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 - 2008, Intel Corporation
   7   All rights reserved. This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15   @par Revision Reference:
  16   This PPI is introduced in PI Version 1.0.
  17
  18 **/
  19
  20 #ifndef __STALL_PPI_H__
  21 #define __STALL_PPI_H__
  22
  23 #define EFI_PEI_STALL_PPI_GUID \
  24   { 0x1f4c6f90, 0xb06b, 0x48d8, {0xa2, 0x01, 0xba, 0xe5, 0xf1, 0xcd, 0x7d, 0x56 } }
  25
  26 typedef struct _EFI_PEI_STALL_PPI EFI_PEI_STALL_PPI;
  27
  28 /**
  29   The Stall() function provides a blocking stall for at least the number
  30   of microseconds stipulated in the final argument of the API.
  31
  32   @param  PeiServices    An indirect pointer to the PEI Services Table
  33                          published by the PEI Foundation.
  34   @param  This           Pointer to the local data for the interface.
  35   @param  Microseconds   Number of microseconds for which to stall.
  36
  37   @retval EFI_SUCCESS    The service provided at least the required delay.
  38
  39 **/
  40 typedef
  41 EFI_STATUS
  42 (EFIAPI *EFI_PEI_STALL)(
  43   IN CONST EFI_PEI_SERVICES     **PeiServices,
  44   IN CONST EFI_PEI_STALL_PPI    *This,
  45   IN UINTN                      Microseconds
  46   );
  47
  48 ///
  49 /// This service provides a simple, blocking stall with platform-specific resolution.
  50 ///
  51 struct _EFI_PEI_STALL_PPI {
  52   ///
  53   /// The resolution in microseconds of the stall services.
  54   ///
  55   UINTN          Resolution;
  56
  57   EFI_PEI_STALL  Stall;
  58 };
  59
  60 extern EFI_GUID gEfiPeiStallPpiGuid;
  61
  62 #endif