X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/e5568f75972dfc723778653c11cb6b4dc825716a..935ed37a5c468c8a1c07408573c08b8b7ef80e8b:/libkern/gen/OSAtomicOperations.c diff --git a/libkern/gen/OSAtomicOperations.c b/libkern/gen/OSAtomicOperations.c index c6e86aaca..bbdb0d970 100644 --- a/libkern/gen/OSAtomicOperations.c +++ b/libkern/gen/OSAtomicOperations.c @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ #include @@ -26,49 +32,77 @@ enum { false = 0, true = 1 }; -#define NULL 0L +#ifndef NULL +#define NULL ((void *)0) +#endif /* * atomic operations * these are _the_ atomic operations, currently cast atop CompareAndSwap, - * which is implemented in assembler. if we are worried about the cost of + * which is implemented in assembler. if we are worried about the cost of * this layering (we shouldn't be), then all this stuff could be * implemented in assembler, as it is in MacOS8/9 * (derived from SuperMario/NativeLibs/IO/DriverServices/Synchronization.s, * which I wrote for NuKernel in a previous life with a different last name...) * * native Boolean CompareAndSwap(UInt32 oldValue, UInt32 newValue, UInt32 * oldValuePtr); + * + * We've since implemented a few more of these -- OSAddAtomic, OSDequeueAtomic, + * OSEnqueueAtomic etc -- in assembler, either for speed or correctness. See also the + * commpage atomic operations, and the platform specific versions. + * Like standards, there are a lot of atomic ops to choose from! */ #ifndef __ppc__ -SInt32 OSAddAtomic(SInt32 amount, SInt32 * value) -{ - SInt32 oldValue; - SInt32 newValue; - - do { - oldValue = *value; - newValue = oldValue + amount; - } while (! OSCompareAndSwap((UInt32) oldValue, (UInt32) newValue, (UInt32 *) value)); - - return oldValue; -} -SInt32 OSIncrementAtomic(SInt32 * value) +SInt32 OSIncrementAtomic(volatile SInt32 * value) { return OSAddAtomic(1, value); } -SInt32 OSDecrementAtomic(SInt32 * value) +SInt32 OSDecrementAtomic(volatile SInt32 * value) { return OSAddAtomic(-1, value); } +#ifdef CMPXCHG8B +void * OSDequeueAtomic(void * volatile * inList, SInt32 inOffset) +{ + /* The _pointer_ is volatile, not the listhead itself */ + void * volatile oldListHead; + void * volatile newListHead; + + do { + oldListHead = *inList; + if (oldListHead == NULL) { + break; + } + + newListHead = *(void * volatile *) (((char *) oldListHead) + inOffset); + } while (! OSCompareAndSwap((UInt32)oldListHead, + (UInt32)newListHead, (volatile UInt32 *)inList)); + return oldListHead; +} + +void OSEnqueueAtomic(void * volatile * inList, void * inNewLink, SInt32 inOffset) +{ + /* The _pointer_ is volatile, not the listhead itself */ + void * volatile oldListHead; + void * volatile newListHead = inNewLink; + void * volatile * newLinkNextPtr = (void * volatile *) (((char *) inNewLink) + inOffset); + + do { + oldListHead = *inList; + *newLinkNextPtr = oldListHead; + } while (! OSCompareAndSwap((UInt32)oldListHead, (UInt32)newListHead, + (volatile UInt32 *)inList)); +} +#endif /* CMPXCHG8B */ #endif /* !__ppc__ */ -static UInt32 OSBitwiseAtomic(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, UInt32 * value) +static UInt32 OSBitwiseAtomic(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, volatile UInt32 * value) { UInt32 oldValue; UInt32 newValue; @@ -81,41 +115,41 @@ static UInt32 OSBitwiseAtomic(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, return oldValue; } -UInt32 OSBitAndAtomic(UInt32 mask, UInt32 * value) +UInt32 OSBitAndAtomic(UInt32 mask, volatile UInt32 * value) { return OSBitwiseAtomic(mask, 0, 0, value); } -UInt32 OSBitOrAtomic(UInt32 mask, UInt32 * value) +UInt32 OSBitOrAtomic(UInt32 mask, volatile UInt32 * value) { return