Commit 3cedbc5a authored by Len Brown's avatar Len Brown
Browse files

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: default avatarLen Brown <len.brown@intel.com>
parent 4beec1d7

drivers/cpufreq/intel_pstate.c

+15 −19
Original line number Diff line number Diff line
@@ -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);

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