[PATCH v2 2/3] PM / EM: Extend em_perf_domain with a flag field

From: Vincent Donnefort
Date: Fri May 21 2021 - 12:54:59 EST


Merge the current "milliwatts" option into a "flag" field. This intends to
prepare the extension of this structure for inefficient states support in
the Energy Model.

Signed-off-by: Vincent Donnefort <vincent.donnefort@xxxxxxx>

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
index 757fc60..9be7bde 100644
--- a/include/linux/energy_model.h
+++ b/include/linux/energy_model.h
@@ -28,8 +28,7 @@ struct em_perf_state {
* em_perf_domain - Performance domain
* @table: List of performance states, in ascending order
* @nr_perf_states: Number of performance states
- * @milliwatts: Flag indicating the power values are in milli-Watts
- * or some other scale.
+ * @flags: See "em_perf_domain flags"
* @cpus: Cpumask covering the CPUs of the domain. It's here
* for performance reasons to avoid potential cache
* misses during energy calculations in the scheduler
@@ -44,10 +43,18 @@ struct em_perf_state {
struct em_perf_domain {
struct em_perf_state *table;
int nr_perf_states;
- int milliwatts;
+ int flags;
unsigned long cpus[];
};

+/*
+ * em_perf_domain flags:
+ *
+ * EM_PERF_DOMAIN_MILLIWATTS: The power values are in milli-Watts or some
+ * other scale.
+ */
+#define EM_PERF_DOMAIN_MILLIWATTS BIT(0)
+
#define em_span_cpus(em) (to_cpumask((em)->cpus))

#ifdef CONFIG_ENERGY_MODEL
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
index c4871a8..638581c 100644
--- a/kernel/power/energy_model.c
+++ b/kernel/power/energy_model.c
@@ -55,7 +55,8 @@ DEFINE_SHOW_ATTRIBUTE(em_debug_cpus);
static int em_debug_units_show(struct seq_file *s, void *unused)
{
struct em_perf_domain *pd = s->private;
- char *units = pd->milliwatts ? "milliWatts" : "bogoWatts";
+ char *units = (pd->flags & EM_PERF_DOMAIN_MILLIWATTS) ?
+ "milliWatts" : "bogoWatts";

seq_printf(s, "%s\n", units);

@@ -341,7 +342,8 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
if (ret)
goto unlock;

- dev->em_pd->milliwatts = milliwatts;
+ if (milliwatts)
+ dev->em_pd->flags |= EM_PERF_DOMAIN_MILLIWATTS;

em_debug_create_pd(dev);
dev_info(dev, "EM: created perf domain\n");
--
2.7.4