269 lines
6.8 KiB
C
269 lines
6.8 KiB
C
/*
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* linux/arch/i386/mm/pgtable.c
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*/
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#include <linux/config.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/smp.h>
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#include <linux/highmem.h>
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#include <linux/slab.h>
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#include <linux/pagemap.h>
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#include <linux/spinlock.h>
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#include <asm/system.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/fixmap.h>
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#include <asm/e820.h>
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#include <asm/tlb.h>
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#include <asm/tlbflush.h>
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void show_mem(void)
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{
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int total = 0, reserved = 0;
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int shared = 0, cached = 0;
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int highmem = 0;
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struct page *page;
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pg_data_t *pgdat;
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unsigned long i;
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struct page_state ps;
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printk(KERN_INFO "Mem-info:\n");
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show_free_areas();
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printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
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for_each_pgdat(pgdat) {
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for (i = 0; i < pgdat->node_spanned_pages; ++i) {
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page = pgdat_page_nr(pgdat, i);
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total++;
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if (PageHighMem(page))
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highmem++;
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if (PageReserved(page))
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reserved++;
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else if (PageSwapCache(page))
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cached++;
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else if (page_count(page))
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shared += page_count(page) - 1;
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}
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}
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printk(KERN_INFO "%d pages of RAM\n", total);
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printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
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printk(KERN_INFO "%d reserved pages\n", reserved);
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printk(KERN_INFO "%d pages shared\n", shared);
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printk(KERN_INFO "%d pages swap cached\n", cached);
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get_page_state(&ps);
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printk(KERN_INFO "%lu pages dirty\n", ps.nr_dirty);
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printk(KERN_INFO "%lu pages writeback\n", ps.nr_writeback);
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printk(KERN_INFO "%lu pages mapped\n", ps.nr_mapped);
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printk(KERN_INFO "%lu pages slab\n", ps.nr_slab);
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printk(KERN_INFO "%lu pages pagetables\n", ps.nr_page_table_pages);
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}
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/*
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* Associate a virtual page frame with a given physical page frame
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* and protection flags for that frame.
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*/
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static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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pgd = swapper_pg_dir + pgd_index(vaddr);
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if (pgd_none(*pgd)) {
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BUG();
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return;
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}
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pud = pud_offset(pgd, vaddr);
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if (pud_none(*pud)) {
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BUG();
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return;
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}
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pmd = pmd_offset(pud, vaddr);
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if (pmd_none(*pmd)) {
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BUG();
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return;
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}
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pte = pte_offset_kernel(pmd, vaddr);
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/* <pfn,flags> stored as-is, to permit clearing entries */
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set_pte(pte, pfn_pte(pfn, flags));
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/*
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* It's enough to flush this one mapping.
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* (PGE mappings get flushed as well)
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*/
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__flush_tlb_one(vaddr);
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}
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/*
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* Associate a large virtual page frame with a given physical page frame
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* and protection flags for that frame. pfn is for the base of the page,
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* vaddr is what the page gets mapped to - both must be properly aligned.
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* The pmd must already be instantiated. Assumes PAE mode.
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*/
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void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
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printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
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return; /* BUG(); */
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}
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if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
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printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
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return; /* BUG(); */
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}
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pgd = swapper_pg_dir + pgd_index(vaddr);
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if (pgd_none(*pgd)) {
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printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
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return; /* BUG(); */
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}
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pud = pud_offset(pgd, vaddr);
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pmd = pmd_offset(pud, vaddr);
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set_pmd(pmd, pfn_pmd(pfn, flags));
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/*
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* It's enough to flush this one mapping.
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* (PGE mappings get flushed as well)
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*/
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__flush_tlb_one(vaddr);
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}
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void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
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{
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unsigned long address = __fix_to_virt(idx);
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if (idx >= __end_of_fixed_addresses) {
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BUG();
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return;
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}
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set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
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}
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pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
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{
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return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
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}
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struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
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{
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struct page *pte;
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#ifdef CONFIG_HIGHPTE
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pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
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#else
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pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
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#endif
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return pte;
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}
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void pmd_ctor(void *pmd, kmem_cache_t *cache, unsigned long flags)
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{
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memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
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}
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/*
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* List of all pgd's needed for non-PAE so it can invalidate entries
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* in both cached and uncached pgd's; not needed for PAE since the
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* kernel pmd is shared. If PAE were not to share the pmd a similar
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* tactic would be needed. This is essentially codepath-based locking
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* against pageattr.c; it is the unique case in which a valid change
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* of kernel pagetables can't be lazily synchronized by vmalloc faults.
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* vmalloc faults work because attached pagetables are never freed.
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* The locking scheme was chosen on the basis of manfred's
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* recommendations and having no core impact whatsoever.
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* -- wli
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*/
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DEFINE_SPINLOCK(pgd_lock);
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struct page *pgd_list;
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static inline void pgd_list_add(pgd_t *pgd)
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{
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struct page *page = virt_to_page(pgd);
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page->index = (unsigned long)pgd_list;
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if (pgd_list)
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pgd_list->private = (unsigned long)&page->index;
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pgd_list = page;
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page->private = (unsigned long)&pgd_list;
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}
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static inline void pgd_list_del(pgd_t *pgd)
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{
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struct page *next, **pprev, *page = virt_to_page(pgd);
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next = (struct page *)page->index;
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pprev = (struct page **)page->private;
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*pprev = next;
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if (next)
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next->private = (unsigned long)pprev;
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}
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void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused)
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{
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unsigned long flags;
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if (PTRS_PER_PMD == 1)
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spin_lock_irqsave(&pgd_lock, flags);
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memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD,
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swapper_pg_dir + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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if (PTRS_PER_PMD > 1)
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return;
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pgd_list_add(pgd);
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spin_unlock_irqrestore(&pgd_lock, flags);
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memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
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}
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/* never called when PTRS_PER_PMD > 1 */
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void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused)
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{
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unsigned long flags; /* can be called from interrupt context */
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spin_lock_irqsave(&pgd_lock, flags);
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pgd_list_del(pgd);
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spin_unlock_irqrestore(&pgd_lock, flags);
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}
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pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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int i;
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pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
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if (PTRS_PER_PMD == 1 || !pgd)
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return pgd;
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for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
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pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
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if (!pmd)
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goto out_oom;
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set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
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}
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return pgd;
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out_oom:
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for (i--; i >= 0; i--)
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kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
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kmem_cache_free(pgd_cache, pgd);
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return NULL;
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}
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void pgd_free(pgd_t *pgd)
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{
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int i;
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/* in the PAE case user pgd entries are overwritten before usage */
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if (PTRS_PER_PMD > 1)
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for (i = 0; i < USER_PTRS_PER_PGD; ++i)
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kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
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/* in the non-PAE case, free_pgtables() clears user pgd entries */
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kmem_cache_free(pgd_cache, pgd);
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}
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