aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/mm/pgtable.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/mm/pgtable.c')
-rw-r--r--arch/x86/mm/pgtable.c160
1 files changed, 150 insertions, 10 deletions
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 7b22adaad4f1..0b97d2c75df3 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -4,6 +4,7 @@
#include <asm/pgtable.h>
#include <asm/tlb.h>
#include <asm/fixmap.h>
+#include <asm/mtrr.h>
#define PGALLOC_GFP GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO
@@ -58,7 +59,7 @@ void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
tlb_remove_page(tlb, pte);
}
-#if PAGETABLE_LEVELS > 2
+#if CONFIG_PGTABLE_LEVELS > 2
void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
{
struct page *page = virt_to_page(pmd);
@@ -74,14 +75,14 @@ void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
tlb_remove_page(tlb, page);
}
-#if PAGETABLE_LEVELS > 3
+#if CONFIG_PGTABLE_LEVELS > 3
void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud)
{
paravirt_release_pud(__pa(pud) >> PAGE_SHIFT);
tlb_remove_page(tlb, virt_to_page(pud));
}
-#endif /* PAGETABLE_LEVELS > 3 */
-#endif /* PAGETABLE_LEVELS > 2 */
+#endif /* CONFIG_PGTABLE_LEVELS > 3 */
+#endif /* CONFIG_PGTABLE_LEVELS > 2 */
static inline void pgd_list_add(pgd_t *pgd)
{
@@ -117,9 +118,9 @@ static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd)
/* If the pgd points to a shared pagetable level (either the
ptes in non-PAE, or shared PMD in PAE), then just copy the
references from swapper_pg_dir. */
- if (PAGETABLE_LEVELS == 2 ||
- (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) ||
- PAGETABLE_LEVELS == 4) {
+ if (CONFIG_PGTABLE_LEVELS == 2 ||
+ (CONFIG_PGTABLE_LEVELS == 3 && SHARED_KERNEL_PMD) ||
+ CONFIG_PGTABLE_LEVELS == 4) {
clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY,
swapper_pg_dir + KERNEL_PGD_BOUNDARY,
KERNEL_PGD_PTRS);
@@ -275,12 +276,87 @@ static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[])
}
}
+/*
+ * Xen paravirt assumes pgd table should be in one page. 64 bit kernel also
+ * assumes that pgd should be in one page.
+ *
+ * But kernel with PAE paging that is not running as a Xen domain
+ * only needs to allocate 32 bytes for pgd instead of one page.
+ */
+#ifdef CONFIG_X86_PAE
+
+#include <linux/slab.h>
+
+#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
+#define PGD_ALIGN 32
+
+static struct kmem_cache *pgd_cache;
+
+static int __init pgd_cache_init(void)
+{
+ /*
+ * When PAE kernel is running as a Xen domain, it does not use
+ * shared kernel pmd. And this requires a whole page for pgd.
+ */
+ if (!SHARED_KERNEL_PMD)
+ return 0;
+
+ /*
+ * when PAE kernel is not running as a Xen domain, it uses
+ * shared kernel pmd. Shared kernel pmd does not require a whole
+ * page for pgd. We are able to just allocate a 32-byte for pgd.
+ * During boot time, we create a 32-byte slab for pgd table allocation.
+ */
+ pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_ALIGN,
+ SLAB_PANIC, NULL);
+ if (!pgd_cache)
+ return -ENOMEM;
+
+ return 0;
+}
+core_initcall(pgd_cache_init);
+
+static inline pgd_t *_pgd_alloc(void)
+{
+ /*
+ * If no SHARED_KERNEL_PMD, PAE kernel is running as a Xen domain.
+ * We allocate one page for pgd.
+ */
+ if (!SHARED_KERNEL_PMD)
+ return (pgd_t *)__get_free_page(PGALLOC_GFP);
+
+ /*
+ * Now PAE kernel is not running as a Xen domain. We can allocate
+ * a 32-byte slab for pgd to save memory space.
+ */
+ return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
+}
+
+static inline void _pgd_free(pgd_t *pgd)
+{
+ if (!SHARED_KERNEL_PMD)
+ free_page((unsigned long)pgd);
+ else
+ kmem_cache_free(pgd_cache, pgd);
+}
+#else
+static inline pgd_t *_pgd_alloc(void)
+{
+ return (pgd_t *)__get_free_page(PGALLOC_GFP);
+}
+
+static inline void _pgd_free(pgd_t *pgd)
+{
+ free_page((unsigned long)pgd);
+}
+#endif /* CONFIG_X86_PAE */
+
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *pgd;
pmd_t *pmds[PREALLOCATED_PMDS];
- pgd = (pgd_t *)__get_free_page(PGALLOC_GFP);
+ pgd = _pgd_alloc();
if (pgd == NULL)
goto out;
@@ -310,7 +386,7 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
out_free_pmds:
free_pmds(mm, pmds);
out_free_pgd:
- free_page((unsigned long)pgd);
+ _pgd_free(pgd);
out:
return NULL;
}
@@ -320,7 +396,7 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
pgd_mop_up_pmds(mm, pgd);
pgd_dtor(pgd);
paravirt_pgd_free(mm, pgd);
- free_page((unsigned long)pgd);
+ _pgd_free(pgd);
}
/*
@@ -485,3 +561,67 @@ void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys,
{
__native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags));
}
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
+{
+ u8 mtrr;
+
+ /*
+ * Do not use a huge page when the range is covered by non-WB type
+ * of MTRRs.
+ */
+ mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE);
+ if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF))
+ return 0;
+
+ prot = pgprot_4k_2_large(prot);
+
+ set_pte((pte_t *)pud, pfn_pte(
+ (u64)addr >> PAGE_SHIFT,
+ __pgprot(pgprot_val(prot) | _PAGE_PSE)));
+
+ return 1;
+}
+
+int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
+{
+ u8 mtrr;
+
+ /*
+ * Do not use a huge page when the range is covered by non-WB type
+ * of MTRRs.
+ */
+ mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE);
+ if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF))
+ return 0;
+
+ prot = pgprot_4k_2_large(prot);
+
+ set_pte((pte_t *)pmd, pfn_pte(
+ (u64)addr >> PAGE_SHIFT,
+ __pgprot(pgprot_val(prot) | _PAGE_PSE)));
+
+ return 1;
+}
+
+int pud_clear_huge(pud_t *pud)
+{
+ if (pud_large(*pud)) {
+ pud_clear(pud);
+ return 1;
+ }
+
+ return 0;
+}
+
+int pmd_clear_huge(pmd_t *pmd)
+{
+ if (pmd_large(*pmd)) {
+ pmd_clear(pmd);
+ return 1;
+ }
+
+ return 0;
+}
+#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */