1#ifndef __LINUX_SMPLOCK_H 2#define __LINUX_SMPLOCK_H 3 4#ifdef CONFIG_LOCK_KERNEL 5#include <linux/sched.h> 6 7#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 20static inline int reacquire_kernel_lock(struct task_struct *task) 21{ 22 if (unlikely(task->lock_depth >= 0)) 23 return __reacquire_kernel_lock(); 24 return 0; 25} 26 27extern void __lockfunc lock_kernel(void) __acquires(kernel_lock); 28extern void __lockfunc unlock_kernel(void) __releases(kernel_lock); 29 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 */ 36static inline void cycle_kernel_lock(void) 37{ 38 lock_kernel(); 39 unlock_kernel(); 40} 41 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) 47#define cycle_kernel_lock() do { } while(0) 48#define reacquire_kernel_lock(task) 0 49#define kernel_locked() 1 50 51#endif /* CONFIG_LOCK_KERNEL */ 52#endif /* __LINUX_SMPLOCK_H */ 53