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| author | H. Peter Anvin <hpa@linux.intel.com> | 2009-01-30 14:50:57 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2009-01-30 14:50:57 -0800 |
| commit | 9b7ed8faa034fc2d350e2eff5c68680eb5c43a07 (patch) | |
| tree | 5c94c34ad30e312604c1ce4f08ab6631b64a94f5 /arch/x86/mm/iomap_32.c | |
| parent | 6522869c34664dd5f05a0a327e93915b1281c90d (diff) | |
| parent | c43e0e46adf79c321ed3fbf0351e1005fb8a2413 (diff) | |
Merge branch 'core/percpu' into x86/paravirt
Diffstat (limited to 'arch/x86/mm/iomap_32.c')
| -rw-r--r-- | arch/x86/mm/iomap_32.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index d0151d8ce45..ca53224fc56 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -17,6 +17,7 @@ */ #include <asm/iomap.h> +#include <asm/pat.h> #include <linux/module.h> /* Map 'pfn' using fixed map 'type' and protections 'prot' @@ -29,6 +30,15 @@ iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot) pagefault_disable(); + /* + * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS. + * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the + * MTRR is UC or WC. UC_MINUS gets the real intention, of the + * user, which is "WC if the MTRR is WC, UC if you can't do that." + */ + if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC)) + prot = PAGE_KERNEL_UC_MINUS; + idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); set_pte(kmap_pte-idx, pfn_pte(pfn, prot)); |