iokit/Kernel/IOPMPowerStateQueue.cpp

   1 /*
   2  * Copyright (c) 2001-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30
  31 #include "IOPMPowerStateQueue.h"
  32 #include "IOKit/IOLocks.h"
  33 #undef super
  34 #define super IOEventSource
  35 OSDefineMetaClassAndStructors(IOPMPowerStateQueue, IOEventSource);
  36
  37 #ifdef __i386__ /* ppc does this right and doesn't need these routines */
  38 static
  39 void *  OSDequeueAtomic(void ** inList, SInt32 inOffset)
  40 {
  41         void *  oldListHead;
  42         void *  newListHead;
  43
  44         do {
  45                 oldListHead = *inList;
  46                 if (oldListHead == NULL) {
  47                         break;
  48                 }
  49
  50                 newListHead = *(void **) (((char *) oldListHead) + inOffset);
  51         } while (! OSCompareAndSwap((UInt32)oldListHead,
  52                                         (UInt32)newListHead, (UInt32 *)inList));
  53         return oldListHead;
  54 }
  55
  56 static
  57 void    OSEnqueueAtomic(void ** inList, void * inNewLink, SInt32 inOffset)
  58 {
  59         void *  oldListHead;
  60         void *  newListHead = inNewLink;
  61         void ** newLinkNextPtr = (void **) (((char *) inNewLink) + inOffset);
  62
  63         do {
  64                 oldListHead = *inList;
  65                 *newLinkNextPtr = oldListHead;
  66         } while (! OSCompareAndSwap((UInt32)oldListHead, (UInt32)newListHead,
  67                                         (UInt32 *)inList));
  68 }
  69 #endif /* __i386__ */
  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 #ifdef __i386__
  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 #ifdef __i386__
 111     IOLockLock(tmpLock);
 112 #endif
 113     OSEnqueueAtomic((void **)&changes, (void *)new_one, 0);
 114 #ifdef __i386__
 115     IOLockUnlock(tmpLock);
 116 #endif
 117     signalWorkAvailable();
 118
 119     return true;
 120 }
 121
 122 // checkForWork() is called in a gated context
 123 bool IOPMPowerStateQueue::checkForWork()
 124 {
 125     PowerChangeEntry            *theNode;
 126     int                         theState;
 127     IOService                   *theTarget;
 128     UInt16                      theAction;
 129
 130     // Dequeue and process the state change request
 131 #ifdef __i386__
 132     IOLockLock(tmpLock);
 133 #endif
 134     if((theNode = (PowerChangeEntry *)OSDequeueAtomic((void **)&changes, 0)))
 135     {
 136 #ifdef __i386__
 137       IOLockUnlock(tmpLock);
 138 #endif
 139         theState = theNode->state;
 140         theTarget = theNode->target;
 141         theAction = theNode->actionType;
 142         IOFree((void *)theNode, sizeof(PowerChangeEntry));
 143
 144         switch (theAction)
 145         {
 146             case kUnIdle:
 147                 theTarget->command_received((void *)theState, 0, 0, 0);
 148                 break;
 149         }
 150     }
 151 #ifdef __i386__
 152     else {
 153       IOLockUnlock(tmpLock);
 154     }
 155 #endif
 156     // Return true if there's more work to be done
 157     if(changes) return true;
 158     else return false;
 159 }