Commit b02aabe8 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

cpufreq: intel_pstate: Eliminate intel_pstate_get_min_max() 



Some computations in intel_pstate_get_min_max() are not necessary
and one of its two callers doesn't even use the full result.

First off, the fixed-point value of cpu->max_perf represents a
non-negative number between 0 and 1 inclusive and cpu->min_perf
cannot be greater than cpu->max_perf.  It is not necessary to check
those conditions every time the numbers in question are used.

Moreover, since intel_pstate_max_within_limits() only needs the
upper boundary, it doesn't make sense to compute the lower one in
there and returning min and max from intel_pstate_get_min_max()
via pointers doesn't look particularly nice.

For the above reasons, drop intel_pstate_get_min_max(), add a helper
to get the base P-state for min/max computations and carry out them
directly in the previous callers of intel_pstate_get_min_max().

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 2bfc4cbb

drivers/cpufreq/intel_pstate.c

+14 −26
Original line number Diff line number Diff line
@@ -1496,26 +1496,10 @@ static int knl_get_turbo_pstate(void) 
	return ret;

}



static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)

static int intel_pstate_get_base_pstate(struct cpudata *cpu)

{

	int max_perf = cpu->pstate.turbo_pstate;

	int max_perf_adj;

	int min_perf;



	if (global.no_turbo || global.turbo_disabled)

		max_perf = cpu->pstate.max_pstate;



	/*

	 * performance can be limited by user through sysfs, by cpufreq

	 * policy, or by cpu specific default values determined through

	 * experimentation.

	 */

	max_perf_adj = fp_ext_toint(max_perf * cpu->max_perf);

	*max = clamp_t(int, max_perf_adj,

			cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);



	min_perf = fp_ext_toint(max_perf * cpu->min_perf);

	*min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf);

	return global.no_turbo || global.turbo_disabled ?

			cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;

}



static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
@@ -1538,11 +1522,13 @@ static void intel_pstate_set_min_pstate(struct cpudata *cpu) 


static void intel_pstate_max_within_limits(struct cpudata *cpu)

{

	int min_pstate, max_pstate;

	int pstate;



	update_turbo_state();

	intel_pstate_get_min_max(cpu, &min_pstate, &max_pstate);

	intel_pstate_set_pstate(cpu, max_pstate);

	pstate = intel_pstate_get_base_pstate(cpu);

	pstate = max(cpu->pstate.min_pstate,

		     fp_ext_toint(pstate * cpu->max_perf));

	intel_pstate_set_pstate(cpu, pstate);

}



static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
@@ -1704,11 +1690,13 @@ static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu) 


static int intel_pstate_prepare_request(struct cpudata *cpu, int pstate)

{

	int max_perf, min_perf;

	int max_pstate = intel_pstate_get_base_pstate(cpu);

	int min_pstate;



	intel_pstate_get_min_max(cpu, &min_perf, &max_perf);

	pstate = clamp_t(int, pstate, min_perf, max_perf);

	return pstate;

	min_pstate = max(cpu->pstate.min_pstate,

			 fp_ext_toint(max_pstate * cpu->min_perf));

	max_pstate = max(min_pstate, fp_ext_toint(max_pstate * cpu->max_perf));

	return clamp_t(int, pstate, min_pstate, max_pstate);

}



static void intel_pstate_update_pstate(struct cpudata *cpu, int pstate)

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