/* * 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; struct page_state ps; printk(KERN_INFO "Mem-info:\n"); show_free_areas(); printk(KERN_INFO "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_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; } } 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); get_page_state(&ps); printk(KERN_INFO "%lu pages dirty\n", ps.nr_dirty); printk(KERN_INFO "%lu pages writeback\n", ps.nr_writeback); printk(KERN_INFO "%lu pages mapped\n", ps.nr_mapped); printk(KERN_INFO "%lu pages slab\n", ps.nr_slab); printk(KERN_INFO "%lu pages pagetables\n", ps.nr_page_table_pages); } /* * 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(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); } 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) { memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t)); spin_lock_irqsave(&pgd_lock, flags); } 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; pgd_list_add(pgd); spin_unlock_irqrestore(&pgd_lock, flags); } /* 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, free_pgtables() clears user pgd entries */ kmem_cache_free(pgd_cache, pgd); }