys_avail[(i - 2) + 1] - vm_first_phys) / PAGE_SIZE;
/*
* Allocate memory for random pmap data structures. Includes the
* pv_head_table.
*/
s = (vm_size_t) (sizeof(struct pv_entry *) * npg);
s = round_page(s);
addr = (vm_offset_t) kmem_alloc(kernel_map, s);
pv_table = (pv_entry_t *) addr;
/*
* init the pv free list
*/
init_pv_entries(npg);
/*
* Now it is safe to enable pv_table recording.
*/
pmap_initialized = TRUE;
}
/*
* Used to map a range of physical addresses into kernel
* virtual address space.
*
* For now, VM is already on, we only need to map the
* specified memory.
*/
vm_offset_t
pmap_map(virt, start, end, prot)
vm_offset_t virt;
vm_offset_t start;
vm_offset_t end;
int prot;
{
while (start < end) {
pmap_enter(kernel_pmap, virt, start, prot, FALSE);
virt += PAGE_SIZE;
start += PAGE_SIZE;
}
return (virt);
}
/***************************************************
* 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 __inline int
pmap_track_modified( vm_offset_t va) {
if ((va < clean_sva) || (va >= clean_eva))
return 1;
else
return 0;
}
/*
* The below are finer grained pmap_update routines. These eliminate
* the gratuitious tlb flushes on non-i386 architectures.
*/
static __inline void
pmap_update_1pg( vm_offset_t va) {
#if defined(I386_CPU) || defined(CYRIX_486DLC)
/* CYRIX Bug? */
if (cpu_class == CPUCLASS_386 || cpu == CPU_486DLC)
pmap_update();
else
#endif
__asm __volatile(".byte 0xf,0x1,0x38": :"a" (va));
}
static __inline void
pmap_update_2pg( vm_offset_t va1, vm_offset_t va2) {
#if defined(I386_CPU) || defined(CYRIX_486DLC)
/* CYRIX Bug? */
if (cpu_class == CPUCLASS_386 || cpu == CPU_486DLC) {
pmap_update();
} else
#endif
{
__asm __volatile(".byte 0xf,0x1,0x38": :"a" (va1));
__asm __volatile(".byte 0xf,0x1,0x38": :"a" (va2));
}
}
static __pure unsigned *
get_ptbase(pmap)
pmap_t pmap;
{
unsigned frame = (unsigned) pmap->pm_pdir[PTDPTDI] & PG_FRAME;
/* are we current address space or kernel? */
if (pmap == kernel_pmap || frame == (((unsigned) PTDpde) & PG_FRAME)) {
return (unsigned *) PTmap;
}
/* otherwise, we are alternate address space */
if (frame != (((unsigned) APTDpde) & PG_FRAME)) {
APTDpde = (pd_entry_t) (frame | PG_RW | PG_V);
pmap_update();
}
return (unsigned *) APTmap;
}
/*
* Routine: pmap_pte
* Function:
* Extract the page table entry associated
* with the given map/virtual_address pair.
*/
__inline unsigned * __pure
pmap_pte(pmap, va)
register pmap_t pmap;
vm_offset_t va;
{
if (pmap && *pmap_pde(pmap, va)) {
return get_ptbase(pmap) + i386_btop(va);
}
return (0);
}
/*
* Super fast pmap_pte routine best used when scanning
* the pv lists. This eliminates many coarse-grained
* pmap_update calls.
*/
__inline unsigned * __pure
pmap_pte_quick(pmap, va)
register pmap_t pmap;
vm_offset_t va;
{
unsigned pde;
if (pde = (unsigned) pmap->pm_pdir[va >> PDRSHIFT]) {
unsigned frame = (unsigned) pmap->pm_pdir[PTDPTDI] & PG_FRAME;
/* are we current address space or kernel? */
if (pmap == kernel_pmap || frame == (((unsigned) PTDpde) & PG_FRAME)) {
return (unsigned *) PTmap + i386_btop(va);
}
* (int *) PMAP1 = (pde & PG_FRAME) | PG_V | PG_RW;
pmap_update_1pg((vm_offset_t) PADDR1);
return PADDR1 + ((unsigned) 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_offset_t __pure
pmap_extract(pmap, va)
register pmap_t pmap;
vm_offset_t va;
{
if (pmap && *pmap_pde(pmap, va)) {
unsigned *pte;
pte = get_ptbase(pmap) + i386_btop(va);
return ((*pte & PG_FRAME) | (va & PAGE_MASK));
}
return 0;
}
/*
* determine if a page is managed (memory vs. device)
*/
static __inline __pure int
pmap_is_managed(pa)
vm_offset_t pa;
{
int i;
if (!pmap_initialized)
return 0;
for (i = 0; phys_avail[i + 1]; i += 2) {
if (pa < phys_avail[i + 1] && pa >= phys_avail[i])
return 1;
}
return 0;
}
/***************************************************
* Low level mapping routines.....
***************************************************/
/*
* 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.
*/
void
pmap_qenter(va, m, count)
vm_offset_t va;
vm_page_t *m;
int count;
{
int i;
register unsigned *pte;
for (i = 0; i < count; i++) {
vm_offset_t tva = va + i * PAGE_SIZE;
unsigned npte = VM_PAGE_TO_PHYS(m[i]) | PG_RW | PG_V;
unsigned opte;
pte = (unsigned *)vtopte(tva);
opte = *pte;
*pte = npte;
if (opte)
pmap_update_1pg(tva);
}
}
/*
* this routine jerks page mappings from the
* kernel -- it is meant only for temporary mappings.
*/
void
pmap_qremove(va, count)
vm_offset_t va;
int count;
{
int i;
register unsigned *pte;
for (i = 0; i < count; i++) {
pte = (unsigned *)vtopte(va);
*pte = 0;
pmap_update_1pg(va);
va += PAGE_SIZE;
}
}
/*
* add a wired page to the kva
* note that in order for the mapping to take effect -- you
* should do a pmap_update after doing the pmap_kenter...
*/
__inline void
pmap_kenter(va, pa)
vm_offset_t va;
register vm_offset_t pa;
{
register unsigned *pte;
unsigned npte, opte;
npte = pa | PG_RW | PG_V;
pte = (unsigned *)vtopte(va);
opte = *pte;
*pte = npte;
if (opte)
pmap_update_1pg(va);
}
/*
* remove a page from the kernel pagetables
*/
__inline void
pmap_kremove(va)
vm_offset_t va;
{
register unsigned *pte;
pte = (unsigned *)vtopte(va);
*pte = 0;
pmap_update_1pg(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 __inline int
pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m) {
vm_page_unhold(m);
if (m->hold_count == 0) {
vm_offset_t pteva;
/*
* unmap the page table page
*/
pmap->pm_pdir[m->pindex] = 0;
--pmap->pm_stats.resident_count;
/*
* Do a pmap_update to make the invalidated mapping
* take effect immediately.
*/
pteva = UPT_MIN_ADDRESS + i386_ptob(m->pindex);
pmap_update_1pg(pteva);
/*
* If the page is finally unwired, simply free it.
*/
--m->wire_count;
if (m->wire_count == 0) {
vm_page_free_zero(m);
--cnt.v_wire_count;
}
return 1;
}
return 0;
}
/*
* After removing a page table entry, this routine is used to
* conditionally free the page, and manage the hold/wire counts.
*/
int
pmap_unuse_pt(pmap, va, mpte)
pmap_t pmap;
vm_offset_t va;
vm_page_t mpte;
{
if (va >= UPT_MIN_ADDRESS)
return 0;
if (mpte == NULL) {
vm_offset_t ptepa;
ptepa = ((vm_offset_t) *pmap_pde(pmap, va));
#if defined(PMAP_DIAGNOSTIC)
if (!ptepa)
panic("pmap_unuse_pt: pagetable page missing, va: 0x%x", va);
#endif
if (!ptepa)
return 0;
mpte = PHYS_TO_VM_PAGE(ptepa);
}
#if defined(PMAP_DIAGNOSTIC)
if (mpte->pindex != (va >> PDRSHIFT))
panic("pmap_unuse_pt: pindex(0x%x) != va(0x%x)",
mpte->pindex, (va >> PDRSHIFT));
if (mpte->hold_count == 0) {
panic("pmap_unuse_pt: hold count < 0, va: 0x%x", va);
}
#endif
return pmap_unwire_pte_hold(pmap, mpte);
}
/*
* 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 ptdpg;
/*
* No need to allocate page table space yet but we do need a valid
* page directory table.
*/
if (pdstackptr > 0) {
--pdstackptr;
pmap->pm_pdir = (pd_entry_t *)pdstack[pdstackptr];
} else {
pmap->pm_pdir =
(pd_entry_t *)kmem_alloc_pageable(kernel_map, PAGE_SIZE);
}
/*
* allocate object for the ptes
*/
pmap->pm_pteobj = vm_object_allocate( OBJT_DEFAULT, PTDPTDI + 1);
/*
* allocate the page directory page
*/
retry:
ptdpg = vm_page_alloc( pmap->pm_pteobj, PTDPTDI, VM_ALLOC_ZERO);
if (ptdpg == NULL) {
VM_WAIT;
goto retry;
}
vm_page_wire(ptdpg);
ptdpg->flags &= ~(PG_MAPPED|PG_BUSY); /* not mapped normally */
ptdpg->valid = VM_PAGE_BITS_ALL;
pmap_kenter((vm_offset_t) pmap->pm_pdir, VM_PAGE_TO_PHYS(ptdpg));
if ((ptdpg->flags & PG_ZERO) == 0)
bzero(pmap->pm_pdir, PAGE_SIZE);
/* wire in kernel global address entries */
bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * PTESIZE);
/* install self-referential address mapping entry */
*(unsigned *) (pmap->pm_pdir + PTDPTDI) =
VM_PAGE_TO_PHYS(ptdpg) | PG_V | PG_RW;
pmap->pm_count = 1;
}
static int
pmap_release_free_page(pmap, p)
struct pmap *pmap;
vm_page_t p;
{
int s;
unsigned *pde = (unsigned *) pmap->pm_pdir;
/*
* This code optimizes the case of freeing non-busy
* page-table pages. Those pages are zero now, and
* might as well be placed directly into the zero queue.
*/
s = splvm();
if (p->flags & PG_BUSY) {
p->flags |= PG_WANTED;
tsleep(p, PVM, "pmaprl", 0);
splx(s);
return 0;
}
/*
* Remove the page table page from the processes address space.
*/
pde[p->pindex] = 0;
--pmap->pm_stats.resident_count;
if (p->hold_count) {
int *kvap;
int i;
#if defined(PMAP_DIAGNOSTIC)
panic("pmap_release: freeing held page table page");
#else
printf("pmap_release: freeing held page table page:\n");
#endif
kvap = (int *)vm_pager_map_page(p);
for(i=0;i<NPTEPG;i++) {
if (kvap[i]) {
printf("pte: 0x%x, index: %d\n", kvap[i],i);
}
}
vm_pager_unmap_page((vm_offset_t)kvap);
/*
* HACK ALERT!!!
* If this failure happens, we must clear the page, because
* there is likely a mapping still valid. This condition
* is an error, but at least this zero operation will mitigate
* some Sig-11's or crashes, because this page is thought
* to be zero. This is a robustness fix, and not meant to
* be a long term work-around.
*/
pmap_zero_page(VM_PAGE_TO_PHYS(p));
}
/*
* Page directory pages need to have the kernel
* stuff cleared, so they can go into the zero queue also.
*/
if (p->pindex == PTDPTDI) {
bzero(pde + KPTDI, nkpt * PTESIZE);
pde[APTDPTDI] = 0;
pmap_kremove((vm_offset_t) pmap->pm_pdir);
}
vm_page_free_zero(p);
splx(s);
return 1;
}
/*
* this routine is called if the page table page is not
* mapped correctly.
*/
static vm_page_t
_pmap_allocpte(pmap, ptepindex)
pmap_t pmap;
int ptepindex;
{
vm_offset_t pteva, ptepa;
vm_page_t m;
/*
* Find or fabricate a new pagetable page
*/
retry:
m = vm_page_lookup(pmap->pm_pteobj, ptepindex);
if (m == NULL) {
m = vm_page_alloc(pmap->pm_pteobj, ptepindex, VM_ALLOC_ZERO);
if (m == NULL) {
VM_WAIT;
goto retry;
}
if ((m->flags & PG_ZERO) == 0)
pmap_zero_page(VM_PAGE_TO_PHYS(m));
m->flags &= ~(PG_ZERO|PG_BUSY);
m->valid = VM_PAGE_BITS_ALL;
} else {
if ((m->flags & PG_BUSY) || m->busy) {
m->flags |= PG_WANTED;
tsleep(m, PVM, "ptewai", 0);
goto retry;
}
}
/*
* mark the object writeable
*/
pmap->pm_pteobj->flags |= OBJ_WRITEABLE;
if (m->queue != PQ_NONE) {
int s = splvm();
vm_page_unqueue(m);
splx(s);
}
if (m->hold_count == 0) {
if (m->wire_count == 0)
++cnt.v_wire_count;
++m->wire_count;
}
/*
* Increment the hold count for the page table page
* (denoting a new mapping.)
