iokit/Kernel/IOPMPowerStateQueue.cpp

   1 /*
   2  * Copyright (c) 2001-2002 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,
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  23  * Please see the License for the specific language governing rights and
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  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include "IOPMPowerStateQueue.h"
  30 #include "IOKit/IOLocks.h"
  31 #undef super
  32 #define super IOEventSource
  33 OSDefineMetaClassAndStructors(IOPMPowerStateQueue, IOEventSource);
  34
  35 #ifdef __i386__ /* ppc does this right and doesn't need these routines */
  36 static
  37 void *  OSDequeueAtomic(void ** inList, SInt32 inOffset)
  38 {
  39         void *  oldListHead;
  40         void *  newListHead;
  41
  42         do {
  43                 oldListHead = *inList;
  44                 if (oldListHead == NULL) {
  45                         break;
  46                 }
  47
  48                 newListHead = *(void **) (((char *) oldListHead) + inOffset);
  49         } while (! OSCompareAndSwap((UInt32)oldListHead,
  50                                         (UInt32)newListHead, (UInt32 *)inList));
  51         return oldListHead;
  52 }
  53
  54 static
  55 void    OSEnqueueAtomic(void ** inList, void * inNewLink, SInt32 inOffset)
  56 {
  57         void *  oldListHead;
  58         void *  newListHead = inNewLink;
  59         void ** newLinkNextPtr = (void **) (((char *) inNewLink) + inOffset);
  60
  61         do {
  62                 oldListHead = *inList;
  63                 *newLinkNextPtr = oldListHead;
  64         } while (! OSCompareAndSwap((UInt32)oldListHead, (UInt32)newListHead,
  65                                         (UInt32 *)inList));
  66 }
  67 #endif /* __i386__ */
  68
  69
  70 IOPMPowerStateQueue *IOPMPowerStateQueue::PMPowerStateQueue(OSObject *inOwner)
  71 {
  72     IOPMPowerStateQueue     *me = new IOPMPowerStateQueue;
  73
  74     if(me && !me->init(inOwner, 0) )
  75     {
  76         me->release();
  77         return NULL;
  78     }
  79
  80     return me;
  81 }
  82
  83 bool IOPMPowerStateQueue::init(OSObject *owner, Action action)
  84 {
  85     if(!(super::init(owner, (IOEventSource::Action) action))) return false;
  86
  87     // Queue of powerstate changes
  88     changes = NULL;
  89 #ifdef __i386__
  90     if (!(tmpLock = IOLockAlloc()))  panic("IOPMPowerStateQueue::init can't alloc lock");
  91 #endif
  92     return true;
  93 }
  94
  95
  96 bool IOPMPowerStateQueue::unIdleOccurred(IOService *inTarget, unsigned long inState)
  97 {
  98     PowerChangeEntry             *new_one = NULL;
  99
 100     new_one = (PowerChangeEntry *)IOMalloc(sizeof(PowerChangeEntry));
 101     if(!new_one) return false;
 102
 103     new_one->actionType = IOPMPowerStateQueue::kUnIdle;
 104     new_one->state = inState;
 105     new_one->target = inTarget;
 106
 107     // Change to queue
 108 #ifdef __i386__
 109     IOLockLock(tmpLock);
 110 #endif
 111     OSEnqueueAtomic((void **)&changes, (void *)new_one, 0);
 112 #ifdef __i386__
 113     IOLockUnlock(tmpLock);
 114 #endif
 115     signalWorkAvailable();
 116
 117     return true;
 118 }
 119
 120 // checkForWork() is called in a gated context
 121 bool IOPMPowerStateQueue::checkForWork()
 122 {
 123     PowerChangeEntry            *theNode;
 124     int                         theState;
 125     IOService                   *theTarget;
 126     UInt16                      theAction;
 127
 128     // Dequeue and process the state change request
 129 #ifdef __i386__
 130     IOLockLock(tmpLock);
 131 #endif
 132     if((theNode = (PowerChangeEntry *)OSDequeueAtomic((void **)&changes, 0)))
 133     {
 134 #ifdef __i386__
 135       IOLockUnlock(tmpLock);
 136 #endif
 137         theState = theNode->state;
 138         theTarget = theNode->target;
 139         theAction = theNode->actionType;
 140         IOFree((void *)theNode, sizeof(PowerChangeEntry));
 141
 142         switch (theAction)
 143         {
 144             case kUnIdle:
 145                 theTarget->command_received((void *)theState, 0, 0, 0);
 146                 break;
 147         }
 148     }
 149 #ifdef __i386__
 150     else {
 151       IOLockUnlock(tmpLock);
 152     }
 153 #endif
 154     // Return true if there's more work to be done
 155     if(changes) return true;
 156     else return false;
 157 }