+++ /dev/null
-/*
- * Copyright 2002 Andi Kleen, SuSE Labs.
- * Thanks to Ben LaHaise for precious feedback.
- */
-
-#include <linux/highmem.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/mm.h>
-
-#include <asm/processor.h>
-#include <asm/tlbflush.h>
-#include <asm/sections.h>
-#include <asm/uaccess.h>
-#include <asm/pgalloc.h>
-
-pte_t *lookup_address(unsigned long address, int *level)
-{
- pgd_t *pgd = pgd_offset_k(address);
- pud_t *pud;
- pmd_t *pmd;
-
- if (pgd_none(*pgd))
- return NULL;
- pud = pud_offset(pgd, address);
- if (pud_none(*pud))
- return NULL;
- pmd = pmd_offset(pud, address);
- if (pmd_none(*pmd))
- return NULL;
- *level = 3;
- if (pmd_large(*pmd))
- return (pte_t *)pmd;
- *level = 4;
-
- return pte_offset_kernel(pmd, address);
-}
-
-static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
-{
- /* change init_mm */
- set_pte_atomic(kpte, pte);
-#ifdef CONFIG_X86_32
- if (SHARED_KERNEL_PMD)
- return;
- {
- struct page *page;
-
- for (page = pgd_list; page; page = (struct page *)page->index) {
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
-
- pgd = (pgd_t *)page_address(page) + pgd_index(address);
- pud = pud_offset(pgd, address);
- pmd = pmd_offset(pud, address);
- set_pte_atomic((pte_t *)pmd, pte);
- }
- }
-#endif
-}
-
-static int split_large_page(pte_t *kpte, unsigned long address)
-{
- pgprot_t ref_prot = pte_pgprot(pte_clrhuge(*kpte));
- gfp_t gfp_flags = GFP_KERNEL;
- unsigned long flags;
- unsigned long addr;
- pte_t *pbase, *tmp;
- struct page *base;
- int i, level;
-
-
-#ifdef CONFIG_DEBUG_PAGEALLOC
- gfp_flags = GFP_ATOMIC;
-#endif
- base = alloc_pages(gfp_flags, 0);
- if (!base)
- return -ENOMEM;
-
- spin_lock_irqsave(&pgd_lock, flags);
- /*
- * Check for races, another CPU might have split this page
- * up for us already:
- */
- tmp = lookup_address(address, &level);
- if (tmp != kpte) {
- WARN_ON_ONCE(1);
- goto out_unlock;
- }
-
- address = __pa(address);
- addr = address & LARGE_PAGE_MASK;
- pbase = (pte_t *)page_address(base);
-#ifdef CONFIG_X86_32
- paravirt_alloc_pt(&init_mm, page_to_pfn(base));
-#endif
-
- for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE)
- set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, ref_prot));
-
- /*
- * Install the new, split up pagetable:
- */
- __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
- base = NULL;
-
-out_unlock:
- spin_unlock_irqrestore(&pgd_lock, flags);
-
- if (base)
- __free_pages(base, 0);
-
- return 0;
-}
-
-static int
-__change_page_attr(unsigned long address, struct page *page, pgprot_t prot)
-{
- struct page *kpte_page;
- int level, err = 0;
- pte_t *kpte;
-
- BUG_ON(PageHighMem(page));
-
-repeat:
- kpte = lookup_address(address, &level);
- if (!kpte)
- return -EINVAL;
-
- kpte_page = virt_to_page(kpte);
- BUG_ON(PageLRU(kpte_page));
- BUG_ON(PageCompound(kpte_page));
-
- /*
- * Better fail early if someone sets the kernel text to NX.
- * Does not cover __inittext
- */
- BUG_ON(address >= (unsigned long)&_text &&
- address < (unsigned long)&_etext &&
- (pgprot_val(prot) & _PAGE_NX));
-
- if (level == 4) {
- set_pte_atomic(kpte, mk_pte(page, canon_pgprot(prot)));
- } else {
- err = split_large_page(kpte, address);
- if (!err)
- goto repeat;
- }
- return err;
-}
-
-/**
- * change_page_attr_addr - Change page table attributes in linear mapping
- * @address: Virtual address in linear mapping.
