projects / apple / libc.git / blame
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|---|---|---|
| b5d655f7 A |
1 | /* |
| 2 | * Copyright (c) 2004 Apple Computer, Inc. All rights reserved. | |
| 3 | * | |
| 4 | * @APPLE_LICENSE_HEADER_START@ | |
| 5 | * | |
| 6 | * This file contains Original Code and/or Modifications of Original Code | |
| 7 | * as defined in and that are subject to the Apple Public Source License | |
| 8 | * Version 2.0 (the 'License'). You may not use this file except in | |
| 9 | * compliance with the License. Please obtain a copy of the License at | |
| 10 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
| 11 | * file. | |
| 12 | * | |
| 13 | * The Original Code and all software distributed under the License are | |
| 14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| 15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, | |
| 16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. | |
| 18 | * Please see the License for the specific language governing rights and | |
| 19 | * limitations under the License. | |
| 20 | * | |
| 21 | * @APPLE_LICENSE_HEADER_END@ | |
| 22 | */ | |
| 23 | ||
| 24 | #include <libkern/OSAtomic.h> | |
| 25 | #include <arm/arch.h> | |
| 26 | ||
| 27 | ||
| 28 | #if !defined(_ARM_ARCH_6) | |
| 29 | ||
| 30 | /* | |
| 31 | * The only atomic operation ARMv4T provides (atomic swap) is not | |
| 32 | * sufficient for the general 32-bit arithmetic and compare-and-swap | |
| 33 | * operations OSAtomic is supposed to provide. So we use a global | |
| 34 | * spin lock around all operations. | |
| 35 | * | |
| 36 | * Since we have only a single, in-order, CPU, we do not need | |
| 37 | * memory barriers for data. | |
| 38 | */ | |
| 39 | ||
| 40 | static OSSpinLock _atomic_lock = OS_SPINLOCK_INIT; | |
| 41 | ||
| 42 | int32_t OSAtomicAdd32( int32_t theAmount, int32_t *theValue ) | |
| 43 | { | |
| 44 | int32_t result; | |
| 45 | ||
| 46 | OSSpinLockLock(&_atomic_lock); | |
| 47 | result = (*theValue += theAmount); | |
| 48 | OSSpinLockUnlock(&_atomic_lock); | |
| 49 | ||
| 50 | return result; | |
| 51 | } | |
| 52 | ||
| 53 | int32_t OSAtomicAdd32Barrier( int32_t theAmount, int32_t *theValue ) | |
| 54 | { | |
| 55 | return OSAtomicAdd32(theAmount, theValue); | |
| 56 | } | |
| 57 | ||
| 58 | int32_t OSAtomicOr32( uint32_t theMask, uint32_t *theValue ) | |
| 59 | { | |
| 60 | int32_t result; | |
| 61 | ||
| 62 | OSSpinLockLock(&_atomic_lock); | |
| 63 | result = (*theValue |= theMask); | |
| 64 | OSSpinLockUnlock(&_atomic_lock); | |
| 65 | ||
| 66 | return result; | |
| 67 | } | |
| 68 | ||
| 69 | int32_t OSAtomicOr32Barrier( uint32_t theMask, uint32_t *theValue ) | |
| 70 | { | |
| 71 | return OSAtomicOr32(theMask, theValue); | |
| 72 | } | |
| 73 | ||
| 74 | int32_t OSAtomicAnd32( uint32_t theMask, uint32_t *theValue ) | |
| 75 | { | |
| 76 | int32_t result; | |
| 77 | ||
| 78 | OSSpinLockLock(&_atomic_lock); | |
| 79 | result = (*theValue &= theMask); | |
| 80 | OSSpinLockUnlock(&_atomic_lock); | |
| 81 | ||
| 82 | return result; | |
| 83 | } | |
| 84 | ||
| 85 | int32_t OSAtomicAnd32Barrier( uint32_t theMask, uint32_t *theValue ) | |
| 86 | { | |
| 87 | return OSAtomicAnd32(theMask, theValue); | |
| 88 | } | |
| 89 | ||
| 90 | int32_t OSAtomicXor32( uint32_t theMask, uint32_t *theValue ) | |
| 91 | { | |
| 92 | int32_t result; | |
| 93 | ||
| 94 | OSSpinLockLock(&_atomic_lock); | |
| 95 | result = (*theValue ^= theMask); | |
| 96 | OSSpinLockUnlock(&_atomic_lock); | |
| 97 | ||
| 98 | return result; | |
| 99 | } | |
| 100 | ||
| 101 | int32_t OSAtomicXor32Barrier( uint32_t theMask, uint32_t *theValue ) | |
| 102 | { | |
| 103 | return OSAtomicXor32(theMask, theValue); | |
| 104 | } | |
| 105 | ||
| 106 | bool OSAtomicCompareAndSwap32( int32_t oldValue, int32_t newValue, int32_t *theValue ) | |
| 107 | { | |
| 108 | bool result; | |
| 109 | ||
| 110 | OSSpinLockLock(&_atomic_lock); | |
| 111 | result = (*theValue == oldValue); | |
| 112 | if (result) *theValue = newValue; | |
| 113 | OSSpinLockUnlock(&_atomic_lock); | |
| 114 | ||
| 115 | return result; | |
| 116 | } | |
| 117 | ||
| 118 | bool OSAtomicCompareAndSwap32Barrier( int32_t oldValue, int32_t newValue, int32_t *theValue ) | |
| 119 | { | |
| 120 | return OSAtomicCompareAndSwap32(oldValue, newValue, theValue); | |
| 121 | } | |
| 122 | ||
| 123 | bool OSAtomicTestAndSet( uint32_t n, void *theAddress ) | |
| 124 | { | |
| 125 | char *byteAddress = ((char*)theAddress + (n>>3)); | |
| 126 | uint32_t byteBit = (0x80>>(n&7)); | |
| 127 | bool result; | |
| 128 | ||
| 129 | OSSpinLockLock(&_atomic_lock); | |
| 130 | result = *byteAddress & byteBit; | |
| 131 | *byteAddress |= byteBit; | |
| 132 | OSSpinLockUnlock(&_atomic_lock); | |
| 133 | ||
| 134 | return result; | |
| 135 | } | |
| 136 | ||
| 137 | bool OSAtomicTestAndSetBarrier( uint32_t n, void *theAddress ) | |
| 138 | { | |
| 139 | return OSAtomicTestAndSet(n, theAddress); | |
| 140 | } | |
| 141 | ||
| 142 | bool OSAtomicTestAndClear( uint32_t n, void *theAddress ) | |
| 143 | { | |
| 144 | char *byteAddress = ((char*)theAddress + (n>>3)); | |
| 145 | uint32_t byteBit = (0x80>>(n&7)); | |
| 146 | bool result; | |
| 147 | ||
| 148 | OSSpinLockLock(&_atomic_lock); | |
| 149 | result = *byteAddress & byteBit; | |
| 150 | *byteAddress &= (~byteBit); | |
| 151 | OSSpinLockUnlock(&_atomic_lock); | |
| 152 | ||
| 153 | return result; | |
| 154 | } | |
| 155 | ||
| 156 | bool OSAtomicTestAndClearBarrier( uint32_t n, void *theAddress ) | |
| 157 | { | |
| 158 | return OSAtomicTestAndClear(n, theAddress); | |
| 159 | } | |
| 160 | ||
| 161 | void OSMemoryBarrier( void ) | |
| 162 | { | |
| 163 | return; | |
| 164 | } | |
| 165 | ||
| 166 | #endif /* !defined(_ARM_ARCH_6) */ |