#endif
}
-#ifdef CONFIG_X86_PAE
-struct kmem_cache_s *pae_pgd_cachep;
+kmem_cache_t *pgd_cache;
+kmem_cache_t *pmd_cache;
void __init pgtable_cache_init(void)
{
- /*
- * PAE pgds must be 16-byte aligned:
- */
- pae_pgd_cachep = kmem_cache_create("pae_pgd", 32, 0,
- SLAB_HWCACHE_ALIGN | SLAB_MUST_HWCACHE_ALIGN, NULL, NULL);
- if (!pae_pgd_cachep)
- panic("init_pae(): Cannot alloc pae_pgd SLAB cache");
+ if (PTRS_PER_PMD > 1) {
+ pmd_cache = kmem_cache_create("pmd",
+ PTRS_PER_PMD*sizeof(pmd_t),
+ PTRS_PER_PMD*sizeof(pmd_t),
+ 0,
+ pmd_ctor,
+ NULL);
+ if (!pmd_cache)
+ panic("pgtable_cache_init(): cannot create pmd cache");
+ }
+ pgd_cache = kmem_cache_create("pgd",
+ PTRS_PER_PGD*sizeof(pgd_t),
+ PTRS_PER_PGD*sizeof(pgd_t),
+ 0,
+ pgd_ctor,
+ PTRS_PER_PMD == 1 ? pgd_dtor : NULL);
+ if (!pgd_cache)
+ panic("pgtable_cache_init(): Cannot create pgd cache");
}
-#endif
/*
* This function cannot be __init, since exceptions don't work in that
static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
{
+ struct page *page;
+ unsigned long flags;
+
set_pte_atomic(kpte, pte); /* change init_mm */
-#ifndef CONFIG_X86_PAE
- {
- struct list_head *l;
- spin_lock(&mmlist_lock);
- list_for_each(l, &init_mm.mmlist) {
- struct mm_struct *mm = list_entry(l, struct mm_struct, mmlist);
- pmd_t *pmd = pmd_offset(pgd_offset(mm, address), address);
- set_pte_atomic((pte_t *)pmd, pte);
- }
- spin_unlock(&mmlist_lock);
+ if (PTRS_PER_PMD > 1)
+ return;
+
+ spin_lock_irqsave(&pgd_lock, flags);
+ for (page = pgd_list; page; page = (struct page *)page->index) {
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pgd = (pgd_t *)page_address(page) + pgd_index(address);
+ pmd = pmd_offset(pgd, address);
+ set_pte_atomic((pte_t *)pmd, pte);
}
-#endif
+ spin_unlock_irqrestore(&pgd_lock, flags);
}
/*
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
+#include <linux/spinlock.h>
#include <asm/system.h>
#include <asm/pgtable.h>
return pte;
}
-#ifdef CONFIG_X86_PAE
+void pmd_ctor(void *pmd, kmem_cache_t *cache, unsigned long flags)
+{
+ memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
+}
-pgd_t *pgd_alloc(struct mm_struct *mm)
+/*
+ * List of all pgd's needed for non-PAE so it can invalidate entries
+ * in both cached and uncached pgd's; not needed for PAE since the
+ * kernel pmd is shared. If PAE were not to share the pmd a similar
+ * tactic would be needed. This is essentially codepath-based locking
+ * against pageattr.c; it is the unique case in which a valid change
+ * of kernel pagetables can't be lazily synchronized by vmalloc faults.
+ * vmalloc faults work because attached pagetables are never freed.
+ * If the locking proves to be non-performant, a ticketing scheme with
+ * checks at dup_mmap(), exec(), and other mmlist addition points
+ * could be used. The locking scheme was chosen on the basis of
+ * manfred's recommendations and having no core impact whatsoever.