*/
++m->hold_count;
/*
* 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);
pteva = UPT_MIN_ADDRESS + i386_ptob(ptepindex);
pmap_update_1pg(pteva);
m->flags |= PG_MAPPED;
return m;
}
static __inline vm_page_t
pmap_allocpte(pmap, va)
pmap_t pmap;
vm_offset_t va;
{
int ptepindex;
vm_offset_t ptepa;
vm_page_t m;
/*
* Calculate pagetable page index
*/
ptepindex = va >> PDRSHIFT;
/*
* Get the page directory entry
*/
ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex];
/*
* 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->hold_count;
return m;
}
/*
* Here if the pte page isn't mapped, or if it has been deallocated.
*/
return _pmap_allocpte(pmap, ptepindex);
}
/***************************************************
* Pmap allocation/deallocation routines.
***************************************************/
/*
* 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)
register struct pmap *pmap;
{
vm_page_t p,n,ptdpg;
vm_object_t object = pmap->pm_pteobj;
if (object->ref_count != 1)
panic("pmap_release: pteobj reference count != 1");
ptdpg = NULL;
retry:
for (p = TAILQ_FIRST(&object->memq); p != NULL; p = n) {
n = TAILQ_NEXT(p, listq);
if (p->pindex == PTDPTDI) {
ptdpg = p;
continue;
}
if (!pmap_release_free_page(pmap, p))
goto retry;
}
if (ptdpg == NULL)
panic("pmap_release: missing page table directory page");
if (!pmap_release_free_page(pmap, ptdpg))
goto retry;
vm_object_deallocate(object);
if (pdstackptr < PDSTACKMAX) {
pdstack[pdstackptr] = (vm_offset_t) pmap->pm_pdir;
++pdstackptr;
} else {
kmem_free(kernel_map, (vm_offset_t) pmap->pm_pdir, PAGE_SIZE);
}
}
/*
* grow the number of kernel page table entries, if needed
*/
void
pmap_growkernel(vm_offset_t addr)
{
struct proc *p;
struct pmap *pmap;
int s;
s = splhigh();
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 = (addr + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
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;
}
++nkpt;
if (!nkpg) {
nkpg = vm_page_alloc(kernel_object, 0, VM_ALLOC_SYSTEM);
if (!nkpg)
panic("pmap_growkernel: no memory to grow kernel");
vm_page_wire(nkpg);
vm_page_remove(nkpg);
pmap_zero_page(VM_PAGE_TO_PHYS(nkpg));
}
pdir_pde(PTD, kernel_vm_end) = (pd_entry_t) (VM_PAGE_TO_PHYS(nkpg) | PG_V | PG_RW);
nkpg = NULL;
for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
if (p->p_vmspace) {
pmap = &p->p_vmspace->vm_pmap;
*pmap_pde(pmap, kernel_vm_end) = pdir_pde(PTD, kernel_vm_end);
}
}
*pmap_pde(kernel_pmap, kernel_vm_end) = pdir_pde(PTD, kernel_vm_end);
kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
}
splx(s);
}
/*
* Retire the given physical map from service.
* Should only be called if the map contains
* no valid mappings.
*/
void
pmap_destroy(pmap)
register pmap_t pmap;
{
int count;
if (pmap == NULL)
return;
count = --pmap->pm_count;
if (count == 0) {
pmap_release(pmap);
free((caddr_t) pmap, M_VMPMAP);
}
}
/*
* Add a reference to the specified pmap.
*/
void
pmap_reference(pmap)
pmap_t pmap;
{
if (pmap != NULL) {
pmap->pm_count++;
}
}
/***************************************************
* page management routines.
***************************************************/
/*
* free the pv_entry back to the free list
*/
static __inline void
free_pv_entry(pv)
pv_entry_t pv;
{
++pv_freelistcnt;
pv->pv_next = pv_freelist;
pv_freelist = 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 __inline pv_entry_t
get_pv_entry()
{
pv_entry_t tmp;
/*
* get more pv_entry pages if needed
*/
if (pv_freelistcnt < PV_FREELIST_MIN || pv_freelist == 0) {
pmap_alloc_pv_entry();
}
/*
* get a pv_entry off of the free list
*/
--pv_freelistcnt;
tmp = pv_freelist;
pv_freelist = tmp->pv_next;
return tmp;
}
/*
* This *strange* allocation routine eliminates the possibility of a malloc
* failure (*FATAL*) for a pv_entry_t data structure.
* also -- this code is MUCH MUCH faster than the malloc equiv...
* We really need to do the slab allocator thingie here.
*/
static void
pmap_alloc_pv_entry()
{
/*
* do we have any pre-allocated map-pages left?
*/
if (npvvapg) {
vm_page_t m;
/*
* allocate a physical page out of the vm system
*/
m = vm_page_alloc(kernel_object,
OFF_TO_IDX(pvva - vm_map_min(kernel_map)),
VM_ALLOC_INTERRUPT);
if (m) {
int newentries;
int i;
pv_entry_t entry;
newentries = (PAGE_SIZE / sizeof(struct pv_entry));
/*
* wire the page
*/
vm_page_wire(m);
m->flags &= ~PG_BUSY;
/*
* let the kernel see it
*/
pmap_kenter(pvva, VM_PAGE_TO_PHYS(m));
entry = (pv_entry_t) pvva;
/*
* update the allocation pointers
*/
pvva += PAGE_SIZE;
--npvvapg;
/*
* free the entries into the free list
*/
for (i = 0; i < newentries; i++) {
free_pv_entry(entry);
entry++;
}
}
}
if (!pv_freelist)
panic("get_pv_entry: cannot get a pv_entry_t");
}
/*
* init the pv_entry allocation system
*/
#define PVSPERPAGE 64
void
init_pv_entries(npg)
int npg;
{
/*
* allocate enough kvm space for PVSPERPAGE entries per page (lots)
* kvm space is fairly cheap, be generous!!! (the system can panic if
* this is too small.)
