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pstate: use MSR_NHM_TURBO_RATIO_LIMIT as maximum single-core turbo ratio

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Balazs Gerofi
2015-07-01 22:18:00 +09:00
parent aa959c6b34
commit 382614ddae
1 changed files with 10 additions and 12 deletions
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22
arch/x86/kernel/cpu.c
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@@ -281,9 +281,12 @@ void init_pstate_and_turbo(void)
* *
* IA32_PERF_CTL (0x199H) bit 15:0: * IA32_PERF_CTL (0x199H) bit 15:0:
* Target performance State Value * Target performance State Value
*
* The base operating ratio can be read
* from MSR_PLATFORM_INFO[15:8].
*/ */
value = rdmsr(MSR_PLATFORM_INFO); value = rdmsr(MSR_PLATFORM_INFO);
value = (value >> 8) & 0xFF; value &= 0xFF00;
/* Turbo boost setting: /* Turbo boost setting:
* Bit 1 of EAX in Leaf 06H (i.e. CPUID.06H:EAX[1]) indicates opportunistic * Bit 1 of EAX in Leaf 06H (i.e. CPUID.06H:EAX[1]) indicates opportunistic
@@ -293,26 +296,21 @@ void init_pstate_and_turbo(void)
* When set to 1: disengages IDA * When set to 1: disengages IDA
* When set to 0: enables IDA * When set to 0: enables IDA
*/ */
if (!no_turbo) { if ((eax & (1 << 1))) {
if (eax & (1 << 1)) { if (!no_turbo) {
uint64_t turbo_value; uint64_t turbo_value;
turbo_value = rdmsr(MSR_NHM_TURBO_RATIO_LIMIT); turbo_value = rdmsr(MSR_NHM_TURBO_RATIO_LIMIT);
turbo_value &= 0xFF; turbo_value &= 0xFF;
if (turbo_value < value) { value = turbo_value << 8;
value = turbo_value;
}
value = value << 8;
/* Disable turbo boost */
//value |= (uint64_t)1 << 32;
/* Enable turbo boost */ /* Enable turbo boost */
value &= ~((uint64_t)1 << 32); value &= ~((uint64_t)1 << 32);
} }
/* Turbo boost feature is supported, but requested to be turned off */
else { else {
value = value << 8; /* Disable turbo boost */
value |= (uint64_t)1 << 32;
} }
} }