include/asm-ppc/spinlock.h

   1 #ifdef __KERNEL__
   2 #ifndef __ASM_SPINLOCK_H
   3 #define __ASM_SPINLOCK_H
   4
   5 /*
   6  * Simple spin lock operations.
   7  */
   8
   9 typedef struct {
  10         volatile unsigned long lock;
  11         volatile unsigned long owner_pc;
  12         volatile unsigned long owner_cpu;
  13 } spinlock_t;
  14
  15 #define SPIN_LOCK_UNLOCKED      (spinlock_t) { 0, 0, 0 }
  16 #define spin_lock_init(lp)      do { (lp)->lock = 0; } while(0)
  17 #define spin_unlock_wait(lp)    do { barrier(); } while((lp)->lock)
  18 #define spin_is_locked(x)       ((x)->lock != 0)
  19
  20 extern void _spin_lock(spinlock_t *lock);
  21 extern void _spin_unlock(spinlock_t *lock);
  22 extern int spin_trylock(spinlock_t *lock);
  23
  24 #define spin_lock(lp)                   _spin_lock(lp)
  25 #define spin_unlock(lp)                 _spin_unlock(lp)
  26
  27 extern unsigned long __spin_trylock(volatile unsigned long *lock);
  28
  29 /*
  30  * Read-write spinlocks, allowing multiple readers
  31  * but only one writer.
  32  *
  33  * NOTE! it is quite common to have readers in interrupts
  34  * but no interrupt writers. For those circumstances we
  35  * can "mix" irq-safe locks - any writer needs to get a
  36  * irq-safe write-lock, but readers can get non-irqsafe
  37  * read-locks.
  38  */
  39 typedef struct {
  40         volatile unsigned long lock;
  41         volatile unsigned long owner_pc;
  42 } rwlock_t;
  43
  44 #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }
  45 #define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
  46
  47 extern void _read_lock(rwlock_t *rw);
  48 extern void _read_unlock(rwlock_t *rw);
  49 extern void _write_lock(rwlock_t *rw);
  50 extern void _write_unlock(rwlock_t *rw);
  51
  52 #define read_lock(rw)           _read_lock(rw)
  53 #define write_lock(rw)          _write_lock(rw)
  54 #define write_unlock(rw)        _write_unlock(rw)
  55 #define read_unlock(rw)         _read_unlock(rw)
  56
  57 #endif /* __ASM_SPINLOCK_H */
  58 #endif /* __KERNEL__ */