diff options
| -rw-r--r-- | arch/x86/mm/pageattr_32.c | 134 |
1 files changed, 87 insertions, 47 deletions
diff --git a/arch/x86/mm/pageattr_32.c b/arch/x86/mm/pageattr_32.c index 1c7bd81a419..251613449dd 100644 --- a/arch/x86/mm/pageattr_32.c +++ b/arch/x86/mm/pageattr_32.c @@ -39,23 +39,26 @@ pte_t *lookup_address(unsigned long address, int *level) static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) { - struct page *page; - /* change init_mm */ set_pte_atomic(kpte, pte); +#ifdef CONFIG_X86_32 if (SHARED_KERNEL_PMD) return; - - 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); + { + 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) @@ -89,7 +92,9 @@ static int split_large_page(pte_t *kpte, unsigned long address) 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)); @@ -109,15 +114,14 @@ out_unlock: return 0; } -static int __change_page_attr(struct page *page, pgprot_t prot) +static int +__change_page_attr(unsigned long address, struct page *page, pgprot_t prot) { struct page *kpte_page; - unsigned long address; int level, err = 0; pte_t *kpte; BUG_ON(PageHighMem(page)); - address = (unsigned long)page_address(page); repeat: kpte = lookup_address(address, &level); @@ -146,51 +150,87 @@ repeat: return err; } -/* - * Change the page attributes of an page in the linear mapping. +/** + * 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_*) * - * 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. + * 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). * - * Caller must call global_flush_tlb() after this. + * See change_page_attr() documentation for more details. */ -int change_page_attr(struct page *page, int numpages, pgprot_t prot) + +int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) { - int err = 0, i; + int err = 0, kernel_map = 0, i; + +#ifdef CONFIG_X86_64 + if (address >= __START_KERNEL_map && + address < __START_KERNEL_map + KERNEL_TEXT_SIZE) { - for (i = 0; i < numpages; i++, page++) { - err = __change_page_attr(page, prot); - if (err) - break; + 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; } -EXPORT_SYMBOL(change_page_attr); -int change_page_attr_addr(unsigned long addr, int numpages, pgprot_t prot) +/** + * 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) { - int i; - unsigned long pfn = (__pa(addr) >> PAGE_SHIFT); - - for (i = 0; i < numpages; i++) { - if (!pfn_valid(pfn + i)) { - WARN_ON_ONCE(1); - break; - } else { - int level; - pte_t *pte = lookup_address(addr + i*PAGE_SIZE, &level); - BUG_ON(pte && pte_none(*pte)); - } - } + unsigned long addr = (unsigned long)page_address(page); - return change_page_attr(virt_to_page(addr), i, prot); + return change_page_attr_addr(addr, numpages, prot); } +EXPORT_SYMBOL(change_page_attr); static void flush_kernel_map(void *arg) { |