*/
npvvapg = ((npg * PVSPERPAGE) * sizeof(struct pv_entry)
+ PAGE_SIZE - 1) / PAGE_SIZE;
pvva = kmem_alloc_pageable(kernel_map, npvvapg * PAGE_SIZE);
/*
* get the first batch of entries
*/
pmap_alloc_pv_entry();
}
/*
* If it is the first entry on the list, it is actually
* in the header and we must copy the following entry up
* to the header. Otherwise we must search the list for
* the entry. In either case we free the now unused entry.
*/
static __inline int
pmap_remove_entry(pmap, ppv, va)
struct pmap *pmap;
pv_entry_t *ppv;
vm_offset_t va;
{
pv_entry_t npv;
int s;
s = splvm();
for (npv = *ppv; npv; (ppv = &npv->pv_next, npv = *ppv)) {
if (pmap == npv->pv_pmap && va == npv->pv_va) {
int rtval = pmap_unuse_pt(pmap, va, npv->pv_ptem);
*ppv = npv->pv_next;
free_pv_entry(npv);
splx(s);
return rtval;
}
}
splx(s);
return 0;
}
/*
* Create a pv entry for page at pa for
* (pmap, va).
*/
static __inline void
pmap_insert_entry(pmap, va, mpte, pa)
pmap_t pmap;
vm_offset_t va;
vm_page_t mpte;
vm_offset_t pa;
{
int s;
pv_entry_t *ppv, pv;
s = splvm();
pv = get_pv_entry();
pv->pv_va = va;
pv->pv_pmap = pmap;
pv->pv_ptem = mpte;
ppv = pa_to_pvh(pa);
if (*ppv)
pv->pv_next = *ppv;
else
pv->pv_next = NULL;
*ppv = pv;
splx(s);
}
/*
* pmap_remove_pte: do the things to unmap a page in a process
*/
static int
pmap_remove_pte(pmap, ptq, va)
struct pmap *pmap;
unsigned *ptq;
vm_offset_t va;
{
unsigned oldpte;
pv_entry_t *ppv;
oldpte = *ptq;
*ptq = 0;
if (oldpte & PG_W)
pmap->pm_stats.wired_count -= 1;
pmap->pm_stats.resident_count -= 1;
if (oldpte & PG_MANAGED) {
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%lx, pte: 0x%lx\n", va, (int) oldpte);
}
#endif
if (pmap_track_modified(va))
PHYS_TO_VM_PAGE(oldpte)->dirty = VM_PAGE_BITS_ALL;
}
ppv = pa_to_pvh(oldpte);
return pmap_remove_entry(pmap, ppv, va);
} else {
return pmap_unuse_pt(pmap, va, NULL);
}
return 0;
}
/*
* Remove a single page from a process address space
*/
static void
pmap_remove_page(pmap, va)
struct pmap *pmap;
register vm_offset_t va;
{
register unsigned *ptq;
/*
* if there is no pte for this address, just skip it!!!
*/
if (*pmap_pde(pmap, va) == 0) {
return;
}
/*
* get a local va for mappings for this pmap.
*/
ptq = get_ptbase(pmap) + i386_btop(va);
if (*ptq) {
(void) pmap_remove_pte(pmap, ptq, va);
pmap_update_1pg(va);
}
return;
}
/*
* 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, sva, eva)
struct pmap *pmap;
register vm_offset_t sva;
register vm_offset_t eva;
{
register unsigned *ptbase;
vm_offset_t pdnxt;
vm_offset_t ptpaddr;
vm_offset_t sindex, eindex;
vm_page_t mpte;
int anyvalid;
vm_offset_t vachanged[VATRACK];
if (pmap == NULL)
return;
/*
* special handling of removing one page. a very
* common operation and easy to short circuit some
* code.
*/
if ((sva + PAGE_SIZE) == eva) {
pmap_remove_page(pmap, sva);
return;
}
anyvalid = 0;
/*
* Get a local virtual address for the mappings that are being
* worked with.
*/
ptbase = get_ptbase(pmap);
sindex = i386_btop(sva);
eindex = i386_btop(eva);
for (; sindex < eindex; sindex = pdnxt) {
/*
* Calculate index for next page table.
*/
pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1));
ptpaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sindex));
/*
* Weed out invalid mappings. Note: we assume that the page
* directory table is always allocated, and in kernel virtual.
*/
if (ptpaddr == 0)
continue;
if (sindex < i386_btop(UPT_MIN_ADDRESS)) {
/*
* get the vm_page_t for the page table page
*/
mpte = PHYS_TO_VM_PAGE(ptpaddr);
/*
* if the pte isn't wired, just skip it.
*/
if (mpte->wire_count == 0)
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 > eindex) {
pdnxt = eindex;
}
for ( ;sindex != pdnxt; sindex++) {
vm_offset_t va;
if (ptbase[sindex] == 0) {
continue;
}
va = i386_ptob(sindex);
if (anyvalid < VATRACK)
vachanged[anyvalid] = va;
anyvalid++;
if (pmap_remove_pte(pmap,
ptbase + sindex, va))
break;
}
}
if (anyvalid) {
if (anyvalid <= VATRACK) {
int i;
for(i=0;i<anyvalid;i++)
pmap_update_1pg(vachanged[i]);
} else {
pmap_update();
}
}
}
/*
* 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...)
*/
static void
pmap_remove_all(pa)
vm_offset_t pa;
{
register pv_entry_t pv, *ppv, npv;
register unsigned *pte, tpte;
vm_page_t m;
int s;
#if defined(PMAP_DIAGNOSTIC)
/*
* XXX this makes pmap_page_protect(NONE) illegal for non-managed
* pages!
*/
if (!pmap_is_managed(pa)) {
panic("pmap_page_protect: illegal for unmanaged page, va: 0x%lx", pa);
}
#endif
s = splvm();
m = NULL;
ppv = pa_to_pvh(pa);
for (pv = *ppv; pv; pv=pv->pv_next) {
pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
if (tpte = *pte) {
pv->pv_pmap->pm_stats.resident_count--;
*pte = 0;
if (tpte & PG_W)
pv->pv_pmap->pm_stats.wired_count--;
/*
* 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%lx, pte: 0x%lx\n", pv->pv_va, tpte);
}
#endif
if (pmap_track_modified(pv->pv_va)) {
if (m == NULL)
m = PHYS_TO_VM_PAGE(pa);
m->dirty = VM_PAGE_BITS_ALL;
}
}
}
}
for (pv = *ppv; pv; pv = npv) {
npv = pv->pv_next;
pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
free_pv_entry(pv);
}
*ppv = NULL;
splx(s);
}
/*
* Set the physical protection on the
* specified range of this map as requested.
