diff options
Diffstat (limited to 'arch/x86/mm/pgtable_32.c')
| -rw-r--r-- | arch/x86/mm/pgtable_32.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c new file mode 100644 index 00000000000..01437c46baa --- /dev/null +++ b/arch/x86/mm/pgtable_32.c @@ -0,0 +1,373 @@ +/* + * linux/arch/i386/mm/pgtable.c + */ + +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/smp.h> +#include <linux/highmem.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/spinlock.h> +#include <linux/module.h> +#include <linux/quicklist.h> + +#include <asm/system.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/fixmap.h> +#include <asm/e820.h> +#include <asm/tlb.h> +#include <asm/tlbflush.h> + +void show_mem(void) +{ + int total = 0, reserved = 0; + int shared = 0, cached = 0; + int highmem = 0; + struct page *page; + pg_data_t *pgdat; + unsigned long i; + unsigned long flags; + + printk(KERN_INFO "Mem-info:\n"); + show_free_areas(); + printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); + for_each_online_pgdat(pgdat) { + pgdat_resize_lock(pgdat, &flags); + for (i = 0; i < pgdat->node_spanned_pages; ++i) { + page = pgdat_page_nr(pgdat, i); + total++; + if (PageHighMem(page)) + highmem++; + if (PageReserved(page)) + reserved++; + else if (PageSwapCache(page)) + cached++; + else if (page_count(page)) + shared += page_count(page) - 1; + } + pgdat_resize_unlock(pgdat, &flags); + } + printk(KERN_INFO "%d pages of RAM\n", total); + printk(KERN_INFO "%d pages of HIGHMEM\n", highmem); + printk(KERN_INFO "%d reserved pages\n", reserved); + printk(KERN_INFO "%d pages shared\n", shared); + printk(KERN_INFO "%d pages swap cached\n", cached); + + printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY)); + printk(KERN_INFO "%lu pages writeback\n", + global_page_state(NR_WRITEBACK)); + printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED)); + printk(KERN_INFO "%lu pages slab\n", + global_page_state(NR_SLAB_RECLAIMABLE) + + global_page_state(NR_SLAB_UNRECLAIMABLE)); + printk(KERN_INFO "%lu pages pagetables\n", + global_page_state(NR_PAGETABLE)); +} + +/* + * Associate a virtual page frame with a given physical page frame + * and protection flags for that frame. + */ +static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + pgd = swapper_pg_dir + pgd_index(vaddr); + if (pgd_none(*pgd)) { + BUG(); + return; + } + pud = pud_offset(pgd, vaddr); + if (pud_none(*pud)) { + BUG(); + return; + } + pmd = pmd_offset(pud, vaddr); + if (pmd_none(*pmd)) { + BUG(); + return; + } + pte = pte_offset_kernel(pmd, vaddr); + if (pgprot_val(flags)) + /* <pfn,flags> stored as-is, to permit clearing entries */ + set_pte(pte, pfn_pte(pfn, flags)); + else + pte_clear(&init_mm, vaddr, pte); + + /* + * It's enough to flush this one mapping. + * (PGE mappings get flushed as well) + */ + __flush_tlb_one(vaddr); +} + +/* + * Associate a large virtual page frame with a given physical page frame + * and protection flags for that frame. pfn is for the base of the page, + * vaddr is what the page gets mapped to - both must be properly aligned. + * The pmd must already be instantiated. Assumes PAE mode. + */ +void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + + if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */ + printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n"); + return; /* BUG(); */ + } + if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */ + printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n"); + return; /* BUG(); */ + } + pgd = swapper_pg_dir + pgd_index(vaddr); + if (pgd_none(*pgd)) { + printk(KERN_WARNING "set_pmd_pfn: pgd_none\n"); + return; /* BUG(); */ + } + pud = pud_offset(pgd, vaddr); + pmd = pmd_offset(pud, vaddr); + set_pmd(pmd, pfn_pmd(pfn, flags)); + /* + * It's enough to flush this one mapping. + * (PGE mappings get flushed as well) + */ + __flush_tlb_one(vaddr); +} + +static int fixmaps; +unsigned long __FIXADDR_TOP = 0xfffff000; +EXPORT_SYMBOL(__FIXADDR_TOP); + +void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags) +{ + unsigned long address = __fix_to_virt(idx); + + if (idx >= __end_of_fixed_addresses) { + BUG(); + return; + } + set_pte_pfn(address, phys >> PAGE_SHIFT, flags); + fixmaps++; +} + +/** + * reserve_top_address - reserves a hole in the top of kernel address space + * @reserve - size of hole to reserve + * + * Can be used to relocate the fixmap area and poke a hole in the top + * of kernel address space to make room for a hypervisor. + */ +void reserve_top_address(unsigned long reserve) +{ + BUG_ON(fixmaps > 0); + printk(KERN_INFO "Reserving virtual address space above 0x%08x\n", + (int)-reserve); + __FIXADDR_TOP = -reserve - PAGE_SIZE; + __VMALLOC_RESERVE += reserve; +} + +pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) +{ + return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); +} + +struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) +{ + struct page *pte; + +#ifdef CONFIG_HIGHPTE + pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0); +#else + pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0); +#endif + return pte; +} + +void pmd_ctor(void *pmd, struct kmem_cache *cache, unsigned long flags) +{ + memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t)); +} + +/* + * 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. + * -- wli + */ +DEFINE_SPINLOCK(pgd_lock); +struct page *pgd_list; + +static inline void pgd_list_add(pgd_t *pgd) +{ + struct page *page = virt_to_page(pgd); + page->index = (unsigned long)pgd_list; + if (pgd_list) + set_page_private(pgd_list, (unsigned long)&page->index); + pgd_list = page; + set_page_private(page, (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(page); + *pprev = next; + if (next) + set_page_private(next, (unsigned long)pprev); +} + + + +#if (PTRS_PER_PMD == 1) +/* Non-PAE pgd constructor */ +static void pgd_ctor(void *pgd) +{ + unsigned long 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); + paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT, + __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 */ +static void pgd_ctor(void *pgd) +{ + /* 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 */ + +static void pgd_dtor(void *pgd) +{ + unsigned long flags; /* can be called from interrupt context */ + + if (SHARED_KERNEL_PMD) + return; + + 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; + pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor); + + if (PTRS_PER_PMD == 1 || !pgd) + return pgd; + + 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))); + } + return pgd; + +out_oom: + for (i--; i >= 0; i--) { + pgd_t pgdent = pgd[i]; + void* pmd = (void *)__va(pgd_val(pgdent)-1); + paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT); + pmd_cache_free(pmd, i); + } + quicklist_free(0, pgd_dtor, pgd); + return NULL; +} + +void pgd_free(pgd_t *pgd) +{ + int i; + + /* in the PAE case user pgd entries are overwritten before usage */ + if (PTRS_PER_PMD > 1) + 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); + pmd_cache_free(pmd, i); + } + /* in the non-PAE case, free_pgtables() clears user pgd entries */ + quicklist_free(0, pgd_dtor, pgd); +} + +void check_pgt_cache(void) +{ + quicklist_trim(0, pgd_dtor, 25, 16); +} + |