1 /** @file
2
3 A DXE_DRIVER providing SMRAM access by producing EFI_SMM_ACCESS2_PROTOCOL.
4
5 Q35 TSEG is expected to have been verified and set up by the SmmAccessPei
6 driver.
7
8 Copyright (C) 2013, 2015, Red Hat, Inc.<BR>
9 Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
10
11 This program and the accompanying materials are licensed and made available
12 under the terms and conditions of the BSD License which accompanies this
13 distribution. The full text of the license may be found at
14 http://opensource.org/licenses/bsd-license.php
15
16 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
17 WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
18
19 **/
20
21 #include <Library/DebugLib.h>
22 #include <Library/PcdLib.h>
23 #include <Library/UefiBootServicesTableLib.h>
24 #include <Protocol/SmmAccess2.h>
25
26 #include "SmramInternal.h"
27
28 /**
29 Opens the SMRAM area to be accessible by a boot-service driver.
30
31 This function "opens" SMRAM so that it is visible while not inside of SMM.
32 The function should return EFI_UNSUPPORTED if the hardware does not support
33 hiding of SMRAM. The function should return EFI_DEVICE_ERROR if the SMRAM
34 configuration is locked.
35
36 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
37
38 @retval EFI_SUCCESS The operation was successful.
39 @retval EFI_UNSUPPORTED The system does not support opening and closing of
40 SMRAM.
41 @retval EFI_DEVICE_ERROR SMRAM cannot be opened, perhaps because it is
42 locked.
43 **/
44 STATIC
45 EFI_STATUS
46 EFIAPI
SmmAccess2DxeOpen(IN EFI_SMM_ACCESS2_PROTOCOL * This)47 SmmAccess2DxeOpen (
48 IN EFI_SMM_ACCESS2_PROTOCOL *This
49 )
50 {
51 return SmramAccessOpen (&This->LockState, &This->OpenState);
52 }
53
54 /**
55 Inhibits access to the SMRAM.
56
57 This function "closes" SMRAM so that it is not visible while outside of SMM.
58 The function should return EFI_UNSUPPORTED if the hardware does not support
59 hiding of SMRAM.
60
61 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
62
63 @retval EFI_SUCCESS The operation was successful.
64 @retval EFI_UNSUPPORTED The system does not support opening and closing of
65 SMRAM.
66 @retval EFI_DEVICE_ERROR SMRAM cannot be closed.
67 **/
68 STATIC
69 EFI_STATUS
70 EFIAPI
SmmAccess2DxeClose(IN EFI_SMM_ACCESS2_PROTOCOL * This)71 SmmAccess2DxeClose (
72 IN EFI_SMM_ACCESS2_PROTOCOL *This
73 )
74 {
75 return SmramAccessClose (&This->LockState, &This->OpenState);
76 }
77
78 /**
79 Inhibits access to the SMRAM.
80
81 This function prohibits access to the SMRAM region. This function is usually
82 implemented such that it is a write-once operation.
83
84 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
85
86 @retval EFI_SUCCESS The device was successfully locked.
87 @retval EFI_UNSUPPORTED The system does not support locking of SMRAM.
88 **/
89 STATIC
90 EFI_STATUS
91 EFIAPI
SmmAccess2DxeLock(IN EFI_SMM_ACCESS2_PROTOCOL * This)92 SmmAccess2DxeLock (
93 IN EFI_SMM_ACCESS2_PROTOCOL *This
94 )
95 {
96 return SmramAccessLock (&This->LockState, &This->OpenState);
97 }
98
99 /**
100 Queries the memory controller for the possible regions that will support
101 SMRAM.
102
103 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
104 @param[in,out] SmramMapSize A pointer to the size, in bytes, of the
105 SmramMemoryMap buffer.
106 @param[in,out] SmramMap A pointer to the buffer in which firmware
107 places the current memory map.
108
109 @retval EFI_SUCCESS The chipset supported the given resource.
110 @retval EFI_BUFFER_TOO_SMALL The SmramMap parameter was too small. The
111 current buffer size needed to hold the memory
112 map is returned in SmramMapSize.
113 **/
114 STATIC
115 EFI_STATUS
116 EFIAPI
SmmAccess2DxeGetCapabilities(IN CONST EFI_SMM_ACCESS2_PROTOCOL * This,IN OUT UINTN * SmramMapSize,IN OUT EFI_SMRAM_DESCRIPTOR * SmramMap)117 SmmAccess2DxeGetCapabilities (
118 IN CONST EFI_SMM_ACCESS2_PROTOCOL *This,
119 IN OUT UINTN *SmramMapSize,
120 IN OUT EFI_SMRAM_DESCRIPTOR *SmramMap
121 )
122 {
123 return SmramAccessGetCapabilities (This->LockState, This->OpenState,
124 SmramMapSize, SmramMap);
125 }
126
127 //
128 // LockState and OpenState will be filled in by the entry point.
129 //
130 STATIC EFI_SMM_ACCESS2_PROTOCOL mAccess2 = {
131 &SmmAccess2DxeOpen,
132 &SmmAccess2DxeClose,
133 &SmmAccess2DxeLock,
134 &SmmAccess2DxeGetCapabilities
135 };
136
137 //
138 // Entry point of this driver.
139 //
140 EFI_STATUS
141 EFIAPI
SmmAccess2DxeEntryPoint(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)142 SmmAccess2DxeEntryPoint (
143 IN EFI_HANDLE ImageHandle,
144 IN EFI_SYSTEM_TABLE *SystemTable
145 )
146 {
147 //
148 // This module should only be included if SMRAM support is required.
149 //
150 ASSERT (FeaturePcdGet (PcdSmmSmramRequire));
151
152 GetStates (&mAccess2.LockState, &mAccess2.OpenState);
153 return gBS->InstallMultipleProtocolInterfaces (&ImageHandle,
154 &gEfiSmmAccess2ProtocolGuid, &mAccess2,
155 NULL);
156 }
157