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>

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index eb8fb62..749513d 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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();