MdePkg/Include/Ppi/DelayedDispatch.h

   1 /** @file
   2     EFI Delayed Dispatch PPI as defined in the PI 1.7 Specification
   3
   4     Provide timed event service in PEI
   5
   6     Copyright (c) 2020, American Megatrends International LLC. All rights reserved.
   7     SPDX-License-Identifier: BSD-2-Clause-Patent
   8 **/
   9
  10 #ifndef __DELAYED_DISPATCH_PPI_H__
  11 #define __DELAYED_DISPATCH_PPI_H__
  12
  13 ///
  14 /// Global ID for EFI_DELAYED_DISPATCH_PPI_GUID
  15 ///
  16 #define EFI_DELAYED_DISPATCH_PPI_GUID \
  17   { \
  18     0x869c711d, 0x649c, 0x44fe, { 0x8b, 0x9e, 0x2c, 0xbb, 0x29, 0x11, 0xc3, 0xe6} } \
  19   }
  20
  21 /**
  22   Delayed Dispatch function.  This routine is called sometime after the required
  23   delay.  Upon return, if NewDelay is 0, the function is unregistered.  If NewDelay
  24   is not zero, this routine will be called again after the new delay period.
  25
  26   @param[in,out] Context         Pointer to Context. Can be updated by routine.
  27   @param[out]    NewDelay        The new delay in us.  Leave at 0 to unregister callback.
  28
  29 **/
  30
  31 typedef
  32 VOID
  33 (EFIAPI *EFI_DELAYED_DISPATCH_FUNCTION)(
  34   IN OUT UINT64 *Context,
  35   OUT UINT32 *NewDelay
  36   );
  37
  38 ///
  39 /// The forward declaration for EFI_DELAYED_DISPATCH_PPI
  40 ///
  41
  42 typedef  struct _EFI_DELAYED_DISPATCH_PPI EFI_DELAYED_DISPATCH_PPI;
  43
  44 /**
  45 Register a callback to be called after a minimum delay has occurred.
  46
  47 This service is the single member function of the EFI_DELAYED_DISPATCH_PPI
  48
  49   @param This           Pointer to the EFI_DELAYED_DISPATCH_PPI instance
  50   @param Function       Function to call back
  51   @param Context        Context data
  52   @param Delay          Delay interval
  53
  54   @retval EFI_SUCCESS               Function successfully loaded
  55   @retval EFI_INVALID_PARAMETER     One of the Arguments is not supported
  56   @retval EFI_OUT_OF_RESOURCES      No more entries
  57
  58 **/
  59 typedef
  60 EFI_STATUS
  61 (EFIAPI *EFI_DELAYED_DISPATCH_REGISTER)(
  62   IN  EFI_DELAYED_DISPATCH_PPI      *This,
  63   IN  EFI_DELAYED_DISPATCH_FUNCTION  Function,
  64   IN  UINT64                     Context,
  65   OUT UINT32                     Delay
  66   );
  67
  68 ///
  69 /// This PPI is a pointer to the Delayed Dispatch Service.
  70 /// This service will be published by the Pei Foundation. The PEI Foundation
  71 /// will use this service to relaunch a known function that requests a delayed
  72 /// execution.
  73 ///
  74 struct _EFI_DELAYED_DISPATCH_PPI {
  75   EFI_DELAYED_DISPATCH_REGISTER    Register;
  76 };
  77
  78 extern EFI_GUID  gEfiPeiDelayedDispatchPpiGuid;
  79
  80 #endif