s390: Use generic idle loop

KAGA-KOKO · KAGA-KOKO · commit 52c0065947b7 · 2013-04-08T17:39:27.000+02:00
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>
diff --git 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
@@ -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
@@ -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
@@ -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();

Original file line number	Diff line number	Diff line change
`@@ -711,8 +711,7 @@ static void __cpuinit smp_start_secondary(void *cpuvoid)`
`711`	`711`	`set_cpu_online(smp_processor_id(), true);`
`712`	`712`	`inc_irq_stat(CPU_RST);`
`713`	`713`	`local_irq_enable();`
`714`		`- /* cpu_idle will call schedule for us */`
`715`		`- cpu_idle();`
	`714`	`+ cpu_startup_entry(CPUHP_ONLINE);`
`716`	`715`	`}`
`717`	`716`
`718`	`717`	`/* Upping and downing of CPUs */`