cpuidle: governors: Consolidate PM QoS handling

There is some code duplication related to the PM QoS handling between
the existing cpuidle governors, so move that code to a common helper
function and call that from the governors.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
index 5d359aff3cc5..9fed1b829292 100644
--- a/drivers/cpuidle/governor.c
+++ b/drivers/cpuidle/governor.c
@@ -8,8 +8,10 @@
  * This code is licenced under the GPL.
  */
 
-#include <linux/mutex.h>
+#include <linux/cpu.h>
 #include <linux/cpuidle.h>
+#include <linux/mutex.h>
+#include <linux/pm_qos.h>
 
 #include "cpuidle.h"
 
@@ -93,3 +95,16 @@ int cpuidle_register_governor(struct cpuidle_governor *gov)
 
 	return ret;
 }
+
+/**
+ * cpuidle_governor_latency_req - Compute a latency constraint for CPU
+ * @cpu: Target CPU
+ */
+int cpuidle_governor_latency_req(unsigned int cpu)
+{
+	int global_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
+	struct device *device = get_cpu_device(cpu);
+	int device_req = dev_pm_qos_raw_read_value(device);
+
+	return device_req < global_req ? device_req : global_req;
+}