diff options
| author | venkatesh.pallipadi@intel.com | 2008-12-18 20:41:32 +0100 |
|---|---|---|
| committer | H. Peter Anvin | 2008-12-18 22:30:16 +0100 |
| commit | 2520bd3123c00272f818a176c92d03c7d0a113d6 (patch) | |
| tree | 1c5f3e47243d77573cb4933dadc5224d2fb32686 | |
| parent | x86: PAT: change pgprot_noncached to uc_minus instead of strong uc - v3 (diff) | |
| download | kernel-qcow2-linux-2520bd3123c00272f818a176c92d03c7d0a113d6.tar.gz kernel-qcow2-linux-2520bd3123c00272f818a176c92d03c7d0a113d6.tar.xz kernel-qcow2-linux-2520bd3123c00272f818a176c92d03c7d0a113d6.zip | |
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>
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 3 | ||||
| -rw-r--r-- | arch/x86/mm/pat.c | 8 | ||||
| -rw-r--r-- | include/asm-generic/pgtable.h | 4 |
3 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 6968d4f6be3e..579f8ceee948 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 1069ffecf77d..d5254bae84f4 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 */ diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index ef87f889ef62..b84633801fb6 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -129,6 +129,10 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres #define move_pte(pte, prot, old_addr, new_addr) (pte) #endif +#ifndef pgprot_writecombine +#define pgprot_writecombine pgprot_noncached +#endif + /* * When walking page tables, get the address of the next boundary, * or the end address of the range if that comes earlier. Although no |