1 /*
2 * Copyright (c) 1998-2000 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 #include <IOKit/pwr_mgt/IOPM.h>
29 #include <IOKit/pwr_mgt/IOPMinformeeList.h>
30 #include <IOKit/pwr_mgt/IOPMinformee.h>
31
32 #define super OSObject
OSDefineMetaClassAndStructors(IOPMinformeeList,OSObject)33 OSDefineMetaClassAndStructors(IOPMinformeeList, OSObject)
34
35 //*********************************************************************************
36 // init
37 //
38 //*********************************************************************************
39 void
40 IOPMinformeeList::initialize( void )
41 {
42 firstItem = NULL;
43 length = 0;
44 }
45
46 //******************************************************************************
47 // getSharedRecursiveLock
48 //
49 //******************************************************************************
50 IORecursiveLock *
getSharedRecursiveLock(void)51 IOPMinformeeList::getSharedRecursiveLock( void )
52 {
53 static IORecursiveLock *sharedListLock = NULL;
54
55 /* A running system could have 50-60+ instances of IOPMInformeeList.
56 * They'll share this lock, since list insertion and removal is relatively
57 * rare, and generally tied to major events like device discovery.
58 *
59 * getSharedRecursiveLock() is called from IOStartIOKit to initialize
60 * the sharedListLock before any IOPMinformeeLists are instantiated.
61 *
62 * The IOPMinformeeList class will be around for the lifetime of the system,
63 * we don't worry about freeing this lock.
64 */
65
66 if (NULL == sharedListLock) {
67 sharedListLock = IORecursiveLockAlloc();
68 }
69 return sharedListLock;
70 }
71
72 //*********************************************************************************
73 // appendNewInformee
74 //
75 //*********************************************************************************
76 IOPMinformee *
appendNewInformee(IOService * newObject)77 IOPMinformeeList::appendNewInformee( IOService * newObject )
78 {
79 IOPMinformee * newInformee;
80
81 if (!newObject) {
82 return NULL;
83 }
84
85 newInformee = IOPMinformee::withObject(newObject);
86
87 if (!newInformee) {
88 return NULL;
89 }
90
91 if (IOPMNoErr == addToList(newInformee)) {
92 return newInformee;
93 } else {
94 newInformee->release();
95 return NULL;
96 }
97 }
98
99
100 //*********************************************************************************
101 // addToList
102 // *OBSOLETE* do not call from outside of this file.
103 // Try appendNewInformee() instead
104 //*********************************************************************************
105 IOReturn
addToList(IOPMinformee * newInformee)106 IOPMinformeeList::addToList( IOPMinformee * newInformee )
107 {
108 IORecursiveLock *listLock = getSharedRecursiveLock();
109 IOReturn ret = kIOReturnError;
110
111 if (!listLock) {
112 return ret;
113 }
114
115 IORecursiveLockLock(listLock);
116
117 // Is new object already in the list?
118 if (findItem(newInformee->whatObject) != NULL) {
119 // object is present; just exit
120 goto unlock_and_exit;
121 }
122
123 // add it to the front of the list
124 newInformee->nextInList = firstItem;
125 firstItem = newInformee;
126 length++;
127 ret = IOPMNoErr;
128
129 unlock_and_exit:
130 IORecursiveLockUnlock(listLock);
131 return ret;
132 }
133
134
135 //*********************************************************************************
136 // removeFromList
137 //
138 // Find the item in the list, unlink it, and free it.
139 //*********************************************************************************
140
141 IOReturn
removeFromList(IOService * theItem)142 IOPMinformeeList::removeFromList( IOService * theItem )
143 {
144 IOPMinformee * item = firstItem;
145 IOPMinformee * temp;
146 IORecursiveLock *listLock = getSharedRecursiveLock();
147
148 if (NULL == item) {
149 return IOPMNoErr;
150 }
151 if (!listLock) {
152 return kIOReturnError;
153 }
154
155 IORecursiveLockLock( listLock );
156
157 if (item->whatObject == theItem) {
158 firstItem = item->nextInList;
159 length--;
160 item->release();
161 goto unlock_and_exit;
162 }
163
164 while (item->nextInList != NULL) {
165 if (item->nextInList->whatObject == theItem) {
166 temp = item->nextInList;
167 item->nextInList = temp->nextInList;
168 length--;
169 temp->release();
170 goto unlock_and_exit;
171 }
172 item = item->nextInList;
173 }
174
175 unlock_and_exit:
176 IORecursiveLockUnlock(listLock);
177 return IOPMNoErr;
178 }
179
180
181 //*********************************************************************************
182 // firstInList
183 //
184 //*********************************************************************************
185
186 IOPMinformee *
firstInList(void)187 IOPMinformeeList::firstInList( void )
188 {
189 return firstItem;
190 }
191
192 //*********************************************************************************
193 // nextInList
194 //
195 //*********************************************************************************
196
197 IOPMinformee *
nextInList(IOPMinformee * currentItem)198 IOPMinformeeList::nextInList( IOPMinformee * currentItem )
199 {
200 if (currentItem != NULL) {
201 return currentItem->nextInList;
202 }
203 return NULL;
204 }
205
206 //*********************************************************************************
207 // numberOfItems
208 //
209 //*********************************************************************************
210
211 unsigned long
numberOfItems(void)212 IOPMinformeeList::numberOfItems( void )
213 {
214 return length;
215 }
216
217 //*********************************************************************************
218 // findItem
219 //
220 // Look through the list for the one which points to the object identified
221 // by the parameter. Return a pointer to the list item or NULL.
222 //*********************************************************************************
223
224 IOPMinformee *
findItem(IOService * driverOrChild)225 IOPMinformeeList::findItem( IOService * driverOrChild )
226 {
227 IOPMinformee * nextObject;
228
229 nextObject = firstInList();
230 while (nextObject != NULL) {
231 if (nextObject->whatObject == driverOrChild) {
232 return nextObject;
233 }
234 nextObject = nextInList(nextObject);
235 }
236 return NULL;
237 }
238
239
240
241 //*********************************************************************************
242 // free
243 //
244 // Free all items in the list, and then free the list itself
245 //*********************************************************************************
246
247 void
free(void)248 IOPMinformeeList::free(void )
249 {
250 IOPMinformee * next = firstItem;
251
252 while (next != NULL) {
253 firstItem = next->nextInList;
254 length--;
255 next->release();
256 next = firstItem;
257 }
258 super::free();
259 }
260