1/*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_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. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /*
29 * Copyright (c) 1997-1998 Apple Computer, Inc.
30 *
31 *
32 * HISTORY
33 *
34 * sdouglas  22 Oct 97 - first checked in from DriverServices
35 * sdouglas  28 Jul 98 - start IOKit
36 */
37
38#include <architecture/ppc/asm_help.h>
39
40;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
41;
42; ENTRY		functionName
43;
44; Assembly directives to begin an exported function.
45;
46; Takes: functionName - name of the exported function
47;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
48
49.macro ENTRY
50    .text
51    .align	2
52    .globl	$0
53$0:
54.endmacro
55
56;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
57
58/*
59int     OSCompareAndSwap( UInt32 oldVal, UInt32 newVal, UInt32 * addr )
60    This is now an alias to hw_compare_and_store, see xnu/libkern/Makefile.
61
62void *	OSDequeueAtomic(void ** inList, SInt32 inOffset)
63    This is also aliased, to hw_dequeue_atomic.
64
65void	OSEnqueueAtomic(void ** inList, void * inNewLink, SInt32 inOffset)
66    This is aliased to hw_queue_atomic.
67*/
68
69/*
70Note:  We can not use the hw_atomic routines provided by osfmk/ppc as
71the return the result of the addition not the original value.
72*/
73/*
74SInt32	OSDecrementAtomic(SInt32 * value)
75*/
76    ENTRY	_OSDecrementAtomic
77    mr		r4, r3
78    li		r3, -1
79    b		_OSAddAtomic
80
81/*
82SInt32	OSIncrementAtomic(SInt32 * value)
83*/
84
85    .align	5
86
87    ENTRY	_OSIncrementAtomic
88    mr		r4, r3
89    li		r3, 1
90
91/*
92SInt32	OSAddAtomic(SInt32 amount, SInt32 * value)
93*/
94
95    ENTRY	_OSAddAtomic
96
97    mr		r5,r3		/* Save the increment */
98.L_AAretry:
99    lwarx	r3, 0, r4	/* Grab the area value */
100    add		r6, r3, r5	/* Add the value */
101    stwcx.	r6, 0, r4	/* Try to save the new value */
102    bne-	.L_AAretry	/* Didn't get it, try again... */
103    blr				/* Return the original value */
104