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-rw-r--r--arch/arm/kernel/process.c58
1 files changed, 32 insertions, 26 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 56820cce91a..39196dff478 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -114,9 +114,6 @@ void arm_machine_restart(char mode, const char *cmd)
114/* 114/*
115 * Function pointers to optional machine specific functions 115 * Function pointers to optional machine specific functions
116 */ 116 */
117void (*pm_idle)(void);
118EXPORT_SYMBOL(pm_idle);
119
120void (*pm_power_off)(void); 117void (*pm_power_off)(void);
121EXPORT_SYMBOL(pm_power_off); 118EXPORT_SYMBOL(pm_power_off);
122 119
@@ -130,20 +127,19 @@ EXPORT_SYMBOL_GPL(arm_pm_restart);
130 */ 127 */
131static void default_idle(void) 128static void default_idle(void)
132{ 129{
133 if (hlt_counter) 130 if (!need_resched())
134 cpu_relax(); 131 arch_idle();
135 else { 132 local_irq_enable();
136 local_irq_disable();
137 if (!need_resched())
138 arch_idle();
139 local_irq_enable();
140 }
141} 133}
142 134
135void (*pm_idle)(void) = default_idle;
136EXPORT_SYMBOL(pm_idle);
137
143/* 138/*
144 * The idle thread. We try to conserve power, while trying to keep 139 * The idle thread, has rather strange semantics for calling pm_idle,
145 * overall latency low. The architecture specific idle is passed 140 * but this is what x86 does and we need to do the same, so that
146 * a value to indicate the level of "idleness" of the system. 141 * things like cpuidle get called in the same way. The only difference
142 * is that we always respect 'hlt_counter' to prevent low power idle.
147 */ 143 */
148void cpu_idle(void) 144void cpu_idle(void)
149{ 145{
@@ -151,21 +147,31 @@ void cpu_idle(void)
151 147
152 /* endless idle loop with no priority at all */ 148 /* endless idle loop with no priority at all */
153 while (1) { 149 while (1) {
154 void (*idle)(void) = pm_idle; 150 tick_nohz_stop_sched_tick(1);
155 151 leds_event(led_idle_start);
152 while (!need_resched()) {
156#ifdef CONFIG_HOTPLUG_CPU 153#ifdef CONFIG_HOTPLUG_CPU
157 if (cpu_is_offline(smp_processor_id())) { 154 if (cpu_is_offline(smp_processor_id()))
158 leds_event(led_idle_start); 155 cpu_die();
159 cpu_die();
160 }
161#endif 156#endif
162 157
163 if (!idle) 158 local_irq_disable();
164 idle = default_idle; 159 if (hlt_counter) {
165 leds_event(led_idle_start); 160 local_irq_enable();
166 tick_nohz_stop_sched_tick(1); 161 cpu_relax();
167 while (!need_resched()) 162 } else {
168 idle(); 163 stop_critical_timings();
164 pm_idle();
165 start_critical_timings();
166 /*
167 * This will eventually be removed - pm_idle
168 * functions should always return with IRQs
169 * enabled.
170 */
171 WARN_ON(irqs_disabled());
172 local_irq_enable();
173 }
174 }
169 leds_event(led_idle_end); 175 leds_event(led_idle_end);
170 tick_nohz_restart_sched_tick(); 176 tick_nohz_restart_sched_tick();
171 preempt_enable_no_resched(); 177 preempt_enable_no_resched();