1/** @file
2  BlockIo implementation for Xen PV Block driver.
3
4  This file is implementing the interface between the actual driver in
5  BlockFront.c to the BlockIo protocol.
6
7  Copyright (C) 2014, Citrix Ltd.
8
9  This program and the accompanying materials
10  are licensed and made available under the terms and conditions of the BSD License
11  which accompanies this distribution.  The full text of the license may be found at
12  http://opensource.org/licenses/bsd-license.php
13
14  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
15  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
16
17**/
18
19#include "XenPvBlkDxe.h"
20
21#include "BlockFront.h"
22
23///
24/// Block I/O Media structure
25///
26GLOBAL_REMOVE_IF_UNREFERENCED
27EFI_BLOCK_IO_MEDIA  gXenPvBlkDxeBlockIoMedia = {
28  0,      // MediaId
29  FALSE,  // RemovableMedia
30  FALSE,  // MediaPresent
31  FALSE,  // LogicalPartition
32  TRUE,   // ReadOnly
33  FALSE,  // WriteCaching
34  512,    // BlockSize
35  512,    // IoAlign, BlockFront does not support less than 512 bits-aligned.
36  0,      // LastBlock
37  0,      // LowestAlignedLba
38  0,      // LogicalBlocksPerPhysicalBlock
39  0       // OptimalTransferLengthGranularity
40};
41
42///
43/// Block I/O Protocol instance
44///
45GLOBAL_REMOVE_IF_UNREFERENCED
46EFI_BLOCK_IO_PROTOCOL  gXenPvBlkDxeBlockIo = {
47  EFI_BLOCK_IO_PROTOCOL_REVISION3,          // Revision
48  &gXenPvBlkDxeBlockIoMedia,                // Media
49  XenPvBlkDxeBlockIoReset,                  // Reset
50  XenPvBlkDxeBlockIoReadBlocks,             // ReadBlocks
51  XenPvBlkDxeBlockIoWriteBlocks,            // WriteBlocks
52  XenPvBlkDxeBlockIoFlushBlocks             // FlushBlocks
53};
54
55
56
57
58/**
59  Read/Write BufferSize bytes from Lba into Buffer.
60
61  This function is commun to XenPvBlkDxeBlockIoReadBlocks and
62  XenPvBlkDxeBlockIoWriteBlocks.
63
64  @param  This       Indicates a pointer to the calling context.
65  @param  MediaId    Id of the media, changes every time the media is replaced.
66  @param  Lba        The starting Logical Block Address to read from/write to.
67  @param  BufferSize Size of Buffer, must be a multiple of device block size.
68  @param  Buffer     A pointer to the destination/source buffer for the data.
69  @param  IsWrite    Indicate if the operation is write or read.
70
71  @return See description of XenPvBlkDxeBlockIoReadBlocks and
72          XenPvBlkDxeBlockIoWriteBlocks.
73**/
74STATIC
75EFI_STATUS
76XenPvBlkDxeBlockIoReadWriteBlocks (
77  IN     EFI_BLOCK_IO_PROTOCOL  *This,
78  IN     UINT32                 MediaId,
79  IN     EFI_LBA                Lba,
80  IN     UINTN                  BufferSize,
81  IN OUT VOID                   *Buffer,
82  IN     BOOLEAN                IsWrite
83  )
84{
85  XEN_BLOCK_FRONT_IO IoData;
86  EFI_BLOCK_IO_MEDIA *Media = This->Media;
87  UINTN Sector;
88  EFI_STATUS Status;
89
90  if (Buffer == NULL) {
91    return EFI_INVALID_PARAMETER;
92  }
93  if (BufferSize == 0) {
94    return EFI_SUCCESS;
95  }
96
97  if (BufferSize % Media->BlockSize != 0) {
98    DEBUG ((EFI_D_ERROR, "XenPvBlkDxe: Bad buffer size: 0x%Lx\n",
99      (UINT64)BufferSize));
100    return EFI_BAD_BUFFER_SIZE;
101  }
102
103  if (Lba > Media->LastBlock ||
104      (BufferSize / Media->BlockSize) - 1 > Media->LastBlock - Lba) {
105    DEBUG ((EFI_D_ERROR,
106      "XenPvBlkDxe: %a with invalid LBA: 0x%Lx, size: 0x%Lx\n",
107      IsWrite ? "Write" : "Read", Lba, (UINT64)BufferSize));
108    return EFI_INVALID_PARAMETER;
109  }
110
111  if (IsWrite && Media->ReadOnly) {
112    return EFI_WRITE_PROTECTED;
113  }
114
115  if ((Media->IoAlign > 1) && (UINTN)Buffer & (Media->IoAlign - 1)) {
116    //
117    // Grub2 does not appear to respect IoAlign of 512, so reallocate the
118    // buffer here.
119    //
120    VOID *NewBuffer;
121
122    //
123    // Try again with a properly aligned buffer.
