/* Atomic operations usable in machine independent code */
#ifndef _LINUX_ATOMIC_H
#define _LINUX_ATOMIC_H
+#include <linux/types.h>
+
#include <asm/atomic.h>
#include <asm/barrier.h>
* barriers on top of the relaxed variant. In the case where the relaxed
* variant is already fully ordered, no additional barriers are needed.
*
- * Besides, if an arch has a special barrier for acquire/release, it could
- * implement its own __atomic_op_* and use the same framework for building
- * variants
- *
- * If an architecture overrides __atomic_op_acquire() it will probably want
- * to define smp_mb__after_spinlock().
+ * If an architecture overrides __atomic_acquire_fence() it will probably
+ * want to define smp_mb__after_spinlock().
*/
-#ifndef __atomic_op_acquire
+#ifndef __atomic_acquire_fence
+#define __atomic_acquire_fence smp_mb__after_atomic
+#endif
+
+#ifndef __atomic_release_fence
+#define __atomic_release_fence smp_mb__before_atomic
+#endif
+
+#ifndef __atomic_pre_full_fence
+#define __atomic_pre_full_fence smp_mb__before_atomic
+#endif
+
+#ifndef __atomic_post_full_fence
+#define __atomic_post_full_fence smp_mb__after_atomic
+#endif
+
#define __atomic_op_acquire(op, args...) \
({ \
typeof(op##_relaxed(args)) __ret = op##_relaxed(args); \
- smp_mb__after_atomic(); \
+ __atomic_acquire_fence(); \
__ret; \
})
-#endif
-#ifndef __atomic_op_release
#define __atomic_op_release(op, args...) \
({ \
- smp_mb__before_atomic(); \
+ __atomic_release_fence(); \
op##_relaxed(args); \
})
-#endif
-#ifndef __atomic_op_fence
#define __atomic_op_fence(op, args...) \
({ \
typeof(op##_relaxed(args)) __ret; \
- smp_mb__before_atomic(); \
+ __atomic_pre_full_fence(); \
__ret = op##_relaxed(args); \
- smp_mb__after_atomic(); \
+ __atomic_post_full_fence(); \
__ret; \
})
-#endif
/* atomic_add_return_relaxed */
#ifndef atomic_add_return_relaxed
#endif
#endif /* atomic_add_return_relaxed */
+#ifndef atomic_inc
+#define atomic_inc(v) atomic_add(1, (v))
+#endif
+
/* atomic_inc_return_relaxed */
#ifndef atomic_inc_return_relaxed
+
+#ifndef atomic_inc_return
+#define atomic_inc_return(v) atomic_add_return(1, (v))
+#define atomic_inc_return_relaxed(v) atomic_add_return_relaxed(1, (v))
+#define atomic_inc_return_acquire(v) atomic_add_return_acquire(1, (v))
+#define atomic_inc_return_release(v) atomic_add_return_release(1, (v))
+#else /* atomic_inc_return */
#define atomic_inc_return_relaxed atomic_inc_return
#define atomic_inc_return_acquire atomic_inc_return
#define atomic_inc_return_release atomic_inc_return
+#endif /* atomic_inc_return */
#else /* atomic_inc_return_relaxed */
#endif
#endif /* atomic_sub_return_relaxed */
+#ifndef atomic_dec
+#define atomic_dec(v) atomic_sub(1, (v))
+#endif
+
/* atomic_dec_return_relaxed */
#ifndef atomic_dec_return_relaxed
+
+#ifndef atomic_dec_return
+#define atomic_dec_return(v) atomic_sub_return(1, (v))
+#define atomic_dec_return_relaxed(v) atomic_sub_return_relaxed(1, (v))
+#define atomic_dec_return_acquire(v) atomic_sub_return_acquire(1, (v))
+#define atomic_dec_return_release(v) atomic_sub_return_release(1, (v))
+#else /* atomic_dec_return */
#define atomic_dec_return_relaxed atomic_dec_return
#define atomic_dec_return_acquire atomic_dec_return
#define atomic_dec_return_release atomic_dec_return
+#endif /* atomic_dec_return */
#else /* atomic_dec_return_relaxed */
#endif
#endif /* atomic_fetch_and_relaxed */
-#ifdef atomic_andnot
-/* atomic_fetch_andnot_relaxed */
+#ifndef atomic_andnot
