diff options
| -rw-r--r-- | arch/x86/include/asm/msr-index.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 18 |
2 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 485b4f1f079..d96bdb25ca3 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -259,6 +259,9 @@ #define MSR_IA32_TEMPERATURE_TARGET 0x000001a2 #define MSR_IA32_ENERGY_PERF_BIAS 0x000001b0 +#define ENERGY_PERF_BIAS_PERFORMANCE 0 +#define ENERGY_PERF_BIAS_NORMAL 6 +#define ENERGY_PERF_BIAS_POWERSAVE 15 #define MSR_IA32_PACKAGE_THERM_STATUS 0x000001b1 diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 1edf5ba4fb2..ed6086eedf1 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -456,6 +456,24 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_VMX)) detect_vmx_virtcap(c); + + /* + * Initialize MSR_IA32_ENERGY_PERF_BIAS if BIOS did not. + * x86_energy_perf_policy(8) is available to change it at run-time + */ + if (cpu_has(c, X86_FEATURE_EPB)) { + u64 epb; + + rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb); + if ((epb & 0xF) == ENERGY_PERF_BIAS_PERFORMANCE) { + printk_once(KERN_WARNING "ENERGY_PERF_BIAS:" + " Set to 'normal', was 'performance'\n" + "ENERGY_PERF_BIAS: View and update with" + " x86_energy_perf_policy(8)\n"); + epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL; + wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb); + } + } } #ifdef CONFIG_X86_32 |