[tip:smp/hotplug] powerpc: Use generic idle loop

tip-bot for Thomas Gleixner
2013-04-08T20:39:48Z

Commit-ID: 799fef06123f86ff69cf754f996219e6ad1678f8
Gitweb: http://git.kernel.org/tip/799fef06123f86ff69cf754f996219e6ad1678f8
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Thu, 21 Mar 2013 22:49:56 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 8 Apr 2013 17:39:27 +0200

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>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/idle.c | 89 +++++++++++++++-------------------------------
arch/powerpc/kernel/smp.c | 2 +-
3 files changed, 31 insertions(+), 61 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ea5bb04..19de32c 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 ea78761..939ea7e 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 76bd9da..ee7ac5e 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();
}