This is a first step towards making the hppa pmap mpsafe. Don't have
an MP hppa system myself, so I would appreciate it someone can give
this a go.
It also enables some debug printfs. So if you give this a spin,
please check if you see any "pmap_destroy" messages in dmesg.
Index: hppa/pmap.c
===================================================================
RCS file: /cvs/src/sys/arch/hppa/hppa/pmap.c,v
retrieving revision 1.165
diff -u -p -r1.165 pmap.c
--- hppa/pmap.c 11 Feb 2015 01:58:57 -0000 1.165
+++ hppa/pmap.c 8 Jul 2015 14:42:18 -0000
@@ -34,6 +34,7 @@
#include <sys/param.h>
#include <sys/systm.h>
+#include <sys/atomic.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/pool.h>
@@ -111,11 +112,25 @@ void pmap_pte_flush(struct pmap *pmap,
void pmap_dump_table(pa_space_t space, vaddr_t sva);
void pmap_dump_pv(paddr_t pa);
#endif
-int pmap_check_alias(struct pv_entry *pve, vaddr_t va,
+int pmap_check_alias(struct vm_page *pg, vaddr_t va,
pt_entry_t pte);
#define IS_IOPAGE(pa) ((pa) >= HPPA_IOBEGIN)
+static inline void
+pmap_lock(struct pmap *pmap)
+{
+ if (pmap != pmap_kernel())
+ mtx_enter(&pmap->pm_mtx);
+}
+
+static inline void
+pmap_unlock(struct pmap *pmap)
+{
+ if (pmap != pmap_kernel())
+ mtx_leave(&pmap->pm_mtx);
+}
+
struct vm_page *
pmap_pagealloc(struct uvm_object *obj, voff_t off)
{
@@ -192,13 +207,24 @@ static __inline pt_entry_t *
pmap_pde_alloc(struct pmap *pm, vaddr_t va, struct vm_page **pdep)
{
struct vm_page *pg;
+ volatile pt_entry_t *pde;
paddr_t pa;
DPRINTF(PDB_FOLLOW|PDB_VP,
("pmap_pde_alloc(%p, 0x%lx, %p)\n", pm, va, pdep));
- if ((pg = pmap_pagealloc(&pm->pm_obj, va)) == NULL)
+ pmap_unlock(pm);
+ pg = pmap_pagealloc(&pm->pm_obj, va);
+ pmap_lock(pm);
+ if (pg == NULL)
return (NULL);
+ pde = pmap_pde_get(pm->pm_pdir, va);
+ if (pde) {
+ pmap_unlock(pm);
+ uvm_pagefree(pg);
+ pmap_lock(pm);
+ return (pt_entry_t *)pde;
+ }
pa = VM_PAGE_TO_PHYS(pg);
@@ -363,12 +389,14 @@ pmap_dump_pv(paddr_t pa)
#endif
int
-pmap_check_alias(struct pv_entry *pve, vaddr_t va, pt_entry_t pte)
+pmap_check_alias(struct vm_page *pg, vaddr_t va, pt_entry_t pte)
{
- int ret;
+ struct pv_entry *pve;
+ int ret = 0;
/* check for non-equ aliased mappings */
- for (ret = 0; pve; pve = pve->pv_next) {
+ mtx_enter(&pg->mdpage.pvh_mtx);
+ for (pve = pg->mdpage.pvh_list; pve; pve = pve->pv_next) {
pte |= pmap_vp_find(pve->pv_pmap, pve->pv_va);
if ((va & HPPA_PGAOFF) != (pve->pv_va & HPPA_PGAOFF) &&
(pte & PTE_PROT(TLB_WRITE))) {
