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OcCpuLib: Read MSR_IA32_TSC_ADJUST only if CPU supports it (#571)
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@t0rr3sp3dr0
t0rr3sp3dr0 authored Dec 28, 2024
1 parent 07e61bf commit 4920897
Showing 1 changed file with 119 additions and 102 deletions.
221 changes: 119 additions & 102 deletions Library/OcCpuLib/FrequencyDetect.c
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Original file line number Diff line number Diff line change
Expand Up @@ -489,14 +489,17 @@ InternalCalculateARTFrequencyIntel (
UINT32 MaxId;
UINT32 CpuVendor;

UINT32 CpuidDenominatorEax;
UINT32 CpuidNumeratorEbx;
UINT32 CpuidARTFrequencyEcx;
CPUID_PROCESSOR_FREQUENCY_EAX CpuidFrequencyEax;
UINT64 TscAdjust;
UINT64 CPUFrequencyFromTSC;
CPUID_VERSION_INFO_EAX CpuidVerEax;
UINT8 Model;
CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_EBX CpuidFeatureFlagsEbx;
CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_ECX CpuidFeatureFlagsEcx;
CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_EDX CpuidFeatureFlagsEdx;
UINT32 CpuidDenominatorEax;
UINT32 CpuidNumeratorEbx;
UINT32 CpuidARTFrequencyEcx;
CPUID_PROCESSOR_FREQUENCY_EAX CpuidFrequencyEax;
UINT64 TscAdjust;
UINT64 CPUFrequencyFromTSC;
CPUID_VERSION_INFO_EAX CpuidVerEax;
UINT8 Model;

if (Recalculate) {
ObtainedARTFreq = FALSE;
Expand All @@ -514,109 +517,123 @@ InternalCalculateARTFrequencyIntel (
//
// Determine our core crystal clock frequency
//
if ((CpuVendor == CPUID_VENDOR_INTEL) && (MaxId >= CPUID_TIME_STAMP_COUNTER)) {
TscAdjust = AsmReadMsr64 (MSR_IA32_TSC_ADJUST);
DEBUG ((DEBUG_INFO, "OCCPU: TSC Adjust %Lu\n", TscAdjust));

if (TscAdjustPtr != NULL) {
*TscAdjustPtr = TscAdjust;
if (CpuVendor == CPUID_VENDOR_INTEL) {
if (MaxId >= CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS) {
AsmCpuidEx (
CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS,
0,
NULL,
&CpuidFeatureFlagsEbx.Uint32,
&CpuidFeatureFlagsEcx.Uint32,
&CpuidFeatureFlagsEdx.Uint32
);
if (CpuidFeatureFlagsEbx.Bits.IA32_TSC_ADJUST == 1) {
TscAdjust = AsmReadMsr64 (MSR_IA32_TSC_ADJUST);
DEBUG ((DEBUG_INFO, "OCCPU: TSC Adjust %Lu\n", TscAdjust));

if (TscAdjustPtr != NULL) {
*TscAdjustPtr = TscAdjust;
}
}
}

AsmCpuid (
CPUID_TIME_STAMP_COUNTER,
&CpuidDenominatorEax,
&CpuidNumeratorEbx,
&CpuidARTFrequencyEcx,
NULL
);
if (CpuidARTFrequencyEcx > 0) {
ARTFrequency = CpuidARTFrequencyEcx;
DEBUG ((DEBUG_INFO, "OCCPU: Queried Core Crystal Clock Frequency %11LuHz\n", ARTFrequency));
} else {
AsmCpuid (CPUID_VERSION_INFO, &CpuidVerEax.Uint32, NULL, NULL, NULL);
Model = (UINT8)CpuidVerEax.Bits.Model | (UINT8)(CpuidVerEax.Bits.ExtendedModelId << 4U);
//
// Fall back to identifying ART frequency based on known models
//
switch (Model) {
case CPU_MODEL_SKYLAKE:
case CPU_MODEL_SKYLAKE_DT:
case CPU_MODEL_KABYLAKE:
case CPU_MODEL_KABYLAKE_DT:
ARTFrequency = CLIENT_ART_CLOCK_SOURCE; // 24 Mhz
break;
case CPU_MODEL_DENVERTON:
ARTFrequency = SERVER_ART_CLOCK_SOURCE; // 25 Mhz
break;
case CPU_MODEL_GOLDMONT:
ARTFrequency = ATOM_ART_CLOCK_SOURCE; // 19.2 Mhz
break;
}
if (MaxId >= CPUID_TIME_STAMP_COUNTER) {
AsmCpuid (
CPUID_TIME_STAMP_COUNTER,
&CpuidDenominatorEax,
&CpuidNumeratorEbx,
&CpuidARTFrequencyEcx,
NULL
);
if (CpuidARTFrequencyEcx > 0) {
ARTFrequency = CpuidARTFrequencyEcx;
DEBUG ((DEBUG_INFO, "OCCPU: Queried Core Crystal Clock Frequency %11LuHz\n", ARTFrequency));
} else {
AsmCpuid (CPUID_VERSION_INFO, &CpuidVerEax.Uint32, NULL, NULL, NULL);
Model = (UINT8)CpuidVerEax.Bits.Model | (UINT8)(CpuidVerEax.Bits.ExtendedModelId << 4U);
//
// Fall back to identifying ART frequency based on known models
//
switch (Model) {
case CPU_MODEL_SKYLAKE:
case CPU_MODEL_SKYLAKE_DT:
case CPU_MODEL_KABYLAKE:
case CPU_MODEL_KABYLAKE_DT:
ARTFrequency = CLIENT_ART_CLOCK_SOURCE; // 24 Mhz
break;
case CPU_MODEL_DENVERTON:
ARTFrequency = SERVER_ART_CLOCK_SOURCE; // 25 Mhz
break;
case CPU_MODEL_GOLDMONT:
ARTFrequency = ATOM_ART_CLOCK_SOURCE; // 19.2 Mhz
break;
}

