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intel_pstate: use updated msr-index.h HWP.EPP values

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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>
This commit is contained in:
Len Brown 2017-05-01 23:06:08 -04:00
parent 4beec1d751
commit 3cedbc5a6d
1 changed files with 15 additions and 19 deletions
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34
drivers/cpufreq/intel_pstate.c
View file

@ -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);