@@ -380,6 +408,7 @@ pmap_check_alias(struct pv_entry *pve, v
ret++;
}
}
+ mtx_leave(&pg->mdpage.pvh_mtx);
return (ret);
}
@@ -416,8 +445,10 @@ pmap_pv_enter(struct vm_page *pg, struct
pve->pv_pmap = pm;
pve->pv_va = va;
pve->pv_ptp = pdep;
+ mtx_enter(&pg->mdpage.pvh_mtx);
pve->pv_next = pg->mdpage.pvh_list;
pg->mdpage.pvh_list = pve;
+ mtx_leave(&pg->mdpage.pvh_mtx);
}
static __inline struct pv_entry *
@@ -425,12 +456,14 @@ pmap_pv_remove(struct vm_page *pg, struc
{
struct pv_entry **pve, *pv;
+ mtx_enter(&pg->mdpage.pvh_mtx);
for (pv = *(pve = &pg->mdpage.pvh_list);
pv; pv = *(pve = &(*pve)->pv_next))
if (pv->pv_pmap == pmap && pv->pv_va == va) {
*pve = pv->pv_next;
break;
}
+ mtx_leave(&pg->mdpage.pvh_mtx);
return (pv);
}
@@ -602,6 +635,7 @@ pmap_init(void)
&pool_allocator_nointr);
pool_init(&pmap_pv_pool, sizeof(struct pv_entry), 0, 0, 0, "pmappv",
NULL);
+ pool_setipl(&pmap_pv_pool, IPL_VM);
pool_setlowat(&pmap_pv_pool, pmap_pvlowat);
pool_sethiwat(&pmap_pv_pool, pmap_pvlowat * 32);
@@ -643,6 +677,8 @@ pmap_create(void)
pmap = pool_get(&pmap_pmap_pool, PR_WAITOK);
+ mtx_init(&pmap->pm_mtx, IPL_VM);
+
uvm_objinit(&pmap->pm_obj, NULL, 1);
for (space = 1 + arc4random_uniform(hppa_sid_max);
@@ -674,7 +710,7 @@ pmap_destroy(struct pmap *pmap)
DPRINTF(PDB_FOLLOW|PDB_PMAP, ("pmap_destroy(%p)\n", pmap));
- refs = --pmap->pm_obj.uo_refs;
+ refs = atomic_dec_int_nv(&pmap->pm_obj.uo_refs);
if (refs > 0)
return;
@@ -686,7 +722,7 @@ pmap_destroy(struct pmap *pmap)
KASSERT(pg != pmap->pm_pdir_pg);
pa = VM_PAGE_TO_PHYS(pg);
-#ifdef PMAPDEBUG
+#ifndef PMAPDEBUG
printf("pmap_destroy(%p): stray ptp 0x%lx w/ %u ents:",
pmap, pa, pg->wire_count - 1);
#endif
@@ -703,7 +739,7 @@ pmap_destroy(struct pmap *pmap)
for (pv = spg->mdpage.pvh_list; pv != NULL; pv = npv) {
npv = pv->pv_next;
if (pv->pv_pmap == pmap) {
-#ifdef PMAPDEBUG
+#ifndef PMAPDEBUG
printf(" 0x%lx", pv->pv_va);
#endif
pmap_remove(pmap, pv->pv_va,
@@ -711,7 +747,7 @@ pmap_destroy(struct pmap *pmap)
}
}
}
-#ifdef PMAPDEBUG
+#ifndef PMAPDEBUG
printf("\n");
#endif
}
@@ -736,7 +772,7 @@ pmap_reference(struct pmap *pmap)
{
DPRINTF(PDB_FOLLOW|PDB_PMAP, ("pmap_reference(%p)\n", pmap));
- pmap->pm_obj.uo_refs++;
+ atomic_inc_int(&pmap->pm_obj.uo_refs);
}
void
@@ -758,11 +794,14 @@ pmap_enter(struct pmap *pmap, vaddr_t va
DPRINTF(PDB_FOLLOW|PDB_ENTER,
("pmap_enter(%p, 0x%lx, 0x%lx, 0x%x, 0x%x)\n",
pmap, va, pa, prot, flags));
+ pmap_lock(pmap);
if (!(pde = pmap_pde_get(pmap->pm_pdir, va)) &&
!(pde = pmap_pde_alloc(pmap, va, &ptp))) {
