1 /** @file
2   Fault Tolerant Write protocol provides boot-time service for fault tolerant
3   write capability for block devices.  The protocol provides for non-volatile
4   storage of the intermediate data and private information a caller would need to
5   recover from a critical fault, such as a power failure.
6 
7 Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
8 This program and the accompanying materials are licensed and made available under
9 the terms and conditions of the BSD License that accompanies this distribution.
10 The full text of the license may be found at
11 http://opensource.org/licenses/bsd-license.php.
12 
13 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
14 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
15 
16 **/
17 
18 #ifndef _FW_FAULT_TOLERANT_WRITE_PROTOCOL_H_
19 #define _FW_FAULT_TOLERANT_WRITE_PROTOCOL_H_
20 
21 #define EFI_FAULT_TOLERANT_WRITE_PROTOCOL_GUID \
22   { \
23     0x3ebd9e82, 0x2c78, 0x4de6, {0x97, 0x86, 0x8d, 0x4b, 0xfc, 0xb7, 0xc8, 0x81 } \
24   }
25 
26 //
27 // Forward reference for pure ANSI compatability
28 //
29 typedef struct _EFI_FAULT_TOLERANT_WRITE_PROTOCOL  EFI_FAULT_TOLERANT_WRITE_PROTOCOL;
30 
31 /**
32   Get the size of the largest block that can be updated in a fault-tolerant manner.
33 
34   @param  This                 Indicates a pointer to the calling context.
35   @param  BlockSize            A pointer to a caller-allocated UINTN that is
36                                updated to indicate the size of the largest block
37                                that can be updated.
38 
39   @retval EFI_SUCCESS          The function completed successfully.
40   @retval EFI_ABORTED          The function could not complete successfully.
41 
42 **/
43 typedef
44 EFI_STATUS
45 (EFIAPI *EFI_FAULT_TOLERANT_WRITE_GET_MAX_BLOCK_SIZE)(
46   IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL    * This,
47   OUT UINTN                               *BlockSize
48   );
49 
50 /**
51   Allocates space for the protocol to maintain information about writes.
52   Since writes must be completed in a fault-tolerant manner and multiple
53   writes require more resources to be successful, this function
54   enables the protocol to ensure that enough space exists to track
55   information about upcoming writes.
56 
57   @param  This                 A pointer to the calling context.
58   @param  CallerId             The GUID identifying the write.
59   @param  PrivateDataSize      The size of the caller's private data  that must be
60                                recorded for each write.
61   @param  NumberOfWrites       The number of fault tolerant block writes that will
62                                need to occur.
63 
64   @retval EFI_SUCCESS          The function completed successfully
65   @retval EFI_ABORTED          The function could not complete successfully.
66   @retval EFI_ACCESS_DENIED    Not all allocated writes have been completed.  All
67                                writes must be completed or aborted before another
68                                fault tolerant write can occur.
69 
70 **/
71 typedef
72 EFI_STATUS
73 (EFIAPI *EFI_FAULT_TOLERANT_WRITE_ALLOCATE)(
74   IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL    * This,
75   IN EFI_GUID                             * CallerId,
76   IN UINTN                                PrivateDataSize,
77   IN UINTN                                NumberOfWrites
78   );
79 
80 /**
81   Starts a target block update. This records information about the write
82   in fault tolerant storage, and will complete the write in a recoverable
83   manner, ensuring at all times that either the original contents or
84   the modified contents are available.
85 
86   @param  This                 The calling context.
87   @param  Lba                  The logical block address of the target block.
88   @param  Offset               The offset within the target block to place the
89                                data.
90   @param  Length               The number of bytes to write to the target block.
91   @param  PrivateData          A pointer to private data that the caller requires
92                                to complete any pending writes in the event of a
93                                fault.
94   @param  FvBlockHandle        The handle of FVB protocol that provides services
95                                for reading, writing, and erasing the target block.
96   @param  Buffer               The data to write.
97 
98   @retval EFI_SUCCESS          The function completed successfully.
99   @retval EFI_ABORTED          The function could not complete successfully.
100   @retval EFI_BAD_BUFFER_SIZE  The write would span a block boundary, which is not
101                                a valid action.
102   @retval EFI_ACCESS_DENIED    No writes have been allocated.
