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 arch_spin_is_locked(x) ((x)->slock == 0) 22 23static inline void arch_spin_lock(arch_spinlock_t *lock) 24{ 25 lock->slock = 0; 26} 27 28static inline void 29arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags) 30{ 31 local_irq_save(flags); 32 lock->slock = 0; 33} 34 35static inline int arch_spin_trylock(arch_spinlock_t *lock) 36{ 37 char oldval = lock->slock; 38 39 lock->slock = 0; 40 41 return oldval > 0; 42} 43 44static inline void arch_spin_unlock(arch_spinlock_t *lock) 45{ 46 lock->slock = 1; 47} 48 49/* 50 * Read-write spinlocks. No debug version. 51 */ 52#define arch_read_lock(lock) do { (void)(lock); } while (0) 53#define arch_write_lock(lock) do { (void)(lock); } while (0) 54#define arch_read_trylock(lock) ({ (void)(lock); 1; }) 55#define arch_write_trylock(lock) ({ (void)(lock); 1; }) 56#define arch_read_unlock(lock) do { (void)(lock); } while (0) 57#define arch_write_unlock(lock) do { (void)(lock); } while (0) 58 59#else /* DEBUG_SPINLOCK */ 60#define arch_spin_is_locked(lock) ((void)(lock), 0) 61/* for sched.c and kernel_lock.c: */ 62# define arch_spin_lock(lock) do { (void)(lock); } while (0) 63# define arch_spin_lock_flags(lock, flags) do { (void)(lock); } while (0) 64# define arch_spin_unlock(lock) do { (void)(lock); } while (0) 65# define arch_spin_trylock(lock) ({ (void)(lock); 1; }) 66#endif /* DEBUG_SPINLOCK */ 67 68#define arch_spin_is_contended(lock) (((void)(lock), 0)) 69 70#define arch_read_can_lock(lock) (((void)(lock), 1)) 71#define arch_write_can_lock(lock) (((void)(lock), 1)) 72 73#define arch_spin_unlock_wait(lock) \ 74 do { cpu_relax(); } while (arch_spin_is_locked(lock)) 75 76#endif /* __LINUX_SPINLOCK_UP_H */ 77