MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c

   1 /** @file
   2
   3   The sample implementation for SMM variable protocol. And this driver
   4   implements  an SMI handler to communicate with the DXE runtime driver
   5   to provide variable services.
   6
   7 Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
   8 This program and the accompanying materials
   9 are licensed and made available under the terms and conditions of the BSD License
  10 which accompanies this distribution.  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 #include <Protocol/SmmFaultTolerantWrite.h>
  18 #include <Library/SmmServicesTableLib.h>
  19
  20 #include "Variable.h"
  21 #include "VariableSmmCommon.h"
  22
  23 extern SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY  *gVariableInfo;
  24 EFI_HANDLE                                           mSmmVariableHandle      = NULL;
  25 EFI_HANDLE                                           mVariableHandle         = NULL;
  26 BOOLEAN                                              mAtRuntime              = FALSE;
  27 EFI_GUID                                             mZeroGuid               = {0, 0, 0, {0, 0, 0, 0, 0, 0, 0, 0}};
  28 EFI_GUID                                             mSmmVariableWriteGuid   = EFI_SMM_VARIABLE_WRITE_GUID;
  29
  30 EFI_SMM_VARIABLE_PROTOCOL      gSmmVariable = {
  31   VariableServiceGetVariable,
  32   VariableServiceGetNextVariableName,
  33   VariableServiceSetVariable,
  34   VariableServiceQueryVariableInfo
  35 };
  36
  37
  38 /**
  39   Return TRUE if ExitBootServices () has been called.
  40
  41   @retval TRUE If ExitBootServices () has been called.
  42 **/
  43 BOOLEAN
  44 AtRuntime (
  45   VOID
  46   )
  47 {
  48   return mAtRuntime;
  49 }
  50
  51 /**
  52   Initializes a basic mutual exclusion lock.
  53
  54   This function initializes a basic mutual exclusion lock to the released state
  55   and returns the lock.  Each lock provides mutual exclusion access at its task
  56   priority level.  Since there is no preemption or multiprocessor support in EFI,
  57   acquiring the lock only consists of raising to the locks TPL.
  58   If Lock is NULL, then ASSERT().
  59   If Priority is not a valid TPL value, then ASSERT().
  60
  61   @param  Lock       A pointer to the lock data structure to initialize.
  62   @param  Priority   EFI TPL is associated with the lock.
  63
  64   @return The lock.
  65
  66 **/
  67 EFI_LOCK *
  68 InitializeLock (
  69   IN OUT EFI_LOCK                         *Lock,
  70   IN EFI_TPL                              Priority
  71   )
  72 {
  73   return Lock;
  74 }
  75
  76 /**
  77   Acquires lock only at boot time. Simply returns at runtime.
  78
  79   This is a temperary function that will be removed when
  80   EfiAcquireLock() in UefiLib can handle the call in UEFI
  81   Runtimer driver in RT phase.
  82   It calls EfiAcquireLock() at boot time, and simply returns
  83   at runtime.
  84
  85   @param  Lock         A pointer to the lock to acquire.
  86
  87 **/
  88 VOID
  89 AcquireLockOnlyAtBootTime (
  90   IN EFI_LOCK                             *Lock
  91   )
  92 {
  93
  94 }
  95
  96
  97 /**
  98   Releases lock only at boot time. Simply returns at runtime.
  99
 100   This is a temperary function which will be removed when
 101   EfiReleaseLock() in UefiLib can handle the call in UEFI
 102   Runtimer driver in RT phase.
 103   It calls EfiReleaseLock() at boot time and simply returns
 104   at runtime.
 105
 106   @param  Lock         A pointer to the lock to release.
 107
 108 **/
 109 VOID
 110 ReleaseLockOnlyAtBootTime (
 111   IN EFI_LOCK                             *Lock
 112   )
 113 {
 114
 115 }
 116
 117 /**
 118   Retrive the SMM Fault Tolerent Write protocol interface.
 119
 120   @param[out] FtwProtocol       The interface of SMM Ftw protocol
 121
 122   @retval EFI_SUCCESS           The SMM FTW protocol instance was found and returned in FtwProtocol.
 123   @retval EFI_NOT_FOUND         The SMM FTW protocol instance was not found.
 124   @retval EFI_INVALID_PARAMETER SarProtocol is NULL.
