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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/mm/pgtable.c | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/mm/pgtable.c')
-rw-r--r-- | arch/i386/mm/pgtable.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c new file mode 100644 index 000000000000..0742d54f8bb0 --- /dev/null +++ b/arch/i386/mm/pgtable.c @@ -0,0 +1,260 @@ +/* + * linux/arch/i386/mm/pgtable.c + */ + +#include <linux/config.h> +#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 <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; + + printk("Mem-info:\n"); + show_free_areas(); + printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); + for_each_pgdat(pgdat) { + for (i = 0; i < pgdat->node_spanned_pages; ++i) { + page = pgdat->node_mem_map + 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; + } + } + printk("%d pages of RAM\n", total); + printk("%d pages of HIGHMEM\n",highmem); + printk("%d reserved pages\n",reserved); + printk("%d pages shared\n",shared); + printk("%d pages swap cached\n",cached); +} + +/* + * 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); + /* <pfn,flags> stored as-is, to permit clearing entries */ + set_pte(pte, pfn_pte(pfn, flags)); + + /* + * 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 ("set_pmd_pfn: vaddr misaligned\n"); + return; /* BUG(); */ + } + if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */ + printk ("set_pmd_pfn: pfn misaligned\n"); + return; /* BUG(); */ + } + pgd = swapper_pg_dir + pgd_index(vaddr); + if (pgd_none(*pgd)) { + printk ("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); +} + +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); +} + +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, kmem_cache_t *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. + * The locking scheme was chosen on the basis of manfred's + * recommendations and having no core impact whatsoever. + * -- 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) + 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)); + + 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)); +} + +/* never called when PTRS_PER_PMD > 1 */ +void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused) +{ + unsigned long flags; /* can be called from interrupt context */ + + spin_lock_irqsave(&pgd_lock, flags); + pgd_list_del(pgd); + spin_unlock_irqrestore(&pgd_lock, flags); +} + +pgd_t *pgd_alloc(struct mm_struct *mm) +{ + int i; + pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL); + + 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(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) +{ + 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_range() clears user pgd entries */ + kmem_cache_free(pgd_cache, pgd); +} |