Currently, if the memory length to be programmed is less than the remaining size
of one Fixed-MTRR supported, RETURN_UNSUPPORTED returned. This is not correct.
This is one regression at 07e889209034ba94bfac9e765b8a50ef344daef2 when we
updated ProgramFixedMtrr() to remove the loop of calculating Fixed-MTRR Mask.
This fix will calculate Right offset in Fixed-MTRR beside left offset. It
supports small length (less than remaining size supported by Fixed-MTRR) to be
programmed.
v2:
1) Remove unnecessary local variable OrMaskTemplate.
2) Exchange LeftByteShift and RightByteShift programm order and correct the
comments.
Cc: Eric Dong <[email protected]>
Cc: Feng Tian <[email protected]>
Cc: Michael Kinney <[email protected]>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <[email protected]>
---
UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 71 ++++++++++++++++++++++++------------
1 file changed, 48 insertions(+), 23 deletions(-)
diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
index c4a39b5..6a6bf76 100644
--- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
+++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
@@ -20,8 +20,8 @@
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
-#define OR_SEED 0x01010101
-#define CLEAR_SEED 0xFFFFFFFF
+#define OR_SEED 0x0101010101010101ull
+#define CLEAR_SEED 0xFFFFFFFFFFFFFFFFull
//
// Context to save and restore when MTRRs are programmed
@@ -462,14 +462,15 @@ ProgramFixedMtrr (
)
{
UINT32 MsrNum;
- UINT32 ByteShift;
- UINT32 OrMask[2];
- UINT32 ClearMask[2];
+ UINT32 LeftByteShift;
+ UINT32 RightByteShift;
+ UINT64 OrMask;
+ UINT64 ClearMask;
UINT64 SubLength;
- *(UINT64 *)OrMask = 0;
- *(UINT64 *)ClearMask = 0;
-
+ //
+ // Find the fixed MTRR index to be programmed
+ //
for (MsrNum = *LastMsrNum + 1; MsrNum < MTRR_NUMBER_OF_FIXED_MTRR; MsrNum++)
{
if ((*Base >= mMtrrLibFixedMtrrTable[MsrNum].BaseAddress) &&
(*Base <
@@ -488,36 +489,60 @@ ProgramFixedMtrr (
}
//
- // We found the fixed MTRR to be programmed
+ // Find the begin offset in fixed MTRR and calculate byte offset of left
shift
//
- ByteShift = ((UINT32)*Base - mMtrrLibFixedMtrrTable[MsrNum].BaseAddress)
+ LeftByteShift = ((UINT32)*Base - mMtrrLibFixedMtrrTable[MsrNum].BaseAddress)
/ mMtrrLibFixedMtrrTable[MsrNum].Length;
- if (ByteShift >= 8) {
+ if (LeftByteShift >= 8) {
return RETURN_UNSUPPORTED;
}
- 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);
+ //
+ // Find the end offset in fixed MTRR and calculate byte offset of right shift
+ //
+ SubLength = mMtrrLibFixedMtrrTable[MsrNum].Length * (8 - LeftByteShift);
+ if (*Length >= SubLength) {
+ RightByteShift = 0;
} else {
- OrMask[0] = (OR_SEED * (UINT32)MemoryCacheType) >> ((8 - ByteShift) *
8);
- ClearMask[0] = CLEAR_SEED >> ((8 - ByteShift) * 8);
+ RightByteShift = 8 - LeftByteShift -
+ (UINT32)(*Length) / mMtrrLibFixedMtrrTable[MsrNum].Length;
+ if ((LeftByteShift >= 8) ||
+ (((UINT32)(*Length) % mMtrrLibFixedMtrrTable[MsrNum].Length) != 0)
+ ) {
+ return RETURN_UNSUPPORTED;
+ }
+ //
+ // Update SubLength by actual length
+ //
+ SubLength = *Length;
}
- SubLength = mMtrrLibFixedMtrrTable[MsrNum].Length * (8 - ByteShift);
- if (*Length < SubLength) {
- return RETURN_UNSUPPORTED;
+ ClearMask = CLEAR_SEED;
+ OrMask = MultU64x32 (OR_SEED, (UINT32)MemoryCacheType);
+
+ if (LeftByteShift != 0) {
+ //
+ // Clear the low bits by LeftByteShift
+ //
+ ClearMask &= LShiftU64 (ClearMask, LeftByteShift * 8);
+ OrMask &= LShiftU64 (OrMask, LeftByteShift * 8);
+ }
+
+ if (RightByteShift != 0) {
+ //
+ // Clear the high bits by RightByteShift
+ //
+ ClearMask &= RShiftU64 (ClearMask, RightByteShift * 8);
+ OrMask &= RShiftU64 (OrMask, RightByteShift * 8);
}
*Length -= SubLength;
*Base += SubLength;
*LastMsrNum = MsrNum;
- *ReturnClearMask = *(UINT64 *)ClearMask;
- *ReturnOrMask = *(UINT64 *)OrMask;
+ *ReturnClearMask = ClearMask;
+ *ReturnOrMask = OrMask;
return RETURN_SUCCESS;
}
--
2.7.4.windows.1
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