/arch/i386/mm/pgtable.c
https://bitbucket.org/evzijst/gittest · C · 260 lines · 192 code · 31 blank · 37 comment · 27 complexity · 0de2d333a7702edc466a39be7fe347a2 MD5 · raw file
- /*
- * 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);
- }