Commit faf7075b authored by Lukasz Luba's avatar Lukasz Luba Committed by Rafael J. Wysocki
Browse files

PM: EM: Introduce em_compute_costs() 



Move the EM costs computation code into a new dedicated function,
em_compute_costs(), that can be reused in other places in the future.

This change is not expected to alter the general functionality.

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 a3c78778

kernel/power/energy_model.c

+43 −29
Original line number Diff line number Diff line
@@ -103,14 +103,52 @@ static void em_debug_create_pd(struct device *dev) {} 
static void em_debug_remove_pd(struct device *dev) {}

#endif



static int em_compute_costs(struct device *dev, struct em_perf_state *table,

			    struct em_data_callback *cb, int nr_states,

			    unsigned long flags)

{

	unsigned long prev_cost = ULONG_MAX;

	u64 fmax;

	int i, ret;



	/* Compute the cost of each performance state. */

	fmax = (u64) table[nr_states - 1].frequency;

	for (i = nr_states - 1; i >= 0; i--) {

		unsigned long power_res, cost;



		if (flags & EM_PERF_DOMAIN_ARTIFICIAL) {

			ret = cb->get_cost(dev, table[i].frequency, &cost);

			if (ret || !cost || cost > EM_MAX_POWER) {

				dev_err(dev, "EM: invalid cost %lu %d\n",

					cost, ret);

				return -EINVAL;

			}

		} else {

			power_res = table[i].power;

			cost = div64_u64(fmax * power_res, table[i].frequency);

		}



		table[i].cost = cost;



		if (table[i].cost >= prev_cost) {

			table[i].flags = EM_PERF_STATE_INEFFICIENT;

			dev_dbg(dev, "EM: OPP:%lu is inefficient\n",

				table[i].frequency);

		} else {

			prev_cost = table[i].cost;

		}

	}



	return 0;

}



static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,

				int nr_states, struct em_data_callback *cb,

				unsigned long flags)

{

	unsigned long power, freq, prev_freq = 0, prev_cost = ULONG_MAX;

	unsigned long power, freq, prev_freq = 0;

	struct em_perf_state *table;

	int i, ret;

	u64 fmax;



	table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL);

	if (!table)
@@ -154,33 +192,9 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, 
		table[i].frequency = prev_freq = freq;

	}



	/* Compute the cost of each performance state. */

	fmax = (u64) table[nr_states - 1].frequency;

	for (i = nr_states - 1; i >= 0; i--) {

		unsigned long power_res, cost;



		if (flags & EM_PERF_DOMAIN_ARTIFICIAL) {

			ret = cb->get_cost(dev, table[i].frequency, &cost);

			if (ret || !cost || cost > EM_MAX_POWER) {

				dev_err(dev, "EM: invalid cost %lu %d\n",

					cost, ret);

	ret = em_compute_costs(dev, table, cb, nr_states, flags);

	if (ret)

		goto free_ps_table;

			}

		} else {

			power_res = table[i].power;

			cost = div64_u64(fmax * power_res, table[i].frequency);

		}



		table[i].cost = cost;



		if (table[i].cost >= prev_cost) {

			table[i].flags = EM_PERF_STATE_INEFFICIENT;

			dev_dbg(dev, "EM: OPP:%lu is inefficient\n",

				table[i].frequency);

		} else {

			prev_cost = table[i].cost;

		}

	}



	pd->table = table;

	pd->nr_perf_states = nr_states;