if (ARTFrequency > 0) {
DEBUG ((DEBUG_INFO, "OCCPU: Known Model Core Crystal Clock Frequency %11LuHz\n", ARTFrequency));
if (ARTFrequency > 0) {
DEBUG ((DEBUG_INFO, "OCCPU: Known Model Core Crystal Clock Frequency %11LuHz\n", ARTFrequency));
}
}
}

if ((CpuidDenominatorEax > 0) && (CpuidNumeratorEbx > 0)) {
//
// Some Intel chips don't report their core crystal clock frequency.
// Calculate it by dividing the TSC frequency by the TSC ratio.
//
if ((ARTFrequency == 0) && (MaxId >= CPUID_PROCESSOR_FREQUENCY)) {
CPUFrequencyFromTSC = InternalCalculateTSCFromPMTimer (Recalculate);
ARTFrequency = BaseMultThenDivU64x64x32 (
CPUFrequencyFromTSC,
CpuidDenominatorEax,
CpuidNumeratorEbx,
NULL
);
if (ARTFrequency > 0ULL) {
DEBUG ((
DEBUG_INFO,
"OCCPU: Core Crystal Clock Frequency from TSC %11LuHz = %11LuHz * %u / %u\n",
ARTFrequency,
CPUFrequencyFromTSC,
CpuidDenominatorEax,
CpuidNumeratorEbx
));
//
// Use the reported CPU frequency rather than deriving it from ARTFrequency
//
AsmCpuid (CPUID_PROCESSOR_FREQUENCY, &CpuidFrequencyEax.Uint32, NULL, NULL, NULL);
CPUFrequencyFromART = MultU64x32 (CpuidFrequencyEax.Bits.ProcessorBaseFrequency, 1000000);
if ((CpuidDenominatorEax > 0) && (CpuidNumeratorEbx > 0)) {
//
// Some Intel chips don't report their core crystal clock frequency.
// Calculate it by dividing the TSC frequency by the TSC ratio.
//
if ((ARTFrequency == 0) && (MaxId >= CPUID_PROCESSOR_FREQUENCY)) {
CPUFrequencyFromTSC = InternalCalculateTSCFromPMTimer (Recalculate);
ARTFrequency = BaseMultThenDivU64x64x32 (
CPUFrequencyFromTSC,
CpuidDenominatorEax,
CpuidNumeratorEbx,
NULL
);
if (ARTFrequency > 0ULL) {
DEBUG ((
DEBUG_INFO,
"OCCPU: Core Crystal Clock Frequency from TSC %11LuHz = %11LuHz * %u / %u\n",
ARTFrequency,
CPUFrequencyFromTSC,
CpuidDenominatorEax,
CpuidNumeratorEbx
));
//
// Use the reported CPU frequency rather than deriving it from ARTFrequency
//
AsmCpuid (CPUID_PROCESSOR_FREQUENCY, &CpuidFrequencyEax.Uint32, NULL, NULL, NULL);
CPUFrequencyFromART = MultU64x32 (CpuidFrequencyEax.Bits.ProcessorBaseFrequency, 1000000);
}
}
}

//
// If we still can't determine the core crystal clock frequency, assume
// it's 24 Mhz like most Intel chips to date.
//
if (ARTFrequency == 0ULL) {
ARTFrequency = DEFAULT_ART_CLOCK_SOURCE;
DEBUG ((DEBUG_INFO, "OCCPU: Fallback Core Crystal Clock Frequency %11LuHz\n", ARTFrequency));
}
//
// If we still can't determine the core crystal clock frequency, assume
// it's 24 Mhz like most Intel chips to date.
//
if (ARTFrequency == 0ULL) {
ARTFrequency = DEFAULT_ART_CLOCK_SOURCE;
DEBUG ((DEBUG_INFO, "OCCPU: Fallback Core Crystal Clock Frequency %11LuHz\n", ARTFrequency));
}

ASSERT (ARTFrequency > 0ULL);
if (CPUFrequencyFromART == 0ULL) {
CPUFrequencyFromART = BaseMultThenDivU64x64x32 (
ARTFrequency,
CpuidNumeratorEbx,
CpuidDenominatorEax,
NULL
);
}
ASSERT (ARTFrequency > 0ULL);
if (CPUFrequencyFromART == 0ULL) {
CPUFrequencyFromART = BaseMultThenDivU64x64x32 (
ARTFrequency,
CpuidNumeratorEbx,
CpuidDenominatorEax,
NULL
);
}

ASSERT (CPUFrequencyFromART > 0ULL);
DEBUG ((
DEBUG_INFO,
"OCCPU: CPUFrequencyFromART %11LuHz %5LuMHz = %Lu * %u / %u\n",
CPUFrequencyFromART,
DivU64x32 (CPUFrequencyFromART, 1000000),
ARTFrequency,
CpuidNumeratorEbx,
CpuidDenominatorEax
));
ASSERT (CPUFrequencyFromART > 0ULL);
DEBUG ((
DEBUG_INFO,
"OCCPU: CPUFrequencyFromART %11LuHz %5LuMHz = %Lu * %u / %u\n",
CPUFrequencyFromART,
DivU64x32 (CPUFrequencyFromART, 1000000),
ARTFrequency,
CpuidNumeratorEbx,
CpuidDenominatorEax
));
}
}
}
}
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