MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c

   1 /** @file
   2
   3   This is a simple fault tolerant write driver that is intended to use in the SMM environment.
   4
   5   This boot service protocol only provides fault tolerant write capability for
   6   block devices.  The protocol has internal non-volatile intermediate storage
   7   of the data and private information. It should be able to recover
   8   automatically from a critical fault, such as power failure.
   9
  10   The implementation uses an FTW (Fault Tolerant Write) Work Space.
  11   This work space is a memory copy of the work space on the Working Block,
  12   the size of the work space is the FTW_WORK_SPACE_SIZE bytes.
  13
  14   The work space stores each write record as EFI_FTW_RECORD structure.
  15   The spare block stores the write buffer before write to the target block.
  16
  17   The write record has three states to specify the different phase of write operation.
  18   1) WRITE_ALLOCATED is that the record is allocated in write space.
  19      The information of write operation is stored in write record structure.
  20   2) SPARE_COMPLETED is that the data from write buffer is writed into the spare block as the backup.
  21   3) WRITE_COMPLETED is that the data is copied from the spare block to the target block.
  22
  23   This driver operates the data as the whole size of spare block.
  24   It first read the SpareAreaLength data from the target block into the spare memory buffer.
  25   Then copy the write buffer data into the spare memory buffer.
  26   Then write the spare memory buffer into the spare block.
  27   Final copy the data from the spare block to the target block.
  28
  29   To make this drive work well, the following conditions must be satisfied:
  30   1. The write NumBytes data must be fit within Spare area.
  31      Offset + NumBytes <= SpareAreaLength
  32   2. The whole flash range has the same block size.
  33   3. Working block is an area which contains working space in its last block and has the same size as spare block.
  34   4. Working Block area must be in the single one Firmware Volume Block range which FVB protocol is produced on.
  35   5. Spare area must be in the single one Firmware Volume Block range which FVB protocol is produced on.
  36   6. Any write data area (SpareAreaLength Area) which the data will be written into must be
  37      in the single one Firmware Volume Block range which FVB protocol is produced on.
  38   7. If write data area (such as Variable range) is enlarged, the spare area range must be enlarged.
  39      The spare area must be enough large to store the write data before write them into the target range.
  40   If one of them is not satisfied, FtwWrite may fail.
  41   Usually, Spare area only takes one block. That's SpareAreaLength = BlockSize, NumberOfSpareBlock = 1.
  42
  43 Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
  44 This program and the accompanying materials
  45 are licensed and made available under the terms and conditions of the BSD License
  46 which accompanies this distribution.  The full text of the license may be found at
  47 http://opensource.org/licenses/bsd-license.php
  48
  49 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  50 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  51
  52 **/
  53
  54 #include <Library/SmmServicesTableLib.h>
  55 #include "FaultTolerantWrite.h"
  56 #include <Protocol/SmmFirmwareVolumeBlock.h>
  57 #include <Protocol/SmmSwapAddressRange.h>
  58 #include <Protocol/SmmFaultTolerantWrite.h>
  59
  60 EFI_EVENT                                 mFvbRegistration = NULL;
  61 EFI_FTW_DEVICE                            *gFtwDevice      = NULL;
  62
  63 /**
  64   Retrive the SMM FVB protocol interface by HANDLE.
  65
  66   @param[in]  FvBlockHandle     The handle of SMM FVB protocol that provides services for
  67                                 reading, writing, and erasing the target block.
  68   @param[out] FvBlock           The interface of SMM FVB protocol
  69
  70   @retval EFI_SUCCESS           The interface information for the specified protocol was returned.
  71   @retval EFI_UNSUPPORTED       The device does not support the SMM FVB protocol.
  72   @retval EFI_INVALID_PARAMETER FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL.
  73
  74 **/
  75 EFI_STATUS
  76 FtwGetFvbByHandle (
  77   IN  EFI_HANDLE                          FvBlockHandle,
  78   OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
  79   )
  80 {
  81   //
  82   // To get the SMM FVB protocol interface on the handle
  83   //
  84   return gSmst->SmmHandleProtocol (
  85                   FvBlockHandle,
  86                   &gEfiSmmFirmwareVolumeBlockProtocolGuid,
  87                   (VOID **) FvBlock
  88                   );
  89 }
  90
  91 /**
  92   Retrive the SMM Swap Address Range protocol interface.
  93
  94   @param[out] SarProtocol       The interface of SMM SAR protocol
  95
  96   @retval EFI_SUCCESS           The SMM SAR protocol instance was found and returned in SarProtocol.
  97   @retval EFI_NOT_FOUND         The SMM SAR protocol instance was not found.
  98   @retval EFI_INVALID_PARAMETER SarProtocol is NULL.
  99
 100 **/
 101 EFI_STATUS
 102 FtwGetSarProtocol (
 103   OUT VOID                                **SarProtocol
 104   )
 105 {
 106   EFI_STATUS                              Status;
 107
 108   //
 109   // Locate Smm Swap Address Range protocol
 110   //
 111   Status = gSmst->SmmLocateProtocol (
 112                     &gEfiSmmSwapAddressRangeProtocolGuid,
 113                     NULL,
 114                     SarProtocol
 115                     );
 116   return Status;
 117 }
 118
 119 /**
 120   Function returns an array of handles that support the SMM FVB protocol
 121   in a buffer allocated from pool.
 122
 123   @param[out]  NumberHandles    The number of handles returned in Buffer.
 124   @param[out]  Buffer           A pointer to the buffer to return the requested
 125                                 array of  handles that support SMM FVB protocol.