*/
void
pmap_protect(pmap, sva, eva, prot)
register pmap_t pmap;
vm_offset_t sva, eva;
vm_prot_t prot;
{
register unsigned *ptbase;
vm_offset_t pdnxt;
vm_offset_t ptpaddr;
vm_offset_t sindex, eindex;
vm_page_t mpte;
int anyvalid;
if (pmap == NULL)
return;
if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
pmap_remove(pmap, sva, eva);
return;
}
if (prot & VM_PROT_WRITE)
return;
anyvalid = 0;
ptbase = get_ptbase(pmap);
sindex = i386_btop(sva);
eindex = i386_btop(eva);
for (; sindex < eindex; sindex = pdnxt) {
pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1));
ptpaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sindex));
/*
* Weed out invalid mappings. Note: we assume that the page
* directory table is always allocated, and in kernel virtual.
*/
if (ptpaddr == 0)
continue;
/*
* Skip page ranges, where the page table page isn't wired.
* If the page table page is not wired, there are no page mappings
* there.
*/
if (sindex < i386_btop(UPT_MIN_ADDRESS)) {
mpte = PHYS_TO_VM_PAGE(ptpaddr);
if (mpte->wire_count == 0)
continue;
}
if (pdnxt > eindex) {
pdnxt = eindex;
}
for (; sindex != pdnxt; sindex++) {
unsigned pbits = ptbase[sindex];
if (pbits & PG_RW) {
if (pbits & PG_M) {
vm_offset_t sva = i386_ptob(sindex);
if (pmap_track_modified(sva)) {
vm_page_t m = PHYS_TO_VM_PAGE(pbits);
m->dirty = VM_PAGE_BITS_ALL;
}
}
ptbase[sindex] = pbits & ~(PG_M|PG_RW);
anyvalid = 1;
}
}
}
if (anyvalid)
pmap_update();
}
/*
* 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, va, pa, prot, wired)
register pmap_t pmap;
vm_offset_t va;
register vm_offset_t pa;
vm_prot_t prot;
boolean_t wired;
{
register unsigned *pte;
vm_offset_t opa;
vm_offset_t origpte, newpte;
vm_page_t mpte;
if (pmap == NULL)
return;
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;
/*
* In the case that a page table page is not
* resident, we are creating it here.
*/
if (va < UPT_MIN_ADDRESS)
mpte = pmap_allocpte(pmap, va);
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=%p, va=0x%lx\n",
pmap->pm_pdir[PTDPTDI], va);
}
origpte = *(vm_offset_t *)pte;
pa &= PG_FRAME;
opa = origpte & PG_FRAME;
/*
* Mapping has not changed, must be protection or wiring change.
*/
if (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%lx, pte: 0x%lx\n", va, origpte);
}
#endif
/*
* We might be turning off write access to the page,
* so we go ahead and sense modify status.
*/
if (origpte & PG_MANAGED) {
vm_page_t m;
if (origpte & PG_M) {
if (pmap_track_modified(va)) {
m = PHYS_TO_VM_PAGE(pa);
m->dirty = VM_PAGE_BITS_ALL;
}
}
pa |= PG_MANAGED;
}
if (mpte)
--mpte->hold_count;
goto validate;
}
/*
* Mapping has changed, invalidate old range and fall through to
* handle validating new mapping.
*/
if (opa) {
int err;
err = pmap_remove_pte(pmap, pte, va);
if (err)
panic("pmap_enter: pte vanished, va: 0x%x", va);
}
/*
* 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_is_managed(pa)) {
pmap_insert_entry(pmap, va, mpte, pa);
pa |= PG_MANAGED;
}
/*
* Increment counters
*/
pmap->pm_stats.resident_count++;
if (wired)
pmap->pm_stats.wired_count++;
validate:
/*
* Now validate mapping with desired protection/wiring.
*/
newpte = (vm_offset_t) (pa | pte_prot(pmap, prot) | PG_V);
if (wired)
newpte |= PG_W;
if (va < UPT_MIN_ADDRESS)
newpte |= PG_U;
/*
* if the mapping or permission bits are different, we need
* to update the pte.
*/
if ((origpte & ~(PG_M|PG_A)) != newpte) {
*pte = newpte;
if (origpte)
pmap_update_1pg(va);
}
}
/*
* 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...
*/
static void
pmap_enter_quick(pmap, va, pa)
register pmap_t pmap;
vm_offset_t va;
register vm_offset_t pa;
{
register unsigned *pte;
vm_page_t mpte;
mpte = NULL;
/*
* In the case that a page table page is not
* resident, we are creating it here.
*/
if (va < UPT_MIN_ADDRESS)
mpte = pmap_allocpte(pmap, va);
/*
* 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 = (unsigned *)vtopte(va);
if (*pte) {
if (mpte)
pmap_unwire_pte_hold(pmap, mpte);
return;
}
/*
* 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.
*/
pmap_insert_entry(pmap, va, mpte, pa);
/*
* Increment counters
*/
pmap->pm_stats.resident_count++;
/*
* Now validate mapping with RO protection
*/
*pte = pa | PG_V | PG_U | PG_MANAGED;
return;
}
#define MAX_INIT_PT (96)
/*
* pmap_object_init_pt preloads the ptes for a given object
* into the specified pmap. This eliminates the blast of soft
* faults on process startup and immediately after an mmap.
*/
void
pmap_object_init_pt(pmap, addr, object, pindex, size, limit)
pmap_t pmap;
vm_offset_t addr;
vm_object_t object;
vm_pindex_t pindex;
vm_size_t size;
int limit;
{
vm_offset_t tmpidx;
int psize;
vm_page_t p;
int objpgs;
psize = i386_btop(size);
if (!pmap || (object->type != OBJT_VNODE) ||
(limit && (psize > MAX_INIT_PT) &&
(object->resident_page_count > MAX_INIT_PT))) {
return;
}
if (psize + pindex > object->size)
psize = object->size - pindex;
/*
* if we are processing a major portion of the object, then scan the
* entire thing.
