Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | |
bf200296 | 6 | disables preeempt. */ |
1da177e4 | 7 | #include <linux/cpu.h> |
eeec4fad | 8 | #include <linux/cpumask.h> |
1da177e4 LT |
9 | #include <asm/system.h> |
10 | ||
11 | #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) | |
5c2aed62 | 12 | |
1da177e4 | 13 | /** |
eeec4fad | 14 | * stop_machine: freeze the machine on all CPUs and run this function |
1da177e4 LT |
15 | * @fn: the function to run |
16 | * @data: the data ptr for the @fn() | |
eeec4fad | 17 | * @cpus: the cpus to run the @fn() on (NULL = any online cpu) |
1da177e4 | 18 | * |
ffdb5976 RR |
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 | |
22 | * @fn() runs. | |
1da177e4 LT |
23 | * |
24 | * This can be thought of as a very heavy write lock, equivalent to | |
25 | * grabbing every spinlock in the kernel. */ | |
41c7bb95 | 26 | int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); |
1da177e4 LT |
27 | |
28 | /** | |
eeec4fad | 29 | * __stop_machine: freeze the machine on all CPUs and run this function |
1da177e4 LT |
30 | * @fn: the function to run |
31 | * @data: the data ptr for the @fn | |
eeec4fad | 32 | * @cpus: the cpus to run the @fn() on (NULL = any online cpu) |
1da177e4 | 33 | * |
ffdb5976 RR |
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. | |
1da177e4 | 36 | */ |
41c7bb95 | 37 | int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); |
9ea09af3 HC |
38 | |
39 | /** | |
40 | * stop_machine_create: create all stop_machine threads | |
41 | * | |
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. | |
45 | */ | |
46 | int stop_machine_create(void); | |
47 | ||
48 | /** | |
49 | * stop_machine_destroy: destroy all stop_machine threads | |
50 | * | |
51 | * Description: This causes all stop_machine threads which were created with | |
52 | * stop_machine_create to be destroyed again. | |
53 | */ | |
54 | void stop_machine_destroy(void); | |
55 | ||
1da177e4 LT |
56 | #else |
57 | ||
eeec4fad | 58 | static inline int stop_machine(int (*fn)(void *), void *data, |
41c7bb95 | 59 | const struct cpumask *cpus) |
1da177e4 LT |
60 | { |
61 | int ret; | |
62 | local_irq_disable(); | |
63 | ret = fn(data); | |
64 | local_irq_enable(); | |
65 | return ret; | |
66 | } | |
9ea09af3 HC |
67 | |
68 | static inline int stop_machine_create(void) { return 0; } | |
69 | static inline void stop_machine_destroy(void) { } | |
70 | ||
1da177e4 LT |
71 | #endif /* CONFIG_SMP */ |
72 | #endif /* _LINUX_STOP_MACHINE */ |