reactos/ntoskrnl/ke/dpc.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 2000, 1999, 1998 David Welch <welch@cwcom.net>,
   4  *                                 Philip Susi <phreak@iag.net>,
   5  *                                 Eric Kohl <ekohl@abo.rhein-zeitung.de>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21 /* $Id: dpc.c,v 1.28 2003/10/12 17:05:45 hbirr Exp $
  22  *
  23  * COPYRIGHT:       See COPYING in the top level directory
  24  * PROJECT:         ReactOS kernel
  25  * FILE:            ntoskrnl/ke/dpc.c
  26  * PURPOSE:         Handle DPCs (Delayed Procedure Calls)
  27  * PROGRAMMER:      David Welch (welch@mcmail.com)
  28  * UPDATE HISTORY:
  29  *                28/05/98: Created
  30  *                12/3/99:  Phillip Susi: Fixed IRQL problem
  31  */
  32
  33 /*
  34  * NOTE: See also the higher level support routines in ntoskrnl/io/dpc.c
  35  */
  36
  37 /* INCLUDES ***************************************************************/
  38
  39 #include <ddk/ntddk.h>
  40 #include <internal/ps.h>
  41
  42 #define NDEBUG
  43 #include <internal/debug.h>
  44
  45 /* TYPES *******************************************************************/
  46
  47 /* GLOBALS ******************************************************************/
  48
  49 static LIST_ENTRY DpcQueueHead; /* Head of the list of pending DPCs */
  50 static KSPIN_LOCK DpcQueueLock; /* Lock for the above list */
  51 /*
  52  * Number of pending DPCs. This is inspected by
  53  * the idle thread to determine if the queue needs to
  54  * be run down
  55  */
  56 ULONG DpcQueueSize = 0;
  57
  58 /* FUNCTIONS ****************************************************************/
  59
  60 /*
  61  * @implemented
  62  */
  63 VOID STDCALL
  64 KeInitializeDpc (PKDPC                  Dpc,
  65                  PKDEFERRED_ROUTINE     DeferredRoutine,
  66                  PVOID                  DeferredContext)
  67 /*
  68  * FUNCTION: Initalizes a DPC
  69  * ARGUMENTS:
  70  *          Dpc = Caller supplied DPC to be initialized
  71  *          DeferredRoutine = Associated DPC callback
  72  *          DeferredContext = Parameter to be passed to the callback
  73  * NOTE: Callers must be running at IRQL PASSIVE_LEVEL
  74  */
  75 {
  76    Dpc->Type = 0;
  77    Dpc->DeferredRoutine = DeferredRoutine;
  78    Dpc->DeferredContext = DeferredContext;
  79    Dpc->Lock = 0;
  80 }
  81
  82 /*
  83  * @implemented
  84  */
  85 VOID STDCALL
  86 KiDispatchInterrupt(VOID)
  87 /*
  88  * FUNCTION: Called to execute queued dpcs
  89  */
  90 {
  91    PLIST_ENTRY current_entry;
  92    PKDPC current;
  93    KIRQL oldlvl;
  94
  95    assert_irql(DISPATCH_LEVEL);
  96
  97    if (DpcQueueSize == 0)
  98      {
  99         return;
 100      }
 101
 102    KeRaiseIrql(HIGH_LEVEL, &oldlvl);
 103    KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
 104
 105    while (!IsListEmpty(&DpcQueueHead))
 106    {
 107       current_entry = RemoveHeadList(&DpcQueueHead);
 108       DpcQueueSize--;
 109       current = CONTAINING_RECORD(current_entry,KDPC,DpcListEntry);
 110       current->Lock=FALSE;
 111       KeReleaseSpinLock(&DpcQueueLock, oldlvl);
 112       current->DeferredRoutine(current,current->DeferredContext,
 113                                current->SystemArgument1,
 114                                current->SystemArgument2);
 115
 116       KeRaiseIrql(HIGH_LEVEL, &oldlvl);