 125
 126 **/
 127 EFI_STATUS
 128 GetFtwProtocol (
 129   OUT VOID                                **FtwProtocol
 130   )
 131 {
 132   EFI_STATUS                              Status;
 133
 134   //
 135   // Locate Smm Fault Tolerent Write protocol
 136   //
 137   Status = gSmst->SmmLocateProtocol (
 138                     &gEfiSmmFaultTolerantWriteProtocolGuid,
 139                     NULL,
 140                     FtwProtocol
 141                     );
 142   return Status;
 143 }
 144
 145
 146 /**
 147   Retrive the SMM FVB protocol interface by HANDLE.
 148
 149   @param[in]  FvBlockHandle     The handle of SMM FVB protocol that provides services for
 150                                 reading, writing, and erasing the target block.
 151   @param[out] FvBlock           The interface of SMM FVB protocol
 152
 153   @retval EFI_SUCCESS           The interface information for the specified protocol was returned.
 154   @retval EFI_UNSUPPORTED       The device does not support the SMM FVB protocol.
 155   @retval EFI_INVALID_PARAMETER FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL.
 156
 157 **/
 158 EFI_STATUS
 159 GetFvbByHandle (
 160   IN  EFI_HANDLE                          FvBlockHandle,
 161   OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
 162   )
 163 {
 164   //
 165   // To get the SMM FVB protocol interface on the handle
 166   //
 167   return gSmst->SmmHandleProtocol (
 168                   FvBlockHandle,
 169                   &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 170                   (VOID **) FvBlock
 171                   );
 172 }
 173
 174
 175 /**
 176   Function returns an array of handles that support the SMM FVB protocol
 177   in a buffer allocated from pool.
 178
 179   @param[out]  NumberHandles    The number of handles returned in Buffer.
 180   @param[out]  Buffer           A pointer to the buffer to return the requested
 181                                 array of  handles that support SMM FVB protocol.
 182
 183   @retval EFI_SUCCESS           The array of handles was returned in Buffer, and the number of
 184                                 handles in Buffer was returned in NumberHandles.
 185   @retval EFI_NOT_FOUND         No SMM FVB handle was found.
 186   @retval EFI_OUT_OF_RESOURCES  There is not enough pool memory to store the matching results.
 187   @retval EFI_INVALID_PARAMETER NumberHandles is NULL or Buffer is NULL.
 188
 189 **/
 190 EFI_STATUS
 191 GetFvbCountAndBuffer (
 192   OUT UINTN                               *NumberHandles,
 193   OUT EFI_HANDLE                          **Buffer
 194   )
 195 {
 196   EFI_STATUS                              Status;
 197   UINTN                                   BufferSize;
 198
 199   if ((NumberHandles == NULL) || (Buffer == NULL)) {
 200     return EFI_INVALID_PARAMETER;
 201   }
 202
 203   BufferSize     = 0;
 204   *NumberHandles = 0;
 205   *Buffer        = NULL;
 206   Status = gSmst->SmmLocateHandle (
 207                     ByProtocol,
 208                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 209                     NULL,
 210                     &BufferSize,
 211                     *Buffer
 212                     );
 213   if (EFI_ERROR(Status) && Status != EFI_BUFFER_TOO_SMALL) {
 214     return EFI_NOT_FOUND;
 215   }
 216
 217   *Buffer = AllocatePool (BufferSize);
 218   if (*Buffer == NULL) {
 219     return EFI_OUT_OF_RESOURCES;
 220   }
 221
 222   Status = gSmst->SmmLocateHandle (
 223                     ByProtocol,
 224                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 225                     NULL,
 226                     &BufferSize,
 227                     *Buffer
 228                     );
 229
 230   *NumberHandles = BufferSize / sizeof(EFI_HANDLE);
 231   if (EFI_ERROR(Status)) {
 232     *NumberHandles = 0;
 233   }
 234
 235   return Status;
 236 }
 237
 238
 239 /**
 240   Get the variable statistics information from the information buffer pointed by gVariableInfo.
 241
 242   @param[in, out]  InfoEntry   A pointer to the buffer of variable information entry.
 243                                On input, point to the variable information returned last time. if
 244                                InfoEntry->VendorGuid is zero, return the first information.
 245                                On output, point to the next variable information.
 246   @param[in, out]  InfoSize    On input, the size of the variable information buffer.
 247                                On output, the returned variable information size.
 248
 249   @retval EFI_SUCCESS          The variable information is found and returned successfully.
 250   @retval EFI_UNSUPPORTED      No variable inoformation exists in variable driver. The
 251                                PcdVariableCollectStatistics should be set TRUE to support it.
 252   @retval EFI_BUFFER_TOO_SMALL The buffer is too small to hold the next variable information.
