powerpc: Use generic idle loop

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: http://lkml.kernel.org/r/20130321215235.026838003@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 31 insertions, 61 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ea5bb045983a..19de32c52da5 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -133,6 +133,7 @@ config PPC
         select HAVE_ARCH_JUMP_LABEL
         select ARCH_HAVE_NMI_SAFE_CMPXCHG
         select GENERIC_SMP_IDLE_THREAD
+        select GENERIC_IDLE_LOOP
         select GENERIC_CMOS_UPDATE
         select GENERIC_TIME_VSYSCALL_OLD
         select GENERIC_CLOCKEVENTS
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
index ea78761aa169..939ea7ef0dc8 100644
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -33,11 +33,6 @@
 #include <asm/runlatch.h>
 #include <asm/smp.h>
 
-#ifdef CONFIG_HOTPLUG_CPU
-#define cpu_should_die()        cpu_is_offline(smp_processor_id())
-#else
-#define cpu_should_die()        0
-#endif
 
 unsigned long cpuidle_disable = IDLE_NO_OVERRIDE;
 EXPORT_SYMBOL(cpuidle_disable);
@@ -50,64 +45,38 @@ static int __init powersave_off(char *arg)
 }
 __setup("powersave=off", powersave_off);
 
-/*
- * The body of the idle task.
- */
-void cpu_idle(void)
+#ifdef CONFIG_HOTPLUG_CPU
+void arch_cpu_idle_dead(void)
 {
-        set_thread_flag(TIF_POLLING_NRFLAG);
-        while (1) {
-                tick_nohz_idle_enter();
-                rcu_idle_enter();
-
-                while (!need_resched() && !cpu_should_die()) {
-                        ppc64_runlatch_off();
-
-                        if (ppc_md.power_save) {
-                                clear_thread_flag(TIF_POLLING_NRFLAG);
-                                /*
-                                 * smp_mb is so clearing of TIF_POLLING_NRFLAG
-                                 * is ordered w.r.t. need_resched() test.
-                                 */
-                                smp_mb();
-                                local_irq_disable();
-
-                                /* Don't trace irqs off for idle */
-                                stop_critical_timings();
-
-                                /* check again after disabling irqs */
-                                if (!need_resched() && !cpu_should_die())
-                                        ppc_md.power_save();
-
-                                start_critical_timings();
-
-                                /* Some power_save functions return with
-                                 * interrupts enabled, some don't.
-                                 */
-                                if (irqs_disabled())
-                                        local_irq_enable();
-                                set_thread_flag(TIF_POLLING_NRFLAG);
-
-                        } else {
-                                /*
-                                 * Go into low thread priority and possibly
-                                 * low power mode.
-                                 */
-                                HMT_low();
-                                HMT_very_low();
-                        }
-                }
+        sched_preempt_enable_no_resched();
+        cpu_die();
+}
+#endif
 
-                HMT_medium();
-                ppc64_runlatch_on();
-                rcu_idle_exit();
-                tick_nohz_idle_exit();
-                if (cpu_should_die()) {
-                        sched_preempt_enable_no_resched();
-                        cpu_die();
-                }
-                schedule_preempt_disabled();
+void arch_cpu_idle(void)
+{
+        ppc64_runlatch_off();
+
+        if (ppc_md.power_save) {
+                ppc_md.power_save();
+                /*
+                 * Some power_save functions return with
+                 * interrupts enabled, some don't.
+                 */
+                if (irqs_disabled())
+                        local_irq_enable();
+        } else {
+                local_irq_enable();
+                /*
+                 * Go into low thread priority and possibly
+                 * low power mode.
+                 */
+                HMT_low();
+                HMT_very_low();
         }
+
+        HMT_medium();
+        ppc64_runlatch_on();
 }
 
 int powersave_nap;
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 76bd9da8cb71..ee7ac5e6e28a 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -669,7 +669,7 @@ __cpuinit void start_secondary(void *unused)
 
         local_irq_enable();
 
-        cpu_idle();
+        cpu_startup_entry(CPUHP_ONLINE);
 
         BUG();
 }