+ * -- wli
+ */
+spinlock_t pgd_lock = SPIN_LOCK_UNLOCKED;
+struct page *pgd_list;
+
+static inline void pgd_list_add(pgd_t *pgd)
{
- int i;
- pgd_t *pgd = kmem_cache_alloc(pae_pgd_cachep, GFP_KERNEL);
-
- if (pgd) {
- for (i = 0; i < USER_PTRS_PER_PGD; i++) {
- unsigned long pmd = __get_free_page(GFP_KERNEL);
- if (!pmd)
- goto out_oom;
- clear_page(pmd);
- set_pgd(pgd + i, __pgd(1 + __pa(pmd)));
- }
- memcpy(pgd + USER_PTRS_PER_PGD,
+ struct page *page = virt_to_page(pgd);
+ page->index = (unsigned long)pgd_list;
+ if (pgd_list)
+ pgd_list->private = (unsigned long)&page->index;
+ pgd_list = page;
+ page->private = (unsigned long)&pgd_list;
+}
+
+static inline void pgd_list_del(pgd_t *pgd)
+{
+ struct page *next, **pprev, *page = virt_to_page(pgd);
+ next = (struct page *)page->index;
+ pprev = (struct page **)page->private;
+ *pprev = next;
+ if (next)
+ next->private = (unsigned long)pprev;
+}
+
+void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused)
+{
+ unsigned long flags;
+
+ if (PTRS_PER_PMD == 1)
+ spin_lock_irqsave(&pgd_lock, flags);
+
+ memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD,
swapper_pg_dir + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
- }
- return pgd;
-out_oom:
- for (i--; i >= 0; i--)
- free_page((unsigned long)__va(pgd_val(pgd[i])-1));
- kmem_cache_free(pae_pgd_cachep, pgd);
- return NULL;
+
+ if (PTRS_PER_PMD > 1)
+ return;
+
+ pgd_list_add(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+ memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
}
-void pgd_free(pgd_t *pgd)
+/* never called when PTRS_PER_PMD > 1 */
+void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused)
{
- int i;
+ unsigned long flags; /* can be called from interrupt context */
- for (i = 0; i < USER_PTRS_PER_PGD; i++)
- free_page((unsigned long)__va(pgd_val(pgd[i])-1));
- kmem_cache_free(pae_pgd_cachep, pgd);
+ spin_lock_irqsave(&pgd_lock, flags);
+ pgd_list_del(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
}
-#else
-
pgd_t *pgd_alloc(struct mm_struct *mm)
{
- pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
+ int i;
+ pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
- if (pgd) {
- memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
- memcpy(pgd + USER_PTRS_PER_PGD,
- swapper_pg_dir + USER_PTRS_PER_PGD,
- (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+ 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);
+ if (!pmd)
+ goto out_oom;
+ set_pgd(&pgd[i], __pgd(1 + __pa((u64)((u32)pmd))));
}
return pgd;
+
+out_oom:
+ for (i--; i >= 0; i--)
+ kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
+ kmem_cache_free(pgd_cache, pgd);
+ return NULL;
}
void pgd_free(pgd_t *pgd)
{
- free_page((unsigned long)pgd);
-}
-
-#endif /* CONFIG_X86_PAE */
+ int i;
+ /* 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)
+ kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
+ /* in the non-PAE case, clear_page_tables() clears user pgd entries */
+ kmem_cache_free(pgd_cache, pgd);
+}
#include <asm/bitops.h>
#endif
-extern pgd_t swapper_pg_dir[1024];
-extern void paging_init(void);
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
/*
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
*/
-extern unsigned long empty_zero_page[1024];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+extern unsigned long empty_zero_page[1024];
+extern pgd_t swapper_pg_dir[1024];
+extern kmem_cache_t *pgd_cache;
+extern kmem_cache_t *pmd_cache;
+extern spinlock_t pgd_lock;
+extern struct page *pgd_list;
+
+void pmd_ctor(void *, kmem_cache_t *, unsigned long);
+void pgd_ctor(void *, kmem_cache_t *, unsigned long);
+void pgd_dtor(void *, kmem_cache_t *, unsigned long);
+void pgtable_cache_init(void);
+void paging_init(void);
#endif /* !__ASSEMBLY__ */
#ifndef __ASSEMBLY__
#ifdef CONFIG_X86_PAE
# include <asm/pgtable-3level.h>
-
-/*
- * Need to initialise the X86 PAE caches
- */
-extern void pgtable_cache_init(void);
-
#else
# include <asm/pgtable-2level.h>
-
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init() do { } while (0)
-
#endif
#endif
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