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path: root/drivers/cpuidle/driver.c
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Diffstat (limited to 'drivers/cpuidle/driver.c')
-rw-r--r--drivers/cpuidle/driver.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 2458a741ad45..06dbe7c86199 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -10,6 +10,7 @@
#include <linux/mutex.h>
#include <linux/module.h>
+#include <linux/sched.h>
#include <linux/cpuidle.h>
#include <linux/cpumask.h>
#include <linux/clockchips.h>
@@ -177,6 +178,45 @@ static void __cpuidle_driver_init(struct cpuidle_driver *drv)
}
}
+#ifdef CONFIG_ARCH_HAS_CPU_RELAX
+static int poll_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ ktime_t t1, t2;
+ s64 diff;
+
+ t1 = ktime_get();
+ local_irq_enable();
+ while (!need_resched())
+ cpu_relax();
+
+ t2 = ktime_get();
+ diff = ktime_to_us(ktime_sub(t2, t1));
+ if (diff > INT_MAX)
+ diff = INT_MAX;
+
+ dev->last_residency = (int) diff;
+
+ return index;
+}
+
+static void poll_idle_init(struct cpuidle_driver *drv)
+{
+ struct cpuidle_state *state = &drv->states[0];
+
+ snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
+ snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
+ state->exit_latency = 0;
+ state->target_residency = 0;
+ state->power_usage = -1;
+ state->flags = 0;
+ state->enter = poll_idle;
+ state->disabled = false;
+}
+#else
+static void poll_idle_init(struct cpuidle_driver *drv) {}
+#endif /* !CONFIG_ARCH_HAS_CPU_RELAX */
+
/**
* __cpuidle_register_driver: register the driver
* @drv: a valid pointer to a struct cpuidle_driver
@@ -210,6 +250,8 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv)
on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,
(void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1);
+ poll_idle_init(drv);
+
return 0;
}