*/
if (psize > (object->size >> 2)) {
objpgs = psize;
for (p = TAILQ_FIRST(&object->memq);
((objpgs > 0) && (p != NULL));
p = TAILQ_NEXT(p, listq)) {
tmpidx = p->pindex;
if (tmpidx < pindex) {
continue;
}
tmpidx -= pindex;
if (tmpidx >= psize) {
continue;
}
if (((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
(p->busy == 0) &&
(p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
if (p->queue == PQ_CACHE)
vm_page_deactivate(p);
p->flags |= PG_BUSY;
pmap_enter_quick(pmap,
addr + i386_ptob(tmpidx),
VM_PAGE_TO_PHYS(p));
p->flags |= PG_MAPPED;
PAGE_WAKEUP(p);
}
objpgs -= 1;
}
} else {
/*
* else lookup the pages one-by-one.
*/
for (tmpidx = 0; tmpidx < psize; tmpidx += 1) {
p = vm_page_lookup(object, tmpidx + pindex);
if (p &&
((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
(p->busy == 0) &&
(p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
if (p->queue == PQ_CACHE)
vm_page_deactivate(p);
p->flags |= PG_BUSY;
pmap_enter_quick(pmap,
addr + i386_ptob(tmpidx),
VM_PAGE_TO_PHYS(p));
p->flags |= PG_MAPPED;
PAGE_WAKEUP(p);
}
}
}
return;
}
/*
* pmap_prefault provides a quick way of clustering
* pagefaults into a processes address space. It is a "cousin"
* of pmap_object_init_pt, except it runs at page fault time instead
* of mmap time.
*/
#define PFBAK 2
#define PFFOR 2
#define PAGEORDER_SIZE (PFBAK+PFFOR)
static int pmap_prefault_pageorder[] = {
-PAGE_SIZE, PAGE_SIZE, -2 * PAGE_SIZE, 2 * PAGE_SIZE
};
void
pmap_prefault(pmap, addra, entry, object)
pmap_t pmap;
vm_offset_t addra;
vm_map_entry_t entry;
vm_object_t object;
{
int i;
vm_offset_t starta;
vm_offset_t addr;
vm_pindex_t pindex;
vm_page_t m;
if (entry->object.vm_object != object)
return;
if (!curproc || (pmap != &curproc->p_vmspace->vm_pmap))
return;
starta = addra - PFBAK * PAGE_SIZE;
if (starta < entry->start) {
starta = entry->start;
} else if (starta > addra) {
starta = 0;
}
for (i = 0; i < PAGEORDER_SIZE; i++) {
vm_object_t lobject;
unsigned *pte;
addr = addra + pmap_prefault_pageorder[i];
if (addr < starta || addr >= entry->end)
continue;
if ((*pmap_pde(pmap, addr)) == NULL)
continue;
pte = (unsigned *) vtopte(addr);
if (*pte)
continue;
pindex = ((addr - entry->start) + entry->offset) >> PAGE_SHIFT;
lobject = object;
for (m = vm_page_lookup(lobject, pindex);
(!m && (lobject->type == OBJT_DEFAULT) && (lobject->backing_object));
lobject = lobject->backing_object) {
if (lobject->backing_object_offset & PAGE_MASK)
break;
pindex += (lobject->backing_object_offset >> PAGE_SHIFT);
m = vm_page_lookup(lobject->backing_object, pindex);
}
/*
* give-up when a page is not in memory
*/
if (m == NULL)
break;
if (((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
(m->busy == 0) &&
(m->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
if (m->queue == PQ_CACHE) {
vm_page_deactivate(m);
}
m->flags |= PG_BUSY;
pmap_enter_quick(pmap, addr, VM_PAGE_TO_PHYS(m));
m->flags |= PG_MAPPED;
PAGE_WAKEUP(m);
}
}
}
/*
* 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 unsigned *pte;
if (pmap == NULL)
return;
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);
}
/*
* 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(dst_pmap, src_pmap, dst_addr, len, src_addr)
pmap_t dst_pmap, 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;
unsigned src_frame, dst_frame;
if (dst_addr != src_addr)
return;
src_frame = ((unsigned) src_pmap->pm_pdir[PTDPTDI]) & PG_FRAME;
if (src_frame != (((unsigned) PTDpde) & PG_FRAME))
return;
dst_frame = ((unsigned) dst_pmap->pm_pdir[PTDPTDI]) & PG_FRAME;
if (dst_frame != (((unsigned) APTDpde) & PG_FRAME)) {
APTDpde = (pd_entry_t) (dst_frame | PG_RW | PG_V);
pmap_update();
}
for(addr = src_addr; addr < end_addr; addr = pdnxt) {
unsigned *src_pte, *dst_pte;
vm_page_t dstmpte, srcmpte;
vm_offset_t srcptepaddr;
if (addr >= UPT_MIN_ADDRESS)
panic("pmap_copy: invalid to pmap_copy page tables\n");
pdnxt = ((addr + PAGE_SIZE*NPTEPG) & ~(PAGE_SIZE*NPTEPG - 1));
srcptepaddr = (vm_offset_t) src_pmap->pm_pdir[addr >> PDRSHIFT];
if (srcptepaddr == 0) {
continue;
}
srcmpte = PHYS_TO_VM_PAGE(srcptepaddr);
if (srcmpte->hold_count == 0)
continue;
if (pdnxt > end_addr)
pdnxt = end_addr;
src_pte = (unsigned *) vtopte(addr);
dst_pte = (unsigned *) avtopte(addr);
while (addr < pdnxt) {
unsigned 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);
if ((*dst_pte == 0) && (ptetemp = *src_pte)) {
/*
* Simply clear the modified and accessed (referenced)
* bits.
*/
*dst_pte = ptetemp & ~(PG_M|PG_A);
dst_pmap->pm_stats.resident_count++;
pmap_insert_entry(dst_pmap, addr, dstmpte,
(ptetemp & PG_FRAME));
} else {
pmap_unwire_pte_hold(dst_pmap, dstmpte);
}
if (dstmpte->hold_count >= srcmpte->hold_count)
break;
}
addr += PAGE_SIZE;
++src_pte;
++dst_pte;
}
}
}
/*
* Routine: pmap_kernel
* Function:
* Returns the physical map handle for the kernel.
*/
pmap_t
pmap_kernel()
{
return (kernel_pmap);
}
/*
* pmap_zero_page zeros the specified (machine independent)
* page by mapping the page into virtual memory and using
* bzero to clear its contents, one machine dependent page
* at a time.
