[RFC 3/9] cpufreq: Add dvfs_possible_from_any_cpu policy flag

From: Viresh Kumar
Date: Thu Mar 09 2017 - 06:48:47 EST


On many platforms any CPU (from any cpufreq policy) can perform DVFS on
behalf of other CPUs. Add a flag to identify such cpufreq policies.

Also enable it for cpufreq-dt driver which is used only on ARM platforms
currently.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/cpufreq/cpufreq-dt.c | 1 +
include/linux/cpufreq.h | 9 +++++++++
2 files changed, 10 insertions(+)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index c943787d761e..e57b45f20544 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -274,6 +274,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
transition_latency = CPUFREQ_ETERNAL;

policy->cpuinfo.transition_latency = transition_latency;
+ policy->dvfs_possible_from_any_cpu = true;

return 0;

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 87165f06a307..9490a314c515 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -120,6 +120,15 @@ struct cpufreq_policy {
bool fast_switch_possible;
bool fast_switch_enabled;

+ /*
+ * Remote DVFS flag (Not added to the driver structure as we don't want
+ * to access another structure from scheduler hotpath).
+ *
+ * Should be set if any CPU (from same or different policy) can do DVFS
+ * on behalf of any other CPU.
+ */
+ bool dvfs_possible_from_any_cpu;
+
/* Cached frequency lookup from cpufreq_driver_resolve_freq. */
unsigned int cached_target_freq;
int cached_resolved_idx;
--
2.7.1.410.g6faf27b