2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
17 #ifndef _ASM_TILE_ATOMIC_H
18 #define _ASM_TILE_ATOMIC_H
22 #include <linux/compiler.h>
23 #include <asm/system.h>
25 #define ATOMIC_INIT(i) { (i) }
28 * atomic_read - read atomic variable
29 * @v: pointer of type atomic_t
31 * Atomically reads the value of @v.
33 static inline int atomic_read(const atomic_t *v)
39 * atomic_sub_return - subtract integer and return
40 * @v: pointer of type atomic_t
41 * @i: integer value to subtract
43 * Atomically subtracts @i from @v and returns @v - @i
45 #define atomic_sub_return(i, v) atomic_add_return((int)(-(i)), (v))
48 * atomic_sub - subtract integer from atomic variable
49 * @i: integer value to subtract
50 * @v: pointer of type atomic_t
52 * Atomically subtracts @i from @v.
54 #define atomic_sub(i, v) atomic_add((int)(-(i)), (v))
57 * atomic_sub_and_test - subtract value from variable and test result
58 * @i: integer value to subtract
59 * @v: pointer of type atomic_t
61 * Atomically subtracts @i from @v and returns true if the result is
62 * zero, or false for all other cases.
64 #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
67 * atomic_inc_return - increment memory and return
68 * @v: pointer of type atomic_t
70 * Atomically increments @v by 1 and returns the new value.
72 #define atomic_inc_return(v) atomic_add_return(1, (v))
75 * atomic_dec_return - decrement memory and return
76 * @v: pointer of type atomic_t
78 * Atomically decrements @v by 1 and returns the new value.
80 #define atomic_dec_return(v) atomic_sub_return(1, (v))
83 * atomic_inc - increment atomic variable
84 * @v: pointer of type atomic_t
86 * Atomically increments @v by 1.
88 #define atomic_inc(v) atomic_add(1, (v))
91 * atomic_dec - decrement atomic variable
92 * @v: pointer of type atomic_t
94 * Atomically decrements @v by 1.
96 #define atomic_dec(v) atomic_sub(1, (v))
99 * atomic_dec_and_test - decrement and test
100 * @v: pointer of type atomic_t
102 * Atomically decrements @v by 1 and returns true if the result is 0.
104 #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
107 * atomic_inc_and_test - increment and test
108 * @v: pointer of type atomic_t
110 * Atomically increments @v by 1 and returns true if the result is 0.
112 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
115 * atomic_add_negative - add and test if negative
116 * @v: pointer of type atomic_t
117 * @i: integer value to add
119 * Atomically adds @i to @v and returns true if the result is
120 * negative, or false when result is greater than or equal to zero.
122 #define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
125 * atomic_inc_not_zero - increment unless the number is zero
126 * @v: pointer of type atomic_t
128 * Atomically increments @v by 1, so long as @v is non-zero.
129 * Returns non-zero if @v was non-zero, and zero otherwise.
131 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
135 * We define xchg() and cmpxchg() in the included headers.
136 * Note that we do not define __HAVE_ARCH_CMPXCHG, since that would imply
137 * that cmpxchg() is an efficient operation, which is not particularly true.
140 /* Nonexistent functions intended to cause link errors. */
141 extern unsigned long __xchg_called_with_bad_pointer(void);
142 extern unsigned long __cmpxchg_called_with_bad_pointer(void);
144 #define tas(ptr) (xchg((ptr), 1))
146 #endif /* __ASSEMBLY__ */
149 #include <asm/atomic_32.h>
151 #include <asm/atomic_64.h>
154 /* Provide the appropriate atomic_long_t definitions. */
156 #include <asm-generic/atomic-long.h>
159 #endif /* _ASM_TILE_ATOMIC_H */