*/
void
pmap_zero_page(phys)
vm_offset_t phys;
{
if (*(int *) CMAP2)
panic("pmap_zero_page: CMAP busy");
*(int *) CMAP2 = PG_V | PG_RW | (phys & PG_FRAME);
bzero(CADDR2, PAGE_SIZE);
*(int *) CMAP2 = 0;
pmap_update_1pg((vm_offset_t) CADDR2);
}
/*
* 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(src, dst)
vm_offset_t src;
vm_offset_t dst;
{
if (*(int *) CMAP1 || *(int *) CMAP2)
panic("pmap_copy_page: CMAP busy");
*(int *) CMAP1 = PG_V | PG_RW | (src & PG_FRAME);
*(int *) CMAP2 = PG_V | PG_RW | (dst & PG_FRAME);
bcopy(CADDR1, CADDR2, PAGE_SIZE);
*(int *) CMAP1 = 0;
*(int *) CMAP2 = 0;
pmap_update_2pg( (vm_offset_t) CADDR1, (vm_offset_t) CADDR2);
}
/*
* Routine: pmap_pageable
* Function:
* Make the specified pages (by pmap, offset)
* pageable (or not) as requested.
*
* A page which is not pageable may not take
* a fault; therefore, its page table entry
* must remain valid for the duration.
*
* This routine is merely advisory; pmap_enter
* will specify that these pages are to be wired
* down (or not) as appropriate.
*/
void
pmap_pageable(pmap, sva, eva, pageable)
pmap_t pmap;
vm_offset_t sva, eva;
boolean_t pageable;
{
}
/*
* this routine returns true if a physical page resides
* in the given pmap.
*/
boolean_t
pmap_page_exists(pmap, pa)
pmap_t pmap;
vm_offset_t pa;
{
register pv_entry_t *ppv, pv;
int s;
if (!pmap_is_managed(pa))
return FALSE;
s = splvm();
ppv = pa_to_pvh(pa);
/*
* Not found, check current mappings returning immediately if found.
*/
for (pv = *ppv; pv; pv = pv->pv_next) {
if (pv->pv_pmap == pmap) {
splx(s);
return TRUE;
}
}
splx(s);
return (FALSE);
}
/*
* pmap_testbit tests bits in pte's
* note that the testbit/changebit routines are inline,
* and a lot of things compile-time evaluate.
*/
static __inline boolean_t
pmap_testbit(pa, bit)
register vm_offset_t pa;
int bit;
{
register pv_entry_t *ppv, pv;
unsigned *pte;
int s;
if (!pmap_is_managed(pa))
return FALSE;
ppv = pa_to_pvh(pa);
if (*ppv == NULL)
return FALSE;
s = splvm();
/*
* Not found, check current mappings returning immediately if found.
*/
for (pv = *ppv ;pv; pv = pv->pv_next) {
/*
* if the bit being tested is the modified bit, then
* mark clean_map and ptes as never
* modified.
*/
if (bit & (PG_A|PG_M)) {
if (!pmap_track_modified(pv->pv_va))
continue;
}
if (!pv->pv_pmap) {
#if defined(PMAP_DIAGNOSTIC)
printf("Null pmap (tb) at va: 0x%lx\n", pv->pv_va);
#endif
continue;
}
pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
if (pte == NULL)
continue;
if (*pte & bit) {
splx(s);
return TRUE;
}
}
splx(s);
return (FALSE);
}
/*
* this routine is used to modify bits in ptes
*/
static __inline void
pmap_changebit(pa, bit, setem)
vm_offset_t pa;
int bit;
boolean_t setem;
{
register pv_entry_t pv, *ppv;
register unsigned *pte;
vm_offset_t va;
int changed;
int s;
if (!pmap_is_managed(pa))
return;
s = splvm();
changed = 0;
ppv = pa_to_pvh(pa);
/*
* Loop over all current mappings setting/clearing as appropos If
* setting RO do we need to clear the VAC?
*/
for ( pv = *ppv; pv; pv = pv->pv_next) {
va = pv->pv_va;
/*
* don't write protect pager mappings
*/
if (!setem && (bit == PG_RW)) {
if (va >= clean_sva && va < clean_eva)
continue;
}
if (!pv->pv_pmap) {
#if defined(PMAP_DIAGNOSTIC)
printf("Null pmap (cb) at va: 0x%lx\n", va);
#endif
continue;
}
pte = pmap_pte_quick(pv->pv_pmap, va);
if (pte == NULL)
continue;
if (setem) {
*(int *)pte |= bit;
changed = 1;
} else {
vm_offset_t pbits = *(vm_offset_t *)pte;
if (pbits & bit)
changed = 1;
if (bit == PG_RW) {
if (pbits & PG_M) {
vm_page_t m;
vm_offset_t pa = pbits & PG_FRAME;
m = PHYS_TO_VM_PAGE(pa);
m->dirty = VM_PAGE_BITS_ALL;
}
*(int *)pte = pbits & ~(PG_M|PG_RW);
} else {
*(int *)pte = pbits & ~bit;
}
}
}
splx(s);
if (changed)
pmap_update();
}
/*
* pmap_page_protect:
*
* Lower the permission for all mappings to a given page.
*/
void
pmap_page_protect(phys, prot)
vm_offset_t phys;
vm_prot_t prot;
{
if ((prot & VM_PROT_WRITE) == 0) {
if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) {
pmap_changebit(phys, PG_RW, FALSE);
} else {
pmap_remove_all(phys);
pmap_update();
}
}
}
vm_offset_t
pmap_phys_address(ppn)
int ppn;
{
return (i386_ptob(ppn));
}
/*
* pmap_is_referenced:
*
* Return whether or not the specified physical page was referenced
* by any physical maps.
*/
boolean_t
pmap_is_referenced(vm_offset_t pa)
{
register pv_entry_t *ppv, pv, lpv;
unsigned *pte;
int s;
if (!pmap_is_managed(pa))
return FALSE;
ppv = pa_to_pvh(pa);
s = splvm();
/*
* Not found, check current mappings returning immediately if found.
*/
for (lpv = NULL, pv = *ppv ;pv; lpv = pv, pv = pv->pv_next) {
/*
* 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 (!pv->pv_pmap) {
continue;
}
pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
if (pte == NULL)
continue;
if ((int) *pte & PG_A) {
if (lpv) {
lpv->pv_next = pv->pv_next;
pv->pv_next = *ppv;
*ppv = pv;
}
splx(s);
return TRUE;
}
}
splx(s);
return (FALSE);
}
/*
* pmap_ts_referenced:
*
* Return the count of reference bits for a page, clearing all of them.