 117       KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
 118    }
 119    KeReleaseSpinLock(&DpcQueueLock, oldlvl);
 120 }
 121
 122 /*
 123  * @implemented
 124  */
 125 BOOLEAN STDCALL
 126 KeRemoveQueueDpc (PKDPC Dpc)
 127 /*
 128  * FUNCTION: Removes DPC object from the system dpc queue
 129  * ARGUMENTS:
 130  *          Dpc = DPC to remove
 131  * RETURNS: TRUE if the DPC was in the queue
 132  *          FALSE otherwise
 133  */
 134 {
 135    KIRQL oldIrql;
 136
 137    KeRaiseIrql(HIGH_LEVEL, &oldIrql);
 138    KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
 139    if (!Dpc->Lock)
 140      {
 141         KeReleaseSpinLock(&DpcQueueLock, oldIrql);
 142         return(FALSE);
 143      }
 144    RemoveEntryList(&Dpc->DpcListEntry);
 145    DpcQueueSize--;
 146    Dpc->Lock=0;
 147    KeReleaseSpinLock(&DpcQueueLock, oldIrql);
 148    return(TRUE);
 149 }
 150
 151 /*
 152  * @implemented
 153  */
 154 BOOLEAN STDCALL
 155 KeInsertQueueDpc (PKDPC Dpc,
 156                   PVOID SystemArgument1,
 157                   PVOID SystemArgument2)
 158 /*
 159  * FUNCTION: Queues a DPC for execution when the IRQL of a processor
 160  * drops below DISPATCH_LEVEL
 161  * ARGUMENTS:
 162  *          Dpc = Initalizes DPC
 163  *          SystemArguments[1-2] = Undocumented
 164  * RETURNS: TRUE if the DPC object wasn't already in the queue
 165  *          FALSE otherwise
 166  */
 167 {
 168    KIRQL oldlvl;
 169    DPRINT("KeInsertQueueDpc(dpc %x, SystemArgument1 %x, SystemArgument2 %x)\n",
 170           Dpc, SystemArgument1, SystemArgument2);
 171
 172    assert(KeGetCurrentIrql()>=DISPATCH_LEVEL);
 173
 174    Dpc->Number=0;
 175    Dpc->Importance=MediumImportance;
 176    Dpc->SystemArgument1=SystemArgument1;
 177    Dpc->SystemArgument2=SystemArgument2;
 178    if (Dpc->Lock)
 179      {
 180         return(FALSE);
 181      }
 182    KeRaiseIrql(HIGH_LEVEL, &oldlvl);
 183    KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
 184    InsertHeadList(&DpcQueueHead,&Dpc->DpcListEntry);
 185    DPRINT("Dpc->DpcListEntry.Flink %x\n", Dpc->DpcListEntry.Flink);
 186    DpcQueueSize++;
 187    Dpc->Lock=(PULONG)1;
 188    KeReleaseSpinLock( &DpcQueueLock, oldlvl );
 189    DPRINT("DpcQueueHead.Flink %x\n",DpcQueueHead.Flink);
 190    DPRINT("Leaving KeInsertQueueDpc()\n",0);
 191    return(TRUE);
 192 }
 193
 194 /*
 195  * FUNCTION: Specifies the DPCs importance
 196  * ARGUMENTS:
 197  *          Dpc = Initalizes DPC
 198  *          Importance = DPC importance
 199  * RETURNS: None
 200  *
 201  * @implemented
 202  */
 203 VOID STDCALL
 204 KeSetImportanceDpc (IN  PKDPC           Dpc,
 205                     IN  KDPC_IMPORTANCE Importance)
 206 {
 207         Dpc->Importance = Importance;
 208 }
 209
 210 /*
 211  * FUNCTION: Specifies on which processor the DPC will run
 212  * ARGUMENTS:
 213  *          Dpc = Initalizes DPC
 214  *          Number = Processor number
 215  * RETURNS: None
 216  *
 217  * @unimplemented
 218  */
 219 VOID STDCALL
 220 KeSetTargetProcessorDpc (IN     PKDPC   Dpc,
 221                          IN     CCHAR   Number)
 222 {
 223         UNIMPLEMENTED;
 224 }
 225
 226 VOID INIT_FUNCTION
 227 KeInitDpc(VOID)
 228 /*
 229  * FUNCTION: Initialize DPC handling
 230  */
 231 {
 232    InitializeListHead(&DpcQueueHead);
 233    KeInitializeSpinLock(&DpcQueueLock);
 234 }
 235
 236 /* EOF */