/* Atomic operations usable in machine independent code */
  #ifndef _LINUX_ATOMIC_H
  #define _LINUX_ATOMIC_H
  #include <asm/atomic.h>
  
  /**
   * atomic_add_unless - add unless the number is already a given value
   * @v: pointer of type atomic_t
   * @a: the amount to add to v...
   * @u: ...unless v is equal to u.
   *
   * Atomically adds @a to @v, so long as @v was not already @u.
   * Returns non-zero if @v was not @u, and zero otherwise.
   */
  static inline int atomic_add_unless(atomic_t *v, int a, int u)
  {
  	return __atomic_add_unless(v, a, u) != u;
  }
  
  /**
   * atomic_inc_not_zero - increment unless the number is zero
   * @v: pointer of type atomic_t
   *
   * Atomically increments @v by 1, so long as @v is non-zero.
   * Returns non-zero if @v was non-zero, and zero otherwise.
   */
  #ifndef atomic_inc_not_zero
  #define atomic_inc_not_zero(v)		atomic_add_unless((v), 1, 0)
  #endif
  
  /**
   * atomic_inc_not_zero_hint - increment if not null
   * @v: pointer of type atomic_t
   * @hint: probable value of the atomic before the increment
   *
   * This version of atomic_inc_not_zero() gives a hint of probable
   * value of the atomic. This helps processor to not read the memory
   * before doing the atomic read/modify/write cycle, lowering
   * number of bus transactions on some arches.
   *
   * Returns: 0 if increment was not done, 1 otherwise.
   */
  #ifndef atomic_inc_not_zero_hint
  static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint)
  {
  	int val, c = hint;
  
  	/* sanity test, should be removed by compiler if hint is a constant */
  	if (!hint)
  		return atomic_inc_not_zero(v);
  
  	do {
  		val = atomic_cmpxchg(v, c, c + 1);
  		if (val == c)
  			return 1;
  		c = val;
  	} while (c);
  
  	return 0;
  }
  #endif
  
  #ifndef atomic_inc_unless_negative
  static inline int atomic_inc_unless_negative(atomic_t *p)
  {
  	int v, v1;
  	for (v = 0; v >= 0; v = v1) {
  		v1 = atomic_cmpxchg(p, v, v + 1);
  		if (likely(v1 == v))
  			return 1;
  	}
  	return 0;
  }
  #endif
  
  #ifndef atomic_dec_unless_positive
  static inline int atomic_dec_unless_positive(atomic_t *p)
  {
  	int v, v1;
  	for (v = 0; v <= 0; v = v1) {
  		v1 = atomic_cmpxchg(p, v, v - 1);
  		if (likely(v1 == v))
  			return 1;
  	}
  	return 0;
  }
  #endif
  
  /*
   * atomic_dec_if_positive - decrement by 1 if old value positive
   * @v: pointer of type atomic_t
   *
   * The function returns the old value of *v minus 1, even if
   * the atomic variable, v, was not decremented.
   */
  #ifndef atomic_dec_if_positive
  static inline int atomic_dec_if_positive(atomic_t *v)
  {
  	int c, old, dec;
  	c = atomic_read(v);
  	for (;;) {
  		dec = c - 1;
  		if (unlikely(dec < 0))
  			break;
  		old = atomic_cmpxchg((v), c, dec);
  		if (likely(old == c))
  			break;
  		c = old;
  	}
  	return dec;
  }
  #endif
  
  #ifndef CONFIG_ARCH_HAS_ATOMIC_OR
  static inline void atomic_or(int i, atomic_t *v)
  {
  	int old;
  	int new;
  
  	do {
  		old = atomic_read(v);
  		new = old | i;
  	} while (atomic_cmpxchg(v, old, new) != old);
  }
  #endif /* #ifndef CONFIG_ARCH_HAS_ATOMIC_OR */
  
  #include <asm-generic/atomic-long.h>
  #ifdef CONFIG_GENERIC_ATOMIC64
  #include <asm-generic/atomic64.h>
  #endif
  #endif /* _LINUX_ATOMIC_H */