 126
 127   @retval EFI_SUCCESS           The array of handles was returned in Buffer, and the number of
 128                                 handles in Buffer was returned in NumberHandles.
 129   @retval EFI_NOT_FOUND         No SMM FVB handle was found.
 130   @retval EFI_OUT_OF_RESOURCES  There is not enough pool memory to store the matching results.
 131   @retval EFI_INVALID_PARAMETER NumberHandles is NULL or Buffer is NULL.
 132
 133 **/
 134 EFI_STATUS
 135 GetFvbCountAndBuffer (
 136   OUT UINTN                               *NumberHandles,
 137   OUT EFI_HANDLE                          **Buffer
 138   )
 139 {
 140   EFI_STATUS                              Status;
 141   UINTN                                   BufferSize;
 142
 143   if ((NumberHandles == NULL) || (Buffer == NULL)) {
 144     return EFI_INVALID_PARAMETER;
 145   }
 146
 147   BufferSize     = 0;
 148   *NumberHandles = 0;
 149   *Buffer        = NULL;
 150   Status = gSmst->SmmLocateHandle (
 151                     ByProtocol,
 152                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 153                     NULL,
 154                     &BufferSize,
 155                     *Buffer
 156                     );
 157   if (EFI_ERROR(Status) && Status != EFI_BUFFER_TOO_SMALL) {
 158     return EFI_NOT_FOUND;
 159   }
 160
 161   *Buffer = AllocatePool (BufferSize);
 162   if (*Buffer == NULL) {
 163     return EFI_OUT_OF_RESOURCES;
 164   }
 165
 166   Status = gSmst->SmmLocateHandle (
 167                     ByProtocol,
 168                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 169                     NULL,
 170                     &BufferSize,
 171                     *Buffer
 172                     );
 173
 174   *NumberHandles = BufferSize / sizeof(EFI_HANDLE);
 175   if (EFI_ERROR(Status)) {
 176     *NumberHandles = 0;
 177   }
 178
 179   return Status;
 180 }
 181
 182
 183 /**
 184   SMM Firmware Volume Block Protocol notification event handler.
 185
 186   @param[in]  Protocol      Points to the protocol's unique identifier
 187   @param[in]  Interface     Points to the interface instance
 188   @param[in]  Handle        The handle on which the interface was installed
 189
 190   @retval EFI_SUCCESS       SmmEventCallback runs successfully
 191
 192  **/
 193 EFI_STATUS
 194 EFIAPI
 195 FvbNotificationEvent (
 196   IN CONST EFI_GUID                       *Protocol,
 197   IN VOID                                 *Interface,
 198   IN EFI_HANDLE                           Handle
 199   )
 200 {
 201   EFI_STATUS                              Status;
 202   EFI_SMM_FAULT_TOLERANT_WRITE_PROTOCOL   *FtwProtocol;
 203
 204   //
 205   // Just return to avoid install SMM FaultTolerantWriteProtocol again
 206   // if SMM Fault Tolerant Write protocol had been installed.
 207   //
 208   Status = gSmst->SmmLocateProtocol (
 209                     &gEfiSmmFaultTolerantWriteProtocolGuid,
 210                     NULL,
 211                     (VOID **) &FtwProtocol
 212                     );
 213   if (!EFI_ERROR (Status)) {
 214     return EFI_SUCCESS;
 215   }
 216
 217   //
 218   // Found proper FVB protocol and initialize FtwDevice for protocol installation
 219   //
 220   Status = InitFtwProtocol (gFtwDevice);
 221   if (EFI_ERROR(Status)) {
 222     return Status;
 223   }
 224
 225   //
 226   // Install protocol interface
 227   //
 228   Status = gSmst->SmmInstallProtocolInterface (
 229                     &gFtwDevice->Handle,
 230                     &gEfiSmmFaultTolerantWriteProtocolGuid,
 231                     EFI_NATIVE_INTERFACE,
 232                     &gFtwDevice->FtwInstance
 233                     );
 234   ASSERT_EFI_ERROR (Status);
 235
 236   return EFI_SUCCESS;
 237 }
 238
 239
 240 /**
 241   This function is the entry point of the Fault Tolerant Write driver.
 242
 243   @param[in] ImageHandle        A handle for the image that is initializing this driver
 244   @param[in] SystemTable        A pointer to the EFI system table
 245
 246   @retval EFI_SUCCESS           The initialization finished successfully.
 247   @retval EFI_OUT_OF_RESOURCES  Allocate memory error
 248   @retval EFI_INVALID_PARAMETER Workspace or Spare block does not exist
 249
 250 **/
 251 EFI_STATUS
 252 EFIAPI
 253 SmmFaultTolerantWriteInitialize (
 254   IN EFI_HANDLE                           ImageHandle,
 255   IN EFI_SYSTEM_TABLE                     *SystemTable
 256   )
 257 {
 258   EFI_STATUS                              Status;
 259
 260   //
 261   // Allocate private data structure for SMM FTW protocol and do some initialization
 262   //
 263   Status = InitFtwDevice (&gFtwDevice);
 264   if (EFI_ERROR(Status)) {
 265     return Status;
 266   }
 267
 268   //
 269   // Register FvbNotificationEvent () notify function.
 270   //
 271   Status = gSmst->SmmRegisterProtocolNotify (
 272                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 273                     FvbNotificationEvent,
 274                     &mFvbRegistration
 275                     );
 276   ASSERT_EFI_ERROR (Status);
 277
 278   FvbNotificationEvent (NULL, NULL, NULL);
 279
 280   return EFI_SUCCESS;
 281 }