Commit a3c78778 authored by Lukasz Luba's avatar Lukasz Luba Committed by Rafael J. Wysocki
Browse files

PM: EM: Refactor em_pd_get_efficient_state() to be more flexible 



The Energy Model (EM) is going to support runtime modification. There
are going to be 2 EM tables which store information. This patch aims
to prepare the code to be generic and use one of the tables. The function
will no longer get a pointer to 'struct em_perf_domain' (the EM) but
instead a pointer to 'struct em_perf_state' (which is one of the EM's
tables).

Prepare em_pd_get_efficient_state() for the upcoming changes and
make it possible to be re-used. Return an index for the best performance
state for a given EM table. The function arguments that are introduced
should allow to work on different performance state arrays. The caller of
em_pd_get_efficient_state() should be able to use the index either
on the default or the modifiable EM table.

Reviewed-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: default avatarHongyan Xia <hongyan.xia2@arm.com>
Reviewed-by: default avatarDietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: default avatarDietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 99907d60

include/linux/energy_model.h

+17 −13
Original line number Diff line number Diff line
@@ -175,33 +175,35 @@ void em_dev_unregister_perf_domain(struct device *dev); 


/**

 * em_pd_get_efficient_state() - Get an efficient performance state from the EM

 * @pd   : Performance domain for which we want an efficient frequency

 * @table:		List of performance states, in ascending order

 * @nr_perf_states:	Number of performance states

 * @freq:		Frequency to map with the EM

 * @pd_flags:		Performance Domain flags

 *

 * It is called from the scheduler code quite frequently and as a consequence

 * doesn't implement any check.

 *

 * Return: An efficient performance state, high enough to meet @freq

 * Return: An efficient performance state id, high enough to meet @freq

 * requirement.

 */

static inline

struct em_perf_state *em_pd_get_efficient_state(struct em_perf_domain *pd,

						unsigned long freq)

static inline int

em_pd_get_efficient_state(struct em_perf_state *table, int nr_perf_states,

			  unsigned long freq, unsigned long pd_flags)

{

	struct em_perf_state *ps;

	int i;



	for (i = 0; i < pd->nr_perf_states; i++) {

		ps = &pd->table[i];

	for (i = 0; i < nr_perf_states; i++) {

		ps = &table[i];

		if (ps->frequency >= freq) {

			if (pd->flags & EM_PERF_DOMAIN_SKIP_INEFFICIENCIES &&

			if (pd_flags & EM_PERF_DOMAIN_SKIP_INEFFICIENCIES &&

			    ps->flags & EM_PERF_STATE_INEFFICIENT)

				continue;

			break;

			return i;

		}

	}



	return ps;

	return nr_perf_states - 1;

}



/**
@@ -226,7 +228,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, 
{

	unsigned long freq, ref_freq, scale_cpu;

	struct em_perf_state *ps;

	int cpu;

	int cpu, i;



	if (!sum_util)

		return 0;
@@ -250,7 +252,9 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, 
	 * Find the lowest performance state of the Energy Model above the

	 * requested frequency.

	 */

	ps = em_pd_get_efficient_state(pd, freq);

	i = em_pd_get_efficient_state(pd->table, pd->nr_perf_states, freq,

				      pd->flags);

	ps = &pd->table[i];



	/*

	 * The capacity of a CPU in the domain at the performance state (ps)