diff options
| -rw-r--r-- | arch/x86/mm/pat.c | 39 | ||||
| -rw-r--r-- | drivers/char/mem.c | 41 | ||||
| -rw-r--r-- | include/asm-x86/pgtable.h | 9 |
3 files changed, 59 insertions, 30 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 72c0f60..64cc0c1 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -419,3 +419,42 @@ int free_memtype(u64 start, u64 end) return err; } + +/* /dev/mem interface. Use the previous mapping */ +pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t vma_prot) +{ + return vma_prot; +} + +int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t *vma_prot) +{ + + if (file->f_flags & O_SYNC) { + *vma_prot = pgprot_noncached(*vma_prot); + return 1; + } + +#ifdef CONFIG_X86_32 + /* + * On the PPro and successors, the MTRRs are used to set + * memory types for physical addresses outside main memory, + * so blindly setting UC or PWT on those pages is wrong. + * For Pentiums and earlier, the surround logic should disable + * caching for the high addresses through the KEN pin, but + * we maintain the tradition of paranoia in this code. + */ + if (!pat_wc_enabled && + ! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) || + test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) || + test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) || + test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) && + (pfn << PAGE_SHIFT) >= __pa(high_memory)) { + *vma_prot = pgprot_noncached(*vma_prot); + return 1; + } +#endif + + return 1; +} diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 83495885..56b2fb4 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -41,36 +41,7 @@ */ static inline int uncached_access(struct file *file, unsigned long addr) { -#if defined(__i386__) && !defined(__arch_um__) - /* - * On the PPro and successors, the MTRRs are used to set - * memory types for physical addresses outside main memory, - * so blindly setting PCD or PWT on those pages is wrong. - * For Pentiums and earlier, the surround logic should disable - * caching for the high addresses through the KEN pin, but - * we maintain the tradition of paranoia in this code. - */ - if (file->f_flags & O_SYNC) - return 1; - return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) ) - && addr >= __pa(high_memory); -#elif defined(__x86_64__) && !defined(__arch_um__) - /* - * This is broken because it can generate memory type aliases, - * which can cause cache corruptions - * But it is only available for root and we have to be bug-to-bug - * compatible with i386. - */ - if (file->f_flags & O_SYNC) - return 1; - /* same behaviour as i386. PAT always set to cached and MTRRs control the - caching behaviour. - Hopefully a full PAT implementation will fix that soon. */ - return 0; -#elif defined(CONFIG_IA64) +#if defined(CONFIG_IA64) /* * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases. */ @@ -283,6 +254,12 @@ static ssize_t write_mem(struct file * file, const char __user * buf, return written; } +int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file, + unsigned long pfn, unsigned long size, pgprot_t *vma_prot) +{ + return 1; +} + #ifndef __HAVE_PHYS_MEM_ACCESS_PROT static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size, pgprot_t vma_prot) @@ -336,6 +313,10 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma) if (!range_is_allowed(vma->vm_pgoff, size)) return -EPERM; + if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, + &vma->vm_page_prot)) + return -EINVAL; + vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, size, vma->vm_page_prot); diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h index f1d9f4a..1902f0a 100644 --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -289,6 +289,15 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) #define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask) +#ifndef __ASSEMBLY__ +#define __HAVE_PHYS_MEM_ACCESS_PROT +struct file; +pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t vma_prot); +int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t *vma_prot); +#endif + #ifdef CONFIG_PARAVIRT #include <asm/paravirt.h> #else /* !CONFIG_PARAVIRT */ |
