1 #ifndef __LINUX_SPINLOCK_UP_H 2 #define __LINUX_SPINLOCK_UP_H 3 4 #ifndef __LINUX_SPINLOCK_H 5 # error "please don't include this file directly" 6 #endif 7 8 /* 9 * include/linux/spinlock_up.h - UP-debug version of spinlocks. 10 * 11 * portions Copyright 2005, Red Hat, Inc., Ingo Molnar 12 * Released under the General Public License (GPL). 13 * 14 * In the debug case, 1 means unlocked, 0 means locked. (the values 15 * are inverted, to catch initialization bugs) 16 * 17 * No atomicity anywhere, we are on UP. 18 */ 19 20 #ifdef CONFIG_DEBUG_SPINLOCK 21 #define __raw_spin_is_locked(x) ((x)->slock == 0) 22 23 static inline void __raw_spin_lock(raw_spinlock_t *lock) 24 { 25 lock->slock = 0; 26 } 27 28 static inline void 29 __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags) 30 { 31 local_irq_save(flags); 32 lock->slock = 0; 33 } 34 35 static inline int __raw_spin_trylock(raw_spinlock_t *lock) 36 { 37 char oldval = lock->slock; 38 39 lock->slock = 0; 40 41 return oldval > 0; 42 } 43 44 static inline void __raw_spin_unlock(raw_spinlock_t *lock) 45 { 46 lock->slock = 1; 47 } 48 49 /* 50 * Read-write spinlocks. No debug version. 51 */ 52 #define __raw_read_lock(lock) do { (void)(lock); } while (0) 53 #define __raw_write_lock(lock) do { (void)(lock); } while (0) 54 #define __raw_read_trylock(lock) ({ (void)(lock); 1; }) 55 #define __raw_write_trylock(lock) ({ (void)(lock); 1; }) 56 #define __raw_read_unlock(lock) do { (void)(lock); } while (0) 57 #define __raw_write_unlock(lock) do { (void)(lock); } while (0) 58 59 #else /* DEBUG_SPINLOCK */ 60 #define __raw_spin_is_locked(lock) ((void)(lock), 0) 61 /* for sched.c and kernel_lock.c: */ 62 # define __raw_spin_lock(lock) do { (void)(lock); } while (0) 63 # define __raw_spin_unlock(lock) do { (void)(lock); } while (0) 64 # define __raw_spin_trylock(lock) ({ (void)(lock); 1; }) 65 #endif /* DEBUG_SPINLOCK */ 66 67 #define __raw_read_can_lock(lock) (((void)(lock), 1)) 68 #define __raw_write_can_lock(lock) (((void)(lock), 1)) 69 70 #define __raw_spin_unlock_wait(lock) \ 71 do { cpu_relax(); } while (__raw_spin_is_locked(lock)) 72 73 #endif /* __LINUX_SPINLOCK_UP_H */ 74
