[PATCH v2 1/5] arch_topology: Introduce thermal pressure update function

@@ -24,6 +24,7 @@
 /* Replace task scheduler's default thermal pressure API */
 #define arch_scale_thermal_pressure topology_get_thermal_pressure
 #define arch_set_thermal_pressure   topology_set_thermal_pressure
+#define arch_thermal_pressure_update	topology_thermal_pressure_update
 
 #else
 

@@ -33,6 +33,7 @@ void update_freq_counters_refs(void);
 /* Replace task scheduler's default thermal pressure API */
 #define arch_scale_thermal_pressure topology_get_thermal_pressure
 #define arch_set_thermal_pressure   topology_set_thermal_pressure
+#define arch_thermal_pressure_update	topology_thermal_pressure_update
 
 #include <asm-generic/topology.h>
 

@@ -25,6 +25,7 @@
 static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data);
 static struct cpumask scale_freq_counters_mask;
 static bool scale_freq_invariant;
+static DEFINE_PER_CPU(u32, freq_factor) = 1;
 
 static bool supports_scale_freq_counters(const struct cpumask *cpus)
 {

@@ -168,6 +169,40 @@ void topology_set_thermal_pressure(const struct cpumask *cpus,
 }
 EXPORT_SYMBOL_GPL(topology_set_thermal_pressure);
 
+/**
+ * topology_thermal_pressure_update() - Update thermal pressure for CPUs
+ * @cpus	: The related CPUs for which capacity has been reduced
+ * @capped_freq	: The maximum allowed frequency that CPUs can run at
+ *
+ * Update the value of thermal pressure for all @cpus in the mask. The
+ * cpumask should include all (online+offline) affected CPUs, to avoid
+ * operating on stale data when hot-plug is used for some CPUs. The
+ * @capped_freq must be less or equal to the max possible frequency and
+ * reflects the currently allowed max CPUs frequency due to thermal capping.
+ * The @capped_freq must be provided in kHz.
+ */
+void topology_thermal_pressure_update(const struct cpumask *cpus,
+				      unsigned long capped_freq)
+{
+	unsigned long max_capacity, capacity;
+	int cpu;
+
+	if (!cpus)
+		return;
+
+	cpu = cpumask_first(cpus);
+	max_capacity = arch_scale_cpu_capacity(cpu);
+
+	/* Convert to MHz scale which is used in 'freq_factor' */
+	capped_freq /= 1000;
+
+	capacity = mult_frac(capped_freq, max_capacity,
+			     per_cpu(freq_factor, cpu));
+
+	arch_set_thermal_pressure(cpus, max_capacity - capacity);
+}
+EXPORT_SYMBOL_GPL(topology_thermal_pressure_update);
+
 static ssize_t cpu_capacity_show(struct device *dev,
 				 struct device_attribute *attr,
 				 char *buf)

@@ -220,7 +255,6 @@ static void update_topology_flags_workfn(struct work_struct *work)
 	update_topology = 0;
 }
 
-static DEFINE_PER_CPU(u32, freq_factor) = 1;
 static u32 *raw_capacity;
 
 static int free_raw_capacity(void)

@@ -59,6 +59,9 @@ static inline unsigned long topology_get_thermal_pressure(int cpu)
 void topology_set_thermal_pressure(const struct cpumask *cpus,
 				   unsigned long th_pressure);
 
+void topology_thermal_pressure_update(const struct cpumask *cpus,
+				      unsigned long capped_freq);
+
 struct cpu_topology {
 	int thread_id;
 	int core_id;

@@ -266,6 +266,13 @@ void arch_set_thermal_pressure(const struct cpumask *cpus,
 { }
 #endif
 
+#ifndef arch_thermal_pressure_update
+static __always_inline
+void arch_thermal_pressure_update(const struct cpumask *cpus,
+				      unsigned long capped_frequency)
+{ }
+#endif
+
 static inline int task_node(const struct task_struct *p)
 {
 	return cpu_to_node(task_cpu(p));