2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
4 * @APPLE_LICENSE_HEADER_START@
6 * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
8 * This file contains Original Code and/or Modifications of Original Code
9 * as defined in and that are subject to the Apple Public Source License
10 * Version 2.0 (the 'License'). You may not use this file except in
11 * compliance with the License. Please obtain a copy of the License at
12 * http://www.opensource.apple.com/apsl/ and read it before using this
15 * The Original Code and all software distributed under the License are
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17 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
18 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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20 * Please see the License for the specific language governing rights and
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26 * Copyright (c) 1997-1998 Apple Computer, Inc.
31 * sdouglas 22 Oct 97 - first checked in from DriverServices
32 * sdouglas 28 Jul 98 - start IOKit
35 #include <architecture/ppc/asm_help.h>
37 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
41 ; Assembly directives to begin an exported function.
43 ; Takes: functionName - name of the exported function
44 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
53 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
56 int OSCompareAndSwap( UInt32 oldVal, UInt32 newVal, UInt32 * addr )
60 ENTRY _OSCompareAndSwap
62 lwz r6,0(r5) // Get the swap value
63 cmpw r6,r3 // Is is the same
64 bne-- .L_CASfail2 // No...
67 lwarx r6,0,r5 // Get it atomically now
69 bne-- .L_CASfail // Nope, go say so and toss reservations...
70 stwcx. r4,0,r5 // Stash the new value
71 bne-- .L_CASretry2 // Just got collision...
77 li a7,-4 // Point to a spot in the red zone
78 stwcx. a7,a7,r1 // Kill reservation
86 SInt32 OSDecrementAtomic(SInt32 * value)
88 ENTRY _OSDecrementAtomic
94 SInt32 OSIncrementAtomic(SInt32 * value)
97 ENTRY _OSIncrementAtomic
102 SInt32 OSAddAtomic(SInt32 amount, SInt32 * value)
107 mr r5,r3 /* Save the increment */
109 lwarx r3, 0, r4 /* Grab the area value */
110 add r6, r3, r5 /* Add the value */
111 stwcx. r6, 0, r4 /* Try to save the new value */
112 bne- .L_AAretry /* Didn't get it, try again... */
113 blr /* Return the original value */