+#define atomic_andnot(i, v) atomic_and(~(int)(i), (v))
+#endif
+
#ifndef atomic_fetch_andnot_relaxed
-#define atomic_fetch_andnot_relaxed atomic_fetch_andnot
-#define atomic_fetch_andnot_acquire atomic_fetch_andnot
-#define atomic_fetch_andnot_release atomic_fetch_andnot
+
+#ifndef atomic_fetch_andnot
+#define atomic_fetch_andnot(i, v) atomic_fetch_and(~(int)(i), (v))
+#define atomic_fetch_andnot_relaxed(i, v) atomic_fetch_and_relaxed(~(int)(i), (v))
+#define atomic_fetch_andnot_acquire(i, v) atomic_fetch_and_acquire(~(int)(i), (v))
+#define atomic_fetch_andnot_release(i, v) atomic_fetch_and_release(~(int)(i), (v))
+#else /* atomic_fetch_andnot */
+#define atomic_fetch_andnot_relaxed atomic_fetch_andnot
+#define atomic_fetch_andnot_acquire atomic_fetch_andnot
+#define atomic_fetch_andnot_release atomic_fetch_andnot
+#endif /* atomic_fetch_andnot */
#else /* atomic_fetch_andnot_relaxed */
__atomic_op_fence(atomic_fetch_andnot, __VA_ARGS__)
#endif
#endif /* atomic_fetch_andnot_relaxed */
-#endif /* atomic_andnot */
/* atomic_fetch_xor_relaxed */
#ifndef atomic_fetch_xor_relaxed
#endif
#endif /* xchg_relaxed */
+/**
+ * atomic_fetch_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, if @v was not already @u.
+ * Returns the original value of @v.
+ */
+#ifndef atomic_fetch_add_unless
+static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
+{
+ int c = atomic_read(v);
+
+ do {
+ if (unlikely(c == u))
+ break;
+ } while (!atomic_try_cmpxchg(v, &c, c + a));
+
+ return c;
+}
+#endif
+
/**
* 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.
+ * Atomically adds @a to @v, if @v was not already @u.
+ * Returns true if the addition was done.
*/
-static inline int atomic_add_unless(atomic_t *v, int a, int u)
+static inline bool atomic_add_unless(atomic_t *v, int a, int u)
{
- return __atomic_add_unless(v, a, u) != u;
+ return atomic_fetch_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.
+ * Atomically increments @v by 1, if @v is non-zero.
+ * Returns true if the increment was done.
*/
#ifndef atomic_inc_not_zero
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#endif
-#ifndef atomic_andnot
-static inline void atomic_andnot(int i, atomic_t *v)
-{
- atomic_and(~i, v);
-}
-
-static inline int atomic_fetch_andnot(int i, atomic_t *v)
-{
- return atomic_fetch_and(~i, v);
-}
-
-static inline int atomic_fetch_andnot_relaxed(int i, atomic_t *v)
+/**
+ * atomic_inc_and_test - increment and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#ifndef atomic_inc_and_test
+static inline bool atomic_inc_and_test(atomic_t *v)
{
- return atomic_fetch_and_relaxed(~i, v);
+ return atomic_inc_return(v) == 0;
}
+#endif
-static inline int atomic_fetch_andnot_acquire(int i, atomic_t *v)
+/**
+ * atomic_dec_and_test - decrement and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+#ifndef atomic_dec_and_test
+static inline bool atomic_dec_and_test(atomic_t *v)
{
- return atomic_fetch_and_acquire(~i, v);
+ return atomic_dec_return(v) == 0;
}
+#endif
-static inline int atomic_fetch_andnot_release(int i, atomic_t *v)
+/**
+ * atomic_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+#ifndef atomic_sub_and_test
+static inline bool atomic_sub_and_test(int i, atomic_t *v)
{
- return atomic_fetch_and_release(~i, v);
+ return atomic_sub_return(i, v) == 0;
}
#endif
/**
- * atomic_inc_not_zero_hint - increment if not null
+ * atomic_add_negative - add and test if negative
+ * @i: integer value to add
* @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.
