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Correct some new and older lurking bugs. Hold count wasn't being

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handled correctly.  Fix some incorrect code that was included
to improve performance. Significantly simplify the pmap_use_pt and
pmap_unuse_pt subroutines.  Add some more diagnostic code.
This commit is contained in:
John Dyson 1996-03-09 07:01:21 +00:00
parent 9ea857084d
commit 9212ebc656
2 changed files with 424 additions and 236 deletions
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318
sys/amd64/amd64/pmap.c
View File

@ -39,7 +39,7 @@
* SUCH DAMAGE.
*
* from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
* $Id: pmap.c,v 1.76 1996/02/25 03:02:44 dyson Exp $
* $Id: pmap.c,v 1.77 1996/02/25 05:08:57 dyson Exp $
*/
/*
@ -111,6 +111,10 @@
#define PMAP_KEEP_PDIRS
#if defined(DIAGNOSTIC)
#define PMAP_DIAGNOSTIC
#endif
static void init_pv_entries __P((int));
/*
@ -185,6 +189,26 @@ static void * pmap_getpdir __P((void));
void pmap_prefault __P((pmap_t pmap, vm_offset_t addra,
vm_map_entry_t entry, vm_object_t object));
#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
/*
* The below are finer grained pmap_update routines. These eliminate
* the gratuitious tlb flushes on non-i386 architectures.
@ -298,62 +322,53 @@ pmap_is_managed(pa)
return 0;
}
/*
* find the vm_page_t of a pte (only) given va of pte and pmap
*/
static __inline vm_page_t
pmap_pte_vm_page(pmap, pt)
pmap_t pmap;
vm_offset_t pt;
{
vm_page_t m;
pt = trunc_page(pt);
pt = (pt - UPT_MIN_ADDRESS) / PAGE_SIZE;
pt = ((vm_offset_t) pmap->pm_pdir[pt]) & PG_FRAME;
m = PHYS_TO_VM_PAGE(pt);
return m;
}
/*
* Wire a page table page
*/
__inline vm_page_t
vm_page_t
pmap_use_pt(pmap, va)
pmap_t pmap;
vm_offset_t va;
{
vm_offset_t pt;
vm_page_t m;
vm_offset_t ptepa;
vm_page_t mpte;
if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized)
if (va >= UPT_MIN_ADDRESS)
return NULL;
pt = (vm_offset_t) vtopte(va);
m = pmap_pte_vm_page(pmap, pt);
vm_page_hold(m);
return m;
ptepa = ((vm_offset_t) *pmap_pde(pmap, va)) & PG_FRAME;
#if defined(PMAP_DIAGNOSTIC)
if (!ptepa)
panic("pmap_use_pt: pagetable page missing, va: 0x%x", va);
#endif
mpte = PHYS_TO_VM_PAGE(ptepa);
++mpte->hold_count;
return mpte;
}
/*
* Unwire a page table page
*/
__inline void
void
pmap_unuse_pt(pmap, va, mpte)
pmap_t pmap;
vm_offset_t va;
vm_page_t mpte;
{
if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized)
if (va >= UPT_MIN_ADDRESS)
return;
if (mpte == NULL) {
vm_offset_t pt;
pt = (vm_offset_t) vtopte(va);
mpte = pmap_pte_vm_page(pmap, pt);
vm_offset_t ptepa;
ptepa = ((vm_offset_t) *pmap_pde(pmap, va)) & PG_FRAME;
#if defined(PMAP_DIAGNOSTIC)
if (!ptepa)
panic("pmap_unuse_pt: pagetable page missing, va: 0x%x", va);
#endif
mpte = PHYS_TO_VM_PAGE(ptepa);
}
#if defined(PMAP_DIAGNOSTIC)
if (mpte->hold_count == 0) {
panic("pmap_unuse_pt: hold count < 0, va: 0x%x", va);
}
#endif
vm_page_unhold(mpte);
if (pmap != kernel_pmap &&
@ -366,7 +381,7 @@ pmap_unuse_pt(pmap, va, mpte)
* up if needed... Also, if the page ends up getting used, it will fault
* back into the process address space and be reactivated.
*/
#ifdef PMAP_FREE_OLD_PTES
#if defined(PMAP_FREE_OLD_PTES)
pmap_page_protect(VM_PAGE_TO_PHYS(mpte), VM_PROT_NONE);
vm_page_free(mpte);
#else
@ -519,7 +534,7 @@ pmap_map(virt, start, end, prot)
return (virt);
}
#ifdef PMAP_KEEP_PDIRS
#if defined(PMAP_KEEP_PDIRS)
int nfreepdir;
caddr_t *pdirlist;
#define NFREEPDIR 3
@ -564,7 +579,7 @@ pmap_pinit(pmap)
* page directory table.
