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. All rights reserved.<BR>
7   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
63