 253
 254 **/
 255 EFI_STATUS
 256 SmmVariableGetStatistics (
 257   IN OUT SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY  *InfoEntry,
 258   IN OUT UINTN                                         *InfoSize
 259   )
 260 {
 261   SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY         *VariableInfo;
 262   UINTN                                                NameLength;
 263   UINTN                                                StatisticsInfoSize;
 264   CHAR16                                               *InfoName;
 265
 266   ASSERT (InfoEntry != NULL);
 267   VariableInfo = gVariableInfo;
 268   if (VariableInfo == NULL) {
 269     return EFI_UNSUPPORTED;
 270   }
 271
 272   StatisticsInfoSize = sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY) + StrSize (VariableInfo->Name);
 273   if (*InfoSize < sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY)) {
 274     *InfoSize = StatisticsInfoSize;
 275     return EFI_BUFFER_TOO_SMALL;
 276   }
 277   InfoName = (CHAR16 *)(InfoEntry + 1);
 278
 279   if (CompareGuid (&InfoEntry->VendorGuid, &mZeroGuid)) {
 280     //
 281     // Return the first variable info
 282     //
 283     CopyMem (InfoEntry, VariableInfo, sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY));
 284     CopyMem (InfoName, VariableInfo->Name, StrSize (VariableInfo->Name));
 285     *InfoSize = StatisticsInfoSize;
 286     return EFI_SUCCESS;
 287   }
 288
 289   //
 290   // Get the next variable info
 291   //
 292   while (VariableInfo != NULL) {
 293     if (CompareGuid (&VariableInfo->VendorGuid, &InfoEntry->VendorGuid)) {
 294       NameLength = StrSize (VariableInfo->Name);
 295       if (NameLength == StrSize (InfoName)) {
 296         if (CompareMem (VariableInfo->Name, InfoName, NameLength) == 0) {
 297           //
 298           // Find the match one
 299           //
 300           VariableInfo = VariableInfo->Next;
 301           break;
 302         }
 303       }
 304     }
 305     VariableInfo = VariableInfo->Next;
 306   };
 307
 308   if (VariableInfo == NULL) {
 309     *InfoSize = 0;
 310     return EFI_SUCCESS;
 311   }
 312
 313   //
 314   // Output the new variable info
 315   //
 316   StatisticsInfoSize = sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY) + StrSize (VariableInfo->Name);
 317   if (*InfoSize < StatisticsInfoSize) {
 318     *InfoSize = StatisticsInfoSize;
 319     return EFI_BUFFER_TOO_SMALL;
 320   }
 321
 322   CopyMem (InfoEntry, VariableInfo, sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY));
 323   CopyMem (InfoName, VariableInfo->Name, StrSize (VariableInfo->Name));
 324   *InfoSize = StatisticsInfoSize;
 325
 326   return EFI_SUCCESS;
 327 }
 328
 329
 330 /**
 331   Communication service SMI Handler entry.
 332
 333   This SMI handler provides services for the variable wrapper driver.
 334
 335   @param[in]     DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
 336   @param[in]     RegisterContext Points to an optional handler context which was specified when the
 337                                  handler was registered.
 338   @param[in, out] CommBuffer     A pointer to a collection of data in memory that will
 339                                  be conveyed from a non-SMM environment into an SMM environment.
 340   @param[in, out] CommBufferSize The size of the CommBuffer.
 341
 342   @retval EFI_SUCCESS                         The interrupt was handled and quiesced. No other handlers
 343                                               should still be called.
 344   @retval EFI_WARN_INTERRUPT_SOURCE_QUIESCED  The interrupt has been quiesced but other handlers should
 345                                               still be called.
 346   @retval EFI_WARN_INTERRUPT_SOURCE_PENDING   The interrupt is still pending and other handlers should still
 347                                               be called.
 348   @retval EFI_INTERRUPT_PENDING               The interrupt could not be quiesced.
