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| author | venkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com> | 2008-03-19 01:00:14 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-17 17:41:19 +0200 |
| commit | 2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6 (patch) | |
| tree | 6c90c0f9f38ff85e2f42ddc0f4ef0291cdd47d38 /include/asm-x86/pat.h | |
| parent | x86: PAT documentation (diff) | |
| download | linux-2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6.tar.xz linux-2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6.zip | |
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/pat.h')
| -rw-r--r-- | include/asm-x86/pat.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/asm-x86/pat.h b/include/asm-x86/pat.h new file mode 100644 index 000000000000..8b822b5a1786 --- /dev/null +++ b/include/asm-x86/pat.h @@ -0,0 +1,16 @@ + +#ifndef _ASM_PAT_H +#define _ASM_PAT_H 1 + +#include <linux/types.h> + +extern int pat_wc_enabled; + +extern void pat_init(void); + +extern int reserve_memtype(u64 start, u64 end, + unsigned long req_type, unsigned long *ret_type); +extern int free_memtype(u64 start, u64 end); + +#endif + |