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authorLinus Torvalds <torvalds@linux-foundation.org>2011-07-22 17:02:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-22 17:02:54 -0700
commit35b004cce1b0880876faecb8e0bd7cb2cb5a59d1 (patch)
tree84ac064e56be49bd57b383392531c5c5ebe0c455 /arch/x86/kernel/cpu
parent0a613b647bac0cfab7b7d81f11271883209a70ef (diff)
parent17edf2d79f1ea6dfdb4c444801d928953b9f98d6 (diff)
downloadblackbird-op-linux-35b004cce1b0880876faecb8e0bd7cb2cb5a59d1.tar.gz
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Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, intel, power: Correct the MSR_IA32_ENERGY_PERF_BIAS message x86, msr: Fix typo in ENERGY_PERF_BIAS_POWERSAVE x86, intel, power: Initialize MSR_IA32_ENERGY_PERF_BIAS
Diffstat (limited to 'arch/x86/kernel/cpu')
-rw-r--r--arch/x86/kernel/cpu/intel.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 1edf5ba4fb2b..ed6086eedf1d 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
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