*/
#ifdef PMAP_KEEP_PDIRS
#if defined(PMAP_KEEP_PDIRS)
pmap->pm_pdir = pmap_getpdir();
#else
pmap->pm_pdir = (pd_entry_t *) kmem_alloc(kernel_map, PAGE_SIZE);
@ -663,7 +678,7 @@ void
pmap_release(pmap)
register struct pmap *pmap;
{
#ifdef PMAP_KEEP_PDIRS
#if defined(PMAP_KEEP_PDIRS)
pmap_freepdir( (void *)pmap->pm_pdir);
#else
kmem_free(kernel_map, (vm_offset_t) pmap->pm_pdir, PAGE_SIZE);
@ -849,7 +864,6 @@ pmap_remove_entry(pmap, pv, va)
{
pv_entry_t npv;
int s;
s = splhigh();
if (pmap == pv->pv_pmap && va == pv->pv_va) {
pmap_unuse_pt(pmap, va, pv->pv_ptem);
@ -892,8 +906,8 @@ pmap_remove(pmap, sva, eva)
pt_entry_t oldpte;
vm_offset_t pdnxt;
vm_offset_t ptepaddr;
vm_page_t mpte;
int update_needed;
vm_page_t mpte;
if (pmap == NULL)
return;
@ -912,22 +926,26 @@ pmap_remove(pmap, sva, eva)
ptq = ptp + i386_btop(sva);
if (!*ptq)
if ((oldpte = *ptq) == 0)
return;
oldpte = *ptq;
if (((int)oldpte) & PG_W)
pmap->pm_stats.wired_count--;
pmap->pm_stats.resident_count--;
*ptq = 0;
pa = ((int)oldpte) & PG_FRAME;
pa = ((vm_offset_t)oldpte) & PG_FRAME;
if (pmap_is_managed(pa)) {
if ((int) oldpte & PG_M) {
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified(oldpte)) {
printf("pmap_remove: modified page not writable: va: 0x%lx, pte: 0x%lx\n", sva, (int) oldpte);
}
#endif
if (sva < USRSTACK + (UPAGES * PAGE_SIZE) ||
(sva >= KERNBASE && (sva < clean_sva || sva >= clean_eva))) {
PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL;
PHYS_TO_VM_PAGE(pa)->dirty = VM_PAGE_BITS_ALL;
}
}
pv = pa_to_pvh(pa);
@ -935,12 +953,15 @@ pmap_remove(pmap, sva, eva)
} else {
pmap_unuse_pt(pmap, sva, NULL);
}
*ptq = 0;
pmap_update_1pg(sva);
return;
}
update_needed = 0;
sva = i386_btop(sva);
pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1));
ptepaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
eva = i386_btop(eva);
@ -949,9 +970,11 @@ pmap_remove(pmap, sva, eva)
while (sva < eva) {
if (sva >= pdnxt) {
pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1));
ptepaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
ptepaddr =
(vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
mpte = NULL;
}
/*
* Weed out invalid mappings. Note: we assume that the page
* directory table is always allocated, and in kernel virtual.
@ -961,20 +984,25 @@ pmap_remove(pmap, sva, eva)
continue;
}
if (mpte == NULL)
mpte = PHYS_TO_VM_PAGE(i386_trunc_page(ptepaddr));
ptepaddr &= PG_FRAME;
if (mpte == NULL) {
mpte = PHYS_TO_VM_PAGE(ptepaddr);
}
if ((mpte->hold_count == 0) && (mpte->wire_count == 0)) {
sva = pdnxt;
continue;
}
if (pdnxt > eva)
if (pdnxt > eva) {
pdnxt = eva;
}
/*
* search for page table entries
*/
while ((sva < pdnxt) && (*(ptp + sva) == 0))
++sva;
if (sva == pdnxt) {
continue;
}
@ -987,6 +1015,7 @@ pmap_remove(pmap, sva, eva)
*/
oldpte = *ptq;
*ptq = 0;
if (((int) oldpte) & PG_W)
pmap->pm_stats.wired_count--;
pmap->pm_stats.resident_count--;
@ -994,16 +1023,21 @@ pmap_remove(pmap, sva, eva)
va = i386_ptob(sva);
++update_needed;
pa = ((int) oldpte) & PG_FRAME;
pa = ((vm_offset_t) oldpte) & PG_FRAME;
if (!pmap_is_managed(pa)) {
pmap_unuse_pt(pmap, (vm_offset_t) va, NULL);
pmap_unuse_pt(pmap, va, NULL);
++sva;
continue;
}
if ((int) oldpte & PG_M) {
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified(oldpte)) {
printf("pmap_remove: modified page not writable: va: 0x%lx, pte: 0x%lx\n", va, (int) oldpte);
}
#endif
if (va < USRSTACK + (UPAGES * PAGE_SIZE) ||
(va >= KERNBASE && (va < clean_sva || va >= clean_eva))) {
PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL;
PHYS_TO_VM_PAGE(pa)->dirty = VM_PAGE_BITS_ALL;
}
}
pv = pa_to_pvh(pa);
@ -1048,7 +1082,7 @@ pmap_remove_all(pa)
if (!pmap_is_managed(pa))
return;
pa = trunc_page(pa);
pa = pa & PG_FRAME;
opv = pa_to_pvh(pa);
if (opv->pv_pmap == NULL)
return;
@ -1073,6 +1107,11 @@ pmap_remove_all(pa)
* Update the vm_page_t clean and reference bits.