OSBitwiseAtomic((UInt32) -1, mask, 0, value); } -UInt32 OSBitXorAtomic(UInt32 mask, UInt32 * value) +UInt32 OSBitXorAtomic(UInt32 mask, volatile UInt32 * value) { return OSBitwiseAtomic((UInt32) -1, 0, mask, value); } -static Boolean OSCompareAndSwap8(UInt8 oldValue8, UInt8 newValue8, UInt8 * value8) +static Boolean OSCompareAndSwap8(UInt8 oldValue8, UInt8 newValue8, volatile UInt8 * value8) { - UInt32 mask = 0x000000ff; - UInt32 alignment = ((UInt32) value8) & (sizeof(UInt32) - 1); - UInt32 shiftValues = (24 << 24) | (16 << 16) | (8 << 8); - int shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment); - UInt32 * value32 = (UInt32 *) (value8 - alignment); - UInt32 oldValue; - UInt32 newValue; + UInt32 mask = 0x000000ff; + UInt32 alignment = ((UInt32) value8) & (sizeof(UInt32) - 1); + UInt32 shiftValues = (24 << 24) | (16 << 16) | (8 << 8); + int shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment); + volatile UInt32 * value32 = (volatile UInt32 *) (value8 - alignment); + UInt32 oldValue; + UInt32 newValue; - mask <<= shift; + mask <<= shift; - oldValue = *value32; - oldValue = (oldValue & ~mask) | (oldValue8 << shift); - newValue = (oldValue & ~mask) | (newValue8 << shift); + oldValue = *value32; + oldValue = (oldValue & ~mask) | (oldValue8 << shift); + newValue = (oldValue & ~mask) | (newValue8 << shift); return OSCompareAndSwap(oldValue, newValue, value32); } -static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, UInt8 * startAddress) +static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, volatile UInt8 * startAddress) { UInt8 mask = 1; UInt8 oldValue; @@ -135,62 +169,31 @@ static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, UInt8 * startAddre return (oldValue & mask) == wantValue; } -Boolean OSTestAndSet(UInt32 bit, UInt8 * startAddress) +Boolean OSTestAndSet(UInt32 bit, volatile UInt8 * startAddress) { return OSTestAndSetClear(bit, true, startAddress); } -Boolean OSTestAndClear(UInt32 bit, UInt8 * startAddress) +Boolean OSTestAndClear(UInt32 bit, volatile UInt8 * startAddress) { return OSTestAndSetClear(bit, false, startAddress); } -void * OSDequeueAtomic(void ** inList, SInt32 inOffset) -{ - void * oldListHead; - void * newListHead; - - do { - oldListHead = *inList; - if (oldListHead == NULL) { - break; - } - - newListHead = *(void **) (((char *) oldListHead) + inOffset); - } while (! OSCompareAndSwap((UInt32)oldListHead, - (UInt32)newListHead, (UInt32 *)inList)); - - return oldListHead; -} - -void OSEnqueueAtomic(void ** inList, void * inNewLink, SInt32 inOffset) -{ - void * oldListHead; - void * newListHead = inNewLink; - void ** newLinkNextPtr = (void **) (((char *) inNewLink) + inOffset); - - do { - oldListHead = *inList; - *newLinkNextPtr = oldListHead; - } while (! OSCompareAndSwap((UInt32)oldListHead, (UInt32)newListHead, - (UInt32 *)inList)); -} - /* * silly unaligned versions */ -SInt8 OSIncrementAtomic8(SInt8 * value) +SInt8 OSIncrementAtomic8(volatile SInt8 * value) { return OSAddAtomic8(1, value); } -SInt8 OSDecrementAtomic8(SInt8 * value) +SInt8 OSDecrementAtomic8(volatile SInt8 * value) { return OSAddAtomic8(-1, value); } -SInt8 OSAddAtomic8(SInt32 amount, SInt8 * value) +SInt8 OSAddAtomic8(SInt32 amount, volatile SInt8 * value) { SInt8 oldValue; SInt8 newValue; @@ -198,12 +201,12 @@ SInt8 OSAddAtomic8(SInt32 amount, SInt8 * value) do { oldValue = *value; newValue = oldValue + amount; - } while (! OSCompareAndSwap8((UInt8) oldValue, (UInt8) newValue, (UInt8 *) value)); + } while (! OSCompareAndSwap8((UInt8) oldValue, (UInt8) newValue, (volatile UInt8 *) value)); return oldValue; } -static UInt8 OSBitwiseAtomic8(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, UInt8 * value) +static UInt8 OSBitwiseAtomic8(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, volatile UInt8 * value) { UInt8 oldValue; UInt8 newValue; @@ -216,51 +219,51 @@ static UInt8 OSBitwiseAtomic8(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, return oldValue; } -UInt8 OSBitAndAtomic8(UInt32 mask, UInt8 * value) +UInt8 OSBitAndAtomic8(UInt32 mask, volatile UInt8 * value) { return OSBitwiseAtomic8(mask, 0, 0, value); } -UInt8 OSBitOrAtomic8(UInt32 mask, UInt8 * value) +UInt8 OSBitOrAtomic8(UInt32 mask, volatile UInt8 * value) { return OSBitwiseAtomic8((UInt32) -1, mask, 0, value); } -UInt8 OSBitXorAtomic8(UInt32 mask, UInt8 * value) +UInt8 OSBitXorAtomic8(UInt32 mask, volatile UInt8 * value) { return OSBitwiseAtomic8((UInt32) -1, 0, mask, value); } -static Boolean OSCompareAndSwap16(UInt16 oldValue16, UInt16 newValue16, UInt16 * value16) +static Boolean OSCompareAndSwap16(UInt16 oldValue16, UInt16 newValue16, volatile UInt16 * value16) { - UInt32 mask = 0x0000ffff; - UInt32 alignment = ((UInt32) value16) & (sizeof(UInt32) - 1); - UInt32 shiftValues = (16 << 24) | (16 << 16); - UInt32 shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment); - UInt32 * value32 = (UInt32 *) (((UInt32) value16) - alignment); - UInt32 oldValue; - UInt32 newValue; + UInt32 mask = 0x0000ffff; + UInt32 alignment = ((UInt32) value16) & (sizeof(UInt32) - 1); + UInt32 shiftValues = (16 << 24) | (16 << 16); + UInt32 shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment); + volatile UInt32 * value32 = (volatile UInt32 *) (((UInt32) value16) - alignment); + UInt32 oldValue; + UInt32 newValue; - mask <<= shift; + mask <<= shift; - oldValue = *value32; - oldValue = (oldValue & ~mask) | (oldValue16 << shift); - newValue = (oldValue & ~mask) | (newValue16 << shift); + oldValue = *value32; + oldValue = (oldValue & ~mask) | (oldValue16 << shift); + newValue = (oldValue & ~mask) | (newValue16 << shift); return OSCompareAndSwap(oldValue, newValue, value32); } -SInt16 OSIncrementAtomic16(SInt16 * value) +SInt16 OSIncrementAtomic16(volatile SInt16 * value) { return OSAddAtomic16(1, value); } -SInt16 OSDecrementAtomic16(SInt16 * value) +SInt16 OSDecrementAtomic16(volatile SInt16 * value) { return OSAddAtomic16(-1, value); } -SInt16 OSAddAtomic16(SInt32 amount, SInt16 * value) +SInt16 OSAddAtomic16(SInt32 amount, volatile SInt16 * value) { SInt16 oldValue; SInt16 newValue; @@ -268,12 +271,12 @@ SInt16 OSAddAtomic16(SInt32 amount, SInt16 * value) do { oldValue = *value; newValue = oldValue + amount; - } while (! OSCompareAndSwap16((UInt16) oldValue, (UInt16) newValue, (UInt16 *) value)); + } while (! OSCompareAndSwap16((UInt16) oldValue, (UInt16) newValue, (volatile UInt16 *) value)); return oldValue; } -static UInt16 OSBitwiseAtomic16(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, UInt16 * value) +static UInt16 OSBitwiseAtomic16(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, volatile UInt16 * value) { UInt16 oldValue; UInt16 newValue; @@ -286,17 +289,17 @@ static UInt16 OSBitwiseAtomic16(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask return oldValue; } -UInt16 OSBitAndAtomic16(UInt32 mask, UInt16 * value) +UInt16 OSBitAndAtomic16(UInt32 mask, volatile UInt16 * value) { return OSBitwiseAtomic16(mask, 0, 0, value); } -UInt16 OSBitOrAtomic16(UInt32 mask, UInt16 * value) +UInt16 OSBitOrAtomic16(UInt32 mask, volatile UInt16 * value) { return OSBitwiseAtomic16((UInt32) -1, mask, 0, value); } -UInt16 OSBitXorAtomic16(UInt32 mask, UInt16 * value) +UInt16 OSBitXorAtomic16(UInt32 mask, volatile UInt16 * value) { return OSBitwiseAtomic16((UInt32) -1, 0, mask, value); }