1 /*
2 * Copyright © 2009 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 * Chris Wilson <chris@chris-wilson.co.uk>
25 *
26 */
27
28 /**
29 * @file xf86atomics.h
30 *
31 * Private definitions for atomic operations
32 */
33
34 #ifndef LIBDRM_ATOMICS_H
35 #define LIBDRM_ATOMICS_H
36
37 #if HAVE_LIBDRM_ATOMIC_PRIMITIVES
38
39 #define HAS_ATOMIC_OPS 1
40
41 typedef struct {
42 int atomic;
43 } atomic_t;
44
45 # define atomic_read(x) ((x)->atomic)
46 # define atomic_set(x, val) ((x)->atomic = (val))
47 # define atomic_inc(x) ((void) __sync_fetch_and_add (&(x)->atomic, 1))
48 # define atomic_inc_return(x) (__sync_add_and_fetch (&(x)->atomic, 1))
49 # define atomic_dec_and_test(x) (__sync_add_and_fetch (&(x)->atomic, -1) == 0)
50 # define atomic_add(x, v) ((void) __sync_add_and_fetch(&(x)->atomic, (v)))
51 # define atomic_dec(x, v) ((void) __sync_sub_and_fetch(&(x)->atomic, (v)))
52 # define atomic_cmpxchg(x, oldv, newv) __sync_val_compare_and_swap (&(x)->atomic, oldv, newv)
53
54 #endif
55
56 #if HAVE_LIB_ATOMIC_OPS
57 #include <atomic_ops.h>
58
59 #define HAS_ATOMIC_OPS 1
60
61 typedef struct {
62 AO_t atomic;
63 } atomic_t;
64
65 # define atomic_read(x) AO_load_full(&(x)->atomic)
66 # define atomic_set(x, val) AO_store_full(&(x)->atomic, (val))
67 # define atomic_inc(x) ((void) AO_fetch_and_add1_full(&(x)->atomic))
68 # define atomic_inc_return(x) (AO_fetch_and_add1_full(&(x)->atomic) + 1)
69 # define atomic_add(x, v) ((void) AO_fetch_and_add_full(&(x)->atomic, (v)))
70 # define atomic_dec(x, v) ((void) AO_fetch_and_add_full(&(x)->atomic, -(v)))
71 # define atomic_dec_and_test(x) (AO_fetch_and_sub1_full(&(x)->atomic) == 1)
72 # define atomic_cmpxchg(x, oldv, newv) AO_compare_and_swap_full(&(x)->atomic, oldv, newv)
73
74 #endif
75
76 #if (defined(__sun) || defined(__NetBSD__)) && !defined(HAS_ATOMIC_OPS) /* Solaris & OpenSolaris & NetBSD */
77
78 #include <sys/atomic.h>
79 #define HAS_ATOMIC_OPS 1
80
81 #if defined(__NetBSD__)
82 #define LIBDRM_ATOMIC_TYPE int
83 #else
84 #define LIBDRM_ATOMIC_TYPE uint_t
85 #endif
86
87 typedef struct { LIBDRM_ATOMIC_TYPE atomic; } atomic_t;
88
89 # define atomic_read(x) (int) ((x)->atomic)
90 # define atomic_set(x, val) ((x)->atomic = (LIBDRM_ATOMIC_TYPE)(val))
91 # define atomic_inc(x) (atomic_inc_uint (&(x)->atomic))
92 # define atomic_inc_return(x) (atomic_inc_uint_nv(&(x)->atomic))
93 # define atomic_dec_and_test(x) (atomic_dec_uint_nv(&(x)->atomic) == 0)
94 # define atomic_add(x, v) (atomic_add_int(&(x)->atomic, (v)))
95 # define atomic_dec(x, v) (atomic_add_int(&(x)->atomic, -(v)))
96 # define atomic_cmpxchg(x, oldv, newv) atomic_cas_uint (&(x)->atomic, oldv, newv)
97
98 #endif
99
100 #if !defined(HAS_ATOMIC_OPS)
101 #error libdrm requires atomic operations, please define them for your CPU/compiler.
102 #endif
103
atomic_add_unless(atomic_t * v,int add,int unless)104 static inline int atomic_add_unless(atomic_t *v, int add, int unless)
105 {
106 int c, old;
107 c = atomic_read(v);
108 while (c != unless && (old = atomic_cmpxchg(v, c, c + add)) != c)
109 c = old;
110 return c == unless;
111 }
112
113 #endif
114