diff options
| author | venkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com> | 2008-03-18 17:00:14 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-17 17:41:19 +0200 |
| commit | 2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6 (patch) | |
| tree | 6c90c0f9f38ff85e2f42ddc0f4ef0291cdd47d38 /include/asm-x86/pgtable.h | |
| parent | d27554d874c7eeb14c8bfecdc39c3a8618cd8d32 (diff) | |
x86: PAT infrastructure patch
Sets up pat_init() infrastructure.
PAT MSR has following setting.
PAT
|PCD
||PWT
|||
000 WB _PAGE_CACHE_WB
001 WC _PAGE_CACHE_WC
010 UC- _PAGE_CACHE_UC_MINUS
011 UC _PAGE_CACHE_UC
We are effectively changing WT from boot time setting to WC.
UC_MINUS is used to provide backward compatibility to existing /dev/mem
users(X).
reserve_memtype and free_memtype are new interfaces for maintaining alias-free
mapping. It is currently implemented in a simple way with a linked list and
not optimized. reserve and free tracks the effective memory type, as a result
of PAT and MTRR setting rather than what is actually requested in PAT.
pat_init piggy backs on mtrr_init as the rules for setting both pat and mtrr
are same.
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 'include/asm-x86/pgtable.h')
| -rw-r--r-- | include/asm-x86/pgtable.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h index 9cf472aeb9c..ca6deb3de7c 100644 --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -57,6 +57,12 @@ #define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) +#define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT) +#define _PAGE_CACHE_WB (0) +#define _PAGE_CACHE_WC (_PAGE_PWT) +#define _PAGE_CACHE_UC_MINUS (_PAGE_PCD) +#define _PAGE_CACHE_UC (_PAGE_PCD | _PAGE_PWT) + #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED) #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_NX) |