1 /*
2 * Copyright (c) 2019, The Linux Foundation. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above
10 * copyright notice, this list of conditions and the following
11 * disclaimer in the documentation and/or other materials provided
12 * with the distribution.
13 * * Neither the name of The Linux Foundation nor the names of its
14 * contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
24 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
26 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
27 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29 #include "AEEatomic.h"
30
atomic_Add(uint32 * volatile puDest,int nAdd)31 uint32 atomic_Add(uint32 * volatile puDest, int nAdd) {
32 uint32 previous;
33 uint32 current;
34 do {
35 current = *puDest;
36 previous = atomic_CompareAndExchange(puDest, current + nAdd, current);
37 } while(previous != current);
38 return (current + nAdd);
39 }
40
atomic_Exchange(uint32 * volatile puDest,uint32 uVal)41 uint32 atomic_Exchange(uint32* volatile puDest, uint32 uVal) {
42 uint32 previous;
43 uint32 current;
44 do {
45 current = *puDest;
46 previous = atomic_CompareAndExchange(puDest, uVal, current);
47 } while(previous != current);
48 return previous;
49 }
50
atomic_CompareOrAdd(uint32 * volatile puDest,uint32 uCompare,int nAdd)51 uint32 atomic_CompareOrAdd(uint32* volatile puDest, uint32 uCompare, int nAdd) {
52 uint32 previous;
53 uint32 current;
54 uint32 result;
55 do {
56 current = *puDest;
57 previous = current;
58 result = current;
59 if(current != uCompare) {
60 previous = atomic_CompareAndExchange(puDest, current + nAdd, current);
61 if(previous == current) {
62 result = current + nAdd;
63 }
64 }
65 } while(previous != current);
66 return result;
67 }
68
69