Commit | Line | Data |
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1da177e4 LT |
1 | #ifndef __LINUX_SMPLOCK_H |
2 | #define __LINUX_SMPLOCK_H | |
3 | ||
f037360f | 4 | #ifdef CONFIG_LOCK_KERNEL |
1da177e4 | 5 | #include <linux/sched.h> |
1da177e4 | 6 | |
1da177e4 LT |
7 | #define kernel_locked() (current->lock_depth >= 0) |
8 | ||
9 | extern int __lockfunc __reacquire_kernel_lock(void); | |
10 | extern 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 | ||
1da177e4 LT |
20 | static inline int reacquire_kernel_lock(struct task_struct *task) |
21 | { | |
22 | if (unlikely(task->lock_depth >= 0)) | |
6478d880 | 23 | return __reacquire_kernel_lock(); |
1da177e4 LT |
24 | return 0; |
25 | } | |
26 | ||
27 | extern void __lockfunc lock_kernel(void) __acquires(kernel_lock); | |
28 | extern void __lockfunc unlock_kernel(void) __releases(kernel_lock); | |
29 | ||
0b280676 JC |
30 | /* |
31 | * Various legacy drivers don't really need the BKL in a specific | |
32 | * function, but they *do* need to know that the BKL became available. | |
33 | * This function just avoids wrapping a bunch of lock/unlock pairs | |
34 | * around code which doesn't really need it. | |
35 | */ | |
36 | static inline void cycle_kernel_lock(void) | |
37 | { | |
38 | lock_kernel(); | |
39 | unlock_kernel(); | |
40 | } | |
41 | ||
1da177e4 LT |
42 | #else |
43 | ||
44 | #define lock_kernel() do { } while(0) | |
45 | #define unlock_kernel() do { } while(0) | |
46 | #define release_kernel_lock(task) do { } while(0) | |
0b280676 | 47 | #define cycle_kernel_lock() do { } while(0) |
1da177e4 LT |
48 | #define reacquire_kernel_lock(task) 0 |
49 | #define kernel_locked() 1 | |
50 | ||
51 | #endif /* CONFIG_LOCK_KERNEL */ | |
52 | #endif /* __LINUX_SMPLOCK_H */ |