| The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | |
| 18 | .text |
| 19 | .align |
| 20 | |
| 21 | .global android_atomic_write |
| 22 | |
| 23 | .global android_atomic_inc |
| 24 | .global android_atomic_dec |
| 25 | |
| 26 | .global android_atomic_add |
| 27 | .global android_atomic_and |
| 28 | .global android_atomic_or |
| 29 | |
| 30 | .global android_atomic_swap |
| 31 | |
| 32 | .global android_atomic_cmpxchg |
| 33 | |
| 34 | |
| 35 | |
| 36 | /* FIXME: On SMP systems memory barriers may be needed */ |
| 37 | #warning "this file is not safe with SMP systems" |
| 38 | |
| 39 | |
| 40 | /* |
| 41 | * ---------------------------------------------------------------------------- |
| 42 | * android_atomic_write |
| 43 | * input: r0=value, r1=address |
| 44 | * output: void |
| 45 | */ |
| 46 | |
| 47 | android_atomic_write: |
| 48 | 1: ldrex r12, [r1] |
| 49 | strex r12, r0, [r1] |
| 50 | cmp r12, #0 |
| 51 | bne 1b |
| 52 | bx lr |
| 53 | |
| 54 | /* |
| 55 | * ---------------------------------------------------------------------------- |
| 56 | * android_atomic_inc |
| 57 | * input: r0 = address |
| 58 | * output: r0 = old value |
| 59 | */ |
| 60 | |
| 61 | android_atomic_inc: |
| 62 | mov r12, r0 |
| 63 | 1: ldrex r0, [r12] |
| 64 | add r2, r0, #1 |
| 65 | strex r1, r2, [r12] |
| 66 | cmp r1, #0 |
| 67 | bxeq lr |
| 68 | b 1b |
| 69 | |
| 70 | /* |
| 71 | * ---------------------------------------------------------------------------- |
| 72 | * android_atomic_dec |
| 73 | * input: r0=address |
| 74 | * output: r0 = old value |
| 75 | */ |
| 76 | |
| 77 | android_atomic_dec: |
| 78 | mov r12, r0 |
| 79 | 1: ldrex r0, [r12] |
| 80 | sub r2, r0, #1 |
| 81 | strex r1, r2, [r12] |
| 82 | cmp r1, #0 |
| 83 | bxeq lr |
| 84 | b 1b |
| 85 | |
| 86 | |
| 87 | /* |
| 88 | * ---------------------------------------------------------------------------- |
| 89 | * android_atomic_add |
| 90 | * input: r0=value, r1=address |
| 91 | * output: r0 = old value |
| 92 | */ |
| 93 | |
| 94 | android_atomic_add: |
| 95 | mov r12, r0 |
| 96 | 1: ldrex r0, [r1] |
| 97 | add r2, r0, r12 |
| 98 | strex r3, r2, [r1] |
| 99 | cmp r3, #0 |
| 100 | bxeq lr |
| 101 | b 1b |
| 102 | |
| 103 | /* |
| 104 | * ---------------------------------------------------------------------------- |
| 105 | * android_atomic_and |
| 106 | * input: r0=value, r1=address |
| 107 | * output: r0 = old value |
| 108 | */ |
| 109 | |
| 110 | android_atomic_and: |
| 111 | mov r12, r0 |
| 112 | 1: ldrex r0, [r1] |
| 113 | and r2, r0, r12 |
| 114 | strex r3, r2, [r1] |
| 115 | cmp r3, #0 |
| 116 | bxeq lr |
| 117 | b 1b |
| 118 | |
| 119 | |
| 120 | /* |
| 121 | * ---------------------------------------------------------------------------- |
| 122 | * android_atomic_or |
| 123 | * input: r0=value, r1=address |
| 124 | * output: r0 = old value |
| 125 | */ |
| 126 | |
| 127 | android_atomic_or: |
| 128 | mov r12, r0 |
| 129 | 1: ldrex r0, [r1] |
| 130 | orr r2, r0, r12 |
| 131 | strex r3, r2, [r1] |
| 132 | cmp r3, #0 |
| 133 | bxeq lr |
| 134 | b 1b |
| 135 | |
| 136 | /* |
| 137 | * ---------------------------------------------------------------------------- |
| 138 | * android_atomic_swap |
| 139 | * input: r0=value, r1=address |
| 140 | * output: r0 = old value |
| 141 | */ |
| 142 | |
| 143 | android_atomic_swap: |
| 144 | swp r0, r0, [r1] |
| 145 | bx lr |
| 146 | |
| 147 | /* |
| 148 | * ---------------------------------------------------------------------------- |
| 149 | * android_atomic_cmpxchg |
| 150 | * input: r0=oldvalue, r1=newvalue, r2=address |
| 151 | * output: r0 = 0 (xchg done) or non-zero (xchg not done) |
| 152 | */ |
| 153 | |
| 154 | android_atomic_cmpxchg: |
| 155 | mov r12, r1 |
| 156 | ldrex r3, [r2] |
| 157 | eors r0, r0, r3 |
| 158 | strexeq r0, r12, [r2] |
| 159 | bx lr |
| 160 | |
| 161 | |
| 162 | |
| 163 | /* |
| 164 | * ---------------------------------------------------------------------------- |
| 165 | * android_atomic_cmpxchg_64 |
| 166 | * input: r0-r1=oldvalue, r2-r3=newvalue, arg4 (on stack)=address |
| 167 | * output: r0 = 0 (xchg done) or non-zero (xchg not done) |
| 168 | */ |
| 169 | /* TODO: NEED IMPLEMENTATION FOR THIS ARCHITECTURE */ |