diff options
| -rw-r--r-- | arch/arm/Kconfig | 3 | ||||
| -rw-r--r-- | arch/arm/include/asm/system.h | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/process.c | 19 |
3 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 7562f884f2c..94360e7a7ab 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -145,6 +145,9 @@ config ARCH_HAS_CPUFREQ and that the relevant menu configurations are displayed for it. +config ARCH_HAS_CPU_IDLE_WAIT + def_bool y + config GENERIC_HWEIGHT bool default y diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index 8ba1ccf82a0..48e360c7432 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -325,6 +325,8 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size extern void disable_hlt(void); extern void enable_hlt(void); +void cpu_idle_wait(void); + #include <asm-generic/cmpxchg-local.h> #if __LINUX_ARM_ARCH__ < 6 diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 401e38be1f7..23def52d2d2 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -135,6 +135,25 @@ EXPORT_SYMBOL(pm_power_off); void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart; EXPORT_SYMBOL_GPL(arm_pm_restart); +static void do_nothing(void *unused) +{ +} + +/* + * cpu_idle_wait - Used to ensure that all the CPUs discard old value of + * pm_idle and update to new pm_idle value. Required while changing pm_idle + * handler on SMP systems. + * + * Caller must have changed pm_idle to the new value before the call. Old + * pm_idle value will not be used by any CPU after the return of this function. + */ +void cpu_idle_wait(void) +{ + smp_mb(); + /* kick all the CPUs so that they exit out of pm_idle */ + smp_call_function(do_nothing, NULL, 1); +} +EXPORT_SYMBOL_GPL(cpu_idle_wait); /* * This is our default idle handler. We need to disable |