diff options
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 19 | ||||
| -rw-r--r-- | arch/x86/pci/i386.c | 12 |
2 files changed, 20 insertions, 11 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 83e69f4a37f..06bbcbd66e9 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -341,6 +341,25 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) #define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask) +static inline int is_new_memtype_allowed(unsigned long flags, + unsigned long new_flags) +{ + /* + * Certain new memtypes are not allowed with certain + * requested memtype: + * - request is uncached, return cannot be write-back + * - request is write-combine, return cannot be write-back + */ + if ((flags == _PAGE_CACHE_UC_MINUS && + new_flags == _PAGE_CACHE_WB) || + (flags == _PAGE_CACHE_WC && + new_flags == _PAGE_CACHE_WB)) { + return 0; + } + + return 1; +} + #ifndef __ASSEMBLY__ /* Indicate that x86 has its own track and untrack pfn vma functions */ #define __HAVE_PFNMAP_TRACKING diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c index f884740da31..5ead808dd70 100644 --- a/arch/x86/pci/i386.c +++ b/arch/x86/pci/i386.c @@ -314,17 +314,7 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, return retval; if (flags != new_flags) { - /* - * Do not fallback to certain memory types with certain - * requested type: - * - request is uncached, return cannot be write-back - * - request is uncached, return cannot be write-combine - * - request is write-combine, return cannot be write-back - */ - if ((flags == _PAGE_CACHE_UC_MINUS && - (new_flags == _PAGE_CACHE_WB)) || - (flags == _PAGE_CACHE_WC && - new_flags == _PAGE_CACHE_WB)) { + if (!is_new_memtype_allowed(flags, new_flags)) { free_memtype(addr, addr+len); return -EINVAL; } |