*/
if ((tpte & PG_M) != 0) {
#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", va, tpte);
}
#endif
if (va < USRSTACK + (UPAGES * PAGE_SIZE) ||
(va >= KERNBASE && (va < clean_sva || va >= clean_eva))) {
m->dirty = VM_PAGE_BITS_ALL;
@ -1082,11 +1121,14 @@ pmap_remove_all(pa)
pv = pv->pv_next;
}
if (opv->pv_pmap != NULL) {
pmap_unuse_pt(opv->pv_pmap, opv->pv_va, opv->pv_ptem);
for (pv = opv->pv_next; pv; pv = npv) {
npv = pv->pv_next;
pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
free_pv_entry(pv);
}
}
opv->pv_pmap = NULL;
opv->pv_next = NULL;
@ -1111,6 +1153,10 @@ pmap_protect(pmap, sva, eva, prot)
register vm_offset_t va;
int i386prot;
register pt_entry_t *ptp;
vm_offset_t pdnxt;
vm_offset_t ptepaddr;
vm_page_t mpte;
int anychanged = 0;
if (pmap == NULL)
@ -1125,42 +1171,54 @@ pmap_protect(pmap, sva, eva, prot)
ptp = get_pt_entry(pmap);
sva = i386_btop(sva);
eva = i386_btop(eva);
sva = i386_btop(sva);
pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1));
ptepaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
mpte = NULL;
while (sva < eva) {
vm_offset_t pdnxt;
vm_offset_t ptepaddr;
vm_page_t mpte;
int pprot;
int pbits;
/*
* Weed out invalid mappings. Note: we assume that the page
* directory table is always allocated, and in kernel virtual.
*/
if (sva >= pdnxt) {
pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1));
ptepaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
ptepaddr =
(vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
mpte = NULL;
}
if (ptepaddr == 0) {
sva = pdnxt;
continue;
}
mpte = PHYS_TO_VM_PAGE(i386_trunc_page(ptepaddr));
ptepaddr &= PG_FRAME;
if (mpte == NULL)
mpte = PHYS_TO_VM_PAGE(ptepaddr);
if ((mpte->hold_count == 0) && (mpte->wire_count == 0)) {
sva = pdnxt;
continue;
}
if (pdnxt > eva)
if (pdnxt > eva) {
pdnxt = eva;
}
/*
* search for page table entries
*/
while ((sva < pdnxt) && (*(ptp + sva) == 0))
++sva;
if (sva == pdnxt)
if (sva == pdnxt) {
continue;
}
pte = ptp + sva;
@ -1171,7 +1229,22 @@ pmap_protect(pmap, sva, eva, prot)
if (va >= UPT_MIN_ADDRESS)
i386prot |= PG_RW;
}
pprot = *(int *)pte & PG_PROT;
pbits = *(int *)pte;
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified((pt_entry_t) pbits)) {
printf("pmap_protect: modified page not writable: va: 0x%lx, pte: 0x%lx\n", va, pbits);
}
#endif
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 &= ~PG_M;
anychanged++;
}
pprot = pbits & PG_PROT;
if (pprot != i386prot) {
pmap_pte_set_prot(pte, i386prot);
anychanged++;
@ -1203,18 +1276,17 @@ pmap_enter(pmap, va, pa, prot, wired)
boolean_t wired;
{
register pt_entry_t *pte;
register pt_entry_t npte;
vm_offset_t opa;
register pv_entry_t pv, npv;
int ptevalid = 0;
int ptevalid;
vm_offset_t origpte, newpte;
if (pmap == NULL)
return;
pv = NULL;
va = trunc_page(va);
pa = trunc_page(pa);
va = va & PG_FRAME;
if (va > VM_MAX_KERNEL_ADDRESS)
panic("pmap_enter: toobig");
@ -1227,7 +1299,11 @@ pmap_enter(pmap, va, pa, prot, wired)
pmap->pm_pdir[PTDPTDI], va);
panic("invalid kernel page directory");
}
opa = pmap_pte_pa(pte);
origpte = *(vm_offset_t *)pte;
opa = origpte & PG_FRAME;
pa = pa & PG_FRAME;
/*
* Mapping has not changed, must be protection or wiring change.
@ -1239,11 +1315,26 @@ pmap_enter(pmap, va, pa, prot, wired)
* are valid mappings in them. Hence, if a user page is wired,
* the PT page will be also.
*/
if (wired && !pmap_pte_w(pte))
if (wired && ((origpte & PG_W) == 0))
pmap->pm_stats.wired_count++;
else if (!wired && pmap_pte_w(pte))
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_M) {
vm_page_t m;
m = PHYS_TO_VM_PAGE(pa);
m->dirty = VM_PAGE_BITS_ALL;
}
goto validate;
}
/*
@ -1252,6 +1343,8 @@ pmap_enter(pmap, va, pa, prot, wired)
*/
if (opa) {
pmap_remove(pmap, va, va + PAGE_SIZE);
opa = 0;
origpte = 0;
}
/*
* Enter on the PV list if part of our managed memory Note that we
@ -1299,40 +1392,30 @@ pmap_enter(pmap, va, pa, prot, wired)
/*
* Now validate mapping with desired protection/wiring.
