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authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-02 16:22:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-02 16:22:27 -0700
commit05bf58ca4b8f0be7d7af830f943f6d6b2c9ccee1 (patch)
tree9c87f7ffb9bbd2d54dd1e3bbfd8ef4eaeec8063b /drivers/cpuidle/cpuidle.c
parentd23082257d83e4bc89727d5aedee197e907999d2 (diff)
parenta1d028bd6d2b7789d15eddfd07c5bea2aaf36040 (diff)
Merge branch 'sched-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull sched/idle changes from Ingo Molnar: "More idle code reorganization, to prepare for more integration. (Sent separately because it depended on pending timer work, which is now upstream)" * 'sched-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/idle: Add more comments to the code sched/idle: Move idle conditions in cpuidle_idle main function sched/idle: Reorganize the idle loop cpuidle/idle: Move the cpuidle_idle_call function to idle.c idle/cpuidle: Split cpuidle_idle_call main function into smaller functions
Diffstat (limited to 'drivers/cpuidle/cpuidle.c')
-rw-r--r--drivers/cpuidle/cpuidle.c107
1 files changed, 56 insertions, 51 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index cb20fd915be8..8236746e46bb 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -65,6 +65,26 @@ int cpuidle_play_dead(void)
}
/**
+ * cpuidle_enabled - check if the cpuidle framework is ready
+ * @dev: cpuidle device for this cpu
+ * @drv: cpuidle driver for this cpu
+ *
+ * Return 0 on success, otherwise:
+ * -NODEV : the cpuidle framework is not available
+ * -EBUSY : the cpuidle framework is not initialized
+ */
+int cpuidle_enabled(struct cpuidle_driver *drv, struct cpuidle_device *dev)
+{
+ if (off || !initialized)
+ return -ENODEV;
+
+ if (!drv || !dev || !dev->enabled)
+ return -EBUSY;
+
+ return 0;
+}
+
+/**
* cpuidle_enter_state - enter the state and update stats
* @dev: cpuidle device for this cpu
* @drv: cpuidle driver for this cpu
@@ -109,63 +129,48 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
}
/**
- * cpuidle_idle_call - the main idle loop
+ * cpuidle_select - ask the cpuidle framework to choose an idle state
+ *
+ * @drv: the cpuidle driver
+ * @dev: the cpuidle device
*
- * NOTE: no locks or semaphores should be used here
- * return non-zero on failure
+ * Returns the index of the idle state.
*/
-int cpuidle_idle_call(void)
+int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
{
- struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
- struct cpuidle_driver *drv;
- int next_state, entered_state;
- bool broadcast;
-
- if (off || !initialized)
- return -ENODEV;
-
- /* check if the device is ready */
- if (!dev || !dev->enabled)
- return -EBUSY;
-
- drv = cpuidle_get_cpu_driver(dev);
-
- /* ask the governor for the next state */
- next_state = cpuidle_curr_governor->select(drv, dev);
- if (need_resched()) {
- dev->last_residency = 0;
- /* give the governor an opportunity to reflect on the outcome */
- if (cpuidle_curr_governor->reflect)
- cpuidle_curr_governor->reflect(dev, next_state);
- local_irq_enable();
- return 0;
- }
-
- broadcast = !!(drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP);
-
- if (broadcast &&
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu))
- return -EBUSY;
-
-
- trace_cpu_idle_rcuidle(next_state, dev->cpu);
-
- if (cpuidle_state_is_coupled(dev, drv, next_state))
- entered_state = cpuidle_enter_state_coupled(dev, drv,
- next_state);
- else
- entered_state = cpuidle_enter_state(dev, drv, next_state);
-
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
+ return cpuidle_curr_governor->select(drv, dev);
+}
- if (broadcast)
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
+/**
+ * cpuidle_enter - enter into the specified idle state
+ *
+ * @drv: the cpuidle driver tied with the cpu
+ * @dev: the cpuidle device
+ * @index: the index in the idle state table
+ *
+ * Returns the index in the idle state, < 0 in case of error.
+ * The error code depends on the backend driver
+ */
+int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev,
+ int index)
+{
+ if (cpuidle_state_is_coupled(dev, drv, index))
+ return cpuidle_enter_state_coupled(dev, drv, index);
+ return cpuidle_enter_state(dev, drv, index);
+}
- /* give the governor an opportunity to reflect on the outcome */
+/**
+ * cpuidle_reflect - tell the underlying governor what was the state
+ * we were in
+ *
+ * @dev : the cpuidle device
+ * @index: the index in the idle state table
+ *
+ */
+void cpuidle_reflect(struct cpuidle_device *dev, int index)
+{
if (cpuidle_curr_governor->reflect)
- cpuidle_curr_governor->reflect(dev, entered_state);
-
- return 0;
+ cpuidle_curr_governor->reflect(dev, index);
}
/**