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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __LINUX_SMPLOCK_H
2#define __LINUX_SMPLOCK_H
3
Al Virof0373602005-11-13 16:06:57 -08004#ifdef CONFIG_LOCK_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#define kernel_locked() (current->lock_depth >= 0)
8
9extern int __lockfunc __reacquire_kernel_lock(void);
10extern void __lockfunc __release_kernel_lock(void);
11
12/*
13 * Release/re-acquire global kernel lock for the scheduler
14 */
15#define release_kernel_lock(tsk) do { \
16 if (unlikely((tsk)->lock_depth >= 0)) \
17 __release_kernel_lock(); \
18} while (0)
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020static inline int reacquire_kernel_lock(struct task_struct *task)
21{
22 if (unlikely(task->lock_depth >= 0))
Ingo Molnar6478d882008-01-25 21:08:33 +010023 return __reacquire_kernel_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 return 0;
25}
26
Frederic Weisbecker925936e2009-09-28 17:12:49 +020027extern void __lockfunc
28_lock_kernel(const char *func, const char *file, int line)
29__acquires(kernel_lock);
Frederic Weisbecker96a2c462009-08-01 01:34:24 +020030
Frederic Weisbecker925936e2009-09-28 17:12:49 +020031extern void __lockfunc
32_unlock_kernel(const char *func, const char *file, int line)
33__releases(kernel_lock);
Frederic Weisbecker96a2c462009-08-01 01:34:24 +020034
Frederic Weisbecker925936e2009-09-28 17:12:49 +020035#define lock_kernel() do { \
36 _lock_kernel(__func__, __FILE__, __LINE__); \
37} while (0)
38
39#define unlock_kernel() do { \
40 _unlock_kernel(__func__, __FILE__, __LINE__); \
41} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Jonathan Corbet0b280672008-05-18 14:27:41 -060043/*
44 * Various legacy drivers don't really need the BKL in a specific
45 * function, but they *do* need to know that the BKL became available.
46 * This function just avoids wrapping a bunch of lock/unlock pairs
47 * around code which doesn't really need it.
48 */
49static inline void cycle_kernel_lock(void)
50{
51 lock_kernel();
52 unlock_kernel();
53}
54
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#else
56
Arnd Bergmann6de5bd12010-09-11 18:00:57 +020057#ifdef CONFIG_BKL /* provoke build bug if not set */
Frederic Weisbecker925936e2009-09-28 17:12:49 +020058#define lock_kernel()
59#define unlock_kernel()
Jonathan Corbet0b280672008-05-18 14:27:41 -060060#define cycle_kernel_lock() do { } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#define kernel_locked() 1
Arnd Bergmann6de5bd12010-09-11 18:00:57 +020062#endif /* CONFIG_BKL */
63
64#define release_kernel_lock(task) do { } while(0)
65#define reacquire_kernel_lock(task) 0
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67#endif /* CONFIG_LOCK_KERNEL */
68#endif /* __LINUX_SMPLOCK_H */