*/
npte = (pt_entry_t) ((int) (pa | pte_prot(pmap, prot) | PG_V));
/*
* When forking (copy-on-write, etc): A process will turn off write
* permissions for any of its writable pages. If the data (object) is
* only referred to by one process, the processes map is modified
* directly as opposed to using the object manipulation routine. When
* using pmap_protect, the modified bits are not kept in the vm_page_t
* data structure. Therefore, when using pmap_enter in vm_fault to
* bring back writability of a page, there has been no memory of the
* modified or referenced bits except at the pte level. this clause
* supports the carryover of the modified and used (referenced) bits.
*/
if (pa == opa)
(int) npte |= (int) *pte & (PG_M | PG_U);
newpte = (vm_offset_t) (pa | pte_prot(pmap, prot) | PG_V);
if (wired)
(int) npte |= PG_W;
newpte |= PG_W;
if (va < UPT_MIN_ADDRESS)
(int) npte |= PG_u;
newpte |= PG_u;
else if (va < UPT_MAX_ADDRESS)
(int) npte |= PG_u | PG_RW;
newpte |= PG_u | PG_RW;
if (*pte != npte) {
if (*pte)
ptevalid++;
*pte = npte;
}
if (ptevalid) {
/*
* if the mapping or permission bits are different, we need
* to update the pte.
*/
if ((origpte & ~(PG_M|PG_U)) != newpte) {
if (origpte)
pmap_update_1pg(va);
} else {
if (pv) {
pv->pv_ptem = pmap_use_pt(pmap, va);
*pte = (pt_entry_t) newpte;
}
if (origpte == 0) {
vm_page_t mpte;
mpte = pmap_use_pt(pmap, va);
if (pv)
pv->pv_ptem = mpte;
}
}
@ -1488,7 +1571,7 @@ pmap_enter_quick(pmap, va, pa)
pmap->pm_stats.resident_count++;
/*
* Now validate mapping with desired protection/wiring.
* Now validate mapping with RO protection
*/
*pte = (pt_entry_t) ((int) (pa | PG_V | PG_u));
@ -1516,7 +1599,8 @@ pmap_object_init_pt(pmap, addr, object, pindex, size)
psize = (size >> PAGE_SHIFT);
if (!pmap || ((psize > MAX_INIT_PT) &&
if (!pmap || (object->type != OBJT_VNODE) ||
((psize > MAX_INIT_PT) &&
(object->resident_page_count > MAX_INIT_PT))) {
return;
}
@ -1743,7 +1827,7 @@ pmap_zero_page(phys)
if (*(int *) CMAP2)
panic("pmap_zero_page: CMAP busy");
*(int *) CMAP2 = PG_V | PG_KW | trunc_page(phys);
*(int *) CMAP2 = PG_V | PG_KW | (phys & PG_FRAME);
bzero(CADDR2, PAGE_SIZE);
*(int *) CMAP2 = 0;
@ -1764,8 +1848,8 @@ pmap_copy_page(src, dst)
if (*(int *) CMAP1 || *(int *) CMAP2)
panic("pmap_copy_page: CMAP busy");
*(int *) CMAP1 = PG_V | PG_KW | trunc_page(src);
*(int *) CMAP2 = PG_V | PG_KW | trunc_page(dst);
*(int *) CMAP1 = PG_V | PG_KW | (src & PG_FRAME);
*(int *) CMAP2 = PG_V | PG_KW | (dst & PG_FRAME);
#if __GNUC__ > 1
memcpy(CADDR2, CADDR1, PAGE_SIZE);
@ -1925,11 +2009,21 @@ pmap_changebit(pa, bit, setem)
}
pte = pmap_pte(pv->pv_pmap, va);
if (setem) {
(int) npte = (int) *pte | bit;
*(int *)pte |= bit;
} else {
(int) npte = (int) *pte & ~bit;
if (bit == PG_RW) {
vm_offset_t pbits = *(vm_offset_t *)pte;
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 &= ~(PG_M|PG_RW);
} else {
*(int *)pte &= ~bit;
}
}
*pte = npte;
}
}
splx(s);
@ -2053,13 +2147,13 @@ pmap_mapdev(pa, size)
vm_offset_t va, tmpva;
pt_entry_t *pte;
pa = trunc_page(pa);
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 = vtopte(tmpva);
*pte = (pt_entry_t) ((int) (pa | PG_RW | PG_V | PG_N));
@ -2072,7 +2166,7 @@ pmap_mapdev(pa, size)
return ((void *) va);
}
#ifdef PMAP_DEBUG
#if defined(PMAP_DEBUG)
pmap_pid_dump(int pid) {
pmap_t pmap;
struct proc *p;
@ -2128,7 +2222,7 @@ pmap_pid_dump(int pid) {
}
#endif
#ifdef DEBUG
#if defined(DEBUG)
static void pads __P((pmap_t pm));
static void pmap_pvdump __P((vm_offset_t pa));

318
sys/i386/i386/pmap.c
View File

@ -39,7 +39,7 @@
* SUCH DAMAGE.
