source: mainline/uspace/lib/c/arch/mips32/include/atomic.h@ e4f2656

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since e4f2656 was e4f2656, checked in by Jakub Jermar <jakub@…>, 14 years ago

Put an explicit nop after the last, branch instruction in inline asm.
(Noticed by Petr Koupy.)

  • Property mode set to 100644
File size: 2.6 KB
Line 
1/*
2 * Copyright (c) 2005 Ondrej Palkovsky
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup libcmips32
30 * @{
31 */
32/** @file
33 * @ingroup libcmips32eb
34 */
35
36#ifndef LIBC_mips32_ATOMIC_H_
37#define LIBC_mips32_ATOMIC_H_
38
39#define LIBC_ARCH_ATOMIC_H_
40
41#include <atomicdflt.h>
42
43#define atomic_inc(x) ((void) atomic_add(x, 1))
44#define atomic_dec(x) ((void) atomic_add(x, -1))
45
46#define atomic_postinc(x) (atomic_add(x, 1) - 1)
47#define atomic_postdec(x) (atomic_add(x, -1) + 1)
48
49#define atomic_preinc(x) atomic_add(x, 1)
50#define atomic_predec(x) atomic_add(x, -1)
51
52/* Atomic addition of immediate value.
53 *
54 * @param val Memory location to which will be the immediate value added.
55 * @param i Signed immediate that will be added to *val.
56 *
57 * @return Value after addition.
58 *
59 */
60static inline atomic_count_t atomic_add(atomic_t *val, atomic_count_t i)
61{
62 atomic_count_t tmp;
63 atomic_count_t v;
64
65 asm volatile (
66 "1:\n"
67 " ll %0, %1\n"
68 " addu %0, %0, %3\n" /* same as add, but never traps on overflow */
69 " move %2, %0\n"
70 " sc %0, %1\n"
71 " beq %0, %4, 1b\n" /* if the atomic operation failed, try again */
72 " nop\n"
73 : "=&r" (tmp),
74 "+m" (val->count),
75 "=&r" (v)
76 : "r" (i),
77 "i" (0)
78 );
79
80 return v;
81}
82
83#endif
84
85/** @}
86 */
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