 349 **/
 350 EFI_STATUS
 351 EFIAPI
 352 SmmVariableHandler (
 353   IN     EFI_HANDLE                                DispatchHandle,
 354   IN     CONST VOID                                *RegisterContext,
 355   IN OUT VOID                                      *CommBuffer,
 356   IN OUT UINTN                                     *CommBufferSize
 357   )
 358 {
 359   EFI_STATUS                                       Status;
 360   SMM_VARIABLE_COMMUNICATE_HEADER                  *SmmVariableFunctionHeader;
 361   SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE         *SmmVariableHeader;
 362   SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME  *GetNextVariableName;
 363   SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO     *QueryVariableInfo;
 364   SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY     *VariableInfo;
 365   UINTN                                            InfoSize;
 366
 367   ASSERT (CommBuffer != NULL);
 368
 369   SmmVariableFunctionHeader = (SMM_VARIABLE_COMMUNICATE_HEADER *)CommBuffer;
 370   switch (SmmVariableFunctionHeader->Function) {
 371     case SMM_VARIABLE_FUNCTION_GET_VARIABLE:
 372       SmmVariableHeader = (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE *) SmmVariableFunctionHeader->Data;
 373       Status = VariableServiceGetVariable (
 374                  SmmVariableHeader->Name,
 375                  &SmmVariableHeader->Guid,
 376                  &SmmVariableHeader->Attributes,
 377                  &SmmVariableHeader->DataSize,
 378                  (UINT8 *)SmmVariableHeader->Name + SmmVariableHeader->NameSize
 379                  );
 380       break;
 381
 382     case SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME:
 383       GetNextVariableName = (SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME *) SmmVariableFunctionHeader->Data;
 384       Status = VariableServiceGetNextVariableName (
 385                  &GetNextVariableName->NameSize,
 386                  GetNextVariableName->Name,
 387                  &GetNextVariableName->Guid
 388                  );
 389       break;
 390
 391     case SMM_VARIABLE_FUNCTION_SET_VARIABLE:
 392       SmmVariableHeader = (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE *) SmmVariableFunctionHeader->Data;
 393       Status = VariableServiceSetVariable (
 394                  SmmVariableHeader->Name,
 395                  &SmmVariableHeader->Guid,
 396                  SmmVariableHeader->Attributes,
 397                  SmmVariableHeader->DataSize,
 398                  (UINT8 *)SmmVariableHeader->Name + SmmVariableHeader->NameSize
 399                  );
 400       break;
 401
 402     case SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO:
 403       QueryVariableInfo = (SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO *) SmmVariableFunctionHeader->Data;
 404       Status = VariableServiceQueryVariableInfo (
 405                  QueryVariableInfo->Attributes,
 406                  &QueryVariableInfo->MaximumVariableStorageSize,
 407                  &QueryVariableInfo->RemainingVariableStorageSize,
 408                  &QueryVariableInfo->MaximumVariableSize
 409                  );
 410       break;
 411
 412     case SMM_VARIABLE_FUNCTION_READY_TO_BOOT:
 413       ReclaimForOS ();
 414       Status = EFI_SUCCESS;
 415       break;
 416
 417     case SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE:
 418       mAtRuntime = TRUE;
 419       Status = EFI_SUCCESS;
 420       break;
 421
 422     case SMM_VARIABLE_FUNCTION_GET_STATISTICS:
 423       VariableInfo = (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY *) SmmVariableFunctionHeader->Data;
 424       InfoSize = *CommBufferSize - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_HEADER, Data);
 425       Status = SmmVariableGetStatistics (VariableInfo, &InfoSize);
 426       *CommBufferSize = InfoSize + OFFSET_OF (SMM_VARIABLE_COMMUNICATE_HEADER, Data);
 427       break;
 428
 429     default:
 430       ASSERT (FALSE);
 431       Status = EFI_UNSUPPORTED;
 432   }
 433
 434   SmmVariableFunctionHeader->ReturnStatus = Status;
 435
 436   return EFI_SUCCESS;
 437 }
 438
 439
 440 /**
 441   SMM Fault Tolerant Write protocol notification event handler.
 442
 443   Non-Volatile variable write may needs FTW protocol to reclaim when
 444   writting variable.
 445
 446   @param  Protocol   Points to the protocol's unique identifier
 447   @param  Interface  Points to the interface instance
 448   @param  Handle     The handle on which the interface was installed
 449
 450   @retval EFI_SUCCESS   SmmEventCallback runs successfully
 451   @retval EFI_NOT_FOUND The Fvb protocol for variable is not found.
 452
 453  **/
 454 EFI_STATUS
 455 EFIAPI
 456 SmmFtwNotificationEvent (
 457   IN CONST EFI_GUID                       *Protocol,
 458   IN VOID                                 *Interface,
 459   IN EFI_HANDLE                           Handle
 460   )
 461 {
 462   EFI_STATUS                              Status;
 463   EFI_SMM_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvbProtocol;
 464   EFI_SMM_FAULT_TOLERANT_WRITE_PROTOCOL   *FtwProtocol;
 465   EFI_PHYSICAL_ADDRESS                    NvStorageVariableBase;
 466
 467   if (mVariableModuleGlobal->FvbInstance != NULL) {
 468     return EFI_SUCCESS;
 469   }
 470
 471   //
 472   // Ensure SMM FTW protocol is installed.
