/*
- * 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 <libkern/OSAtomic.h>
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;
-}
+#if defined(__i386__) || defined(__x86_64__)
+/* Implemented in assembly for i386 and x86_64 */
+#else
+#error Unsupported arch
+#endif
-SInt32 OSIncrementAtomic(SInt32 * value)
+#undef OSIncrementAtomic
+SInt32 OSIncrementAtomic(volatile SInt32 * value)
{
return OSAddAtomic(1, value);
}
-SInt32 OSDecrementAtomic(SInt32 * value)
+#undef OSDecrementAtomic
+SInt32 OSDecrementAtomic(volatile SInt32 * value)
{
return OSAddAtomic(-1, value);
}
-#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;
return oldValue;
}
-UInt32 OSBitAndAtomic(UInt32 mask, UInt32 * value)
+#undef OSBitAndAtomic
+UInt32 OSBitAndAtomic(UInt32 mask, volatile UInt32 * value)
{
return OSBitwiseAtomic(mask, 0, 0, value);
}
-UInt32 OSBitOrAtomic(UInt32 mask, UInt32 * value)
+#undef OSBitOrAtomic
+UInt32 OSBitOrAtomic(UInt32 mask, volatile UInt32 * value)
{
return OSBitwiseAtomic((UInt32) -1, mask, 0, value);
}
-UInt32 OSBitXorAtomic(UInt32 mask, UInt32 * value)
+#undef OSBitXorAtomic
+UInt32 OSBitXorAtomic(UInt32 mask, volatile UInt32 * value)
{
return OSBitwiseAtomic((UInt32) -1, 0, mask, value);
}
-
-static Boolean OSCompareAndSwap8(UInt8 oldValue8, UInt8 newValue8, UInt8 * value8)
+#if defined(__i386__) || defined(__x86_64__)
+static Boolean OSCompareAndSwap8(UInt8 oldValue8, UInt8 newValue8, volatile UInt8 * value8)
{
- UInt32 mask = 0x000000ff;
- UInt32 newbits = (UInt32) newValue8;
- int shift;
- UInt32 alignment = ((UInt32) value8) & (sizeof(UInt32) - 1);
- UInt32 oldValue;
- UInt32 newValue;
- UInt32 * value;
-
- switch (alignment) {
- default:
- // assert(false);
- case 0:
- value = (UInt32 *) value8;
- shift = 24;
- break;
- case 1:
- value = (UInt32 *) (value8 + 1);
- shift = 16;
- break;
- case 2:
- value = (UInt32 *) (value8 + 2);
- shift = 8;
- break;
- case 3:
- value = (UInt32 *) (value8 + 3);
- shift = 0;
- break;
- }
+ UInt32 mask = 0x000000ff;
+ UInt32 alignment = (UInt32)((unsigned long) value8) & (sizeof(UInt32) - 1);
+ UInt32 shiftValues = (24 << 24) | (16 << 16) | (8 << 8);
+ int shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment);
+ volatile UInt32 * value32 = (volatile UInt32 *) ((uintptr_t)value8 - alignment);
+ UInt32 oldValue;
+ UInt32 newValue;
mask <<= shift;
- newbits <<= shift;
-
- oldValue = *value;
- newValue = (oldValue & ~mask) | (newbits & mask);
-
- return OSCompareAndSwap(oldValue, newValue, value);
+
+ oldValue = *value32;
+ oldValue = (oldValue & ~mask) | (oldValue8 << shift);
+ newValue = (oldValue & ~mask) | (newValue8 << shift);
+
+ return OSCompareAndSwap(oldValue, newValue, value32);
}
+#endif
-static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, UInt8 * startAddress)
+static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, volatile UInt8 * startAddress)
{
UInt8 mask = 1;
UInt8 oldValue;
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)
+#if defined(__i386__) || defined(__x86_64__)
+SInt8 OSAddAtomic8(SInt32 amount, volatile SInt8 * value)
{
SInt8 oldValue;
SInt8 newValue;
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;
}
+#endif
-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;
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)
+#if defined(__i386__) || defined(__x86_64__)
+static Boolean OSCompareAndSwap16(UInt16 oldValue16, UInt16 newValue16, volatile UInt16 * value16)
{
- UInt32 mask = 0x0000ffff;
- UInt32 newbits = (UInt32) newValue16;
- int shift;
- UInt32 alignment = ((UInt32) value16) & (sizeof(UInt32) - 1);
- UInt32 oldValue;
- UInt32 newValue;
- UInt32 * value;
-
- if (alignment == 2) {
- value = (UInt32 *) (value16 - 1);
- shift = 0;
- }
- else {
- // assert(alignment == 0);
- value = (UInt32 *) value16;
- shift = 16;
- }
+ UInt32 mask = 0x0000ffff;
+ UInt32 alignment = (UInt32)((unsigned long) value16) & (sizeof(UInt32) - 1);
+ UInt32 shiftValues = (16 << 24) | (16 << 16);
+ UInt32 shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment);
+ volatile UInt32 * value32 = (volatile UInt32 *) (((unsigned long) value16) - alignment);
+ UInt32 oldValue;
+ UInt32 newValue;
mask <<= shift;
- newbits <<= shift;
-
- oldValue = *value;
- newValue = (oldValue & ~mask) | (newbits & mask);
-
- return OSCompareAndSwap(oldValue, newValue, value);
+
+ oldValue = *value32;
+ oldValue = (oldValue & ~mask) | (oldValue16 << shift);
+ newValue = (oldValue & ~mask) | (newValue16 << shift);
+
+ return OSCompareAndSwap(oldValue, newValue, value32);
}
+#endif
-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)
+#if defined(__i386__) || defined(__x86_64__)
+SInt16 OSAddAtomic16(SInt32 amount, volatile SInt16 * value)
{
SInt16 oldValue;
SInt16 newValue;
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;
}
+#endif
-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;
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);
}
projects / apple / xnu.git / blobdiff