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
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   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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  27  */
  28
  29 #include "IOPMPowerStateQueue.h"
  30 #include "IOKit/IOLocks.h"
  31 #undef super
  32 #define super IOEventSource
  33 OSDefineMetaClassAndStructors(IOPMPowerStateQueue, IOEventSource);
  34
  35 #ifndef __ppc__ /* ppc does this right and doesn't need these routines */
  36 static
  37 void *  OSDequeueAtomic(void * volatile * inList, SInt32 inOffset)
  38 {
  39         /* The _pointer_ is volatile, not the listhead itself */
  40         void * volatile oldListHead;
  41         void * volatile newListHead;
  42
  43         do {
  44                 oldListHead = *inList;
  45                 if (oldListHead == NULL) {
  46                         break;
  47                 }
  48
  49                 newListHead = *(void * volatile *) (((char *) oldListHead) + inOffset);
  50         } while (! OSCompareAndSwap((UInt32)oldListHead,
  51                                         (UInt32)newListHead, (volatile UInt32 *)inList));
  52         return oldListHead;
  53 }
  54
  55 static
  56 void    OSEnqueueAtomic(void * volatile * inList, void * inNewLink, SInt32 inOffset)
  57 {
  58         /* The _pointer_ is volatile, not the listhead itself */
  59         void *  volatile oldListHead;
  60         void *  volatile newListHead = inNewLink;
  61         void * volatile *       newLinkNextPtr = (void * volatile *) (((char *) inNewLink) + inOffset);
  62
  63         do {
  64                 oldListHead = *inList;
  65                 *newLinkNextPtr = oldListHead;
  66         } while (! OSCompareAndSwap((UInt32)oldListHead, (UInt32)newListHead,
  67                                         (volatile UInt32 *)inList));
  68 }
  69 #endif /* ! __ppc__ */
  70
  71
  72 IOPMPowerStateQueue *IOPMPowerStateQueue::PMPowerStateQueue(OSObject *inOwner)
  73 {
  74     IOPMPowerStateQueue     *me = new IOPMPowerStateQueue;
  75
  76     if(me && !me->init(inOwner, 0) )
  77     {
  78         me->release();
  79         return NULL;
  80     }
  81
  82     return me;
  83 }
  84
  85 bool IOPMPowerStateQueue::init(OSObject *owner, Action action)
  86 {
  87     if(!(super::init(owner, (IOEventSource::Action) action))) return false;
  88
  89     // Queue of powerstate changes
  90     changes = NULL;
  91 #ifndef __ppc__
  92     if (!(tmpLock = IOLockAlloc()))  panic("IOPMPowerStateQueue::init can't alloc lock");
  93 #endif
  94     return true;
  95 }
  96
  97
  98 bool IOPMPowerStateQueue::unIdleOccurred(IOService *inTarget, unsigned long inState)
  99 {
 100     PowerChangeEntry             *new_one = NULL;
 101
 102     new_one = (PowerChangeEntry *)IOMalloc(sizeof(PowerChangeEntry));
 103     if(!new_one) return false;
 104
 105     new_one->actionType = IOPMPowerStateQueue::kUnIdle;
 106     new_one->state = inState;
 107     new_one->target = inTarget;
 108
 109     // Change to queue
 110 #ifndef __ppc__
 111     IOLockLock(tmpLock);
 112 #endif
 113     OSEnqueueAtomic((void **)&changes, (void *)new_one, 0);
 114 #ifndef __ppc__
 115     IOLockUnlock(tmpLock);
 116 #endif
 117     signalWorkAvailable();
 118
 119     return true;
 120 }
 121
 122 bool IOPMPowerStateQueue::featureChangeOccurred(
 123     uint32_t inState,
 124     IOService *inTarget)
 125 {
 126     PowerChangeEntry             *new_one = NULL;
 127
 128     new_one = (PowerChangeEntry *)IOMalloc(sizeof(PowerChangeEntry));
 129     if(!new_one) return false;
 130
 131     new_one->actionType = IOPMPowerStateQueue::kPMFeatureChange;
 132     new_one->state = inState;
 133     new_one->target = inTarget;
 134
 135     // Change to queue
 136 #ifdef __i386__
 137     IOLockLock(tmpLock);
 138 #endif
 139     OSEnqueueAtomic((void **)&changes, (void *)new_one, 0);
 140 #ifdef __i386__
 141     IOLockUnlock(tmpLock);
 142 #endif
 143     signalWorkAvailable();
 144
 145     return true;
 146 }
 147
 148
 149 // checkForWork() is called in a gated context
 150 bool IOPMPowerStateQueue::checkForWork()
 151 {
 152     PowerChangeEntry            *theNode;
 153     uint32_t                    theState;
 154     IOService                   *theTarget;
 155     uint16_t                    theAction;
 156
 157     // Dequeue and process the state change request
 158 #ifndef __ppc__
 159     IOLockLock(tmpLock);
 160 #endif
 161     if((theNode = (PowerChangeEntry *)OSDequeueAtomic((void **)&changes, 0)))
 162     {
 163 #ifndef __ppc__
 164       IOLockUnlock(tmpLock);
 165 #endif
 166         theState = theNode->state;
 167         theTarget = theNode->target;
 168         theAction = theNode->actionType;
 169         IOFree((void *)theNode, sizeof(PowerChangeEntry));
 170
 171         switch (theAction)
 172         {
 173             case kUnIdle:
 174                 theTarget->command_received((void *)theState, 0, 0, 0);
 175                 break;
 176
 177             case kPMFeatureChange:
 178                 theTarget->messageClients(theState, theTarget);
 179                 break;
 180         }
 181     }
 182 #ifndef __ppc__
 183     else {
 184       IOLockUnlock(tmpLock);
 185     }
 186 #endif
 187     // Return true if there's more work to be done
 188     if(changes) return true;
 189     else return false;
 190 }