- if (flags & PMAP_CANFAIL)
+ if (flags & PMAP_CANFAIL) {
+ pmap_unlock(pmap);
return (ENOMEM);
+ }
panic("pmap_enter: cannot allocate pde");
}
@@ -788,7 +827,9 @@ pmap_enter(struct pmap *pmap, vaddr_t va
pg = PHYS_TO_VM_PAGE(PTE_PAGE(pte));
if (pg != NULL) {
pve = pmap_pv_remove(pg, pmap, va);
+ mtx_enter(&pg->mdpage.pvh_mtx);
pg->mdpage.pvh_attrs |= pmap_pvh_attrs(pte);
+ mtx_leave(&pg->mdpage.pvh_mtx);
}
} else {
DPRINTF(PDB_ENTER,
@@ -803,12 +844,14 @@ pmap_enter(struct pmap *pmap, vaddr_t va
if (pmap_initialized && (pg = PHYS_TO_VM_PAGE(PTE_PAGE(pa)))) {
if (!pve && !(pve = pmap_pv_alloc())) {
- if (flags & PMAP_CANFAIL)
+ if (flags & PMAP_CANFAIL) {
+ pmap_unlock(pmap);
return (ENOMEM);
+ }
panic("pmap_enter: no pv entries available");
}
pte |= PTE_PROT(pmap_prot(pmap, prot));
- if (pmap_check_alias(pg->mdpage.pvh_list, va, pte))
+ if (pmap_check_alias(pg, va, pte))
pmap_page_remove(pg);
pmap_pv_enter(pg, pve, pmap, va, ptp);
} else if (pve)
@@ -825,6 +868,7 @@ enter:
pmap_pte_set(pde, va, pte);
DPRINTF(PDB_FOLLOW|PDB_ENTER, ("pmap_enter: leaving\n"));
+ pmap_unlock(pmap);
return (0);
}
@@ -841,6 +885,7 @@ pmap_remove(struct pmap *pmap, vaddr_t s
DPRINTF(PDB_FOLLOW|PDB_REMOVE,
("pmap_remove(%p, 0x%lx, 0x%lx)\n", pmap, sva, eva));
+ pmap_lock(pmap);
for (batch = 0; sva < eva; sva += PAGE_SIZE) {
pdemask = sva & PDE_MASK;
@@ -872,8 +917,9 @@ pmap_remove(struct pmap *pmap, vaddr_t s
if (pmap_initialized &&
(pg = PHYS_TO_VM_PAGE(PTE_PAGE(pte)))) {
-
+ mtx_enter(&pg->mdpage.pvh_mtx);
pg->mdpage.pvh_attrs |= pmap_pvh_attrs(pte);
+ mtx_leave(&pg->mdpage.pvh_mtx);
if ((pve = pmap_pv_remove(pg, pmap, sva)))
pmap_pv_free(pve);
} else {
@@ -887,6 +933,7 @@ pmap_remove(struct pmap *pmap, vaddr_t s
}
DPRINTF(PDB_FOLLOW|PDB_REMOVE, ("pmap_remove: leaving\n"));
+ pmap_unlock(pmap);
}
void
@@ -899,6 +946,7 @@ pmap_write_protect(struct pmap *pmap, va
DPRINTF(PDB_FOLLOW|PDB_PMAP,
("pmap_write_protect(%p, %lx, %lx, %x)\n", pmap, sva, eva, prot));
+ pmap_lock(pmap);
sva = trunc_page(sva);
tlbprot = PTE_PROT(pmap_prot(pmap, prot));
@@ -924,8 +972,11 @@ pmap_write_protect(struct pmap *pmap, va
continue;
pg = PHYS_TO_VM_PAGE(PTE_PAGE(pte));
- if (pg != NULL)
+ if (pg != NULL) {
+ mtx_enter(&pg->mdpage.pvh_mtx);
pg->mdpage.pvh_attrs |= pmap_pvh_attrs(pte);
+ mtx_leave(&pg->mdpage.pvh_mtx);
+ }
pmap_pte_flush(pmap, sva, pte);
pte &= ~PTE_PROT(TLB_AR_MASK);
@@ -933,28 +984,36 @@ pmap_write_protect(struct pmap *pmap, va
pmap_pte_set(pde, sva, pte);
}
}
+