*
* from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
* $Id: pmap.c,v 1.76 1996/02/25 03:02:44 dyson Exp $
* $Id: pmap.c,v 1.77 1996/02/25 05:08:57 dyson Exp $
*/
/*
@ -111,6 +111,10 @@
#define PMAP_KEEP_PDIRS
#if defined(DIAGNOSTIC)
#define PMAP_DIAGNOSTIC
#endif
static void init_pv_entries __P((int));
/*
@ -185,6 +189,26 @@ static void * pmap_getpdir __P((void));
void pmap_prefault __P((pmap_t pmap, vm_offset_t addra,
vm_map_entry_t entry, vm_object_t object));
#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
/*
* The below are finer grained pmap_update routines. These eliminate
* the gratuitious tlb flushes on non-i386 architectures.
@ -298,62 +322,53 @@ pmap_is_managed(pa)
return 0;
}
/*
* find the vm_page_t of a pte (only) given va of pte and pmap
*/
static __inline vm_page_t
pmap_pte_vm_page(pmap, pt)
pmap_t pmap;
vm_offset_t pt;
{
vm_page_t m;
pt = trunc_page(pt);
pt = (pt - UPT_MIN_ADDRESS) / PAGE_SIZE;
pt = ((vm_offset_t) pmap->pm_pdir[pt]) & PG_FRAME;
m = PHYS_TO_VM_PAGE(pt);
return m;
}
/*
* Wire a page table page
*/
__inline vm_page_t
vm_page_t
pmap_use_pt(pmap, va)
pmap_t pmap;
vm_offset_t va;
{
vm_offset_t pt;
vm_page_t m;
vm_offset_t ptepa;
vm_page_t mpte;
if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized)
if (va >= UPT_MIN_ADDRESS)
return NULL;
pt = (vm_offset_t) vtopte(va);
m = pmap_pte_vm_page(pmap, pt);
vm_page_hold(m);
return m;
ptepa = ((vm_offset_t) *pmap_pde(pmap, va)) & PG_FRAME;
#if defined(PMAP_DIAGNOSTIC)
if (!ptepa)
panic("pmap_use_pt: pagetable page missing, va: 0x%x", va);
#endif
mpte = PHYS_TO_VM_PAGE(ptepa);
++mpte->hold_count;
return mpte;
}
/*
* Unwire a page table page
*/
__inline void
void
pmap_unuse_pt(pmap, va, mpte)
pmap_t pmap;
vm_offset_t va;
vm_page_t mpte;
{
if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized)
if (va >= UPT_MIN_ADDRESS)
return;
if (mpte == NULL) {
vm_offset_t pt;
pt = (vm_offset_t) vtopte(va);
mpte = pmap_pte_vm_page(pmap, pt);
vm_offset_t ptepa;
ptepa = ((vm_offset_t) *pmap_pde(pmap, va)) & PG_FRAME;
#if defined(PMAP_DIAGNOSTIC)
if (!ptepa)
panic("pmap_unuse_pt: pagetable page missing, va: 0x%x", va);
#endif
mpte = PHYS_TO_VM_PAGE(ptepa);
}
#if defined(PMAP_DIAGNOSTIC)
if (mpte->hold_count == 0) {
panic("pmap_unuse_pt: hold count < 0, va: 0x%x", va);
}
#endif
vm_page_unhold(mpte);
if (pmap != kernel_pmap &&
@ -366,7 +381,7 @@ pmap_unuse_pt(pmap, va, mpte)
* up if needed... Also, if the page ends up getting used, it will fault
* back into the process address space and be reactivated.
*/
#ifdef PMAP_FREE_OLD_PTES
#if defined(PMAP_FREE_OLD_PTES)
pmap_page_protect(VM_PAGE_TO_PHYS(mpte), VM_PROT_NONE);
vm_page_free(mpte);
#else
@ -519,7 +534,7 @@ pmap_map(virt, start, end, prot)
return (virt);
}
#ifdef PMAP_KEEP_PDIRS
#if defined(PMAP_KEEP_PDIRS)
int nfreepdir;
caddr_t *pdirlist;
#define NFREEPDIR 3
@ -564,7 +579,7 @@ pmap_pinit(pmap)
* page directory table.