124    //
125    NewBuffer = AllocateAlignedPages((BufferSize + EFI_PAGE_SIZE) / EFI_PAGE_SIZE,
126                                     Media->IoAlign);
127    if (!IsWrite) {
128      Status = XenPvBlkDxeBlockIoReadBlocks (This, MediaId,
129                                             Lba, BufferSize, NewBuffer);
130      CopyMem (Buffer, NewBuffer, BufferSize);
131    } else {
132      CopyMem (NewBuffer, Buffer, BufferSize);
133      Status = XenPvBlkDxeBlockIoWriteBlocks (This, MediaId,
134                                              Lba, BufferSize, NewBuffer);
135    }
136    FreeAlignedPages (NewBuffer, (BufferSize + EFI_PAGE_SIZE) / EFI_PAGE_SIZE);
137    return Status;
138  }
139
140  IoData.Dev = XEN_BLOCK_FRONT_FROM_BLOCK_IO (This);
141  Sector = (UINTN)MultU64x32 (Lba, Media->BlockSize / 512);
142
143  while (BufferSize > 0) {
144    if (((UINTN)Buffer & EFI_PAGE_MASK) == 0) {
145      IoData.Size = MIN (BLKIF_MAX_SEGMENTS_PER_REQUEST * EFI_PAGE_SIZE,
146                         BufferSize);
147    } else {
148      IoData.Size = MIN ((BLKIF_MAX_SEGMENTS_PER_REQUEST - 1) * EFI_PAGE_SIZE,
149                         BufferSize);
150    }
151
152    IoData.Buffer = Buffer;
153    IoData.Sector = Sector;
154    BufferSize -= IoData.Size;
155    Buffer = (VOID*) ((UINTN) Buffer + IoData.Size);
156    Sector += IoData.Size / 512;
157    Status = XenPvBlockIo (&IoData, IsWrite);
158    if (EFI_ERROR (Status)) {
159      DEBUG ((EFI_D_ERROR, "XenPvBlkDxe: Error durring %a operation.\n",
160              IsWrite ? "write" : "read"));
161      return Status;
162    }
163  }
164  return EFI_SUCCESS;
165}
166
167
168/**
169  Read BufferSize bytes from Lba into Buffer.
170
171  @param  This       Indicates a pointer to the calling context.
172  @param  MediaId    Id of the media, changes every time the media is replaced.
173  @param  Lba        The starting Logical Block Address to read from
174  @param  BufferSize Size of Buffer, must be a multiple of device block size.
175  @param  Buffer     A pointer to the destination buffer for the data. The caller is
176                     responsible for either having implicit or explicit ownership of the buffer.
177
178  @retval EFI_SUCCESS           The data was read correctly from the device.
179  @retval EFI_DEVICE_ERROR      The device reported an error while performing the read.
180  @retval EFI_NO_MEDIA          There is no media in the device.
181  @retval EFI_MEDIA_CHANGED     The MediaId does not matched the current device.
182  @retval EFI_BAD_BUFFER_SIZE   The Buffer was not a multiple of the block size of the device.
183  @retval EFI_INVALID_PARAMETER The read request contains LBAs that are not valid,
184                                or the buffer is not on proper alignment.
185
186**/
187EFI_STATUS
188EFIAPI
189XenPvBlkDxeBlockIoReadBlocks (
190  IN  EFI_BLOCK_IO_PROTOCOL         *This,
191  IN  UINT32                        MediaId,
192  IN  EFI_LBA                       Lba,
193  IN  UINTN                         BufferSize,
194  OUT VOID                          *Buffer
195  )
196{
197  return XenPvBlkDxeBlockIoReadWriteBlocks (This,
198      MediaId, Lba, BufferSize, Buffer, FALSE);
199}
200
201/**
202  Write BufferSize bytes from Lba into Buffer.
203
204  @param  This       Indicates a pointer to the calling context.
205  @param  MediaId    The media ID that the write request is for.
206  @param  Lba        The starting logical block address to be written. The caller is
207                     responsible for writing to only legitimate locations.
208  @param  BufferSize Size of Buffer, must be a multiple of device block size.
209  @param  Buffer     A pointer to the source buffer for the data.
210
211  @retval EFI_SUCCESS           The data was written correctly to the device.
212  @retval EFI_WRITE_PROTECTED   The device can not be written to.
213  @retval EFI_DEVICE_ERROR      The device reported an error while performing the write.
214  @retval EFI_NO_MEDIA          There is no media in the device.
215  @retval EFI_MEDIA_CHNAGED     The MediaId does not matched the current device.
216  @retval EFI_BAD_BUFFER_SIZE   The Buffer was not a multiple of the block size of the device.
217  @retval EFI_INVALID_PARAMETER The write request contains LBAs that are not valid,
218                                or the buffer is not on proper alignment.
219
220**/
221EFI_STATUS
222EFIAPI
223XenPvBlkDxeBlockIoWriteBlocks (
224  IN EFI_BLOCK_IO_PROTOCOL          *This,
225  IN UINT32                         MediaId,
226  IN EFI_LBA                        Lba,
227  IN UINTN                          BufferSize,
228  IN VOID                           *Buffer
229  )
230{
231  return XenPvBlkDxeBlockIoReadWriteBlocks (This,
232      MediaId, Lba, BufferSize, Buffer, TRUE);
233}
234
235/**
236  Flush the Block Device.
237
238  @param  This              Indicates a pointer to the calling context.
239
240  @retval EFI_SUCCESS       All outstanding data was written to the device
241  @retval EFI_DEVICE_ERROR  The device reported an error while writting back the data
242  @retval EFI_NO_MEDIA      There is no media in the device.
243
244**/
245EFI_STATUS
246EFIAPI
247XenPvBlkDxeBlockIoFlushBlocks (
248  IN EFI_BLOCK_IO_PROTOCOL  *This
249  )
250{
251  XenPvBlockSync (XEN_BLOCK_FRONT_FROM_BLOCK_IO (This));
252  return EFI_SUCCESS;
253}
254
255/**
256  Reset the block device hardware.
257
258  @param[in]  This                 Indicates a pointer to the calling context.
259  @param[in]  ExtendedVerification Not used.
260
261  @retval EFI_SUCCESS          The device was reset.
262
263**/
264EFI_STATUS
265EFIAPI
266XenPvBlkDxeBlockIoReset (
267  IN EFI_BLOCK_IO_PROTOCOL   *This,
268  IN BOOLEAN                 ExtendedVerification
269  )
270{
271  //
272  // Since the initialization of the devices is done, then the device is
273  // working correctly.
274  //
275  return EFI_SUCCESS;
276}
277