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sh: Use generic idle loop

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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>
This commit is contained in:
Thomas Gleixner 2013-03-21 22:49:59 +01:00
parent 99444202b9
commit dc775dd886
3 changed files with 16 additions and 93 deletions
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2
arch/sh/Kconfig
View File

@ -33,6 +33,8 @@ config SUPERH
select GENERIC_ATOMIC64
select GENERIC_IRQ_SHOW
select GENERIC_SMP_IDLE_THREAD
select GENERIC_IDLE_LOOP
select GENERIC_IDLE_POLL_SETUP
select GENERIC_CLOCKEVENTS
select GENERIC_CMOS_UPDATE if SH_SH03 || SH_DREAMCAST
select GENERIC_STRNCPY_FROM_USER

105
arch/sh/kernel/idle.c
View File

@ -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)
{
local_irq_enable();
while (!need_resched())
cpu_relax();
}
void default_idle(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();
set_bl_bit();
local_irq_enable();
/* Isn't this racy ? */
cpu_sleep();
clear_bl_bit();
}
/*
* 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_dead(void)
{
unsigned int cpu = smp_processor_id();
play_dead();
}
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();
}
void arch_cpu_idle(void)
{
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)

2
arch/sh/kernel/smp.c
View File

@ -203,7 +203,7 @@ asmlinkage void __cpuinit start_secondary(void)
set_cpu_online(cpu, true);
per_cpu(cpu_state, cpu) = CPU_ONLINE;
cpu_idle();
cpu_startup_entry(CPUHP_ONLINE);
}
extern struct {