1 /* $NetBSD: atomic_cas_generic.c,v 1.3 2021/03/14 22:56:39 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: atomic_cas_generic.c,v 1.3 2021/03/14 22:56:39 christos Exp $");
31
32 /*
33 * This is basically common/lib/libc/atomic/atomic_init_testset.c
34 * which always assumes MP and never uses RAS. This is used only on
35 * some archs. See Makefile.rumpkern for more information.
36 */
37
38 #include "atomic_op_namespace.h"
39
40 #include <sys/types.h>
41 #include <sys/atomic.h>
42 #include <sys/lock.h>
43
44 #define I2 __SIMPLELOCK_UNLOCKED, __SIMPLELOCK_UNLOCKED,
45 #define I16 I2 I2 I2 I2 I2 I2 I2 I2
46 #define I128 I16 I16 I16 I16 I16 I16 I16 I16
47
48 static __cpu_simple_lock_t atomic_locks32[128] = { I128 };
49
50 uint32_t
_atomic_cas_32(volatile uint32_t * ptr,uint32_t old,uint32_t new)51 _atomic_cas_32(volatile uint32_t *ptr, uint32_t old, uint32_t new)
52 {
53 __cpu_simple_lock_t *lock;
54 uint32_t ret;
55
56 lock = &atomic_locks32[((uintptr_t)ptr >> 3) & 127];
57 __cpu_simple_lock(lock);
58 ret = *ptr;
59 if (__predict_true(ret == old)) {
60 *ptr = new;
61 }
62 __cpu_simple_unlock(lock);
63
64 return ret;
65 }
66
67 #undef atomic_cas_32
68 atomic_op_alias(atomic_cas_32,_atomic_cas_32)
69 atomic_op_alias(atomic_cas_32_ni,_atomic_cas_32)
70 __strong_alias(_atomic_cas_32_ni,_atomic_cas_32)
71
72 #ifdef _LP64
73 static __cpu_simple_lock_t atomic_locks64[128] = { I128 };
74
75 uint64_t
_atomic_cas_64(volatile uint64_t * ptr,uint64_t old,uint64_t new)76 _atomic_cas_64(volatile uint64_t *ptr, uint64_t old, uint64_t new)
77 {
78 __cpu_simple_lock_t *lock;
79 uint64_t ret;
80
81 lock = &atomic_locks64[((uintptr_t)ptr >> 4) & 127];
82 __cpu_simple_lock(lock);
83 ret = *ptr;
84 if (__predict_true(ret == old)) {
85 *ptr = new;
86 }
87 __cpu_simple_unlock(lock);
88
89 return ret;
90 }
91
92 #undef atomic_cas_64
93 atomic_op_alias(atomic_cas_64,_atomic_cas_64)
94 atomic_op_alias(atomic_cas_64_ni,_atomic_cas_64)
95 __strong_alias(_atomic_cas_64_ni,_atomic_cas_64)
96
97 #endif
98
99 #undef atomic_cas_uint
100 #undef atomic_cas_ulong
101 #undef atomic_cas_ptr
102
103 atomic_op_alias(atomic_cas_uint,_atomic_cas_32)
104 __strong_alias(_atomic_cas_uint,_atomic_cas_32)
105 atomic_op_alias(atomic_cas_uint_ni,_atomic_cas_32)
106 __strong_alias(_atomic_cas_uint_ni,_atomic_cas_32)
107
108 #ifdef _LP64
109 atomic_op_alias(atomic_cas_ulong,_atomic_cas_64)
110 __strong_alias(_atomic_cas_ulong,_atomic_cas_64)
111 atomic_op_alias(atomic_cas_ulong_ni,_atomic_cas_64)
112 __strong_alias(_atomic_cas_ulong_ni,_atomic_cas_64)
113 atomic_op_alias(atomic_cas_ptr,_atomic_cas_64)
114 __strong_alias(_atomic_cas_ptr,_atomic_cas_64)
115 atomic_op_alias(atomic_cas_ptr_ni,_atomic_cas_64)
116 __strong_alias(_atomic_cas_ptr_ni,_atomic_cas_64)
117 #else
118 atomic_op_alias(atomic_cas_ulong,_atomic_cas_32)
119 __strong_alias(_atomic_cas_ulong,_atomic_cas_32)
120 atomic_op_alias(atomic_cas_ulong_ni,_atomic_cas_32)
121 __strong_alias(_atomic_cas_ulong_ni,_atomic_cas_32)
122 atomic_op_alias(atomic_cas_ptr,_atomic_cas_32)
123 __strong_alias(_atomic_cas_ptr,_atomic_cas_32)
124 atomic_op_alias(atomic_cas_ptr_ni,_atomic_cas_32)
125 __strong_alias(_atomic_cas_ptr_ni,_atomic_cas_32)
126 #endif
127