+ pmap_unlock(pmap);
}
void
pmap_page_remove(struct vm_page *pg)
{
- struct pv_entry *pve, *ppve;
+ struct pv_entry *pve;
DPRINTF(PDB_FOLLOW|PDB_PV, ("pmap_page_remove(%p)\n", pg));
if (pg->mdpage.pvh_list == NULL)
return;
- for (pve = pg->mdpage.pvh_list; pve;
- pve = (ppve = pve)->pv_next, pmap_pv_free(ppve)) {
+ mtx_enter(&pg->mdpage.pvh_mtx);
+ while ((pve = pg->mdpage.pvh_list)) {
struct pmap *pmap = pve->pv_pmap;
vaddr_t va = pve->pv_va;
volatile pt_entry_t *pde;
pt_entry_t pte;
+ u_int attrs;
+ pg->mdpage.pvh_list = pve->pv_next;
+ pmap_reference(pmap);
+ mtx_leave(&pg->mdpage.pvh_mtx);
+
+ pmap_lock(pmap);
pde = pmap_pde_get(pmap->pm_pdir, va);
pte = pmap_pte_get(pde, va);
- pg->mdpage.pvh_attrs |= pmap_pvh_attrs(pte);
+ attrs = pmap_pvh_attrs(pte);
pmap_pte_flush(pmap, va, pte);
if (pte & PTE_PROT(TLB_WIRED))
@@ -962,8 +1021,14 @@ pmap_page_remove(struct vm_page *pg)
pmap->pm_stats.resident_count--;
pmap_pte_set(pde, va, 0);
+ pmap_unlock(pmap);
+
+ pmap_destroy(pmap);
+ pmap_pv_free(pve);
+ mtx_enter(&pg->mdpage.pvh_mtx);
+ pg->mdpage.pvh_attrs |= attrs;
}
- pg->mdpage.pvh_list = NULL;
+ mtx_leave(&pg->mdpage.pvh_mtx);
DPRINTF(PDB_FOLLOW|PDB_PV, ("pmap_page_remove: leaving\n"));
}
@@ -975,6 +1040,7 @@ pmap_unwire(struct pmap *pmap, vaddr_t v
pt_entry_t pte = 0;
DPRINTF(PDB_FOLLOW|PDB_PMAP, ("pmap_unwire(%p, 0x%lx)\n", pmap, va));
+ pmap_lock(pmap);
if ((pde = pmap_pde_get(pmap->pm_pdir, va))) {
pte = pmap_pte_get(pde, va);
@@ -987,6 +1053,7 @@ pmap_unwire(struct pmap *pmap, vaddr_t v
}
DPRINTF(PDB_FOLLOW|PDB_PMAP, ("pmap_unwire: leaving\n"));
+ pmap_unlock(pmap);
#ifdef DIAGNOSTIC
if (!pte)
@@ -1003,6 +1070,7 @@ pmap_changebit(struct vm_page *pg, u_int
DPRINTF(PDB_FOLLOW|PDB_BITS,
("pmap_changebit(%p, %x, %x)\n", pg, set, clear));
+ mtx_enter(&pg->mdpage.pvh_mtx);
res = pg->mdpage.pvh_attrs = 0;
for (pve = pg->mdpage.pvh_list; pve; pve = pve->pv_next) {
struct pmap *pmap = pve->pv_pmap;
@@ -1030,6 +1098,7 @@ pmap_changebit(struct vm_page *pg, u_int
}
}
}
+ mtx_leave(&pg->mdpage.pvh_mtx);
return ((res & (clear | set)) != 0);
}
@@ -1039,16 +1108,20 @@ pmap_testbit(struct vm_page *pg, u_int b
{
struct pv_entry *pve;
pt_entry_t pte;
+ boolean_t ret;
DPRINTF(PDB_FOLLOW|PDB_BITS, ("pmap_testbit(%p, %x)\n", pg, bit));
+ mtx_enter(&pg->mdpage.pvh_mtx);
for (pve = pg->mdpage.pvh_list; !(pg->mdpage.pvh_attrs & bit) && pve;
pve = pve->pv_next) {
pte = pmap_vp_find(pve->pv_pmap, pve->pv_va);
pg->mdpage.pvh_attrs |= pmap_pvh_attrs(pte);
}