*
*/
int
pmap_ts_referenced(vm_offset_t pa)
{
register pv_entry_t *ppv, pv;
unsigned *pte;
int s;
int rtval = 0;
vm_offset_t vachanged[VATRACK];
if (!pmap_is_managed(pa))
return FALSE;
s = splvm();
ppv = pa_to_pvh(pa);
if (*ppv == NULL) {
splx(s);
return 0;
}
/*
* Not found, check current mappings returning immediately if found.
*/
for (pv = *ppv ;pv; pv = pv->pv_next) {
/*
* 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 (!pv->pv_pmap) {
continue;
}
pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
if (pte == NULL)
continue;
if (*pte & PG_A) {
if (rtval < VATRACK)
vachanged[rtval] = pv->pv_va;
rtval++;
*pte &= ~PG_A;
}
}
splx(s);
if (rtval) {
if (rtval <= VATRACK) {
int i;
for(i=0;i<rtval;i++)
pmap_update_1pg(vachanged[i]);
} else {
pmap_update();
}
}
return (rtval);
}
/*
* pmap_is_modified:
*
* Return whether or not the specified physical page was modified
* in any physical maps.
*/
boolean_t
pmap_is_modified(vm_offset_t pa)
{
return pmap_testbit((pa), PG_M);
}
/*
* Clear the modify bits on the specified physical page.
*/
void
pmap_clear_modify(vm_offset_t pa)
{
pmap_changebit((pa), PG_M, FALSE);
}
/*
* pmap_clear_reference:
*
* Clear the reference bit on the specified physical page.
*/
void
pmap_clear_reference(vm_offset_t pa)
{
pmap_changebit((pa), PG_A, FALSE);
}
/*
* Miscellaneous support routines follow
*/
static void
i386_protection_init()
{
register int *kp, prot;
kp = protection_codes;
for (prot = 0; prot < 8; prot++) {
switch (prot) {
case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_NONE:
/*
* Read access is also 0. There isn't any execute bit,
* so just make it readable.
*/
case VM_PROT_READ | VM_PROT_NONE | VM_PROT_NONE:
case VM_PROT_READ | VM_PROT_NONE | VM_PROT_EXECUTE:
case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_EXECUTE:
*kp++ = 0;
break;
case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_NONE:
case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_EXECUTE:
case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_NONE:
case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE:
*kp++ = PG_RW;
break;
}
}
}
/*
* 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. The non-cacheable bits are set on each
* mapped page.
*/
void *
pmap_mapdev(pa, size)
vm_offset_t pa;
vm_size_t size;
{
vm_offset_t va, tmpva;
unsigned *pte;
size = roundup(size, PAGE_SIZE);
va = kmem_alloc_pageable(kernel_map, size);
if (!va)
panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
pa = pa & PG_FRAME;
for (tmpva = va; size > 0;) {
pte = (unsigned *)vtopte(tmpva);
*pte = pa | PG_RW | PG_V | PG_N;
size -= PAGE_SIZE;
tmpva += PAGE_SIZE;
pa += PAGE_SIZE;
}
pmap_update();
return ((void *) va);
}
/*
* perform the pmap work for mincore
*/
int
pmap_mincore(pmap, addr)
pmap_t pmap;
vm_offset_t addr;
{
unsigned *ptep, pte;
int val = 0;
ptep = pmap_pte(pmap, addr);
if (ptep == 0) {
return 0;
}
if (pte = *ptep) {
vm_offset_t pa;
val = MINCORE_INCORE;
pa = pte & PG_FRAME;
/*
* Modified by us
*/
if (pte & PG_M)
val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER;
/*
* Modified by someone
*/
else if (PHYS_TO_VM_PAGE(pa)->dirty ||
pmap_is_modified(pa))
val |= MINCORE_MODIFIED_OTHER;
/*
* Referenced by us
*/
if (pte & PG_U)
val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER;
/*
* Referenced by someone
*/
else if ((PHYS_TO_VM_PAGE(pa)->flags & PG_REFERENCED) ||
pmap_is_referenced(pa))
val |= MINCORE_REFERENCED_OTHER;
}
return val;
}
#if defined(PMAP_DEBUG)
pmap_pid_dump(int pid) {
pmap_t pmap;
struct proc *p;
int npte = 0;
int index;
for (p = allproc.lh_first; p != NULL; p = p->p_list.le_next) {
if (p->p_pid != pid)
continue;
if (p->p_vmspace) {
int i,j;
index = 0;
pmap = &p->p_vmspace->vm_pmap;
for(i=0;i<1024;i++) {
pd_entry_t *pde;
unsigned *pte;
unsigned base = i << PDRSHIFT;
pde = &pmap->pm_pdir[i];
if (pde && pmap_pde_v(pde)) {
for(j=0;j<1024;j++) {
unsigned va = base + (j << PAGE_SHIFT);
if (va >= (vm_offset_t) VM_MIN_KERNEL_ADDRESS) {
if (index) {
index = 0;
printf("\n");
}
return npte;
}
pte = pmap_pte( pmap, va);
if (pte && pmap_pte_v(pte)) {
vm_offset_t pa;
vm_page_t m;
pa = *(int *)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(" ");
}
}
}
}
}
}
}
return npte;
}
#endif
#if defined(DEBUG)
static void pads __P((pmap_t pm));
static void pmap_pvdump __P((vm_offset_t pa));
/* print address space of pmap*/
static void
pads(pm)
pmap_t pm;
{
unsigned va, i, j;
unsigned *ptep;
if (pm == kernel_pmap)
return;
for (i = 0; i < 1024; i++)
if (pm->pm_pdir[i])
for (j = 0; j < 1024; 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, *(int *) ptep);
};
}
static void
pmap_pvdump(pa)
vm_offset_t pa;
{
register pv_entry_t pv;
printf("pa %x", pa);
for (pv = pa_to_pvh(pa); pv; pv = pv->pv_next) {
#ifdef used_to_be
printf(" -> pmap %x, va %x, flags %x",
pv->pv_pmap, pv->pv_va, pv->pv_flags);
#endif
printf(" -> pmap %x, va %x",
pv->pv_pmap, pv->pv_va);
pads(pv->pv_pmap);
}
printf(" ");
}
#endif
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