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UefiCpuPkg/MtrrLib: Remove the loop of calculating Fixed-MTRR Mask

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Introduce the 32bit mask seeds to calculate Fixed-MTRR or&and mask values. It
could avoid the loop operation and 64bit shift operations.

Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
This commit is contained in:
Jeff Fan 2016-04-21 10:28:17 +08:00
parent aaa1e579a5
commit 07e8892090
1 changed files with 23 additions and 16 deletions
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39
UefiCpuPkg/Library/MtrrLib/MtrrLib.c
View File

@ -20,6 +20,9 @@
#include <Library/BaseMemoryLib.h> #include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h> #include <Library/DebugLib.h>
#define OR_SEED 0x01010101
#define CLEAR_SEED 0xFFFFFFFF
// //
// Context to save and restore when MTRRs are programmed // Context to save and restore when MTRRs are programmed
// //
@ -460,11 +463,12 @@ ProgramFixedMtrr (
{ {
UINT32 MsrNum; UINT32 MsrNum;
UINT32 ByteShift; UINT32 ByteShift;
UINT64 OrMask; UINT32 OrMask[2];
UINT64 ClearMask; UINT32 ClearMask[2];
UINT64 SubLength;
OrMask = 0; *(UINT64 *)OrMask = 0;
ClearMask = 0; *(UINT64 *)ClearMask = 0;
for (MsrNum = *LastMsrNum + 1; MsrNum < MTRR_NUMBER_OF_FIXED_MTRR; MsrNum++) { for (MsrNum = *LastMsrNum + 1; MsrNum < MTRR_NUMBER_OF_FIXED_MTRR; MsrNum++) {
if ((*Base >= mMtrrLibFixedMtrrTable[MsrNum].BaseAddress) && if ((*Base >= mMtrrLibFixedMtrrTable[MsrNum].BaseAddress) &&
@ -493,24 +497,27 @@ ProgramFixedMtrr (
return RETURN_UNSUPPORTED; return RETURN_UNSUPPORTED;
} }
for ( if (ByteShift < 4) {
; OrMask[0] = OR_SEED * (UINT32)MemoryCacheType;
((ByteShift < 8) && (*Length >= mMtrrLibFixedMtrrTable[MsrNum].Length)); ClearMask[0] = CLEAR_SEED;
ByteShift++ OrMask[1] = (OR_SEED * (UINT32)MemoryCacheType) >> ((4 - ByteShift) * 8);
) { ClearMask[1] = CLEAR_SEED >> ((4 - ByteShift) * 8);
OrMask |= LShiftU64 ((UINT64) MemoryCacheType, (UINT32) (ByteShift * 8)); } else {
ClearMask |= LShiftU64 ((UINT64) 0xFF, (UINT32) (ByteShift * 8)); OrMask[0] = (OR_SEED * (UINT32)MemoryCacheType) >> ((8 - ByteShift) * 8);
*Length -= mMtrrLibFixedMtrrTable[MsrNum].Length; ClearMask[0] = CLEAR_SEED >> ((8 - ByteShift) * 8);
*Base += mMtrrLibFixedMtrrTable[MsrNum].Length;
} }
if (ByteShift < 8 && (*Length != 0)) { SubLength = mMtrrLibFixedMtrrTable[MsrNum].Length * (8 - ByteShift);
if (*Length < SubLength) {
return RETURN_UNSUPPORTED; return RETURN_UNSUPPORTED;
} }
*Length -= SubLength;
*Base += SubLength;
*LastMsrNum = MsrNum; *LastMsrNum = MsrNum;
*ReturnClearMask = ClearMask; *ReturnClearMask = *(UINT64 *)ClearMask;
*ReturnOrMask = OrMask; *ReturnOrMask = *(UINT64 *)OrMask;
return RETURN_SUCCESS; return RETURN_SUCCESS;
} }