drivers base/arch_topology: allow inlining cpu-invariant accounting support

Allow inlining of topology_get_cpu_scale() into the task
scheduler fast path (e.g. __update_load_avg_se()) by coding it as a
static inline function in the arch topology header file.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/arch_topology.c

@@ -37,12 +37,7 @@ void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
 }
 
 static DEFINE_MUTEX(cpu_scale_mutex);
-static DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
-
-unsigned long topology_get_cpu_scale(struct sched_domain *sd, int cpu)
-{
-	return per_cpu(cpu_scale, cpu);
-}
+DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
 
 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
 {

include/linux/arch_topology.h

@@ -12,8 +12,14 @@ void topology_normalize_cpu_scale(void);
 struct device_node;
 bool topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu);
 
+DECLARE_PER_CPU(unsigned long, cpu_scale);
+
 struct sched_domain;
-unsigned long topology_get_cpu_scale(struct sched_domain *sd, int cpu);
+static inline
+unsigned long topology_get_cpu_scale(struct sched_domain *sd, int cpu)
+{
+	return per_cpu(cpu_scale, cpu);
+}
 
 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity);