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| author | venkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com> | 2009-01-10 03:13:10 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-13 21:13:00 +0300 |
| commit | afc7d20c8429f32f19d47367fdc36eeed2334ec3 (patch) | |
| tree | e817ea903498dcce184a758efb44d6e29223cfa3 /arch/x86/include | |
| parent | a36706131182f5507d1e2cfbf391b0fa8d72203c (diff) | |
| download | linux-afc7d20c8429f32f19d47367fdc36eeed2334ec3.tar.xz | |
x86 PAT: consolidate old memtype new memtype check into a function
Impact: cleanup
Move the new memtype old memtype allowed check to header so that is can be
shared by other users. Subsequent patch uses this in pat.c in remap_pfn_range()
code path. No functionality change in this patch.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 83e69f4a37f0..06bbcbd66e9c 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 |