*/
#ifdef PMAP_KEEP_PDIRS
#if defined(PMAP_KEEP_PDIRS)
pmap->pm_pdir = pmap_getpdir();
#else
pmap->pm_pdir = (pd_entry_t *) kmem_alloc(kernel_map, PAGE_SIZE);
@ -663,7 +678,7 @@ void
pmap_release(pmap)
register struct pmap *pmap;
{
#ifdef PMAP_KEEP_PDIRS
#if defined(PMAP_KEEP_PDIRS)
pmap_freepdir( (void *)pmap->pm_pdir);
#else
kmem_free(kernel_map, (vm_offset_t) pmap->pm_pdir, PAGE_SIZE);
@ -849,7 +864,6 @@ pmap_remove_entry(pmap, pv, va)
{
pv_entry_t npv;
int s;
s = splhigh();
if (pmap == pv->pv_pmap && va == pv->pv_va) {
pmap_unuse_pt(pmap, va, pv->pv_ptem);
@ -892,8 +906,8 @@ pmap_remove(pmap, sva, eva)
pt_entry_t oldpte;
vm_offset_t pdnxt;
vm_offset_t ptepaddr;
vm_page_t mpte;
int update_needed;
vm_page_t mpte;
if (pmap == NULL)
return;
@ -912,22 +926,26 @@ pmap_remove(pmap, sva, eva)
ptq = ptp + i386_btop(sva);
if (!*ptq)
if ((oldpte = *ptq) == 0)
return;
oldpte = *ptq;
if (((int)oldpte) & PG_W)
pmap->pm_stats.wired_count--;
pmap->pm_stats.resident_count--;
*ptq = 0;
pa = ((int)oldpte) & PG_FRAME;
pa = ((vm_offset_t)oldpte) & PG_FRAME;
if (pmap_is_managed(pa)) {
if ((int) oldpte & PG_M) {
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified(oldpte)) {
printf("pmap_remove: modified page not writable: va: 0x%lx, pte: 0x%lx\n", sva, (int) oldpte);
}
#endif
if (sva < USRSTACK + (UPAGES * PAGE_SIZE) ||
(sva >= KERNBASE && (sva < clean_sva || sva >= clean_eva))) {
PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL;
PHYS_TO_VM_PAGE(pa)->dirty = VM_PAGE_BITS_ALL;
}
}
pv = pa_to_pvh(pa);
@ -935,12 +953,15 @@ pmap_remove(pmap, sva, eva)
} else {
pmap_unuse_pt(pmap, sva, NULL);
}
*ptq = 0;
pmap_update_1pg(sva);
return;
}
update_needed = 0;
sva = i386_btop(sva);
pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1));
ptepaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
eva = i386_btop(eva);
@ -949,9 +970,11 @@ pmap_remove(pmap, sva, eva)
while (sva < eva) {
if (sva >= pdnxt) {
pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1));
ptepaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
ptepaddr =
(vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
mpte = NULL;
}
/*
* Weed out invalid mappings. Note: we assume that the page
* directory table is always allocated, and in kernel virtual.
@ -961,20 +984,25 @@ pmap_remove(pmap, sva, eva)
continue;
}
if (mpte == NULL)
mpte = PHYS_TO_VM_PAGE(i386_trunc_page(ptepaddr));
ptepaddr &= PG_FRAME;
if (mpte == NULL) {
mpte = PHYS_TO_VM_PAGE(ptepaddr);
}
if ((mpte->hold_count == 0) && (mpte->wire_count == 0)) {
sva = pdnxt;
continue;
}
if (pdnxt > eva)
if (pdnxt > eva) {
pdnxt = eva;
}
/*
* search for page table entries
*/
while ((sva < pdnxt) && (*(ptp + sva) == 0))
++sva;
if (sva == pdnxt) {
continue;
}
@ -987,6 +1015,7 @@ pmap_remove(pmap, sva, eva)
*/
oldpte = *ptq;
*ptq = 0;
if (((int) oldpte) & PG_W)
pmap->pm_stats.wired_count--;
pmap->pm_stats.resident_count--;
@ -994,16 +1023,21 @@ pmap_remove(pmap, sva, eva)
va = i386_ptob(sva);
++update_needed;
pa = ((int) oldpte) & PG_FRAME;
pa = ((vm_offset_t) oldpte) & PG_FRAME;
if (!pmap_is_managed(pa)) {
pmap_unuse_pt(pmap, (vm_offset_t) va, NULL);
pmap_unuse_pt(pmap, va, NULL);
++sva;
continue;
}
if ((int) oldpte & PG_M) {
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified(oldpte)) {
printf("pmap_remove: modified page not writable: va: 0x%lx, pte: 0x%lx\n", va, (int) oldpte);
}
#endif
if (va < USRSTACK + (UPAGES * PAGE_SIZE) ||
(va >= KERNBASE && (va < clean_sva || va >= clean_eva))) {
PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL;
PHYS_TO_VM_PAGE(pa)->dirty = VM_PAGE_BITS_ALL;
}
}
pv = pa_to_pvh(pa);
@ -1048,7 +1082,7 @@ pmap_remove_all(pa)
if (!pmap_is_managed(pa))
return;
pa = trunc_page(pa);
pa = pa & PG_FRAME;
opv = pa_to_pvh(pa);
if (opv->pv_pmap == NULL)
return;
@ -1073,6 +1107,11 @@ pmap_remove_all(pa)
* Update the vm_page_t clean and reference bits.
