[PATCH v5 05/23] PM: EM: Refactor a new function em_compute_costs()

Lukasz Luba
2023-11-29T11:08:33Z

Refactor a dedicated function which will be easier to maintain and re-use
in future. The upcoming changes for the modifiable EM perf_state table
will use it (instead of duplicating the code).

This change is not expected to alter the general functionality.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
kernel/power/energy_model.c | 72 ++++++++++++++++++++++---------------
1 file changed, 43 insertions(+), 29 deletions(-)

diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
index aa7c89f9e115..3bea930410c6 100644
--- a/kernel/power/energy_model.c
+++ b/kernel/power/energy_model.c
@@ -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);
- 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;
- }
- }
+ ret = em_compute_costs(dev, table, cb, nr_states, flags);
+ if (ret)
+ goto free_ps_table;

pd->table = table;
pd->nr_perf_states = nr_states;
--
2.25.1