[tip:smp/hotplug] s390: Use generic idle loop

tip-bot for Thomas Gleixner
2013-04-08T20:41:00Z

Commit-ID: 52c0065947b7f78a3d9808b421006a3d870d1f92
Gitweb: http://git.kernel.org/tip/52c0065947b7f78a3d9808b421006a3d870d1f92
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Thu, 21 Mar 2013 22:49:57 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 8 Apr 2013 17:39:27 +0200

s390: 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>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Link: http://lkml.kernel.org/r/20130321215235.090816526@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/s390/Kconfig | 1 +
arch/s390/kernel/process.c | 32 +++++++++-----------------------
arch/s390/kernel/smp.c | 3 +--
arch/s390/kernel/vtime.c | 5 -----
4 files changed, 11 insertions(+), 30 deletions(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index eb8fb62..749513d 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -97,6 +97,7 @@ config S390
select CLONE_BACKWARDS2
select GENERIC_CLOCKEVENTS
select GENERIC_CPU_DEVICES if !SMP
+ select GENERIC_IDLE_LOOP
select GENERIC_KERNEL_THREAD
select GENERIC_SMP_IDLE_THREAD
select GENERIC_TIME_VSYSCALL_OLD
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 536d645..2bc3edd 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -61,18 +61,8 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
return sf->gprs[8];
}

-/*
- * The idle loop on a S390...
- */
-static void default_idle(void)
+void arch_cpu_idle(void)
{
- if (cpu_is_offline(smp_processor_id()))
- cpu_die();
- local_irq_disable();
- if (need_resched()) {
- local_irq_enable();
- return;
- }
local_mcck_disable();
if (test_thread_flag(TIF_MCCK_PENDING)) {
local_mcck_enable();
@@ -83,19 +73,15 @@ static void default_idle(void)
vtime_stop_cpu();
}

-void cpu_idle(void)
+void arch_cpu_idle_exit(void)
{
- for (;;) {
- tick_nohz_idle_enter();
- rcu_idle_enter();
- while (!need_resched() && !test_thread_flag(TIF_MCCK_PENDING))
- default_idle();
- rcu_idle_exit();
- tick_nohz_idle_exit();
- if (test_thread_flag(TIF_MCCK_PENDING))
- s390_handle_mcck();
- schedule_preempt_disabled();
- }
+ if (test_thread_flag(TIF_MCCK_PENDING))
+ s390_handle_mcck();
+}
+
+void arch_cpu_idle_dead(void)
+{
+ cpu_die();
}

extern void __kprobes kernel_thread_starter(void);
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 549c9d1..6ff5845 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -711,8 +711,7 @@ static void __cpuinit smp_start_secondary(void *cpuvoid)
set_cpu_online(smp_processor_id(), true);
inc_irq_stat(CPU_RST);
local_irq_enable();
- /* cpu_idle will call schedule for us */
- cpu_idle();
+ cpu_startup_entry(CPUHP_ONLINE);
}

/* Upping and downing of CPUs */
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index a0042ac..3fb0935 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -158,8 +158,6 @@ void __kprobes vtime_stop_cpu(void)
unsigned long psw_mask;

trace_hardirqs_on();
- /* Don't trace preempt off for idle. */
- stop_critical_timings();

/* Wait for external, I/O or machine check interrupt. */
psw_mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_DAT |
@@ -169,9 +167,6 @@ void __kprobes vtime_stop_cpu(void)
/* Call the assembler magic in entry.S */
psw_idle(idle, psw_mask);

- /* Reenable preemption tracer. */
- start_critical_timings();
-
/* Account time spent with enabled wait psw loaded as idle time. */
idle->sequence++;
smp_wmb();