*/
if ((tpte & PG_M) != 0) {
#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", va, tpte);
}
#endif
if (va < USRSTACK + (UPAGES * PAGE_SIZE) ||
(va >= KERNBASE && (va < clean_sva || va >= clean_eva))) {
m->dirty = VM_PAGE_BITS_ALL;
@ -1082,11 +1121,14 @@ pmap_remove_all(pa)
pv = pv->pv_next;
}
if (opv->pv_pmap != NULL) {
pmap_unuse_pt(opv->pv_pmap, opv->pv_va, opv->pv_ptem);
for (pv = opv->pv_next; pv; pv = npv) {
npv = pv->pv_next;
pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
free_pv_entry(pv);
}
}
opv->pv_pmap = NULL;
opv->pv_next = NULL;
@ -1111,6 +1153,10 @@ pmap_protect(pmap, sva, eva, prot)
register vm_offset_t va;
int i386prot;
register pt_entry_t *ptp;
vm_offset_t pdnxt;
vm_offset_t ptepaddr;
vm_page_t mpte;
int anychanged = 0;
if (pmap == NULL)
@ -1125,42 +1171,54 @@ pmap_protect(pmap, sva, eva, prot)
ptp = get_pt_entry(pmap);
sva = i386_btop(sva);
eva = i386_btop(eva);
sva = i386_btop(sva);
pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1));
ptepaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
mpte = NULL;
while (sva < eva) {
vm_offset_t pdnxt;
vm_offset_t ptepaddr;
vm_page_t mpte;
int pprot;
int pbits;
/*
* Weed out invalid mappings. Note: we assume that the page
* directory table is always allocated, and in kernel virtual.
*/
if (sva >= pdnxt) {
pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1));
ptepaddr = (vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
ptepaddr =
(vm_offset_t) *pmap_pde(pmap, i386_ptob(sva));
mpte = NULL;
}
if (ptepaddr == 0) {
sva = pdnxt;
continue;
}
mpte = PHYS_TO_VM_PAGE(i386_trunc_page(ptepaddr));
ptepaddr &= PG_FRAME;
if (mpte == NULL)
mpte = PHYS_TO_VM_PAGE(ptepaddr);
if ((mpte->hold_count == 0) && (mpte->wire_count == 0)) {
sva = pdnxt;
continue;
}
if (pdnxt > eva)
if (pdnxt > eva) {
pdnxt = eva;
}
/*
* search for page table entries
*/
while ((sva < pdnxt) && (*(ptp + sva) == 0))
++sva;
if (sva == pdnxt)
if (sva == pdnxt) {
continue;
}
pte = ptp + sva;
@ -1171,7 +1229,22 @@ pmap_protect(pmap, sva, eva, prot)
if (va >= UPT_MIN_ADDRESS)
i386prot |= PG_RW;
}
pprot = *(int *)pte & PG_PROT;
pbits = *(int *)pte;
#if defined(PMAP_DIAGNOSTIC)
if (pmap_nw_modified((pt_entry_t) pbits)) {
printf("pmap_protect: modified page not writable: va: 0x%lx, pte: 0x%lx\n", va, pbits);
}
#endif
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 &= ~PG_M;
anychanged++;
}
pprot = pbits & PG_PROT;
if (pprot != i386prot) {
pmap_pte_set_prot(pte, i386prot);
anychanged++;
@ -1203,18 +1276,17 @@ pmap_enter(pmap, va, pa, prot, wired)
boolean_t wired;
{
register pt_entry_t *pte;
register pt_entry_t npte;
vm_offset_t opa;
register pv_entry_t pv, npv;
int ptevalid = 0;
int ptevalid;
vm_offset_t origpte, newpte;
if (pmap == NULL)
return;
pv = NULL;
va = trunc_page(va);
pa = trunc_page(pa);
va = va & PG_FRAME;
if (va > VM_MAX_KERNEL_ADDRESS)
panic("pmap_enter: toobig");
@ -1227,7 +1299,11 @@ pmap_enter(pmap, va, pa, prot, wired)
pmap->pm_pdir[PTDPTDI], va);
panic("invalid kernel page directory");
}
opa = pmap_pte_pa(pte);
origpte = *(vm_offset_t *)pte;
opa = origpte & PG_FRAME;
pa = pa & PG_FRAME;
/*
* Mapping has not changed, must be protection or wiring change.
@ -1239,11 +1315,26 @@ pmap_enter(pmap, va, pa, prot, wired)
* are valid mappings in them. Hence, if a user page is wired,
* the PT page will be also.
*/
if (wired && !pmap_pte_w(pte))
if (wired && ((origpte & PG_W) == 0))
pmap->pm_stats.wired_count++;
else if (!wired && pmap_pte_w(pte))
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_M) {
vm_page_t m;
m = PHYS_TO_VM_PAGE(pa);
m->dirty = VM_PAGE_BITS_ALL;
}
goto validate;
}
/*
@ -1252,6 +1343,8 @@ pmap_enter(pmap, va, pa, prot, wired)
*/
if (opa) {
pmap_remove(pmap, va, va + PAGE_SIZE);
opa = 0;
origpte = 0;
}
/*
* Enter on the PV list if part of our managed memory Note that we
@ -1299,40 +1392,30 @@ pmap_enter(pmap, va, pa, prot, wired)
/*
* Now validate mapping with desired protection/wiring.
