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/*
* BK Id: SCCS/s.spinlock.h 1.9 08/21/01 16:07:48 trini
*/
#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H
#include <asm/system.h>
#undef SPINLOCK_DEBUG
/*
* Simple spin lock operations.
*/
typedef struct {
volatile unsigned long lock;
#ifdef SPINLOCK_DEBUG
volatile unsigned long owner_pc;
volatile unsigned long owner_cpu;
#endif
} spinlock_t;
#ifdef __KERNEL__
#if SPINLOCK_DEBUG
#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))
#ifndef SPINLOCK_DEBUG
static inline void 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\
stwcx. %2,0,%1\n\
bne- 2b\n\
isync"
: "=&r"(tmp)
: "r"(&lock->lock), "r"(1)
: "cr0", "memory");
}
static inline void spin_unlock(spinlock_t *lock)
{
__asm__ __volatile__("eieio # spin_unlock": : :"memory");
lock->lock = 0;
}
#define spin_trylock(lock) (!test_and_set_bit(0,(lock)))
#else
extern void _spin_lock(spinlock_t *lock);
extern void _spin_unlock(spinlock_t *lock);
extern int spin_trylock(spinlock_t *lock);
extern unsigned long __spin_trylock(volatile unsigned long *lock);
#define spin_lock(lp) _spin_lock(lp)
#define spin_unlock(lp) _spin_unlock(lp)
#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 unsigned long lock;
#ifdef SPINLOCK_DEBUG
volatile unsigned long owner_pc;
#endif
} rwlock_t;
#if SPINLOCK_DEBUG
#define RWLOCK_DEBUG_INIT , 0
#else
#define RWLOCK_DEBUG_INIT /* */
#endif
#define RW_LOCK_UNLOCKED (rwlock_t) { 0 RWLOCK_DEBUG_INIT }
#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
#ifndef SPINLOCK_DEBUG
static __inline__ void read_lock(rwlock_t *rw)
{
unsigned 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\
stwcx. %0,0,%1\n\
bne- 2b\n\
isync"
: "=&r"(tmp)
: "r"(&rw->lock)
: "cr0", "memory");
}
static __inline__ void read_unlock(rwlock_t *rw)
{
unsigned int tmp;
__asm__ __volatile__(
"eieio # read_unlock\n\
1: lwarx %0,0,%1\n\
addic %0,%0,-1\n\
stwcx. %0,0,%1\n\
bne- 1b"
: "=&r"(tmp)
: "r"(&rw->lock)
: "cr0", "memory");
}
static __inline__ void write_lock(rwlock_t *rw)
{
unsigned 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\
stwcx. %2,0,%1\n\
bne- 2b\n\
isync"
: "=&r"(tmp)
: "r"(&rw->lock), "r"(-1)
: "cr0", "memory");
}
static __inline__ void write_unlock(rwlock_t *rw)
{
__asm__ __volatile__("eieio # write_unlock": : :"memory");
rw->lock = 0;
}
#else
extern void _read_lock(rwlock_t *rw);
extern void _read_unlock(rwlock_t *rw);
extern void _write_lock(rwlock_t *rw);
extern void _write_unlock(rwlock_t *rw);
#define read_lock(rw) _read_lock(rw)
#define write_lock(rw) _write_lock(rw)
#define write_unlock(rw) _write_unlock(rw)
#define read_unlock(rw) _read_unlock(rw)
#endif
#endif /* __ASM_SPINLOCK_H */
#endif /* __KERNEL__ */
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