REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2040
Supports new logic which detect current value before set new value.
Only set new value when current value not same as new value.
Signed-off-by: Eric Dong <eric.d...@intel.com>
Cc: Ray Ni <ray...@intel.com>
Cc: Laszlo Ersek <ler...@redhat.com>
---
.../CpuFeaturesInitialize.c | 141 ++++++++++++------
1 file changed, 93 insertions(+), 48 deletions(-)
diff --git a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
index fb0535edd6..2b8816e1d8 100644
--- a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
+++ b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
@@ -744,6 +744,58 @@ LibWaitForSemaphore (
) != Value);
}
+/**
+ Read / write CR value.
+
+ @param[in] CrIndex The CR index which need to read/write.
+ @param[in] Read Read or write. TRUE is read.
+ @param[in,out] CrValue CR value.
+
+ @retval EFI_SUCCESS means read/write success, else return EFI_UNSUPPORTED.
+**/
+UINTN
+ReadWriteCr (
+ IN UINT32 CrIndex,
+ IN BOOLEAN Read,
+ IN OUT UINTN *CrValue
+ )
+{
+ switch (CrIndex) {
+ case 0:
+ if (Read) {
+ *CrValue = AsmReadCr0 ();
+ } else {
+ AsmWriteCr0 (*CrValue);
+ }
+ break;
+ case 2:
+ if (Read) {
+ *CrValue = AsmReadCr2 ();
+ } else {
+ AsmWriteCr2 (*CrValue);
+ }
+ break;
+ case 3:
+ if (Read) {
+ *CrValue = AsmReadCr3 ();
+ } else {
+ AsmWriteCr3 (*CrValue);
+ }
+ break;
+ case 4:
+ if (Read) {
+ *CrValue = AsmReadCr4 ();
+ } else {
+ AsmWriteCr4 (*CrValue);
+ }
+ break;
+ default:
+ return EFI_UNSUPPORTED;;
+ }
+
+ return EFI_SUCCESS;
+}
+
/**
Initialize the CPU registers from a register table.
@@ -773,6 +825,8 @@ ProgramProcessorRegister (
UINTN ProcessorIndex;
UINTN ValidThreadCount;
UINT32 *ValidCoreCountPerPackage;
+ EFI_STATUS Status;
+ UINT64 CurrentValue;
//
// Traverse Register Table of this logical processor
@@ -791,60 +845,51 @@ ProgramProcessorRegister (
// The specified register is Control Register
//
case ControlRegister:
- switch (RegisterTableEntry->Index) {
- case 0:
- Value = AsmReadCr0 ();
- Value = (UINTN) BitFieldWrite64 (
- Value,
- RegisterTableEntry->ValidBitStart,
- RegisterTableEntry->ValidBitStart +
RegisterTableEntry->ValidBitLength - 1,
- RegisterTableEntry->Value
- );
- AsmWriteCr0 (Value);
- break;
- case 2:
- Value = AsmReadCr2 ();
- Value = (UINTN) BitFieldWrite64 (
- Value,
- RegisterTableEntry->ValidBitStart,
- RegisterTableEntry->ValidBitStart +
RegisterTableEntry->ValidBitLength - 1,
- RegisterTableEntry->Value
- );
- AsmWriteCr2 (Value);
- break;
- case 3:
- Value = AsmReadCr3 ();
- Value = (UINTN) BitFieldWrite64 (
- Value,
- RegisterTableEntry->ValidBitStart,
- RegisterTableEntry->ValidBitStart +
RegisterTableEntry->ValidBitLength - 1,
- RegisterTableEntry->Value
- );
- AsmWriteCr3 (Value);
- break;
- case 4:
- Value = AsmReadCr4 ();
- Value = (UINTN) BitFieldWrite64 (
- Value,
- RegisterTableEntry->ValidBitStart,
- RegisterTableEntry->ValidBitStart +
RegisterTableEntry->ValidBitLength - 1,
- RegisterTableEntry->Value
- );
- AsmWriteCr4 (Value);
- break;
- case 8:
- //
- // Do we need to support CR8?
- //
- break;
- default:
- break;
+ Status = ReadWriteCr(RegisterTableEntry->Index, TRUE, &Value);
+ if (EFI_ERROR (Status)) {
+ return;
+ }
+ if (RegisterTableEntry->DetectIt) {
+ CurrentValue = BitFieldRead64(
+ Value,
+ RegisterTableEntry->ValidBitStart,
+ RegisterTableEntry->ValidBitStart +
RegisterTableEntry->ValidBitLength - 1
+ );
+ if (CurrentValue == RegisterTableEntry->Value) {
+ return;
+ }
}
+ Value = (UINTN) BitFieldWrite64 (
+ Value,
+ RegisterTableEntry->ValidBitStart,
+ RegisterTableEntry->ValidBitStart +
RegisterTableEntry->ValidBitLength - 1,
+ RegisterTableEntry->Value
+ );
+ ReadWriteCr (RegisterTableEntry->Index, FALSE, &Value);
break;
+
//
// The specified register is Model Specific Register
//
case Msr:
+ if (RegisterTableEntry->DetectIt) {
+ Value = (UINTN)AsmReadMsr64 (RegisterTableEntry->Index);
+ if (RegisterTableEntry->ValidBitLength >= 64) {
+ if (Value == RegisterTableEntry->Value) {
+ return;
+ }
+ } else {
+ CurrentValue = BitFieldRead64(
+ Value,
+ RegisterTableEntry->ValidBitStart,
+ RegisterTableEntry->ValidBitStart +
RegisterTableEntry->ValidBitLength - 1
+ );
+ if (CurrentValue == RegisterTableEntry->Value) {
+ return;
+ }
+ }
+ }
+
if (RegisterTableEntry->ValidBitLength >= 64) {
//
// If length is not less than 64 bits, then directly write without
reading
--
2.21.0.windows.1
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