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author | Thomas Gleixner <tglx@linutronix.de> | 2007-10-11 11:16:18 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2007-10-11 11:16:18 +0200 |
commit | 4ec0f73f27cbcf728311d8da7994477c1bd4edbb (patch) | |
tree | 5832608ec0e9aeadea59e68b72fdd130818f8674 /arch/x86_64/mm/pageattr.c | |
parent | 5140b4f77d75debc47ccb9b77e00d2e1c68e1a3e (diff) | |
download | linux-4ec0f73f27cbcf728311d8da7994477c1bd4edbb.tar.bz2 |
x86_64: prepare shared mm/pageattr.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86_64/mm/pageattr.c')
-rw-r--r-- | arch/x86_64/mm/pageattr.c | 249 |
1 files changed, 0 insertions, 249 deletions
diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c deleted file mode 100644 index 10b9809ce821..000000000000 --- a/arch/x86_64/mm/pageattr.c +++ /dev/null @@ -1,249 +0,0 @@ -/* - * Copyright 2002 Andi Kleen, SuSE Labs. - * Thanks to Ben LaHaise for precious feedback. - */ - -#include <linux/mm.h> -#include <linux/sched.h> -#include <linux/highmem.h> -#include <linux/module.h> -#include <linux/slab.h> -#include <asm/uaccess.h> -#include <asm/processor.h> -#include <asm/tlbflush.h> -#include <asm/io.h> - -pte_t *lookup_address(unsigned long address) -{ - pgd_t *pgd = pgd_offset_k(address); - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - if (pgd_none(*pgd)) - return NULL; - pud = pud_offset(pgd, address); - if (!pud_present(*pud)) - return NULL; - pmd = pmd_offset(pud, address); - if (!pmd_present(*pmd)) - return NULL; - if (pmd_large(*pmd)) - return (pte_t *)pmd; - pte = pte_offset_kernel(pmd, address); - if (pte && !pte_present(*pte)) - pte = NULL; - return pte; -} - -static struct page *split_large_page(unsigned long address, pgprot_t prot, - pgprot_t ref_prot) -{ - int i; - unsigned long addr; - struct page *base = alloc_pages(GFP_KERNEL, 0); - pte_t *pbase; - if (!base) - return NULL; - /* - * page_private is used to track the number of entries in - * the page table page have non standard attributes. - */ - SetPagePrivate(base); - page_private(base) = 0; - - address = __pa(address); - addr = address & LARGE_PAGE_MASK; - pbase = (pte_t *)page_address(base); - for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) { - pbase[i] = pfn_pte(addr >> PAGE_SHIFT, - addr == address ? prot : ref_prot); - } - return base; -} - -static void cache_flush_page(void *adr) -{ - int i; - for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size) - asm volatile("clflush (%0)" :: "r" (adr + i)); -} - -static void flush_kernel_map(void *arg) -{ - struct list_head *l = (struct list_head *)arg; - struct page *pg; - - /* When clflush is available always use it because it is - much cheaper than WBINVD. */ - /* clflush is still broken. Disable for now. */ - if (1 || !cpu_has_clflush) - asm volatile("wbinvd" ::: "memory"); - else list_for_each_entry(pg, l, lru) { - void *adr = page_address(pg); - cache_flush_page(adr); - } - __flush_tlb_all(); -} - -static inline void flush_map(struct list_head *l) -{ - on_each_cpu(flush_kernel_map, l, 1, 1); -} - -static LIST_HEAD(deferred_pages); /* protected by init_mm.mmap_sem */ - -static inline void save_page(struct page *fpage) -{ - if (!test_and_set_bit(PG_arch_1, &fpage->flags)) - list_add(&fpage->lru, &deferred_pages); -} - -/* - * No more special protections in this 2/4MB area - revert to a - * large page again. - */ -static void revert_page(unsigned long address, pgprot_t ref_prot) -{ - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t large_pte; - unsigned long pfn; - - pgd = pgd_offset_k(address); - BUG_ON(pgd_none(*pgd)); - pud = pud_offset(pgd,address); - BUG_ON(pud_none(*pud)); - pmd = pmd_offset(pud, address); - BUG_ON(pmd_val(*pmd) & _PAGE_PSE); - pfn = (__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT; - large_pte = pfn_pte(pfn, ref_prot); - large_pte = pte_mkhuge(large_pte); - set_pte((pte_t *)pmd, large_pte); -} - -static int -__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, - pgprot_t ref_prot) -{ - pte_t *kpte; - struct page *kpte_page; - pgprot_t ref_prot2; - - kpte = lookup_address(address); - if (!kpte) return 0; - kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK); - BUG_ON(PageLRU(kpte_page)); - BUG_ON(PageCompound(kpte_page)); - if (pgprot_val(prot) != pgprot_val(ref_prot)) { - if (!pte_huge(*kpte)) { - set_pte(kpte, pfn_pte(pfn, prot)); - } else { - /* - * split_large_page will take the reference for this - * change_page_attr on the split page. - */ - struct page *split; - ref_prot2 = pte_pgprot(pte_clrhuge(*kpte)); - split = split_large_page(address, prot, ref_prot2); - if (!split) - return -ENOMEM; - set_pte(kpte, mk_pte(split, ref_prot2)); - kpte_page = split; - } - page_private(kpte_page)++; - } else if (!pte_huge(*kpte)) { - set_pte(kpte, pfn_pte(pfn, ref_prot)); - BUG_ON(page_private(kpte_page) == 0); - page_private(kpte_page)--; - } else - BUG(); - - /* on x86-64 the direct mapping set at boot is not using 4k pages */ - BUG_ON(PageReserved(kpte_page)); - - save_page(kpte_page); - if (page_private(kpte_page) == 0) - revert_page(address, ref_prot); - return 0; -} - -/* - * Change the page attributes of an page in the linear mapping. - * - * 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. - * - * The caller needs to ensure that there are no conflicting mappings elsewhere. - * This function only deals with the kernel linear map. - * - * Caller must call global_flush_tlb() after this. - */ -int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) -{ - int err = 0, kernel_map = 0; - int i; - - if (address >= __START_KERNEL_map - && address < __START_KERNEL_map + KERNEL_TEXT_SIZE) { - address = (unsigned long)__va(__pa(address)); - kernel_map = 1; - } - - down_write(&init_mm.mmap_sem); - 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, prot, PAGE_KERNEL); - if (err) - break; - } - /* Handle kernel mapping too which aliases part of the - * 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, prot2, - PAGE_KERNEL_EXEC); - } - } - up_write(&init_mm.mmap_sem); - return err; -} - -/* Don't call this for MMIO areas that may not have a mem_map entry */ -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); -} - -void global_flush_tlb(void) -{ - struct page *pg, *next; - struct list_head l; - - down_read(&init_mm.mmap_sem); - list_replace_init(&deferred_pages, &l); - up_read(&init_mm.mmap_sem); - - flush_map(&l); - - list_for_each_entry_safe(pg, next, &l, lru) { - list_del(&pg->lru); - clear_bit(PG_arch_1, &pg->flags); - if (page_private(pg) != 0) - continue; - ClearPagePrivate(pg); - __free_page(pg); - } -} - -EXPORT_SYMBOL(change_page_attr); -EXPORT_SYMBOL(global_flush_tlb); |