sched/idle: Reflow cpuidle_idle_call()

Apply goto to reduce lines and nesting levels.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-cc6vb0snt3sr7op6rlbfeqfh@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 58 insertions, 73 deletions

diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index ed67f0cd2906..88a6bc43738b 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -73,7 +73,7 @@ static int cpuidle_idle_call(void)
 {
         struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
-        int next_state, entered_state, ret;
+        int next_state, entered_state;
         bool broadcast;
 
         /*
@@ -102,90 +102,75 @@ static int cpuidle_idle_call(void)
          * Check if the cpuidle framework is ready, otherwise fallback
          * to the default arch specific idle method
          */
-        ret = cpuidle_enabled(drv, dev);
-
-        if (!ret) {
-                /*
-                 * Ask the governor to choose an idle state it thinks
-                 * it is convenient to go to. There is *always* a
-                 * convenient idle state
-                 */
-                next_state = cpuidle_select(drv, dev);
-
+        if (cpuidle_enabled(drv, dev)) {
+use_default:
                 /*
-                 * The idle task must be scheduled, it is pointless to
-                 * go to idle, just update no idle residency and get
-                 * out of this function
+                 * We can't use the cpuidle framework, let's use the default
+                 * idle routine.
                  */
-                if (current_clr_polling_and_test()) {
-                        dev->last_residency = 0;
-                        entered_state = next_state;
+                if (current_clr_polling_and_test())
                         local_irq_enable();
-                } else {
-                        broadcast = !!(drv->states[next_state].flags &
-                                       CPUIDLE_FLAG_TIMER_STOP);
-
-                        if (broadcast) {
-                                /*
-                                 * Tell the time framework to switch
-                                 * to a broadcast timer because our
-                                 * local timer will be shutdown. If a
-                                 * local timer is used from another
-                                 * cpu as a broadcast timer, this call
-                                 * may fail if it is not available
-                                 */
-                                ret = clockevents_notify(
-                                        CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
-                                        &dev->cpu);
-                        }
-
-                        if (!ret) {
-                                trace_cpu_idle_rcuidle(next_state, dev->cpu);
-
-                                /*
-                                 * Enter the idle state previously
-                                 * returned by the governor
-                                 * decision. This function will block
-                                 * until an interrupt occurs and will
-                                 * take care of re-enabling the local
-                                 * interrupts
-                                 */
-                                entered_state = cpuidle_enter(drv, dev,
-                                                              next_state);
-
-                                trace_cpu_idle_rcuidle(PWR_EVENT_EXIT,
-                                                       dev->cpu);
-
-                                if (broadcast)
-                                        clockevents_notify(
-                                                CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
-                                                &dev->cpu);
-
-                                /*
-                                 * Give the governor an opportunity to reflect on the
-                                 * outcome
-                                 */
-                                cpuidle_reflect(dev, entered_state);
-                        }
-                }
+                else
+                        arch_cpu_idle();
+
+                goto exit_idle;
         }
 
         /*
-         * We can't use the cpuidle framework, let's use the default
-         * idle routine
+         * Ask the governor to choose an idle state it thinks
+         * it is convenient to go to. There is *always* a
+         * convenient idle state
          */
-        if (ret) {
-                if (!current_clr_polling_and_test())
-                        arch_cpu_idle();
-                else
-                        local_irq_enable();
+        next_state = cpuidle_select(drv, dev);
+
+        /*
+         * The idle task must be scheduled, it is pointless to
+         * go to idle, just update no idle residency and get
+         * out of this function
+         */
+        if (current_clr_polling_and_test()) {
+                dev->last_residency = 0;
+                entered_state = next_state;
+                local_irq_enable();
+                goto exit_idle;
         }
 
+        broadcast = !!(drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP);
+
+        /*
+         * Tell the time framework to switch to a broadcast timer
+         * because our local timer will be shutdown. If a local timer
+         * is used from another cpu as a broadcast timer, this call may
+         * fail if it is not available
+         */
+        if (broadcast &&
+            clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu))
+                goto use_default;
+
+        trace_cpu_idle_rcuidle(next_state, dev->cpu);
+
+        /*
+         * Enter the idle state previously returned by the governor decision.
+         * This function will block until an interrupt occurs and will take
+         * care of re-enabling the local interrupts
+         */
+        entered_state = cpuidle_enter(drv, dev, next_state);
+
+        trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
+
+        if (broadcast)
+                clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
+
+        /*
+         * Give the governor an opportunity to reflect on the outcome
+         */
+        cpuidle_reflect(dev, entered_state);
+
+exit_idle:
         __current_set_polling();
 
         /*
-         * It is up to the idle functions to enable back the local
-         * interrupt
+         * It is up to the idle functions to reenable local interrupts
          */
         if (WARN_ON_ONCE(irqs_disabled()))
                 local_irq_enable();