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authorLen Brown <len.brown@intel.com>2017-05-01 23:06:08 -0400
committerLen Brown <len.brown@intel.com>2017-05-11 21:27:53 -0400
commit3cedbc5a6d7f7c5539e139f89ec9f6e1ed668418 (patch)
treea00534027c4ac7a238791527a0a9ccc810ab87e9 /drivers/cpufreq/intel_pstate.c
parent4beec1d7519691b4b6c6b764e75b4e694a09c5f7 (diff)
intel_pstate: use updated msr-index.h HWP.EPP values
intel_pstate exports sysfs attributes for setting and observing HWP.EPP. These attributes use strings to describe 4 operating states, and inside the driver, these strings are mapped to numerical register values. The authorative mapping between the strings and numerical HWP.EPP values are now globally defined in msr-index.h, replacing the out-dated mapping that were open-coded into intel_pstate.c new old string --- --- ------ 0 0 performance 128 64 balance_performance 192 128 balance_power 255 192 power Note that the HW and BIOS default value on most system is 128, which intel_pstate will now call "balance_performance" while it used to call it "balance_power". Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
-rw-r--r--drivers/cpufreq/intel_pstate.c34
1 files changed, 15 insertions, 19 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 50bd6d987fc3..ab8ebaeb3621 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -716,6 +716,12 @@ static const char * const energy_perf_strings[] = {
"power",
NULL
};
+static const unsigned int epp_values[] = {
+ HWP_EPP_PERFORMANCE,
+ HWP_EPP_BALANCE_PERFORMANCE,
+ HWP_EPP_BALANCE_POWERSAVE,
+ HWP_EPP_POWERSAVE
+};
static int intel_pstate_get_energy_pref_index(struct cpudata *cpu_data)
{
@@ -727,17 +733,14 @@ static int intel_pstate_get_energy_pref_index(struct cpudata *cpu_data)
return epp;
if (static_cpu_has(X86_FEATURE_HWP_EPP)) {
- /*
- * Range:
- * 0x00-0x3F : Performance
- * 0x40-0x7F : Balance performance
- * 0x80-0xBF : Balance power
- * 0xC0-0xFF : Power
- * The EPP is a 8 bit value, but our ranges restrict the
- * value which can be set. Here only using top two bits
- * effectively.
- */
- index = (epp >> 6) + 1;
+ if (epp == HWP_EPP_PERFORMANCE)
+ return 1;
+ if (epp <= HWP_EPP_BALANCE_PERFORMANCE)
+ return 2;
+ if (epp <= HWP_EPP_BALANCE_POWERSAVE)
+ return 3;
+ else
+ return 4;
} else if (static_cpu_has(X86_FEATURE_EPB)) {
/*
* Range:
@@ -775,15 +778,8 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
value &= ~GENMASK_ULL(31, 24);
- /*
- * If epp is not default, convert from index into
- * energy_perf_strings to epp value, by shifting 6
- * bits left to use only top two bits in epp.
- * The resultant epp need to shifted by 24 bits to
- * epp position in MSR_HWP_REQUEST.
- */
if (epp == -EINVAL)
- epp = (pref_index - 1) << 6;
+ epp = epp_values[pref_index - 1];
value |= (u64)epp << 24;
ret = wrmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, value);