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-rw-r--r--arch/i386/kernel/paravirt.c1
-rw-r--r--arch/i386/mm/fault.c5
-rw-r--r--arch/i386/mm/init.c18
-rw-r--r--arch/i386/mm/pageattr.c2
-rw-r--r--arch/i386/mm/pgtable.c88
5 files changed, 90 insertions, 24 deletions
diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c
index 47d075bdfb95..2040a831d5b3 100644
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -132,6 +132,7 @@ struct paravirt_ops paravirt_ops = {
.name = "bare hardware",
.paravirt_enabled = 0,
.kernel_rpl = 0,
+ .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
.patch = native_patch,
.banner = default_banner,
diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
index c6a0a06258e6..f534c29e80b2 100644
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -603,7 +603,6 @@ do_sigbus:
force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk);
}
-#ifndef CONFIG_X86_PAE
void vmalloc_sync_all(void)
{
/*
@@ -616,6 +615,9 @@ void vmalloc_sync_all(void)
static unsigned long start = TASK_SIZE;
unsigned long address;
+ if (SHARED_KERNEL_PMD)
+ return;
+
BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK);
for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) {
if (!test_bit(pgd_index(address), insync)) {
@@ -638,4 +640,3 @@ void vmalloc_sync_all(void)
start = address + PGDIR_SIZE;
}
}
-#endif
diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c
index e8545dcf06c5..dbe16f63a566 100644
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -745,6 +745,8 @@ struct kmem_cache *pmd_cache;
void __init pgtable_cache_init(void)
{
+ size_t pgd_size = PTRS_PER_PGD*sizeof(pgd_t);
+
if (PTRS_PER_PMD > 1) {
pmd_cache = kmem_cache_create("pmd",
PTRS_PER_PMD*sizeof(pmd_t),
@@ -754,13 +756,23 @@ void __init pgtable_cache_init(void)
NULL);
if (!pmd_cache)
panic("pgtable_cache_init(): cannot create pmd cache");
+
+ if (!SHARED_KERNEL_PMD) {
+ /* If we're in PAE mode and have a non-shared
+ kernel pmd, then the pgd size must be a
+ page size. This is because the pgd_list
+ links through the page structure, so there
+ can only be one pgd per page for this to
+ work. */
+ pgd_size = PAGE_SIZE;
+ }
}
pgd_cache = kmem_cache_create("pgd",
- PTRS_PER_PGD*sizeof(pgd_t),
- PTRS_PER_PGD*sizeof(pgd_t),
+ pgd_size,
+ pgd_size,
0,
pgd_ctor,
- PTRS_PER_PMD == 1 ? pgd_dtor : NULL);
+ (!SHARED_KERNEL_PMD) ? pgd_dtor : NULL);
if (!pgd_cache)
panic("pgtable_cache_init(): Cannot create pgd cache");
}
diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index ea6b6d4a0a2a..47bd477c8ecc 100644
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -91,7 +91,7 @@ static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
unsigned long flags;
set_pte_atomic(kpte, pte); /* change init_mm */
- if (PTRS_PER_PMD > 1)
+ if (SHARED_KERNEL_PMD)
return;
spin_lock_irqsave(&pgd_lock, flags);
diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c
index 99c09edc3dbb..9a96c1647428 100644
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -232,42 +232,92 @@ static inline void pgd_list_del(pgd_t *pgd)
set_page_private(next, (unsigned long)pprev);
}
+#if (PTRS_PER_PMD == 1)
+/* Non-PAE pgd constructor */
void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
{
unsigned long flags;
- if (PTRS_PER_PMD == 1) {
- memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
- spin_lock_irqsave(&pgd_lock, flags);
- }
+ /* !PAE, no pagetable sharing */
+ memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+
+ spin_lock_irqsave(&pgd_lock, flags);
+ /* must happen under lock */
clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
swapper_pg_dir + USER_PTRS_PER_PGD,
KERNEL_PGD_PTRS);
-
- if (PTRS_PER_PMD > 1)
- return;
-
- /* must happen under lock */
paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
- __pa(swapper_pg_dir) >> PAGE_SHIFT,
- USER_PTRS_PER_PGD, PTRS_PER_PGD - USER_PTRS_PER_PGD);
-
+ __pa(swapper_pg_dir) >> PAGE_SHIFT,
+ USER_PTRS_PER_PGD,
+ KERNEL_PGD_PTRS);
pgd_list_add(pgd);
spin_unlock_irqrestore(&pgd_lock, flags);
}
+#else /* PTRS_PER_PMD > 1 */
+/* PAE pgd constructor */
+void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
+{
+ /* PAE, kernel PMD may be shared */
+
+ if (SHARED_KERNEL_PMD) {
+ clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
+ swapper_pg_dir + USER_PTRS_PER_PGD,
+ KERNEL_PGD_PTRS);
+ } else {
+ unsigned long flags;
+
+ memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+ spin_lock_irqsave(&pgd_lock, flags);
+ pgd_list_add(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+ }
+}
+#endif /* PTRS_PER_PMD */
-/* never called when PTRS_PER_PMD > 1 */
void pgd_dtor(void *pgd, struct kmem_cache *cache, unsigned long unused)
{
unsigned long flags; /* can be called from interrupt context */
+ BUG_ON(SHARED_KERNEL_PMD);
+
paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
spin_lock_irqsave(&pgd_lock, flags);
pgd_list_del(pgd);
spin_unlock_irqrestore(&pgd_lock, flags);
}
+#define UNSHARED_PTRS_PER_PGD \
+ (SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
+
+/* If we allocate a pmd for part of the kernel address space, then
+ make sure its initialized with the appropriate kernel mappings.
+ Otherwise use a cached zeroed pmd. */
+static pmd_t *pmd_cache_alloc(int idx)
+{
+ pmd_t *pmd;
+
+ if (idx >= USER_PTRS_PER_PGD) {
+ pmd = (pmd_t *)__get_free_page(GFP_KERNEL);
+
+ if (pmd)
+ memcpy(pmd,
+ (void *)pgd_page_vaddr(swapper_pg_dir[idx]),
+ sizeof(pmd_t) * PTRS_PER_PMD);
+ } else
+ pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+
+ return pmd;
+}
+
+static void pmd_cache_free(pmd_t *pmd, int idx)
+{
+ if (idx >= USER_PTRS_PER_PGD)
+ free_page((unsigned long)pmd);
+ else
+ kmem_cache_free(pmd_cache, pmd);
+}
+
pgd_t *pgd_alloc(struct mm_struct *mm)
{
int i;
@@ -276,10 +326,12 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
if (PTRS_PER_PMD == 1 || !pgd)
return pgd;
- for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
- pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+ for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
+ pmd_t *pmd = pmd_cache_alloc(i);
+
if (!pmd)
goto out_oom;
+
paravirt_alloc_pd(__pa(pmd) >> PAGE_SHIFT);
set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
}
@@ -290,7 +342,7 @@ out_oom:
pgd_t pgdent = pgd[i];
void* pmd = (void *)__va(pgd_val(pgdent)-1);
paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
- kmem_cache_free(pmd_cache, pmd);
+ pmd_cache_free(pmd, i);
}
kmem_cache_free(pgd_cache, pgd);
return NULL;
@@ -302,11 +354,11 @@ void pgd_free(pgd_t *pgd)
/* in the PAE case user pgd entries are overwritten before usage */
if (PTRS_PER_PMD > 1)
- for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
+ for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
pgd_t pgdent = pgd[i];
void* pmd = (void *)__va(pgd_val(pgdent)-1);
paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
- kmem_cache_free(pmd_cache, pmd);
+ pmd_cache_free(pmd, i);
}
/* in the non-PAE case, free_pgtables() clears user pgd entries */
kmem_cache_free(pgd_cache, pgd);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 19:10:46 +0000