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#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 */
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