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 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 reacquire_kernel_lock(struct task_struct * task)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 27 extern void __lockfunc lock_kernel(void) __acquires(kernel_lock); 28 extern 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 */ cycle_kernel_lock(void)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