diff options
author | Takashi Iwai <tiwai@suse.de> | 2009-02-09 17:20:13 +0100 |
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committer | Takashi Iwai <tiwai@suse.de> | 2009-02-09 17:20:13 +0100 |
commit | d9f8e9c34150ebec2be07bb95b6a23d99ba1f6de (patch) | |
tree | 1e8c402df9b1154f4ca37eb5242f960ef7aab747 /arch/x86/mm/iomap_32.c | |
parent | 2ebfb8eeb8f244f9d25937d31a947895cf819e26 (diff) | |
parent | 8bd4bb7a35e8ebb015a531218614c48e10a3c4ee (diff) |
Merge branch 'topic/quirk-cleanup' into topic/misc
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)); |