 473   //
 474   Status = GetFtwProtocol (&FtwProtocol);
 475   if (EFI_ERROR (Status)) {
 476     return Status;
 477   }
 478
 479   //
 480   // Find the proper FVB protocol for variable.
 481   //
 482   NvStorageVariableBase = (EFI_PHYSICAL_ADDRESS) PcdGet64 (PcdFlashNvStorageVariableBase64);
 483   if (NvStorageVariableBase == 0) {
 484     NvStorageVariableBase = (EFI_PHYSICAL_ADDRESS) PcdGet32 (PcdFlashNvStorageVariableBase);
 485   }
 486   Status = GetFvbInfoByAddress (NvStorageVariableBase, NULL, &FvbProtocol);
 487   if (EFI_ERROR (Status)) {
 488     return EFI_NOT_FOUND;
 489   }
 490
 491   mVariableModuleGlobal->FvbInstance = FvbProtocol;
 492
 493   Status = VariableWriteServiceInitialize ();
 494   ASSERT_EFI_ERROR (Status);
 495
 496   //
 497   // Notify the variable wrapper driver the variable write service is ready
 498   //
 499   Status = gBS->InstallProtocolInterface (
 500                   &mSmmVariableHandle,
 501                   &mSmmVariableWriteGuid,
 502                   EFI_NATIVE_INTERFACE,
 503                   NULL
 504                   );
 505   ASSERT_EFI_ERROR (Status);
 506
 507   return EFI_SUCCESS;
 508 }
 509
 510
 511 /**
 512   Variable Driver main entry point. The Variable driver places the 4 EFI
 513   runtime services in the EFI System Table and installs arch protocols
 514   for variable read and write services being availible. It also registers
 515   a notification function for an EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE event.
 516
 517   @param[in] ImageHandle    The firmware allocated handle for the EFI image.
 518   @param[in] SystemTable    A pointer to the EFI System Table.
 519
 520   @retval EFI_SUCCESS       Variable service successfully initialized.
 521
 522 **/
 523 EFI_STATUS
 524 EFIAPI
 525 VariableServiceInitialize (
 526   IN EFI_HANDLE                           ImageHandle,
 527   IN EFI_SYSTEM_TABLE                     *SystemTable
 528   )
 529 {
 530   EFI_STATUS                              Status;
 531   EFI_HANDLE                              VariableHandle;
 532   VOID                                    *SmmFtwRegistration;
 533
 534   //
 535   // Variable initialize.
 536   //
 537   Status = VariableCommonInitialize ();
 538   ASSERT_EFI_ERROR (Status);
 539
 540   //
 541   // Install the Smm Variable Protocol on a new handle.
 542   //
 543   VariableHandle = NULL;
 544   Status = gSmst->SmmInstallProtocolInterface (
 545                     &VariableHandle,
 546                     &gEfiSmmVariableProtocolGuid,
 547                     EFI_NATIVE_INTERFACE,
 548                     &gSmmVariable
 549                     );
 550   ASSERT_EFI_ERROR (Status);
 551
 552   ///
 553   /// Register SMM variable SMI handler
 554   ///
 555   VariableHandle = NULL;
 556   Status = gSmst->SmiHandlerRegister (SmmVariableHandler, &gEfiSmmVariableProtocolGuid, &VariableHandle);
 557   ASSERT_EFI_ERROR (Status);
 558
 559   //
 560   // Notify the variable wrapper driver the variable service is ready
 561   //
 562   Status = SystemTable->BootServices->InstallProtocolInterface (
 563                                         &mVariableHandle,
 564                                         &gEfiSmmVariableProtocolGuid,
 565                                         EFI_NATIVE_INTERFACE,
 566                                         &gSmmVariable
 567                                         );
 568   ASSERT_EFI_ERROR (Status);
 569
 570   //
 571   // Register FtwNotificationEvent () notify function.
 572   //
 573   Status = gSmst->SmmRegisterProtocolNotify (
 574                     &gEfiSmmFaultTolerantWriteProtocolGuid,
 575                     SmmFtwNotificationEvent,
 576                     &SmmFtwRegistration
 577                     );
 578   ASSERT_EFI_ERROR (Status);
 579
 580   SmmFtwNotificationEvent (NULL, NULL, NULL);
 581
 582   return EFI_SUCCESS;
 583 }
 584
 585