#ifndef _LINUX_STOP_MACHINE #define _LINUX_STOP_MACHINE /* "Bogolock": stop the entire machine, disable interrupts. This is a very heavy lock, which is equivalent to grabbing every spinlock (and more). So the "read" side to such a lock is anything which disables preeempt. */ #include <linux/cpu.h> #include <linux/cpumask.h> #include <asm/system.h> #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) /** * stop_machine: freeze the machine on all CPUs and run this function * @fn: the function to run * @data: the data ptr for the @fn() * @cpus: the cpus to run the @fn() on (NULL = any online cpu) * * Description: This causes a thread to be scheduled on every cpu, * each of which disables interrupts. The result is that noone is * holding a spinlock or inside any other preempt-disabled region when * @fn() runs. * * This can be thought of as a very heavy write lock, equivalent to * grabbing every spinlock in the kernel. */ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); /** * __stop_machine: freeze the machine on all CPUs and run this function * @fn: the function to run * @data: the data ptr for the @fn * @cpus: the cpus to run the @fn() on (NULL = any online cpu) * * Description: This is a special version of the above, which assumes cpus * won't come or go while it's being called. Used by hotplug cpu. */ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); /** * stop_machine_create: create all stop_machine threads * * Description: This causes all stop_machine threads to be created before * stop_machine actually gets called. This can be used by subsystems that * need a non failing stop_machine infrastructure. */ int stop_machine_create(void); /** * stop_machine_destroy: destroy all stop_machine threads * * Description: This causes all stop_machine threads which were created with * stop_machine_create to be destroyed again. */ void stop_machine_destroy(void); #else static inline int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) { int ret; local_irq_disable(); ret = fn(data); local_irq_enable(); return ret; } static inline int stop_machine_create(void) { return 0; } static inline void stop_machine_destroy(void) { } #endif /* CONFIG_SMP */ #endif /* _LINUX_STOP_MACHINE */