diff options
Diffstat (limited to 'include/asm-ppc/spinlock.h')
| -rw-r--r-- | include/asm-ppc/spinlock.h | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/include/asm-ppc/spinlock.h b/include/asm-ppc/spinlock.h new file mode 100644 index 00000000000..909199aae10 --- /dev/null +++ b/include/asm-ppc/spinlock.h @@ -0,0 +1,215 @@ +#ifndef __ASM_SPINLOCK_H +#define __ASM_SPINLOCK_H + +#include <asm/system.h> + +/* + * Simple spin lock operations. + */ + +typedef struct { + volatile unsigned long lock; +#ifdef CONFIG_DEBUG_SPINLOCK + volatile unsigned long owner_pc; + volatile unsigned long owner_cpu; +#endif +#ifdef CONFIG_PREEMPT + unsigned int break_lock; +#endif +} spinlock_t; + +#ifdef __KERNEL__ +#ifdef CONFIG_DEBUG_SPINLOCK +#define SPINLOCK_DEBUG_INIT , 0, 0 +#else +#define SPINLOCK_DEBUG_INIT /* */ +#endif + +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 SPINLOCK_DEBUG_INIT } + +#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) + +#ifndef CONFIG_DEBUG_SPINLOCK + +static inline void _raw_spin_lock(spinlock_t *lock) +{ + unsigned long tmp; + + __asm__ __volatile__( + "b 1f # spin_lock\n\ +2: lwzx %0,0,%1\n\ + cmpwi 0,%0,0\n\ + bne+ 2b\n\ +1: lwarx %0,0,%1\n\ + cmpwi 0,%0,0\n\ + bne- 2b\n" + PPC405_ERR77(0,%1) +" stwcx. %2,0,%1\n\ + bne- 2b\n\ + isync" + : "=&r"(tmp) + : "r"(&lock->lock), "r"(1) + : "cr0", "memory"); +} + +static inline void _raw_spin_unlock(spinlock_t *lock) +{ + __asm__ __volatile__("eieio # spin_unlock": : :"memory"); + lock->lock = 0; +} + +#define _raw_spin_trylock(l) (!test_and_set_bit(0,&(l)->lock)) + +#else + +extern void _raw_spin_lock(spinlock_t *lock); +extern void _raw_spin_unlock(spinlock_t *lock); +extern int _raw_spin_trylock(spinlock_t *lock); + +#endif + +/* + * Read-write spinlocks, allowing multiple readers + * but only one writer. + * + * NOTE! it is quite common to have readers in interrupts + * but no interrupt writers. For those circumstances we + * can "mix" irq-safe locks - any writer needs to get a + * irq-safe write-lock, but readers can get non-irqsafe + * read-locks. + */ +typedef struct { + volatile signed int lock; +#ifdef CONFIG_PREEMPT + unsigned int break_lock; +#endif +} rwlock_t; + +#define RW_LOCK_UNLOCKED (rwlock_t) { 0 } +#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0) + +#define read_can_lock(rw) ((rw)->lock >= 0) +#define write_can_lock(rw) (!(rw)->lock) + +#ifndef CONFIG_DEBUG_SPINLOCK + +static __inline__ int _raw_read_trylock(rwlock_t *rw) +{ + signed int tmp; + + __asm__ __volatile__( +"2: lwarx %0,0,%1 # read_trylock\n\ + addic. %0,%0,1\n\ + ble- 1f\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1\n\ + bne- 2b\n\ + isync\n\ +1:" + : "=&r"(tmp) + : "r"(&rw->lock) + : "cr0", "memory"); + + return tmp > 0; +} + +static __inline__ void _raw_read_lock(rwlock_t *rw) +{ + signed int tmp; + + __asm__ __volatile__( + "b 2f # read_lock\n\ +1: lwzx %0,0,%1\n\ + cmpwi 0,%0,0\n\ + blt+ 1b\n\ +2: lwarx %0,0,%1\n\ + addic. %0,%0,1\n\ + ble- 1b\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1\n\ + bne- 2b\n\ + isync" + : "=&r"(tmp) + : "r"(&rw->lock) + : "cr0", "memory"); +} + +static __inline__ void _raw_read_unlock(rwlock_t *rw) +{ + signed int tmp; + + __asm__ __volatile__( + "eieio # read_unlock\n\ +1: lwarx %0,0,%1\n\ + addic %0,%0,-1\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1\n\ + bne- 1b" + : "=&r"(tmp) + : "r"(&rw->lock) + : "cr0", "memory"); +} + +static __inline__ int _raw_write_trylock(rwlock_t *rw) +{ + signed int tmp; + + __asm__ __volatile__( +"2: lwarx %0,0,%1 # write_trylock\n\ + cmpwi 0,%0,0\n\ + bne- 1f\n" + PPC405_ERR77(0,%1) +" stwcx. %2,0,%1\n\ + bne- 2b\n\ + isync\n\ +1:" + : "=&r"(tmp) + : "r"(&rw->lock), "r"(-1) + : "cr0", "memory"); + + return tmp == 0; +} + +static __inline__ void _raw_write_lock(rwlock_t *rw) +{ + signed int tmp; + + __asm__ __volatile__( + "b 2f # write_lock\n\ +1: lwzx %0,0,%1\n\ + cmpwi 0,%0,0\n\ + bne+ 1b\n\ +2: lwarx %0,0,%1\n\ + cmpwi 0,%0,0\n\ + bne- 1b\n" + PPC405_ERR77(0,%1) +" stwcx. %2,0,%1\n\ + bne- 2b\n\ + isync" + : "=&r"(tmp) + : "r"(&rw->lock), "r"(-1) + : "cr0", "memory"); +} + +static __inline__ void _raw_write_unlock(rwlock_t *rw) +{ + __asm__ __volatile__("eieio # write_unlock": : :"memory"); + rw->lock = 0; +} + +#else + +extern void _raw_read_lock(rwlock_t *rw); +extern void _raw_read_unlock(rwlock_t *rw); +extern void _raw_write_lock(rwlock_t *rw); +extern void _raw_write_unlock(rwlock_t *rw); +extern int _raw_read_trylock(rwlock_t *rw); +extern int _raw_write_trylock(rwlock_t *rw); + +#endif + +#endif /* __ASM_SPINLOCK_H */ +#endif /* __KERNEL__ */ |