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| Rev | Author | Line No. | Line |
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| 2128 | jermar | 1 | /* |
| 2287 | jancik | 2 | * Copyright (c) 2007 Michal Kebrt |
| 2128 | jermar | 3 | * All rights reserved. |
| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | /** @addtogroup libcarm32 |
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| 30 | * @{ |
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| 31 | */ |
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| 32 | /** @file |
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| 2350 | kebrt | 33 | * @brief Atomic operations. |
| 2128 | jermar | 34 | */ |
| 35 | |||
| 36 | #ifndef LIBC_arm32_ATOMIC_H_ |
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| 37 | #define LIBC_arm32_ATOMIC_H_ |
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| 38 | |||
| 39 | /** Atomic addition. |
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| 40 | * |
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| 2350 | kebrt | 41 | * @param val Where to add. |
| 42 | * @param i Value to be added. |
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| 2128 | jermar | 43 | * |
| 44 | * @return Value after addition. |
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| 45 | */ |
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| 2287 | jancik | 46 | static inline long atomic_add(atomic_t *val, int i) |
| 2128 | jermar | 47 | { |
| 2287 | jancik | 48 | int ret; |
| 49 | volatile long * mem = &(val->count); |
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| 50 | |||
| 51 | asm volatile ( |
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| 52 | "1: \n" |
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| 53 | "ldr r2, [%1] \n" |
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| 54 | "add r3, r2, %2 \n" |
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| 55 | "str r3, %0 \n" |
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| 56 | "swp r3, r3, [%1] \n" |
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| 57 | "cmp r3, r2 \n" |
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| 58 | "bne 1b \n" |
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| 59 | |||
| 60 | : "=m" (ret) |
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| 61 | : "r" (mem), "r" (i) |
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| 62 | : "r3", "r2" |
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| 63 | ); |
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| 64 | |||
| 65 | return ret; |
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| 2128 | jermar | 66 | } |
| 67 | |||
| 2350 | kebrt | 68 | |
| 69 | /** Atomic increment. |
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| 70 | * |
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| 71 | * @param val Variable to be incremented. |
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| 72 | */ |
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| 2128 | jermar | 73 | static inline void atomic_inc(atomic_t *val) { atomic_add(val, 1); } |
| 2350 | kebrt | 74 | |
| 75 | /** Atomic decrement. |
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| 76 | * |
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| 77 | * @param val Variable to be decremented. |
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| 78 | */ |
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| 2128 | jermar | 79 | static inline void atomic_dec(atomic_t *val) { atomic_add(val, -1); } |
| 80 | |||
| 2350 | kebrt | 81 | /** Atomic pre-increment. |
| 82 | * |
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| 83 | * @param val Variable to be incremented. |
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| 84 | * @return Value after incrementation. |
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| 85 | */ |
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| 2313 | kebrt | 86 | static inline long atomic_preinc(atomic_t *val) { return atomic_add(val, 1); } |
| 2350 | kebrt | 87 | |
| 88 | /** Atomic pre-decrement. |
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| 89 | * |
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| 90 | * @param val Variable to be decremented. |
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| 91 | * @return Value after decrementation. |
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| 92 | */ |
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| 2313 | kebrt | 93 | static inline long atomic_predec(atomic_t *val) { return atomic_add(val, -1); } |
| 2128 | jermar | 94 | |
| 2350 | kebrt | 95 | /** Atomic post-increment. |
| 96 | * |
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| 97 | * @param val Variable to be incremented. |
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| 98 | * @return Value before incrementation. |
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| 99 | */ |
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| 2313 | kebrt | 100 | static inline long atomic_postinc(atomic_t *val) { return atomic_add(val, 1) - 1; } |
| 2350 | kebrt | 101 | |
| 102 | /** Atomic post-decrement. |
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| 103 | * |
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| 104 | * @param val Variable to be decremented. |
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| 105 | * @return Value before decrementation. |
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| 106 | */ |
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| 2313 | kebrt | 107 | static inline long atomic_postdec(atomic_t *val) { return atomic_add(val, -1) + 1; } |
| 2128 | jermar | 108 | |
| 2350 | kebrt | 109 | |
| 2128 | jermar | 110 | #endif |
| 111 | |||
| 112 | /** @} |
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| 113 | */ |