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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - include/linux/stop_machine.h
1 #ifndef _LINUX_STOP_MACHINE
2 #define _LINUX_STOP_MACHINE
3 /* "Bogolock": stop the entire machine, disable interrupts. This is a
4 very heavy lock, which is equivalent to grabbing every spinlock
5 (and more). So the "read" side to such a lock is anything which
8 #include <linux/cpumask.h>
9 #include <asm/system.h>
11 #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
14 * stop_machine: freeze the machine on all CPUs and run this function
15 * @fn: the function to run
16 * @data: the data ptr for the @fn()
17 * @cpus: the cpus to run the @fn() on (NULL = any online cpu)
19 * Description: This causes a thread to be scheduled on every cpu,
20 * each of which disables interrupts. The result is that noone is
21 * holding a spinlock or inside any other preempt-disabled region when
24 * This can be thought of as a very heavy write lock, equivalent to
25 * grabbing every spinlock in the kernel. */
26 int stop_machine(int (*fn
)(void *), void *data
, const struct cpumask
*cpus
);
29 * __stop_machine: freeze the machine on all CPUs and run this function
30 * @fn: the function to run
31 * @data: the data ptr for the @fn
32 * @cpus: the cpus to run the @fn() on (NULL = any online cpu)
34 * Description: This is a special version of the above, which assumes cpus
35 * won't come or go while it's being called. Used by hotplug cpu.
37 int __stop_machine(int (*fn
)(void *), void *data
, const struct cpumask
*cpus
);
40 * stop_machine_create: create all stop_machine threads
42 * Description: This causes all stop_machine threads to be created before
43 * stop_machine actually gets called. This can be used by subsystems that
44 * need a non failing stop_machine infrastructure.
46 int stop_machine_create(void);
49 * stop_machine_destroy: destroy all stop_machine threads
51 * Description: This causes all stop_machine threads which were created with
52 * stop_machine_create to be destroyed again.
54 void stop_machine_destroy(void);
58 static inline int stop_machine(int (*fn
)(void *), void *data
,
59 const struct cpumask
*cpus
)
68 static inline int stop_machine_create(void) { return 0; }
69 static inline void stop_machine_destroy(void) { }
71 #endif /* CONFIG_SMP */
72 #endif /* _LINUX_STOP_MACHINE */