diff options
| author | Dong, Eric <eric.dong@intel.com> | 2019-08-16 11:57:29 +0800 |
|---|---|---|
| committer | Ray Ni <ray.ni@intel.com> | 2019-08-21 02:44:49 +0800 |
| commit | 95cfe6c24714a11c894070a0bf2f2ba08f0ff68b (patch) | |
| tree | df0900119f550d57cbf85a5ef833c5d1cd2dd01d /UefiCpuPkg/Library/RegisterCpuFeaturesLib | |
| parent | 6b3645ade5c0b1ff4c6f9cdcb64a2eea40fa80c1 (diff) | |
| download | edk2-95cfe6c24714a11c894070a0bf2f2ba08f0ff68b.tar.gz edk2-95cfe6c24714a11c894070a0bf2f2ba08f0ff68b.tar.bz2 edk2-95cfe6c24714a11c894070a0bf2f2ba08f0ff68b.zip | |
UefiCpuPkg/RegisterCpuFeaturesLib: Supports test then write new value logic.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2040
Supports new logic which test current value before write new value.
Only write new value when current value not same as new value.
Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Diffstat (limited to 'UefiCpuPkg/Library/RegisterCpuFeaturesLib')
| -rw-r--r-- | UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c index 63bc50a55f..0a4fcff033 100644 --- a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c +++ b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c @@ -826,6 +826,7 @@ ProgramProcessorRegister ( UINTN ValidThreadCount;
UINT32 *ValidCoreCountPerPackage;
EFI_STATUS Status;
+ UINT64 CurrentValue;
//
// Traverse Register Table of this logical processor
@@ -848,7 +849,16 @@ ProgramProcessorRegister ( if (EFI_ERROR (Status)) {
break;
}
-
+ if (RegisterTableEntry->TestThenWrite) {
+ CurrentValue = BitFieldRead64 (
+ Value,
+ RegisterTableEntry->ValidBitStart,
+ RegisterTableEntry->ValidBitStart + RegisterTableEntry->ValidBitLength - 1
+ );
+ if (CurrentValue == RegisterTableEntry->Value) {
+ break;
+ }
+ }
Value = (UINTN) BitFieldWrite64 (
Value,
RegisterTableEntry->ValidBitStart,
@@ -857,10 +867,29 @@ ProgramProcessorRegister ( );
ReadWriteCr (RegisterTableEntry->Index, FALSE, &Value);
break;
+
//
// The specified register is Model Specific Register
//
case Msr:
+ if (RegisterTableEntry->TestThenWrite) {
+ Value = (UINTN)AsmReadMsr64 (RegisterTableEntry->Index);
+ if (RegisterTableEntry->ValidBitLength >= 64) {
+ if (Value == RegisterTableEntry->Value) {
+ break;
+ }
+ } else {
+ CurrentValue = BitFieldRead64 (
+ Value,
+ RegisterTableEntry->ValidBitStart,
+ RegisterTableEntry->ValidBitStart + RegisterTableEntry->ValidBitLength - 1
+ );
+ if (CurrentValue == RegisterTableEntry->Value) {
+ break;
+ }
+ }
+ }
+
if (RegisterTableEntry->ValidBitLength >= 64) {
//
// If length is not less than 64 bits, then directly write without reading
|