*/
npte = (pt_entry_t) ((int) (pa | pte_prot(pmap, prot) | PG_V));
/*
* When forking (copy-on-write, etc): A process will turn off write
* permissions for any of its writable pages. If the data (object) is
* only referred to by one process, the processes map is modified
* directly as opposed to using the object manipulation routine. When
* using pmap_protect, the modified bits are not kept in the vm_page_t
* data structure. Therefore, when using pmap_enter in vm_fault to
* bring back writability of a page, there has been no memory of the
* modified or referenced bits except at the pte level. this clause
* supports the carryover of the modified and used (referenced) bits.
*/
if (pa == opa)
(int) npte |= (int) *pte & (PG_M | PG_U);
newpte = (vm_offset_t) (pa | pte_prot(pmap, prot) | PG_V);
if (wired)
(int) npte |= PG_W;
newpte |= PG_W;
if (va < UPT_MIN_ADDRESS)
(int) npte |= PG_u;
newpte |= PG_u;
else if (va < UPT_MAX_ADDRESS)
(int) npte |= PG_u | PG_RW;
newpte |= PG_u | PG_RW;
if (*pte != npte) {
if (*pte)
ptevalid++;
*pte = npte;
}
if (ptevalid) {
/*
* if the mapping or permission bits are different, we need
* to update the pte.
*/
if ((origpte & ~(PG_M|PG_U)) != newpte) {
if (origpte)
pmap_update_1pg(va);
} else {
if (pv) {
pv->pv_ptem = pmap_use_pt(pmap, va);
*pte = (pt_entry_t) newpte;
}
if (origpte == 0) {
vm_page_t mpte;
mpte = pmap_use_pt(pmap, va);
if (pv)
pv->pv_ptem = mpte;
}
}
@ -1488,7 +1571,7 @@ pmap_enter_quick(pmap, va, pa)
pmap->pm_stats.resident_count++;
/*
* Now validate mapping with desired protection/wiring.
* Now validate mapping with RO protection
*/
*pte = (pt_entry_t) ((int) (pa | PG_V | PG_u));
@ -1516,7 +1599,8 @@ pmap_object_init_pt(pmap, addr, object, pindex, size)
psize = (size >> PAGE_SHIFT);
if (!pmap || ((psize > MAX_INIT_PT) &&
if (!pmap || (object->type != OBJT_VNODE) ||
((psize > MAX_INIT_PT) &&
(object->resident_page_count > MAX_INIT_PT))) {
return;
}
@ -1743,7 +1827,7 @@ pmap_zero_page(phys)
if (*(int *) CMAP2)
panic("pmap_zero_page: CMAP busy");
*(int *) CMAP2 = PG_V | PG_KW | trunc_page(phys);
*(int *) CMAP2 = PG_V | PG_KW | (phys & PG_FRAME);
bzero(CADDR2, PAGE_SIZE);
*(int *) CMAP2 = 0;
@ -1764,8 +1848,8 @@ pmap_copy_page(src, dst)
if (*(int *) CMAP1 || *(int *) CMAP2)
panic("pmap_copy_page: CMAP busy");
*(int *) CMAP1 = PG_V | PG_KW | trunc_page(src);
*(int *) CMAP2 = PG_V | PG_KW | trunc_page(dst);
*(int *) CMAP1 = PG_V | PG_KW | (src & PG_FRAME);
*(int *) CMAP2 = PG_V | PG_KW | (dst & PG_FRAME);
#if __GNUC__ > 1
memcpy(CADDR2, CADDR1, PAGE_SIZE);
@ -1925,11 +2009,21 @@ pmap_changebit(pa, bit, setem)
}
pte = pmap_pte(pv->pv_pmap, va);
if (setem) {
(int) npte = (int) *pte | bit;
*(int *)pte |= bit;
} else {
(int) npte = (int) *pte & ~bit;
if (bit == PG_RW) {
vm_offset_t pbits = *(vm_offset_t *)pte;
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 &= ~(PG_M|PG_RW);
} else {
*(int *)pte &= ~bit;
}
}
*pte = npte;
}
}
splx(s);
@ -2053,13 +2147,13 @@ pmap_mapdev(pa, size)
vm_offset_t va, tmpva;
pt_entry_t *pte;
pa = trunc_page(pa);
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 = vtopte(tmpva);
*pte = (pt_entry_t) ((int) (pa | PG_RW | PG_V | PG_N));
@ -2072,7 +2166,7 @@ pmap_mapdev(pa, size)
return ((void *) va);
}
#ifdef PMAP_DEBUG
#if defined(PMAP_DEBUG)
pmap_pid_dump(int pid) {
pmap_t pmap;
struct proc *p;
@ -2128,7 +2222,7 @@ pmap_pid_dump(int pid) {
}
#endif
#ifdef DEBUG
#if defined(DEBUG)
static void pads __P((pmap_t pm));
static void pmap_pvdump __P((vm_offset_t pa));