- * @numpages: Number of pages to change
- * @prot: New page table attribute (PAGE_*)
- *
- * Change page attributes of a page in the direct mapping. This is a variant
- * of change_page_attr() that also works on memory holes that do not have
- * mem_map entry (pfn_valid() is false).
- *
- * See change_page_attr() documentation for more details.
- */
-
-int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
-{
- int err = 0, kernel_map = 0, i;
-
-#ifdef CONFIG_X86_64
- if (address >= __START_KERNEL_map &&
- address < __START_KERNEL_map + KERNEL_TEXT_SIZE) {
-
- address = (unsigned long)__va(__pa(address));
- kernel_map = 1;
- }
-#endif
-
- for (i = 0; i < numpages; i++, address += PAGE_SIZE) {
- unsigned long pfn = __pa(address) >> PAGE_SHIFT;
-
- if (!kernel_map || pte_present(pfn_pte(0, prot))) {
- err = __change_page_attr(address, pfn_to_page(pfn), prot);
- if (err)
- break;
- }
-#ifdef CONFIG_X86_64
- /*
- * Handle kernel mapping too which aliases part of
- * lowmem:
- */
- if (__pa(address) < KERNEL_TEXT_SIZE) {
- unsigned long addr2;
- pgprot_t prot2;
-
- addr2 = __START_KERNEL_map + __pa(address);
- /* Make sure the kernel mappings stay executable */
- prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot)));
- err = __change_page_attr(addr2, pfn_to_page(pfn), prot2);
- }
-#endif
- }
-
- return err;
-}
-
-/**
- * change_page_attr - Change page table attributes in the linear mapping.
- * @page: First page to change
- * @numpages: Number of pages to change
- * @prot: New protection/caching type (PAGE_*)
- *
- * Returns 0 on success, otherwise a negated errno.
- *
- * This should be used when a page is mapped with a different caching policy
- * than write-back somewhere - some CPUs do not like it when mappings with
- * different caching policies exist. This changes the page attributes of the
- * in kernel linear mapping too.
- *
- * Caller must call global_flush_tlb() later to make the changes active.
- *
- * The caller needs to ensure that there are no conflicting mappings elsewhere
- * (e.g. in user space) * This function only deals with the kernel linear map.
- *
- * For MMIO areas without mem_map use change_page_attr_addr() instead.
- */
-int change_page_attr(struct page *page, int numpages, pgprot_t prot)
-{
- unsigned long addr = (unsigned long)page_address(page);
-
- return change_page_attr_addr(addr, numpages, prot);
-}
-EXPORT_SYMBOL(change_page_attr);
-
-static void flush_kernel_map(void *arg)
-{
- /*
- * Flush all to work around Errata in early athlons regarding
- * large page flushing.
- */
- __flush_tlb_all();
-
- if (boot_cpu_data.x86_model >= 4)
- wbinvd();
-}
-
-void global_flush_tlb(void)
-{
- BUG_ON(irqs_disabled());
-
- on_each_cpu(flush_kernel_map, NULL, 1, 1);
-}
-EXPORT_SYMBOL(global_flush_tlb);
-
-#ifdef CONFIG_DEBUG_PAGEALLOC
-void kernel_map_pages(struct page *page, int numpages, int enable)
-{
- if (PageHighMem(page))
- return;
- if (!enable) {
- debug_check_no_locks_freed(page_address(page),
- numpages * PAGE_SIZE);
- }
-
- /*
- * If page allocator is not up yet then do not call c_p_a():
- */
- if (!debug_pagealloc_enabled)
- return;
-
- /*
- * the return value is ignored - the calls cannot fail,
- * large pages are disabled at boot time.
- */
- change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
-
- /*
- * we should perform an IPI and flush all tlbs,
- * but that can deadlock->flush only current cpu.
- */
- __flush_tlb_all();
-}
-#endif
projects / linux-2.6 / commitdiff