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 SPDX-License-Identifier: BSD-2-Clause-Patent
12
13 **/
14
15 #include <Library/DebugLib.h>
16 #include <Library/PcdLib.h>
17 #include <Library/UefiBootServicesTableLib.h>
18 #include <Protocol/SmmAccess2.h>
19
20 #include "SmramInternal.h"
21
22 /**
23 Opens the SMRAM area to be accessible by a boot-service driver.
24
25 This function "opens" SMRAM so that it is visible while not inside of SMM.
26 The function should return EFI_UNSUPPORTED if the hardware does not support
27 hiding of SMRAM. The function should return EFI_DEVICE_ERROR if the SMRAM
28 configuration is locked.
29
30 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
31
32 @retval EFI_SUCCESS The operation was successful.
33 @retval EFI_UNSUPPORTED The system does not support opening and closing of
34 SMRAM.
35 @retval EFI_DEVICE_ERROR SMRAM cannot be opened, perhaps because it is
36 locked.
37 **/
38 STATIC
39 EFI_STATUS
40 EFIAPI
SmmAccess2DxeOpen(IN EFI_SMM_ACCESS2_PROTOCOL * This)41 SmmAccess2DxeOpen (
42 IN EFI_SMM_ACCESS2_PROTOCOL *This
43 )
44 {
45 return SmramAccessOpen (&This->LockState, &This->OpenState);
46 }
47
48 /**
49 Inhibits access to the SMRAM.
50
51 This function "closes" SMRAM so that it is not visible while outside of SMM.
52 The function should return EFI_UNSUPPORTED if the hardware does not support
53 hiding of SMRAM.
54
55 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
56
57 @retval EFI_SUCCESS The operation was successful.
58 @retval EFI_UNSUPPORTED The system does not support opening and closing of
59 SMRAM.
60 @retval EFI_DEVICE_ERROR SMRAM cannot be closed.
61 **/
62 STATIC
63 EFI_STATUS
64 EFIAPI
SmmAccess2DxeClose(IN EFI_SMM_ACCESS2_PROTOCOL * This)65 SmmAccess2DxeClose (
66 IN EFI_SMM_ACCESS2_PROTOCOL *This
67 )
68 {
69 return SmramAccessClose (&This->LockState, &This->OpenState);
70 }
71
72 /**
73 Inhibits access to the SMRAM.
74
75 This function prohibits access to the SMRAM region. This function is usually
76 implemented such that it is a write-once operation.
77
78 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
79
80 @retval EFI_SUCCESS The device was successfully locked.
81 @retval EFI_UNSUPPORTED The system does not support locking of SMRAM.
82 **/
83 STATIC
84 EFI_STATUS
85 EFIAPI
SmmAccess2DxeLock(IN EFI_SMM_ACCESS2_PROTOCOL * This)86 SmmAccess2DxeLock (
87 IN EFI_SMM_ACCESS2_PROTOCOL *This
88 )
89 {
90 return SmramAccessLock (&This->LockState, &This->OpenState);
91 }
92
93 /**
94 Queries the memory controller for the possible regions that will support
95 SMRAM.
96
97 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
98 @param[in,out] SmramMapSize A pointer to the size, in bytes, of the
99 SmramMemoryMap buffer.
100 @param[in,out] SmramMap A pointer to the buffer in which firmware
101 places the current memory map.
102
103 @retval EFI_SUCCESS The chipset supported the given resource.
104 @retval EFI_BUFFER_TOO_SMALL The SmramMap parameter was too small. The
105 current buffer size needed to hold the memory
106 map is returned in SmramMapSize.
107 **/
108 STATIC
109 EFI_STATUS
110 EFIAPI
SmmAccess2DxeGetCapabilities(IN CONST EFI_SMM_ACCESS2_PROTOCOL * This,IN OUT UINTN * SmramMapSize,IN OUT EFI_SMRAM_DESCRIPTOR * SmramMap)111 SmmAccess2DxeGetCapabilities (
112 IN CONST EFI_SMM_ACCESS2_PROTOCOL *This,
113 IN OUT UINTN *SmramMapSize,
114 IN OUT EFI_SMRAM_DESCRIPTOR *SmramMap
115 )
116 {
117 return SmramAccessGetCapabilities (This->LockState, This->OpenState,
118 SmramMapSize, SmramMap);
119 }
120
121 //
122 // LockState and OpenState will be filled in by the entry point.
123 //
124 STATIC EFI_SMM_ACCESS2_PROTOCOL mAccess2 = {
125 &SmmAccess2DxeOpen,
126 &SmmAccess2DxeClose,
127 &SmmAccess2DxeLock,
128 &SmmAccess2DxeGetCapabilities
129 };
130
131 //
132 // Entry point of this driver.
133 //
134 EFI_STATUS
135 EFIAPI
SmmAccess2DxeEntryPoint(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)136 SmmAccess2DxeEntryPoint (
137 IN EFI_HANDLE ImageHandle,
138 IN EFI_SYSTEM_TABLE *SystemTable
139 )
140 {
141 //
142 // This module should only be included if SMRAM support is required.
143 //
144 ASSERT (FeaturePcdGet (PcdSmmSmramRequire));
145
146 InitQ35TsegMbytes ();
147 GetStates (&mAccess2.LockState, &mAccess2.OpenState);
148
149 //
150 // SmramAccessLock() depends on "mQ35SmramAtDefaultSmbase"; init the latter
151 // just before exposing the former via EFI_SMM_ACCESS2_PROTOCOL.Lock().
152 //
153 InitQ35SmramAtDefaultSmbase ();
154
155 return gBS->InstallMultipleProtocolInterfaces (&ImageHandle,
156 &gEfiSmmAccess2ProtocolGuid, &mAccess2,
157 NULL);
158 }
159