MdeModulePkg/Library/DxeDpcLib/DpcLib.c

   1 /** @file
   2   Help functions to access UDP service.
   3
   4 Copyright (c) 2005 - 2007, Intel Corporation. All rights reserved.<BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 **/
  13
  14 #include <Uefi.h>
  15 #include <Library/DebugLib.h>
  16 #include <Library/UefiBootServicesTableLib.h>
  17 #include <Protocol/Dpc.h>
  18
  19 //
  20 // Pointer to the DPC Protocol
  21 //
  22 EFI_DPC_PROTOCOL  *mDpc;
  23
  24 /**
  25   This constructor function caches the EFI_DPC_PROTOCOL pointer.
  26
  27   @param[in] ImageHandle The firmware allocated handle for the EFI image.
  28   @param[in] SystemTable A pointer to the EFI System Table.
  29
  30   @retval EFI_SUCCESS The constructor always return EFI_SUCCESS.
  31
  32 **/
  33 EFI_STATUS
  34 EFIAPI
  35 DpcLibConstructor (
  36   IN EFI_HANDLE        ImageHandle,
  37   IN EFI_SYSTEM_TABLE  *SystemTable
  38   )
  39 {
  40   EFI_STATUS  Status;
  41
  42   //
  43   // Locate the EFI_DPC_PROTOCOL in the handle database
  44   //
  45   Status = gBS->LocateProtocol (&gEfiDpcProtocolGuid, NULL, (VOID **)&mDpc);
  46   ASSERT_EFI_ERROR (Status);
  47
  48   return EFI_SUCCESS;
  49 }
  50
  51 /**
  52   Add a Deferred Procedure Call to the end of the DPC queue.
  53
  54   @param[in]  DpcTpl        The EFI_TPL that the DPC should be invoked.
  55   @param[in]  DpcProcedure  Pointer to the DPC's function.
  56   @param[in]  DpcContext    Pointer to the DPC's context.  Passed to DpcProcedure
  57                             when DpcProcedure is invoked.
  58
  59   @retval EFI_SUCCESS            The DPC was queued.
  60   @retval EFI_INVALID_PARAMETER  DpcTpl is not a valid EFI_TPL.
  61   @retval EFI_INVALID_PARAMETER  DpcProcedure is NULL.
  62   @retval EFI_OUT_OF_RESOURCES   There are not enough resources available to
  63                                  add the DPC to the queue.
  64
  65 **/
  66 EFI_STATUS
  67 EFIAPI
  68 QueueDpc (
  69   IN EFI_TPL            DpcTpl,
  70   IN EFI_DPC_PROCEDURE  DpcProcedure,
  71   IN VOID               *DpcContext    OPTIONAL
  72   )
  73 {
  74   //
  75   // Call the EFI_DPC_PROTOCOL to queue the DPC
  76   //
  77   return mDpc->QueueDpc (mDpc, DpcTpl, DpcProcedure, DpcContext);
  78 }
  79
  80 /**
  81   Dispatch the queue of DPCs.  ALL DPCs that have been queued with a DpcTpl
  82   value greater than or equal to the current TPL are invoked in the order that
  83   they were queued.  DPCs with higher DpcTpl values are invoked before DPCs with
  84   lower DpcTpl values.
  85
  86   @retval EFI_SUCCESS    One or more DPCs were invoked.
  87   @retval EFI_NOT_FOUND  No DPCs were invoked.
  88
  89 **/
  90 EFI_STATUS
  91 EFIAPI
  92 DispatchDpc (
  93   VOID
  94   )
  95 {
  96   //
  97   // Call the EFI_DPC_PROTOCOL to dispatch previously queued DPCs
  98   //
  99   return mDpc->DispatchDpc (mDpc);
 100 }