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 22 #define __raw_spin_is_locked(x) ((x)->slock == 0) 23 24 static inline void __raw_spin_lock(raw_spinlock_t *lock) 25 { 26 lock->slock = 0; 27 } 28 29 static inline void 30 __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags) 31 { 32 local_irq_save(flags); 33 lock->slock = 0; 34 } 35 36 static inline int __raw_spin_trylock(raw_spinlock_t *lock) 37 { 38 char oldval = lock->slock; 39 40 lock->slock = 0; 41 42 return oldval > 0; 43 } 44 45 static inline void __raw_spin_unlock(raw_spinlock_t *lock) 46 { 47 lock->slock = 1; 48 } 49 50 /* 51 * Read-write spinlocks. No debug version. 52 */ 53 #define __raw_read_lock(lock) do { (void)(lock); } while (0) 54 #define __raw_write_lock(lock) do { (void)(lock); } while (0) 55 #define __raw_read_trylock(lock) ({ (void)(lock); 1; }) 56 #define __raw_write_trylock(lock) ({ (void)(lock); 1; }) 57 #define __raw_read_unlock(lock) do { (void)(lock); } while (0) 58 #define __raw_write_unlock(lock) do { (void)(lock); } while (0) 59 60 #else /* DEBUG_SPINLOCK */ 61 #define __raw_spin_is_locked(lock) ((void)(lock), 0) 62 /* for sched.c and kernel_lock.c: */ 63 # define __raw_spin_lock(lock) do { (void)(lock); } while (0) 64 # define __raw_spin_unlock(lock) do { (void)(lock); } while (0) 65 # define __raw_spin_trylock(lock) ({ (void)(lock); 1; }) 66 #endif /* DEBUG_SPINLOCK */ 67 68 #define __raw_read_can_lock(lock) (((void)(lock), 1)) 69 #define __raw_write_can_lock(lock) (((void)(lock), 1)) 70 71 #define __raw_spin_unlock_wait(lock) \ 72 do { cpu_relax(); } while (__raw_spin_is_locked(lock)) 73 74 #endif /* __LINUX_SPINLOCK_UP_H */ 75