On 07/27/2017 11:46 PM, Viresh Kumar wrote:
On many platforms, CPUs can do DVFS across cpufreq policies. i.e CPU from policy-A can change frequency of CPUs belonging to policy-B.
This is quite common in case of ARM platforms where we don't configure any per-cpu register.
Add a flag to identify such platforms and update cpufreq_can_do_remote_dvfs() to allow remote callbacks if this flag is set.
Also enable the flag for cpufreq-dt driver which is used only on ARM platforms currently.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
drivers/cpufreq/cpufreq-dt.c | 1 + include/linux/cpufreq.h | 18 ++++++++++++++++-- 2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c index fef3c2160691..d83ab94d041a 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 b3b6e8203e82..227cd0f13300 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -127,6 +127,15 @@ struct cpufreq_policy { */ unsigned int transition_delay_us;
- /*
* 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 CPUs can do DVFS on behalf of other CPUs from* different cpufreq policies.*/- bool dvfs_possible_from_any_cpu;
Seems reasonable. This is something that can be easily set by the driver.
/* Cached frequency lookup from cpufreq_driver_resolve_freq. */unsigned int cached_target_freq; int cached_resolved_idx; @@ -564,8 +573,13 @@ struct governor_attr {
static inline bool cpufreq_can_do_remote_dvfs(struct cpufreq_policy *policy) {
- /* Allow remote callbacks only on the CPUs sharing cpufreq policy */
- if (cpumask_test_cpu(smp_processor_id(), policy->cpus))
/*
* Allow remote callbacks if:* - dvfs_possible_from_any_cpu flag is set* - the local and remote CPUs share cpufreq policy*/if (policy->dvfs_possible_from_any_cpu ||
cpumask_test_cpu(smp_processor_id(), policy->cpus))return true;
return false;
Acked-by: Saravana Kannan skannan@codeaurora.org
-- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project