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

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