#define __ASM_SPINLOCK_H
#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/spinlock_types.h>
-/* Note that PA-RISC has to use `1' to mean unlocked and `0' to mean locked
- * since it only has load-and-zero. Moreover, at least on some PA processors,
- * the semaphore address has to be 16-byte aligned.
- */
-
-#undef SPIN_LOCK_UNLOCKED
-#define SPIN_LOCK_UNLOCKED (spinlock_t) { { 1, 1, 1, 1 } }
-
-#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
-
-static inline int spin_is_locked(spinlock_t *x)
+static inline int __raw_spin_is_locked(raw_spinlock_t *x)
{
volatile unsigned int *a = __ldcw_align(x);
return *a == 0;
}
-#define spin_unlock_wait(x) do { barrier(); } while(spin_is_locked(x))
-#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
+#define __raw_spin_lock(lock) __raw_spin_lock_flags(lock, 0)
+#define __raw_spin_unlock_wait(x) \
+ do { cpu_relax(); } while (__raw_spin_is_locked(x))
-static inline void _raw_spin_lock(spinlock_t *x)
+static inline void __raw_spin_lock_flags(raw_spinlock_t *x,
+ unsigned long flags)
{
- volatile unsigned int *a = __ldcw_align(x);
+ volatile unsigned int *a;
+
+ mb();
+ a = __ldcw_align(x);
while (__ldcw(a) == 0)
- while (*a == 0);
+ while (*a == 0)
+ if (flags & PSW_SM_I) {
+ local_irq_enable();
+ cpu_relax();
+ local_irq_disable();
+ } else
+ cpu_relax();
+ mb();
}
-static inline void _raw_spin_unlock(spinlock_t *x)
+static inline void __raw_spin_unlock(raw_spinlock_t *x)
{
- volatile unsigned int *a = __ldcw_align(x);
+ volatile unsigned int *a;
+ mb();
+ a = __ldcw_align(x);
*a = 1;
+ mb();
}
-static inline int _raw_spin_trylock(spinlock_t *x)
+static inline int __raw_spin_trylock(raw_spinlock_t *x)
{
- volatile unsigned int *a = __ldcw_align(x);
- return __ldcw(a) != 0;
+ volatile unsigned int *a;
+ int ret;
+
+ mb();
+ a = __ldcw_align(x);
+ ret = __ldcw(a) != 0;
+ mb();
+
+ return ret;
}
-
+
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
*/
-typedef struct {
- spinlock_t lock;
- volatile int counter;
-} rwlock_t;
-
-#define RW_LOCK_UNLOCKED (rwlock_t) { { { 1, 1, 1, 1 } }, 0 }
-
-#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while (0)
-#define rwlock_is_locked(lp) ((lp)->counter != 0)
+#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
/* read_lock, read_unlock are pretty straightforward. Of course it somehow
* sucks we end up saving/restoring flags twice for read_lock_irqsave aso. */
-static __inline__ void _raw_read_lock(rwlock_t *rw)
+static __inline__ void __raw_read_lock(raw_rwlock_t *rw)
{
- unsigned long flags;
- local_irq_save(flags);
- _raw_spin_lock(&rw->lock);
+ __raw_spin_lock(&rw->lock);
rw->counter++;
- _raw_spin_unlock(&rw->lock);
- local_irq_restore(flags);
+ __raw_spin_unlock(&rw->lock);
}
-static __inline__ void _raw_read_unlock(rwlock_t *rw)
+static __inline__ void __raw_read_unlock(raw_rwlock_t *rw)
{
- unsigned long flags;
- local_irq_save(flags);
- _raw_spin_lock(&rw->lock);
+ __raw_spin_lock(&rw->lock);
rw->counter--;
- _raw_spin_unlock(&rw->lock);
- local_irq_restore(flags);
+ __raw_spin_unlock(&rw->lock);
}
/* write_lock is less trivial. We optimistically grab the lock and check
* writers) in interrupt handlers someone fucked up and we'd dead-lock
* sooner or later anyway. prumpf */
-static __inline__ void _raw_write_lock(rwlock_t *rw)
+static __inline__ void __raw_write_lock(raw_rwlock_t *rw)
{
retry:
- _raw_spin_lock(&rw->lock);
+ __raw_spin_lock(&rw->lock);
if(rw->counter != 0) {
/* this basically never happens */
- _raw_spin_unlock(&rw->lock);
+ __raw_spin_unlock(&rw->lock);
- while(rw->counter != 0);
+ while (rw->counter != 0)
+ cpu_relax();
goto retry;
}
/* write_unlock is absolutely trivial - we don't have to wait for anything */
-static __inline__ void _raw_write_unlock(rwlock_t *rw)
+static __inline__ void __raw_write_unlock(raw_rwlock_t *rw)
{
rw->counter = 0;
- _raw_spin_unlock(&rw->lock);
+ __raw_spin_unlock(&rw->lock);
}
-static __inline__ int is_read_locked(rwlock_t *rw)
+static __inline__ int __raw_write_trylock(raw_rwlock_t *rw)
{
- return rw->counter > 0;
+ __raw_spin_lock(&rw->lock);
+ if (rw->counter != 0) {
+ /* this basically never happens */
+ __raw_spin_unlock(&rw->lock);
+
+ return 0;
+ }
+
+ /* got it. now leave without unlocking */
+ rw->counter = -1; /* remember we are locked */
+ return 1;
}
-static __inline__ int is_write_locked(rwlock_t *rw)
+/*
+ * read_can_lock - would read_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+static __inline__ int __raw_read_can_lock(raw_rwlock_t *rw)
+{
+ return rw->counter >= 0;
+}
+
+/*
+ * write_can_lock - would write_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+static __inline__ int __raw_write_can_lock(raw_rwlock_t *rw)
{
- return rw->counter < 0;
+ return !rw->counter;
}
#endif /* __ASM_SPINLOCK_H */
git://git.onelab.eu / linux-2.6.git / blobdiff