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2e5d9c857d
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>
17 lines
278 B
C
17 lines
278 B
C
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#ifndef _ASM_PAT_H
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#define _ASM_PAT_H 1
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#include <linux/types.h>
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extern int pat_wc_enabled;
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extern void pat_init(void);
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extern int reserve_memtype(u64 start, u64 end,
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unsigned long req_type, unsigned long *ret_type);
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extern int free_memtype(u64 start, u64 end);
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#endif
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