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author | Thomas Gleixner <tglx@linutronix.de> | 2013-03-21 22:49:59 +0100 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2013-04-08 17:39:28 +0200 |
commit | dc775dd886618a1ea6f092bfb3ddc78660aa1a19 (patch) | |
tree | 601656205d801b13ee0d4bca634244fdb0882e28 /arch/sh/kernel/idle.c | |
parent | 99444202b924e916aad95073d23f9995ae8eb558 (diff) | |
download | op-kernel-dev-dc775dd886618a1ea6f092bfb3ddc78660aa1a19.zip op-kernel-dev-dc775dd886618a1ea6f092bfb3ddc78660aa1a19.tar.gz |
sh: 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: Paul Mundt <lethal@linux-sh.org>
Link: http://lkml.kernel.org/r/20130321215235.216323644@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/sh/kernel/idle.c')
-rw-r--r-- | arch/sh/kernel/idle.c | 101 |
1 files changed, 11 insertions, 90 deletions
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c index 3d5a1b3..2ea4483 100644 --- a/arch/sh/kernel/idle.c +++ b/arch/sh/kernel/idle.c @@ -24,98 +24,24 @@ static void (*sh_idle)(void); -static int hlt_counter; - -static int __init nohlt_setup(char *__unused) -{ - hlt_counter = 1; - return 1; -} -__setup("nohlt", nohlt_setup); - -static int __init hlt_setup(char *__unused) -{ - hlt_counter = 0; - return 1; -} -__setup("hlt", hlt_setup); - -static inline int hlt_works(void) -{ - return !hlt_counter; -} - -/* - * On SMP it's slightly faster (but much more power-consuming!) - * to poll the ->work.need_resched flag instead of waiting for the - * cross-CPU IPI to arrive. Use this option with caution. - */ -static void poll_idle(void) +void default_idle(void) { + set_bl_bit(); local_irq_enable(); - while (!need_resched()) - cpu_relax(); + /* Isn't this racy ? */ + cpu_sleep(); + clear_bl_bit(); } -void default_idle(void) +void arch_cpu_idle_dead(void) { - if (hlt_works()) { - clear_thread_flag(TIF_POLLING_NRFLAG); - smp_mb__after_clear_bit(); - - set_bl_bit(); - if (!need_resched()) { - local_irq_enable(); - cpu_sleep(); - } else - local_irq_enable(); - - set_thread_flag(TIF_POLLING_NRFLAG); - clear_bl_bit(); - } else - poll_idle(); + play_dead(); } -/* - * The idle thread. There's no useful work to be done, so just try to conserve - * power and have a low exit latency (ie sit in a loop waiting for somebody to - * say that they'd like to reschedule) - */ -void cpu_idle(void) +void arch_cpu_idle(void) { - unsigned int cpu = smp_processor_id(); - - set_thread_flag(TIF_POLLING_NRFLAG); - - /* endless idle loop with no priority at all */ - while (1) { - tick_nohz_idle_enter(); - rcu_idle_enter(); - - while (!need_resched()) { - check_pgt_cache(); - rmb(); - - if (cpu_is_offline(cpu)) - play_dead(); - - local_irq_disable(); - /* Don't trace irqs off for idle */ - stop_critical_timings(); - if (cpuidle_idle_call()) - sh_idle(); - /* - * Sanity check to ensure that sh_idle() returns - * with IRQs enabled - */ - WARN_ON(irqs_disabled()); - start_critical_timings(); - } - - rcu_idle_exit(); - tick_nohz_idle_exit(); - schedule_preempt_disabled(); - } + if (cpuidle_idle_call()) + sh_idle(); } void __init select_idle_routine(void) @@ -123,13 +49,8 @@ void __init select_idle_routine(void) /* * If a platform has set its own idle routine, leave it alone. */ - if (sh_idle) - return; - - if (hlt_works()) + if (!sh_idle) sh_idle = default_idle; - else - sh_idle = poll_idle; } void stop_this_cpu(void *unused) |