MdeModulePkg/Library/DxeDpcLib/DpcLib.c

   1 /** @file
   2
   3 Copyright (c) 2007, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   DpcLib.c
  15
  16 Abstract:
  17
  18 **/
  19
  20 #include <PiDxe.h>
  21 #include <Library/DebugLib.h>
  22 #include <Library/UefiBootServicesTableLib.h>
  23 #include <Protocol/Dpc.h>
  24
  25 //
  26 // Pointer to the DPC Protocol
  27 //
  28 EFI_DPC_PROTOCOL  *mDpc;
  29
  30 /**
  31   This constructor function caches the EFI_DPC_PROTOCOL pointer.
  32
  33   @param[in] ImageHandle The firmware allocated handle for the EFI image.
  34   @param[in] SystemTable A pointer to the EFI System Table.
  35
  36   @retval EFI_SUCCESS The constructor always return EFI_SUCCESS.
  37
  38 **/
  39 EFI_STATUS
  40 EFIAPI
  41 DpcLibConstructor (
  42   IN EFI_HANDLE        ImageHandle,
  43   IN EFI_SYSTEM_TABLE  *SystemTable
  44   )
  45 {
  46   EFI_STATUS  Status;
  47
  48   //
  49   // Locate the EFI_DPC_PROTOCOL in the handle database
  50   //
  51   Status = gBS->LocateProtocol (&gEfiDpcProtocolGuid, NULL, (VOID **)&mDpc);
  52   ASSERT_EFI_ERROR (Status);
  53
  54   return EFI_SUCCESS;
  55 }
  56
  57 /**
  58   Add a Deferred Procedure Call to the end of the DPC queue.
  59
  60   @param  DpcTpl        The EFI_TPL that the DPC should be invoked.
  61   @param  DpcProcedure  Pointer to the DPC's function.
  62   @param  DpcContext    Pointer to the DPC's context.  Passed to DpcProcedure
  63                         when DpcProcedure is invoked.
  64
  65   @retval EFI_SUCCESS            The DPC was queued.
  66   @retval EFI_INVALID_PARAMETER  DpcTpl is not a valid EFI_TPL.
  67   @retval EFI_INVALID_PARAMETER  DpcProcedure is NULL.
  68   @retval EFI_OUT_OF_RESOURCES   There are not enough resources available to
  69                                  add the DPC to the queue.
  70
  71 **/
  72 EFI_STATUS
  73 EFIAPI
  74 QueueDpc (
  75   IN EFI_TPL            DpcTpl,
  76   IN EFI_DPC_PROCEDURE  DpcProcedure,
  77   IN VOID               *DpcContext
  78   )
  79 {
  80   //
  81   // Call the EFI_DPC_PROTOCOL to queue the DPC
  82   //
  83   return mDpc->QueueDpc (mDpc, DpcTpl, DpcProcedure, DpcContext);
  84 }
  85
  86 /**
  87   Dispatch the queue of DPCs.  ALL DPCs that have been queued with a DpcTpl
  88   value greater than or equal to the current TPL are invoked in the order that
  89   they were queued.  DPCs with higher DpcTpl values are invoked before DPCs with
  90   lower DpcTpl values.
  91
  92   @retval EFI_SUCCESS    One or more DPCs were invoked.
  93   @retval EFI_NOT_FOUND  No DPCs were invoked.
  94
  95 **/
  96 EFI_STATUS
  97 EFIAPI
  98 DispatchDpc (
  99   VOID
 100   )
 101 {
 102   //
 103   // Call the EFI_DPC_PROTOCOL to dispatch previously queued DPCs
 104   //
 105   return mDpc->DispatchDpc (mDpc);
 106 }