103   @retval EFI_NOT_READY        The last write has not been completed. Restart()
104                                must be called to complete it.
105 
106 **/
107 typedef
108 EFI_STATUS
109 (EFIAPI *EFI_FAULT_TOLERANT_WRITE_WRITE)(
110   IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     * This,
111   IN EFI_LBA                               Lba,
112   IN UINTN                                 Offset,
113   IN UINTN                                 Length,
114   IN VOID                                  *PrivateData,
115   IN EFI_HANDLE                            FvbHandle,
116   IN VOID                                  *Buffer
117   );
118 
119 /**
120   Restarts a previously interrupted write. The caller must provide the
121   block protocol needed to complete the interrupted write.
122 
123   @param  This                 The calling context.
124   @param  FvBlockProtocol      The handle of FVB protocol that provides services.
125                                for reading, writing, and erasing the target block.
126 
127   @retval EFI_SUCCESS          The function completed successfully.
128   @retval EFI_ABORTED          The function could not complete successfully.
129   @retval EFI_ACCESS_DENIED    No pending writes exist.
130 
131 **/
132 typedef
133 EFI_STATUS
134 (EFIAPI *EFI_FAULT_TOLERANT_WRITE_RESTART)(
135   IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     * This,
136   IN EFI_HANDLE                            FvbHandle
137   );
138 
139 /**
140   Aborts all previously allocated writes.
141 
142   @param  This                 The calling context.
143 
144   @retval EFI_SUCCESS          The function completed successfully.
145   @retval EFI_ABORTED          The function could not complete successfully.
146   @retval EFI_NOT_FOUND        No allocated writes exist.
147 
148 **/
149 typedef
150 EFI_STATUS
151 (EFIAPI *EFI_FAULT_TOLERANT_WRITE_ABORT)(
152   IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     * This
153   );
154 
155 /**
156   Starts a target block update. This function records information about the write
157   in fault-tolerant storage and completes the write in a recoverable
158   manner, ensuring at all times that either the original contents or
159   the modified contents are available.
160 
161   @param  This                 Indicates a pointer to the calling context.
162   @param  CallerId             The GUID identifying the last write.
163   @param  Lba                  The logical block address of the last write.
164   @param  Offset               The offset within the block of the last write.
165   @param  Length               The length of the last write.
166   @param  PrivateDataSize      On input, the size of the PrivateData buffer. On
167                                output, the size of the private data stored for
168                                this write.
169   @param  PrivateData          A pointer to a buffer. The function will copy
170                                PrivateDataSize bytes from the private data stored
171                                for this write.
172   @param  Complete             A Boolean value with TRUE indicating that the write
173                                was completed.
174 
175   @retval EFI_SUCCESS          The function completed successfully.
176   @retval EFI_ABORTED          The function could not complete successfully.
177   @retval EFI_NOT_FOUND        No allocated writes exist.
178 
179 **/
180 typedef
181 EFI_STATUS
182 (EFIAPI *EFI_FAULT_TOLERANT_WRITE_GET_LAST_WRITE)(
183   IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     * This,
184   OUT EFI_GUID                             * CallerId,
185   OUT EFI_LBA                              *Lba,
186   OUT UINTN                                *Offset,
187   OUT UINTN                                *Length,
188   IN OUT UINTN                             *PrivateDataSize,
189   OUT VOID                                 *PrivateData,
190   OUT BOOLEAN                              *Complete
191   );
192 
193 //
194 // Protocol declaration
195 //
196 struct _EFI_FAULT_TOLERANT_WRITE_PROTOCOL {
197   EFI_FAULT_TOLERANT_WRITE_GET_MAX_BLOCK_SIZE GetMaxBlockSize;
198   EFI_FAULT_TOLERANT_WRITE_ALLOCATE           Allocate;
199   EFI_FAULT_TOLERANT_WRITE_WRITE              Write;
200   EFI_FAULT_TOLERANT_WRITE_RESTART            Restart;
201   EFI_FAULT_TOLERANT_WRITE_ABORT              Abort;
202   EFI_FAULT_TOLERANT_WRITE_GET_LAST_WRITE     GetLastWrite;
203 };
204 
205 extern EFI_GUID gEfiFaultTolerantWriteProtocolGuid;
206 
207 #endif
208