projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | #ifndef __LINUX_SMPLOCK_H |
| 2 | #define __LINUX_SMPLOCK_H | |
| 3 | ||
| 4 | #include <linux/config.h> | |
| 5 | #include <linux/sched.h> | |
| 6 | #include <linux/spinlock.h> | |
| 7 | ||
| 8 | #ifdef CONFIG_LOCK_KERNEL | |
| 9 | ||
| 10 | #define kernel_locked() (current->lock_depth >= 0) | |
| 11 | ||
| 12 | extern int __lockfunc __reacquire_kernel_lock(void); | |
| 13 | extern void __lockfunc __release_kernel_lock(void); | |
| 14 | ||
| 15 | /* | |
| 16 | * Release/re-acquire global kernel lock for the scheduler | |
| 17 | */ | |
| 18 | #define release_kernel_lock(tsk) do { \ | |
| 19 | if (unlikely((tsk)->lock_depth >= 0)) \ | |
| 20 | __release_kernel_lock(); \ | |
| 21 | } while (0) | |
| 22 | ||
| 23 | /* | |
| 24 | * Non-SMP kernels will never block on the kernel lock, | |
| 25 | * so we are better off returning a constant zero from | |
| 26 | * reacquire_kernel_lock() so that the compiler can see | |
| 27 | * it at compile-time. | |
| 28 | */ | |
| 29 | #if defined(CONFIG_SMP) && !defined(CONFIG_PREEMPT_BKL) | |
| 30 | # define return_value_on_smp return | |
| 31 | #else | |
| 32 | # define return_value_on_smp | |
| 33 | #endif | |
| 34 | ||
| 35 | static inline int reacquire_kernel_lock(struct task_struct *task) | |
| 36 | { | |
| 37 | if (unlikely(task->lock_depth >= 0)) | |
| 38 | return_value_on_smp __reacquire_kernel_lock(); | |
| 39 | return 0; | |
| 40 | } | |
| 41 | ||
| 42 | extern void __lockfunc lock_kernel(void) __acquires(kernel_lock); | |
| 43 | extern void __lockfunc unlock_kernel(void) __releases(kernel_lock); | |
| 44 | ||
| 45 | #else | |
| 46 | ||
| 47 | #define lock_kernel() do { } while(0) | |
| 48 | #define unlock_kernel() do { } while(0) | |
| 49 | #define release_kernel_lock(task) do { } while(0) | |
| 50 | #define reacquire_kernel_lock(task) 0 | |
| 51 | #define kernel_locked() 1 | |
| 52 | ||
| 53 | #endif /* CONFIG_LOCK_KERNEL */ | |
| 54 | #endif /* __LINUX_SMPLOCK_H */ |