PM: EM: Mark inefficiencies in CPUFreq

The Energy Model has a 1:1 mapping between OPPs and performance states
(em_perf_state). If a CPUFreq driver registers an Energy Model,
inefficiencies found by the latter can be applied to CPUFreq.

Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
index d353ef29e37f5f1bb3429588878ebf46d66dbed5..0153b0ca7b23e86fa65025f24bf659d241e9bfc8 100644 (file)
--- a/kernel/power/energy_model.c
+++ b/kernel/power/energy_model.c
@@ -10,6 +10,7 @@
 #define pr_fmt(fmt) "energy_model: " fmt
 
 #include <linux/cpu.h>
+#include <linux/cpufreq.h>
 #include <linux/cpumask.h>
 #include <linux/debugfs.h>
 #include <linux/energy_model.h>
@@ -231,6 +232,43 @@ static int em_create_pd(struct device *dev, int nr_states,
        return 0;
 }
 
+static void em_cpufreq_update_efficiencies(struct device *dev)
+{
+       struct em_perf_domain *pd = dev->em_pd;
+       struct em_perf_state *table;
+       struct cpufreq_policy *policy;
+       int found = 0;
+       int i;
+
+       if (!_is_cpu_device(dev) || !pd)
+               return;
+
+       policy = cpufreq_cpu_get(cpumask_first(em_span_cpus(pd)));
+       if (!policy) {
+               dev_warn(dev, "EM: Access to CPUFreq policy failed");
+               return;
+       }
+
+       table = pd->table;
+
+       for (i = 0; i < pd->nr_perf_states; i++) {
+               if (!(table[i].flags & EM_PERF_STATE_INEFFICIENT))
+                       continue;
+
+               if (!cpufreq_table_set_inefficient(policy, table[i].frequency))
+                       found++;
+       }
+
+       if (!found)
+               return;
+
+       /*
+        * Efficiencies have been installed in CPUFreq, inefficient frequencies
+        * will be skipped. The EM can do the same.
+        */
+       pd->flags |= EM_PERF_DOMAIN_SKIP_INEFFICIENCIES;
+}
+
 /**
  * em_pd_get() - Return the performance domain for a device
  * @dev : Device to find the performance domain for
@@ -347,6 +385,8 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
        if (milliwatts)
                dev->em_pd->flags |= EM_PERF_DOMAIN_MILLIWATTS;
 
+       em_cpufreq_update_efficiencies(dev);
+
        em_debug_create_pd(dev);
        dev_info(dev, "EM: created perf domain\n");