+ * Atomically adds @i to @v and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
*/
-#ifndef atomic_inc_not_zero_hint
-static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint)
+#ifndef atomic_add_negative
+static inline bool atomic_add_negative(int i, atomic_t *v)
{
- 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;
+ return atomic_add_return(i, v) < 0;
}
#endif
#ifndef atomic_inc_unless_negative
-static inline int atomic_inc_unless_negative(atomic_t *p)
+static inline bool atomic_inc_unless_negative(atomic_t *v)
{
- 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;
+ int c = atomic_read(v);
+
+ do {
+ if (unlikely(c < 0))
+ return false;
+ } while (!atomic_try_cmpxchg(v, &c, c + 1));
+
+ return true;
}
#endif
#ifndef atomic_dec_unless_positive
-static inline int atomic_dec_unless_positive(atomic_t *p)
+static inline bool atomic_dec_unless_positive(atomic_t *v)
{
- 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;
+ int c = atomic_read(v);
+
+ do {
+ if (unlikely(c > 0))
+ return false;
+ } while (!atomic_try_cmpxchg(v, &c, c - 1));
+
+ return true;
}
#endif
#ifndef atomic_dec_if_positive
static inline int atomic_dec_if_positive(atomic_t *v)
{
- int c, old, dec;
- c = atomic_read(v);
- for (;;) {
+ int dec, c = atomic_read(v);
+
+ do {
dec = c - 1;
if (unlikely(dec < 0))
break;
- old = atomic_cmpxchg((v), c, dec);
- if (likely(old == c))
- break;
- c = old;
- }
+ } while (!atomic_try_cmpxchg(v, &c, dec));
+
return dec;
}
#endif
#endif
#endif /* atomic64_add_return_relaxed */
+#ifndef atomic64_inc
+#define atomic64_inc(v) atomic64_add(1, (v))
+#endif
+
/* atomic64_inc_return_relaxed */
#ifndef atomic64_inc_return_relaxed
+
+#ifndef atomic64_inc_return
+#define atomic64_inc_return(v) atomic64_add_return(1, (v))
+#define atomic64_inc_return_relaxed(v) atomic64_add_return_relaxed(1, (v))
+#define atomic64_inc_return_acquire(v) atomic64_add_return_acquire(1, (v))
+#define atomic64_inc_return_release(v) atomic64_add_return_release(1, (v))
+#else /* atomic64_inc_return */
#define atomic64_inc_return_relaxed atomic64_inc_return
#define atomic64_inc_return_acquire atomic64_inc_return
#define atomic64_inc_return_release atomic64_inc_return
+#endif /* atomic64_inc_return */
#else /* atomic64_inc_return_relaxed */
#endif
#endif /* atomic64_sub_return_relaxed */
+#ifndef atomic64_dec
+#define atomic64_dec(v) atomic64_sub(1, (v))
+#endif
+
/* atomic64_dec_return_relaxed */
#ifndef atomic64_dec_return_relaxed
+
+#ifndef atomic64_dec_return
+#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
+#define atomic64_dec_return_relaxed(v) atomic64_sub_return_relaxed(1, (v))
+#define atomic64_dec_return_acquire(v) atomic64_sub_return_acquire(1, (v))
+#define atomic64_dec_return_release(v) atomic64_sub_return_release(1, (v))
+#else /* atomic64_dec_return */
#define atomic64_dec_return_relaxed atomic64_dec_return
#define atomic64_dec_return_acquire atomic64_dec_return
#define atomic64_dec_return_release atomic64_dec_return
+#endif /* atomic64_dec_return */
#else /* atomic64_dec_return_relaxed */
#endif
#endif /* atomic64_fetch_and_relaxed */
-#ifdef atomic64_andnot
-/* atomic64_fetch_andnot_relaxed */
+#ifndef atomic64_andnot
+#define atomic64_andnot(i, v) atomic64_and(~(long long)(i), (v))
+#endif
+
#ifndef atomic64_fetch_andnot_relaxed
-#define atomic64_fetch_andnot_relaxed atomic64_fetch_andnot
-#define atomic64_fetch_andnot_acquire atomic64_fetch_andnot
-#define atomic64_fetch_andnot_release atomic64_fetch_andnot
+
+#ifndef atomic64_fetch_andnot
+#define atomic64_fetch_andnot(i, v) atomic64_fetch_and(~(long long)(i), (v))
+#define atomic64_fetch_andnot_relaxed(i, v) atomic64_fetch_and_relaxed(~(long long)(i), (v))
+#define atomic64_fetch_andnot_acquire(i, v) atomic64_fetch_and_acquire(~(long long)(i), (v))
+#define atomic64_fetch_andnot_release(i, v) atomic64_fetch_and_release(~(long long)(i), (v))
+#else /* atomic64_fetch_andnot */
+#define atomic64_fetch_andnot_relaxed atomic64_fetch_andnot
+#define atomic64_fetch_andnot_acquire atomic64_fetch_andnot
+#define atomic64_fetch_andnot_release atomic64_fetch_andnot
+#endif /* atomic64_fetch_andnot */
#else /* atomic64_fetch_andnot_relaxed */
__atomic_op_fence(atomic64_fetch_andnot, __VA_ARGS__)
#endif
#endif /* atomic64_fetch_andnot_relaxed */
-#endif /* atomic64_andnot */
/* atomic64_fetch_xor_relaxed */
#ifndef atomic64_fetch_xor_relaxed
#define atomic64_try_cmpxchg_release atomic64_try_cmpxchg
#endif /* atomic64_try_cmpxchg */
-#ifndef atomic64_andnot
-static inline void atomic64_andnot(long long i, atomic64_t *v)
+/**
+ * atomic64_fetch_add_unless - add unless the number is already a given value
+ * @v: pointer of type atomic64_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, if @v was not already @u.
