Commit a365ab6b authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

cpufreq: intel_pstate: Implement the ->adjust_perf() callback 



Make intel_pstate expose the ->adjust_perf() callback when it
operates in the passive mode with HWP enabled which causes the
schedutil governor to use that callback instead of ->fast_switch().

The minimum and target performance-level values passed by the
governor to ->adjust_perf() are converted to HWP.REQ.MIN and
HWP.REQ.DESIRED, respectively, which allows the processor to
adjust its configuration to maximize energy-efficiency while
providing sufficient capacity.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent ee2cc427

drivers/cpufreq/intel_pstate.c

+58 −12
Original line number Diff line number Diff line
@@ -2526,20 +2526,19 @@ static void intel_cpufreq_trace(struct cpudata *cpu, unsigned int trace_type, in 
		fp_toint(cpu->iowait_boost * 100));

}



static void intel_cpufreq_adjust_hwp(struct cpudata *cpu, u32 target_pstate,

				     bool strict, bool fast_switch)

static void intel_cpufreq_adjust_hwp(struct cpudata *cpu, u32 min, u32 max,

				     u32 desired, bool fast_switch)

{

	u64 prev = READ_ONCE(cpu->hwp_req_cached), value = prev;



	value &= ~HWP_MIN_PERF(~0L);

	value |= HWP_MIN_PERF(target_pstate);

	value |= HWP_MIN_PERF(min);



	/*

	 * The entire MSR needs to be updated in order to update the HWP min

	 * field in it, so opportunistically update the max too if needed.

	 */

	value &= ~HWP_MAX_PERF(~0L);

	value |= HWP_MAX_PERF(strict ? target_pstate : cpu->max_perf_ratio);

	value |= HWP_MAX_PERF(max);



	value &= ~HWP_DESIRED_PERF(~0L);

	value |= HWP_DESIRED_PERF(desired);



	if (value == prev)

		return;
@@ -2569,11 +2568,15 @@ static int intel_cpufreq_update_pstate(struct cpufreq_policy *policy, 
	int old_pstate = cpu->pstate.current_pstate;



	target_pstate = intel_pstate_prepare_request(cpu, target_pstate);

	if (hwp_active)

		intel_cpufreq_adjust_hwp(cpu, target_pstate,

					 policy->strict_target, fast_switch);

	else if (target_pstate != old_pstate)

	if (hwp_active) {

		int max_pstate = policy->strict_target ?

					target_pstate : cpu->max_perf_ratio;



		intel_cpufreq_adjust_hwp(cpu, target_pstate, max_pstate, 0,

					 fast_switch);

	} else if (target_pstate != old_pstate) {

		intel_cpufreq_adjust_perf_ctl(cpu, target_pstate, fast_switch);

	}



	cpu->pstate.current_pstate = target_pstate;
@@ -2634,6 +2637,47 @@ static unsigned int intel_cpufreq_fast_switch(struct cpufreq_policy *policy, 
	return target_pstate * cpu->pstate.scaling;

}



static void intel_cpufreq_adjust_perf(unsigned int cpunum,

				      unsigned long min_perf,

				      unsigned long target_perf,

				      unsigned long capacity)

{

	struct cpudata *cpu = all_cpu_data[cpunum];

	int old_pstate = cpu->pstate.current_pstate;

	int cap_pstate, min_pstate, max_pstate, target_pstate;



	update_turbo_state();

	cap_pstate = global.turbo_disabled ? cpu->pstate.max_pstate :

					     cpu->pstate.turbo_pstate;



	/* Optimization: Avoid unnecessary divisions. */



	target_pstate = cap_pstate;

	if (target_perf < capacity)

		target_pstate = DIV_ROUND_UP(cap_pstate * target_perf, capacity);



	min_pstate = cap_pstate;

	if (min_perf < capacity)

		min_pstate = DIV_ROUND_UP(cap_pstate * min_perf, capacity);



	if (min_pstate < cpu->pstate.min_pstate)

		min_pstate = cpu->pstate.min_pstate;



	if (min_pstate < cpu->min_perf_ratio)

		min_pstate = cpu->min_perf_ratio;



	max_pstate = min(cap_pstate, cpu->max_perf_ratio);

	if (max_pstate < min_pstate)

		max_pstate = min_pstate;



	target_pstate = clamp_t(int, target_pstate, min_pstate, max_pstate);



	intel_cpufreq_adjust_hwp(cpu, min_pstate, max_pstate, target_pstate, true);



	cpu->pstate.current_pstate = target_pstate;

	intel_cpufreq_trace(cpu, INTEL_PSTATE_TRACE_FAST_SWITCH, old_pstate);

}



static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy)

{

	int max_state, turbo_max, min_freq, max_freq, ret;
@@ -3032,6 +3076,8 @@ static int __init intel_pstate_init(void) 
			intel_pstate.attr = hwp_cpufreq_attrs;

			intel_cpufreq.attr = hwp_cpufreq_attrs;

			intel_cpufreq.flags |= CPUFREQ_NEED_UPDATE_LIMITS;

			intel_cpufreq.fast_switch = NULL;

			intel_cpufreq.adjust_perf = intel_cpufreq_adjust_perf;

			if (!default_driver)

				default_driver = &intel_pstate;

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