From 2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6 Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Tue, 18 Mar 2008 17:00:14 -0700 Subject: 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 Signed-off-by: Suresh Siddha Signed-off-by: Ingo Molnar --- include/asm-x86/pat.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) create mode 100644 include/asm-x86/pat.h (limited to 'include/asm-x86/pat.h') 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 + +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 + -- cgit v1.2.1