Viewing file:  spinlock.h (3.23 KB) -rw-r--r--
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#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H
#include <asm/system.h>
/*
* Simple spin lock operations.
*
* (the type definitions are in asm/raw_spinlock_types.h)
*/
#define __raw_spin_is_locked(x) ((x)->slock != 0)
#define __raw_spin_unlock_wait(lock) \
do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0)
#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
static inline void __raw_spin_lock(raw_spinlock_t *lock)
{
unsigned long tmp;
__asm__ __volatile__(
"b 1f # __raw_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->slock), "r"(1)
: "cr0", "memory");
}
static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
__asm__ __volatile__("eieio # __raw_spin_unlock": : :"memory");
lock->slock = 0;
}
#define __raw_spin_trylock(l) (!test_and_set_bit(0,(volatile unsigned long *)(&(l)->slock)))
/*
* 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.
*/
#define __raw_read_can_lock(rw) ((rw)->lock >= 0)
#define __raw_write_can_lock(rw) (!(rw)->lock)
static __inline__ int __raw_read_trylock(raw_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(raw_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(raw_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(raw_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(raw_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(raw_rwlock_t *rw)
{
__asm__ __volatile__("eieio # write_unlock": : :"memory");
rw->lock = 0;
}
#define _raw_spin_relax(lock) cpu_relax()
#define _raw_read_relax(lock) cpu_relax()
#define _raw_write_relax(lock) cpu_relax()
#endif /* __ASM_SPINLOCK_H */
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