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authorIonela Voinescu <ionela.voinescu@arm.com>2020-03-05 09:06:25 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2020-03-06 16:02:50 +0000
commitbbce8eaa603236bf958b0d24e6377b3f3b623991 (patch)
tree496e87419e608317e2ac43a45ca53b66dbcdebc1
parentDocumentation: arm64: document support for the AMU extension (diff)
downloadlinux-dev-bbce8eaa603236bf958b0d24e6377b3f3b623991.tar.xz
linux-dev-bbce8eaa603236bf958b0d24e6377b3f3b623991.zip
cpufreq: add function to get the hardware max frequency
Add weak function to return the hardware maximum frequency of a CPU, with the default implementation returning cpuinfo.max_freq, which is the best information we can generically get from the cpufreq framework. The default can be overwritten by a strong function in platforms that want to provide an alternative implementation, with more accurate information, obtained either from hardware or firmware. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--drivers/cpufreq/cpufreq.c20
-rw-r--r--include/linux/cpufreq.h5
2 files changed, 25 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index cbe6c94bf158..985228aee46f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1725,6 +1725,26 @@ unsigned int cpufreq_quick_get_max(unsigned int cpu)
}
EXPORT_SYMBOL(cpufreq_quick_get_max);
+/**
+ * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU
+ * @cpu: CPU number
+ *
+ * The default return value is the max_freq field of cpuinfo.
+ */
+__weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ unsigned int ret_freq = 0;
+
+ if (policy) {
+ ret_freq = policy->cpuinfo.max_freq;
+ cpufreq_cpu_put(policy);
+ }
+
+ return ret_freq;
+}
+EXPORT_SYMBOL(cpufreq_get_hw_max_freq);
+
static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
{
if (unlikely(policy_is_inactive(policy)))
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 0fb561d1b524..f7240251a949 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -205,6 +205,7 @@ static inline bool policy_is_shared(struct cpufreq_policy *policy)
unsigned int cpufreq_get(unsigned int cpu);
unsigned int cpufreq_quick_get(unsigned int cpu);
unsigned int cpufreq_quick_get_max(unsigned int cpu);
+unsigned int cpufreq_get_hw_max_freq(unsigned int cpu);
void disable_cpufreq(void);
u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
@@ -232,6 +233,10 @@ static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
{
return 0;
}
+static inline unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)
+{
+ return 0;
+}
static inline void disable_cpufreq(void) { }
#endif