smp: Implement kick_all_cpus_sync()

Will replace the misnomed cpu_idle_wait() function which is copied a
gazillion times all over arch/*

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120507175652.049316594@linutronix.de
This commit is contained in:
Thomas Gleixner 2012-05-07 17:59:48 +00:00
parent 9cd75e13de
commit f37f435f33
2 changed files with 27 additions and 0 deletions

View File

@ -81,6 +81,8 @@ void __smp_call_function_single(int cpuid, struct call_single_data *data,
int smp_call_function_any(const struct cpumask *mask,
smp_call_func_t func, void *info, int wait);
void kick_all_cpus_sync(void);
/*
* Generic and arch helpers
*/
@ -192,6 +194,8 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
return smp_call_function_single(0, func, info, wait);
}
static inline void kick_all_cpus_sync(void) { }
#endif /* !SMP */
/*

View File

@ -795,3 +795,26 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
}
}
EXPORT_SYMBOL(on_each_cpu_cond);
static void do_nothing(void *unused)
{
}
/**
* kick_all_cpus_sync - Force all cpus out of idle
*
* Used to synchronize the update of pm_idle function pointer. It's
* called after the pointer is updated and returns after the dummy
* callback function has been executed on all cpus. The execution of
* the function can only happen on the remote cpus after they have
* left the idle function which had been called via pm_idle function
* pointer. So it's guaranteed that nothing uses the previous pointer
* anymore.
*/
void kick_all_cpus_sync(void)
{
/* Make sure the change is visible before we kick the cpus */
smp_mb();
smp_call_function(do_nothing, NULL, 1);
}
EXPORT_SYMBOL_GPL(kick_all_cpus_sync);