diff options
Diffstat (limited to 'include/asm-arm/spinlock.h')
| -rw-r--r-- | include/asm-arm/spinlock.h | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/include/asm-arm/spinlock.h b/include/asm-arm/spinlock.h deleted file mode 100644 index 1f906d09b68..00000000000 --- a/include/asm-arm/spinlock.h +++ /dev/null @@ -1,195 +0,0 @@ -#ifndef __ASM_SPINLOCK_H -#define __ASM_SPINLOCK_H - -#if __LINUX_ARM_ARCH__ < 6 -#error SMP not supported on pre-ARMv6 CPUs -#endif - -/* - * ARMv6 Spin-locking. - * - * We exclusively read the old value. If it is zero, we may have - * won the lock, so we try exclusively storing it. A memory barrier - * is required after we get a lock, and before we release it, because - * V6 CPUs are assumed to have weakly ordered memory. - * - * Unlocked value: 0 - * Locked value: 1 - */ -typedef struct { - volatile unsigned int lock; -#ifdef CONFIG_PREEMPT - unsigned int break_lock; -#endif -} spinlock_t; - -#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } - -#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while (0) -#define spin_is_locked(x) ((x)->lock != 0) -#define spin_unlock_wait(x) do { barrier(); } while (spin_is_locked(x)) -#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) - -static inline void _raw_spin_lock(spinlock_t *lock) -{ - unsigned long tmp; - - __asm__ __volatile__( -"1: ldrex %0, [%1]\n" -" teq %0, #0\n" -" strexeq %0, %2, [%1]\n" -" teqeq %0, #0\n" -" bne 1b" - : "=&r" (tmp) - : "r" (&lock->lock), "r" (1) - : "cc"); - - smp_mb(); -} - -static inline int _raw_spin_trylock(spinlock_t *lock) -{ - unsigned long tmp; - - __asm__ __volatile__( -" ldrex %0, [%1]\n" -" teq %0, #0\n" -" strexeq %0, %2, [%1]" - : "=&r" (tmp) - : "r" (&lock->lock), "r" (1) - : "cc"); - - if (tmp == 0) { - smp_mb(); - return 1; - } else { - return 0; - } -} - -static inline void _raw_spin_unlock(spinlock_t *lock) -{ - smp_mb(); - - __asm__ __volatile__( -" str %1, [%0]" - : - : "r" (&lock->lock), "r" (0) - : "cc"); -} - -/* - * RWLOCKS - */ -typedef struct { - volatile unsigned int lock; -#ifdef CONFIG_PREEMPT - unsigned int break_lock; -#endif -} rwlock_t; - -#define RW_LOCK_UNLOCKED (rwlock_t) { 0 } -#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while (0) -#define rwlock_is_locked(x) (*((volatile unsigned int *)(x)) != 0) - -/* - * Write locks are easy - we just set bit 31. When unlocking, we can - * just write zero since the lock is exclusively held. - */ -static inline void _raw_write_lock(rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__( -"1: ldrex %0, [%1]\n" -" teq %0, #0\n" -" strexeq %0, %2, [%1]\n" -" teq %0, #0\n" -" bne 1b" - : "=&r" (tmp) - : "r" (&rw->lock), "r" (0x80000000) - : "cc"); - - smp_mb(); -} - -static inline int _raw_write_trylock(rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__( -"1: ldrex %0, [%1]\n" -" teq %0, #0\n" -" strexeq %0, %2, [%1]" - : "=&r" (tmp) - : "r" (&rw->lock), "r" (0x80000000) - : "cc"); - - if (tmp == 0) { - smp_mb(); - return 1; - } else { - return 0; - } -} - -static inline void _raw_write_unlock(rwlock_t *rw) -{ - smp_mb(); - - __asm__ __volatile__( - "str %1, [%0]" - : - : "r" (&rw->lock), "r" (0) - : "cc"); -} - -/* - * Read locks are a bit more hairy: - * - Exclusively load the lock value. - * - Increment it. - * - Store new lock value if positive, and we still own this location. - * If the value is negative, we've already failed. - * - If we failed to store the value, we want a negative result. - * - If we failed, try again. - * Unlocking is similarly hairy. We may have multiple read locks - * currently active. However, we know we won't have any write - * locks. - */ -static inline void _raw_read_lock(rwlock_t *rw) -{ - unsigned long tmp, tmp2; - - __asm__ __volatile__( -"1: ldrex %0, [%2]\n" -" adds %0, %0, #1\n" -" strexpl %1, %0, [%2]\n" -" rsbpls %0, %1, #0\n" -" bmi 1b" - : "=&r" (tmp), "=&r" (tmp2) - : "r" (&rw->lock) - : "cc"); - - smp_mb(); -} - -static inline void _raw_read_unlock(rwlock_t *rw) -{ - unsigned long tmp, tmp2; - - smp_mb(); - - __asm__ __volatile__( -"1: ldrex %0, [%2]\n" -" sub %0, %0, #1\n" -" strex %1, %0, [%2]\n" -" teq %1, #0\n" -" bne 1b" - : "=&r" (tmp), "=&r" (tmp2) - : "r" (&rw->lock) - : "cc"); -} - -#define _raw_read_trylock(lock) generic_raw_read_trylock(lock) - -#endif /* __ASM_SPINLOCK_H */ |