spinlock.h

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#ifndef __SPINLOCK_H__
#define __SPINLOCK_H__

#include <gctypes.h>
#include <lwp_threads.h>

typedef struct {
 vu32 lock;
} spinlock_t;

#define SPIN_LOCK_UNLOCKED (spinlock_t){0}

#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; }while(0)

static __inline__ u32 _test_and_set(u32 *atomic)
{
 register u32 ret;

 __asm__ __volatile__ ("1: lwarx %0,0,%1\n"
 " cmpwi 0,%0,0\n"
 " bne- 2f\n"
 " stwcx. %2,0,%1\n"
 " bne- 1b\n"
 " isync\n"
 "2:" : "=&r"(ret)
 : "r"(atomic), "r"(1)
 : "cr0", "memory");

 return ret;
}

static __inline__ u32 atomic_inc(u32 *pint)
{
 register u32 ret;
 __asm__ __volatile__(
 "1: lwarx %0,0,%1\n\
 addi %0,%0,1\n\
 stwcx. %0,0,%1\n\
 bne- 1b\n\
 isync\n"
 : "=&r"(ret) : "r"(pint)
 : "cr0", "memory");
 return ret;
}

static __inline__ u32 atomic_dec(u32 *pint)
{
 register u32 ret;
 __asm__ __volatile__(
 "1: lwarx %0,0,%1\n\
 addi %0,%0,-1\n\
 stwcx. %0,0,%1\n\
 bne- 1b\n\
 isync\n"
 : "=&r"(ret) : "r"(pint)
 : "cr0", "memory");
 return ret;
}

static __inline__ void spin_lock(spinlock_t *lock)
{
 register u32 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), "r"(1)
 : "cr0", "memory");
}

static __inline__ void spin_lock_irqsave(spinlock_t *lock,register u32 *p_isr_level)
{
 register u32 level;
 register u32 tmp;

 _CPU_ISR_Disable(level);

 __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), "r"(1)
 : "cr0", "memory");

 *p_isr_level = level;
}

static __inline__ void spin_unlock(spinlock_t *lock)
{
 __asm__ __volatile__("eieio # spin_unlock": : :"memory");
 lock->lock = 0;
}

static __inline__ void spin_unlock_irqrestore(spinlock_t *lock,register u32 isr_level)
{
 __asm__ __volatile__(
 "eieio # spin_unlock"
 : : :"memory");
 lock->lock = 0;

 _CPU_ISR_Restore(isr_level);
}

typedef struct {
 vu32 lock;
} rwlock_t;

#define RW_LOCK_UNLOCKED (rwlock_t){0}

#define read_lock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; }while(0)

static __inline__ void read_lock(rwlock_t *rw)
{
 register u32 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)
{
 register u32 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)
{
 register u32 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;
}


#endif