diff options
Diffstat (limited to 'xenolinux-2.4.21-pre4-sparse/arch/xeno/mm/pageattr.c')
| -rw-r--r-- | xenolinux-2.4.21-pre4-sparse/arch/xeno/mm/pageattr.c | 175 |
1 files changed, 0 insertions, 175 deletions
diff --git a/xenolinux-2.4.21-pre4-sparse/arch/xeno/mm/pageattr.c b/xenolinux-2.4.21-pre4-sparse/arch/xeno/mm/pageattr.c deleted file mode 100644 index 8d3b3e3856..0000000000 --- a/xenolinux-2.4.21-pre4-sparse/arch/xeno/mm/pageattr.c +++ /dev/null @@ -1,175 +0,0 @@ -/* - * Copyright 2002 Andi Kleen, SuSE Labs. - * Thanks to Ben LaHaise for precious feedback. - */ - -#include <linux/config.h> -#include <linux/mm.h> -#include <linux/sched.h> -#include <linux/highmem.h> -#include <linux/module.h> -#include <asm/uaccess.h> -#include <asm/processor.h> - -/* Should move most of this stuff into the appropiate includes */ -#define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1)) -#define LARGE_PAGE_SIZE (1UL << PMD_SHIFT) - -static inline pte_t *lookup_address(unsigned long address) -{ - pmd_t *pmd; - pgd_t *pgd = pgd_offset(&init_mm, address); - - if (pgd_none(*pgd)) - return NULL; - if (pgd_val(*pgd) & _PAGE_PSE) - return (pte_t *)pgd; - pmd = pmd_offset(pgd, address); - if (pmd_none(*pmd)) - return NULL; - if (pmd_val(*pmd) & _PAGE_PSE) - return (pte_t *)pmd; - return pte_offset(pmd, address); -} - -static struct page *split_large_page(unsigned long address, pgprot_t prot) -{ - int i; - unsigned long addr; - struct page *base = alloc_pages(GFP_KERNEL, 0); - pte_t *pbase; - if (!base) - return NULL; - 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] = mk_pte_phys(addr, - addr == address ? prot : PAGE_KERNEL); - } - return base; -} - -static void flush_kernel_map(void * address) -{ - if (!test_bit(X86_FEATURE_SELFSNOOP, boot_cpu_data.x86_capability)) { - /* Could use CLFLUSH here if the CPU supports it (Hammer,P4) */ - if (boot_cpu_data.x86_model >= 4) - asm volatile("wbinvd":::"memory"); - } - - /* Do global flush here to work around large page flushing errata - in some early Athlons */ - __flush_tlb_all(); -} - -static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) -{ - set_pte_atomic(kpte, pte); /* change init_mm */ -#ifndef CONFIG_X86_PAE - { - struct list_head *l; - spin_lock(&mmlist_lock); - list_for_each(l, &init_mm.mmlist) { - struct mm_struct *mm = list_entry(l, struct mm_struct, mmlist); - pmd_t *pmd = pmd_offset(pgd_offset(mm, address), address); - set_pte_atomic((pte_t *)pmd, pte); - } - spin_unlock(&mmlist_lock); - } -#endif -} - -/* no more special protections in this 2/4MB area - revert to a - large page again. */ -static inline void revert_page(struct page *kpte_page, unsigned long address) -{ - pte_t *linear = (pte_t *) - pmd_offset(pgd_offset(&init_mm, address), address); - set_pmd_pte(linear, address, - mk_pte_phys(__pa(address & LARGE_PAGE_MASK), - MAKE_GLOBAL(_KERNPG_TABLE|_PAGE_PSE))); -} - -/* - * 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. - * When page is in highmem it must never be kmap'ed. - */ -static int -__change_page_attr(struct page *page, pgprot_t prot, struct page **oldpage) -{ - pte_t *kpte; - unsigned long address; - struct page *kpte_page; - -#ifdef CONFIG_HIGHMEM - if (page >= highmem_start_page) - BUG(); -#endif - address = (unsigned long)page_address(page); - kpte = lookup_address(address); - if (!kpte) - return -EINVAL; - kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK); - if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) { - if ((pte_val(*kpte) & _PAGE_PSE) == 0) { - pte_t old = *kpte; - pte_t standard = mk_pte(page, PAGE_KERNEL); - - set_pte_atomic(kpte, mk_pte(page, prot)); - if (pte_same(old,standard)) - atomic_inc(&kpte_page->count); - } else { - struct page *split = split_large_page(address, prot); - if (!split) - return -ENOMEM; - atomic_inc(&kpte_page->count); - set_pmd_pte(kpte,address,mk_pte(split, PAGE_KERNEL)); - } - } else if ((pte_val(*kpte) & _PAGE_PSE) == 0) { - set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL)); - atomic_dec(&kpte_page->count); - } - - if (cpu_has_pse && (atomic_read(&kpte_page->count) == 1)) { - *oldpage = kpte_page; - revert_page(kpte_page, address); - } - return 0; -} - -int change_page_attr(struct page *page, int numpages, pgprot_t prot) -{ - int err = 0; - struct page *fpage; - int i; - - down_write(&init_mm.mmap_sem); - for (i = 0; i < numpages; i++, page++) { - fpage = NULL; - err = __change_page_attr(page, prot, &fpage); - if (err) - break; - if (fpage || i == numpages-1) { - void *address = page_address(page); -#ifdef CONFIG_SMP - smp_call_function(flush_kernel_map, address, 1, 1); -#endif - flush_kernel_map(address); - if (fpage) - __free_page(fpage); - } - } - up_write(&init_mm.mmap_sem); - return err; -} - -EXPORT_SYMBOL(change_page_attr); |