diff options
| author | venkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com> | 2008-12-18 11:41:32 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2008-12-18 13:30:16 -0800 |
| commit | 2520bd3123c00272f818a176c92d03c7d0a113d6 (patch) | |
| tree | 1c5f3e47243d77573cb4933dadc5224d2fb32686 /arch/x86 | |
| parent | 8a7b12f70fb135a1b1d865687de3edcdc780f6d1 (diff) | |
x86: PAT: add pgprot_writecombine() interface for drivers - v3
Impact: New mm functionality.
Add pgprot_writecombine. pgprot_writecombine will be aliased to
pgprot_noncached when not supported by the architecture.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 3 | ||||
| -rw-r--r-- | arch/x86/mm/pat.c | 8 |
2 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 6968d4f6be3..579f8ceee94 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -168,6 +168,9 @@ #ifndef __ASSEMBLY__ +#define pgprot_writecombine pgprot_writecombine +extern pgprot_t pgprot_writecombine(pgprot_t prot); + /* * ZERO_PAGE is a global shared page that is always zero: used * for zero-mapped memory areas etc.. diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 1069ffecf77..d5254bae84f 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -832,6 +832,14 @@ void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, } } +pgprot_t pgprot_writecombine(pgprot_t prot) +{ + if (pat_enabled) + return __pgprot(pgprot_val(prot) | _PAGE_CACHE_WC); + else + return pgprot_noncached(prot); +} + #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT) /* get Nth element of the linked list */ |