MdePkg/Include/Ppi/Stall.h

   1 /** @file
   2   This file declares Stall PPI.
   3
   4   This ppi abstracts the blocking stall service to other agents.
   5
   6   Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9   @par Revision Reference:
  10   This PPI is introduced in PI Version 1.0.
  11
  12 **/
  13
  14 #ifndef __STALL_PPI_H__
  15 #define __STALL_PPI_H__
  16
  17 #define EFI_PEI_STALL_PPI_GUID \
  18   { 0x1f4c6f90, 0xb06b, 0x48d8, {0xa2, 0x01, 0xba, 0xe5, 0xf1, 0xcd, 0x7d, 0x56 } }
  19
  20 typedef struct _EFI_PEI_STALL_PPI EFI_PEI_STALL_PPI;
  21
  22 /**
  23   The Stall() function provides a blocking stall for at least the number
  24   of microseconds stipulated in the final argument of the API.
  25
  26   @param  PeiServices    An indirect pointer to the PEI Services Table
  27                          published by the PEI Foundation.
  28   @param  This           Pointer to the local data for the interface.
  29   @param  Microseconds   Number of microseconds for which to stall.
  30
  31   @retval EFI_SUCCESS    The service provided at least the required delay.
  32
  33 **/
  34 typedef
  35 EFI_STATUS
  36 (EFIAPI *EFI_PEI_STALL)(
  37   IN CONST EFI_PEI_SERVICES     **PeiServices,
  38   IN CONST EFI_PEI_STALL_PPI    *This,
  39   IN UINTN                      Microseconds
  40   );
  41
  42 ///
  43 /// This service provides a simple, blocking stall with platform-specific resolution.
  44 ///
  45 struct _EFI_PEI_STALL_PPI {
  46   ///
  47   /// The resolution in microseconds of the stall services.
  48   ///
  49   UINTN            Resolution;
  50
  51   EFI_PEI_STALL    Stall;
  52 };
  53
  54 extern EFI_GUID  gEfiPeiStallPpiGuid;
  55
  56 #endif