+ ret = ((pg->mdpage.pvh_attrs & bit) != 0);
+ mtx_leave(&pg->mdpage.pvh_mtx);
- return ((pg->mdpage.pvh_attrs & bit) != 0);
+ return ret;
}
boolean_t
@@ -1089,6 +1162,7 @@ pmap_flush_page(struct vm_page *pg, int
struct pv_entry *pve;
/* purge cache for all possible mappings for the pa */
+ mtx_enter(&pg->mdpage.pvh_mtx);
for (pve = pg->mdpage.pvh_list; pve; pve = pve->pv_next) {
if (purge)
pdcache(pve->pv_pmap->pm_space, pve->pv_va, PAGE_SIZE);
@@ -1098,6 +1172,7 @@ pmap_flush_page(struct vm_page *pg, int
pdtlb(pve->pv_pmap->pm_space, pve->pv_va);
pitlb(pve->pv_pmap->pm_space, pve->pv_va);
}
+ mtx_leave(&pg->mdpage.pvh_mtx);
}
void
@@ -1157,8 +1232,7 @@ pmap_kenter_pa(vaddr_t va, paddr_t pa, v
struct vm_page *pg;
if (pmap_initialized && (pg = PHYS_TO_VM_PAGE(PTE_PAGE(pte)))) {
-
- if (pmap_check_alias(pg->mdpage.pvh_list, va, pte))
+ if (pmap_check_alias(pg, va, pte))
Debugger();
}
}
@@ -1202,8 +1276,9 @@ pmap_kremove(vaddr_t va, vsize_t size)
pmap_pte_flush(pmap_kernel(), va, pte);
pmap_pte_set(pde, va, 0);
if (pmap_initialized && (pg = PHYS_TO_VM_PAGE(PTE_PAGE(pte)))) {
-
+ mtx_enter(&pg->mdpage.pvh_mtx);
pg->mdpage.pvh_attrs |= pmap_pvh_attrs(pte);
+ mtx_leave(&pg->mdpage.pvh_mtx);
/* just in case we have enter/kenter mismatch */
if ((pve = pmap_pv_remove(pg, pmap_kernel(), va)))
pmap_pv_free(pve);
Index: include/pmap.h
===================================================================
RCS file: /cvs/src/sys/arch/hppa/include/pmap.h,v
retrieving revision 1.49
diff -u -p -r1.49 pmap.h
--- include/pmap.h 15 Feb 2015 21:34:33 -0000 1.49
+++ include/pmap.h 8 Jul 2015 14:42:18 -0000
@@ -32,11 +32,12 @@
#include <uvm/uvm_object.h>
#ifdef _KERNEL
+#include <sys/mutex.h>
#include <machine/pte.h>
struct pmap {
- struct uvm_object pm_obj; /* object (lck by object lock) */
-#define pm_lock pm_obj.vmobjlock
+ struct mutex pm_mtx;
+ struct uvm_object pm_obj;
struct vm_page *pm_ptphint;
struct vm_page *pm_pdir_pg; /* vm_page for pdir */
volatile u_int32_t *pm_pdir; /* page dir (read-only after create) */
@@ -160,11 +161,13 @@ pmap_protect(struct pmap *pmap, vaddr_t
#if !defined(_LOCORE)
struct pv_entry;
struct vm_page_md {
- struct pv_entry *pvh_list; /* head of list (locked by pvh_lock) */
+ struct mutex pvh_mtx;
+ struct pv_entry *pvh_list; /* head of list (locked by pvh_mtx) */
u_int pvh_attrs; /* to preserve ref/mod */
};
#define VM_MDPAGE_INIT(pg) do { \
+ mtx_init(&(pg)->mdpage.pvh_mtx, IPL_VM); \
(pg)->mdpage.pvh_list = NULL; \
(pg)->mdpage.pvh_attrs = 0; \
} while (0)