+ * Returns the original value of @v.
+ */
+#ifndef atomic64_fetch_add_unless
+static inline long long atomic64_fetch_add_unless(atomic64_t *v, long long a,
+ long long u)
{
- atomic64_and(~i, v);
+ long long c = atomic64_read(v);
+
+ do {
+ if (unlikely(c == u))
+ break;
+ } while (!atomic64_try_cmpxchg(v, &c, c + a));
+
+ return c;
}
+#endif
-static inline long long atomic64_fetch_andnot(long long i, atomic64_t *v)
+/**
+ * atomic64_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, if @v was not already @u.
+ * Returns true if the addition was done.
+ */
+static inline bool atomic64_add_unless(atomic64_t *v, long long a, long long u)
{
- return atomic64_fetch_and(~i, v);
+ return atomic64_fetch_add_unless(v, a, u) != u;
}
-static inline long long atomic64_fetch_andnot_relaxed(long long i, atomic64_t *v)
+/**
+ * atomic64_inc_not_zero - increment unless the number is zero
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically increments @v by 1, if @v is non-zero.
+ * Returns true if the increment was done.
+ */
+#ifndef atomic64_inc_not_zero
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+#endif
+
+/**
+ * atomic64_inc_and_test - increment and test
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#ifndef atomic64_inc_and_test
+static inline bool atomic64_inc_and_test(atomic64_t *v)
{
- return atomic64_fetch_and_relaxed(~i, v);
+ return atomic64_inc_return(v) == 0;
}
+#endif
-static inline long long atomic64_fetch_andnot_acquire(long long i, atomic64_t *v)
+/**
+ * atomic64_dec_and_test - decrement and test
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+#ifndef atomic64_dec_and_test
+static inline bool atomic64_dec_and_test(atomic64_t *v)
{
- return atomic64_fetch_and_acquire(~i, v);
+ return atomic64_dec_return(v) == 0;
}
+#endif
-static inline long long atomic64_fetch_andnot_release(long long i, atomic64_t *v)
+/**
+ * atomic64_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+#ifndef atomic64_sub_and_test
+static inline bool atomic64_sub_and_test(long long i, atomic64_t *v)
+{
+ return atomic64_sub_return(i, v) == 0;
+}
+#endif
+
+/**
+ * atomic64_add_negative - add and test if negative
+ * @i: integer value to add
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically adds @i to @v and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+#ifndef atomic64_add_negative
+static inline bool atomic64_add_negative(long long i, atomic64_t *v)
{
- return atomic64_fetch_and_release(~i, v);
+ return atomic64_add_return(i, v) < 0;
+}
+#endif
+
+#ifndef atomic64_inc_unless_negative
+static inline bool atomic64_inc_unless_negative(atomic64_t *v)
+{
+ long long c = atomic64_read(v);
+
+ do {
+ if (unlikely(c < 0))
+ return false;
+ } while (!atomic64_try_cmpxchg(v, &c, c + 1));
+
+ return true;
+}
+#endif
+
+#ifndef atomic64_dec_unless_positive
+static inline bool atomic64_dec_unless_positive(atomic64_t *v)
+{
+ long long c = atomic64_read(v);
+
+ do {
+ if (unlikely(c > 0))
+ return false;
+ } while (!atomic64_try_cmpxchg(v, &c, c - 1));
+
+ return true;
+}
+#endif
+
+/*
+ * atomic64_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic64_t
+ *
+ * The function returns the old value of *v minus 1, even if
+ * the atomic64 variable, v, was not decremented.
+ */
+#ifndef atomic64_dec_if_positive
+static inline long long atomic64_dec_if_positive(atomic64_t *v)
+{
+ long long dec, c = atomic64_read(v);
+
+ do {
+ dec = c - 1;
+ if (unlikely(dec < 0))
+ break;
+ } while (!atomic64_try_cmpxchg(v, &c, dec));
+
+ return dec;
}
#endif
git.samba.org / sfrench / cifs-2.6.git / blobdiff