Commit 157386b6 authored by Philippe Longepe's avatar Philippe Longepe Committed by Rafael J. Wysocki
Browse files

cpufreq: intel_pstate: Configurable algorithm to get target pstate 



Target systems using different cpus have different power and performance
requirements. They may use different algorithms to get the next P-state
based on their power or performance preference.

For example, power-constrained systems may not want to use
high-performance P-states as aggressively as a full-size desktop or a
server platform. A server platform may want to run close to the max to
achieve better performance, while laptop-like systems may prefer
sacrificing performance for longer battery lifes.

For the above reasons, modify intel_pstate to allow the target P-state
selection algorithm to be depend on the CPU ID.

Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: default avatarPhilippe Longepe <philippe.longepe@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 40be4c3c

drivers/cpufreq/intel_pstate.c

+17 −13
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ static inline int ceiling_fp(int32_t x) 


struct sample {

	int32_t core_pct_busy;

	int32_t busy_scaled;

	u64 aperf;

	u64 mperf;

	u64 tsc;
@@ -133,6 +134,7 @@ struct pstate_funcs { 
	int (*get_scaling)(void);

	void (*set)(struct cpudata*, int pstate);

	void (*get_vid)(struct cpudata *);

	int32_t (*get_target_pstate)(struct cpudata *);

};



struct cpu_defaults {
@@ -140,6 +142,8 @@ struct cpu_defaults { 
	struct pstate_funcs funcs;

};



static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu);



static struct pstate_adjust_policy pid_params;

static struct pstate_funcs pstate_funcs;

static int hwp_active;
@@ -738,6 +742,7 @@ static struct cpu_defaults core_params = { 
		.get_turbo = core_get_turbo_pstate,

		.get_scaling = core_get_scaling,

		.set = core_set_pstate,

		.get_target_pstate = get_target_pstate_use_performance,

	},

};
@@ -758,6 +763,7 @@ static struct cpu_defaults silvermont_params = { 
		.set = atom_set_pstate,

		.get_scaling = silvermont_get_scaling,

		.get_vid = atom_get_vid,

		.get_target_pstate = get_target_pstate_use_performance,

	},

};
@@ -778,6 +784,7 @@ static struct cpu_defaults airmont_params = { 
		.set = atom_set_pstate,

		.get_scaling = airmont_get_scaling,

		.get_vid = atom_get_vid,

		.get_target_pstate = get_target_pstate_use_performance,

	},

};
@@ -797,6 +804,7 @@ static struct cpu_defaults knl_params = { 
		.get_turbo = knl_get_turbo_pstate,

		.get_scaling = core_get_scaling,

		.set = core_set_pstate,

		.get_target_pstate = get_target_pstate_use_performance,

	},

};
@@ -922,7 +930,7 @@ static inline void intel_pstate_set_sample_time(struct cpudata *cpu) 
	mod_timer_pinned(&cpu->timer, jiffies + delay);

}



static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)

static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu)

{

	int32_t core_busy, max_pstate, current_pstate, sample_ratio;

	s64 duration_us;
@@ -960,30 +968,24 @@ static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu) 
		core_busy = mul_fp(core_busy, sample_ratio);

	}



	return core_busy;

	cpu->sample.busy_scaled = core_busy;

	return cpu->pstate.current_pstate - pid_calc(&cpu->pid, core_busy);

}



static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)

{

	int32_t busy_scaled;

	struct _pid *pid;

	signed int ctl;

	int from;

	int from, target_pstate;

	struct sample *sample;



	from = cpu->pstate.current_pstate;



	pid = &cpu->pid;

	busy_scaled = intel_pstate_get_scaled_busy(cpu);

	target_pstate = pstate_funcs.get_target_pstate(cpu);



	ctl = pid_calc(pid, busy_scaled);



	/* Negative values of ctl increase the pstate and vice versa */

	intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl, true);

	intel_pstate_set_pstate(cpu, target_pstate, true);



	sample = &cpu->sample;

	trace_pstate_sample(fp_toint(sample->core_pct_busy),

		fp_toint(busy_scaled),

		fp_toint(sample->busy_scaled),

		from,

		cpu->pstate.current_pstate,

		sample->mperf,
@@ -1237,6 +1239,8 @@ static void copy_cpu_funcs(struct pstate_funcs *funcs) 
	pstate_funcs.get_scaling = funcs->get_scaling;

	pstate_funcs.set       = funcs->set;

	pstate_funcs.get_vid   = funcs->get_vid;

	pstate_funcs.get_target_pstate = funcs->get_target_pstate;



}



#if IS_ENABLED(CONFIG_ACPI)

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