MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c

   1 /** @file
   2   Support routines for memory allocation routines based
   3   on SMM Services Table services for SMM phase drivers.
   4
   5   The PI System Management Mode Core Interface Specification only allows the use
   6   of EfiRuntimeServicesCode and EfiRuntimeServicesData memory types for memory
   7   allocations through the SMM Services Table as the SMRAM space should be
   8   reserved after BDS phase.  The functions in the Memory Allocation Library use
   9   EfiBootServicesData as the default memory allocation type.  For this SMM
  10   specific instance of the Memory Allocation Library, EfiRuntimeServicesData
  11   is used as the default memory type for all allocations. In addition,
  12   allocation for the Reserved memory types are not supported and will always
  13   return NULL.
  14
  15   Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
  16   This program and the accompanying materials
  17   are licensed and made available under the terms and conditions of the BSD License
  18   which accompanies this distribution.  The full text of the license may be found at
  19   http://opensource.org/licenses/bsd-license.php.
  20
  21   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  22   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  23
  24 **/
  25
  26 #include <PiSmm.h>
  27
  28 #include <Protocol/SmmAccess2.h>
  29 #include <Library/MemoryAllocationLib.h>
  30 #include <Library/UefiBootServicesTableLib.h>
  31 #include <Library/SmmServicesTableLib.h>
  32 #include <Library/BaseMemoryLib.h>
  33 #include <Library/DebugLib.h>
  34
  35 EFI_SMRAM_DESCRIPTOR  *mSmramRanges;
  36 UINTN                 mSmramRangeCount;
  37
  38 /**
  39   The constructor function caches SMRAM ranges that are present in the system.
  40
  41   It will ASSERT() if SMM Access2 Protocol doesn't exist.
  42   It will ASSERT() if SMRAM ranges can't be got.
  43   It will ASSERT() if Resource can't be allocated for cache SMRAM range.
  44   It will always return EFI_SUCCESS.
  45
  46   @param  ImageHandle   The firmware allocated handle for the EFI image.
  47   @param  SystemTable   A pointer to the EFI System Table.
  48
  49   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  50
  51 **/
  52 EFI_STATUS
  53 EFIAPI
  54 SmmMemoryAllocationLibConstructor (
  55   IN EFI_HANDLE        ImageHandle,
  56   IN EFI_SYSTEM_TABLE  *SystemTable
  57   )
  58 {
  59   EFI_STATUS                Status;
  60   EFI_SMM_ACCESS2_PROTOCOL  *SmmAccess;
  61   UINTN                     Size;
  62
  63   //
  64   // Locate SMM Access2 Protocol
  65   //
  66   Status = gBS->LocateProtocol (
  67                   &gEfiSmmAccess2ProtocolGuid,
  68                   NULL,
  69                   (VOID **)&SmmAccess
  70                   );
  71   ASSERT_EFI_ERROR (Status);
  72
  73   //
  74   // Get SMRAM range information
  75   //
  76   Size = 0;
  77   Status = SmmAccess->GetCapabilities (SmmAccess, &Size, NULL);
  78   ASSERT (Status == EFI_BUFFER_TOO_SMALL);
  79
  80   mSmramRanges = (EFI_SMRAM_DESCRIPTOR *) AllocatePool (Size);
  81   ASSERT (mSmramRanges != NULL);
  82
  83   Status = SmmAccess->GetCapabilities (SmmAccess, &Size, mSmramRanges);
  84   ASSERT_EFI_ERROR (Status);
  85
  86   mSmramRangeCount = Size / sizeof (EFI_SMRAM_DESCRIPTOR);
  87
  88   return EFI_SUCCESS;
  89 }
  90
  91 /**
  92   If SMM driver exits with an error, it must call this routine
  93   to free the allocated resource before the exiting.
  94
  95   @param[in]  ImageHandle   The firmware allocated handle for the EFI image.
  96   @param[in]  SystemTable   A pointer to the EFI System Table.
  97
  98   @retval     EFI_SUCCESS   The deconstructor always returns EFI_SUCCESS.
  99 **/
 100 EFI_STATUS
 101 EFIAPI
 102 SmmMemoryAllocationLibDestructor (
 103   IN EFI_HANDLE        ImageHandle,
 104   IN EFI_SYSTEM_TABLE  *SystemTable
 105   )
 106 {
 107   FreePool (mSmramRanges);
 108
 109   return EFI_SUCCESS;
 110 }
 111
 112 /**
 113   Check whether the start address of buffer is within any of the SMRAM ranges.
 114
 115   @param[in]  Buffer   The pointer to the buffer to be checked.
 116
 117   @retval     TRUE     The buffer is in SMRAM ranges.
 118   @retval     FALSE    The buffer is out of SMRAM ranges.
 119 **/
 120 BOOLEAN
 121 EFIAPI
 122 BufferInSmram (
 123   IN VOID *Buffer
 124   )
 125 {
 126   UINTN  Index;
 127
 128   for (Index = 0; Index < mSmramRangeCount; Index ++) {
 129     if (((EFI_PHYSICAL_ADDRESS) (UINTN) Buffer >= mSmramRanges[Index].CpuStart) &&
 130         ((EFI_PHYSICAL_ADDRESS) (UINTN) Buffer < (mSmramRanges[Index].CpuStart + mSmramRanges[Index].PhysicalSize))) {
 131       return TRUE;
 132     }
 133   }
 134
 135   return FALSE;
 136 }
 137
 138 /**
 139   Allocates one or more 4KB pages of a certain memory type.
 140
 141   Allocates the number of 4KB pages of a certain memory type and returns a pointer
 142   to the allocated buffer.  The buffer returned is aligned on a 4KB boundary.  If
 143   Pages is 0, then NULL is returned.   If there is not enough memory remaining to
 144   satisfy the request, then NULL is returned.
 145
 146   @param  MemoryType            The type of memory to allocate.
 147   @param  Pages                 The number of 4 KB pages to allocate.
 148
 149   @return A pointer to the allocated buffer or NULL if allocation fails.
 150
 151 **/
 152 VOID *
 153 InternalAllocatePages (
 154   IN EFI_MEMORY_TYPE  MemoryType,
 155   IN UINTN            Pages
 156   )
 157 {
 158   EFI_STATUS            Status;
 159   EFI_PHYSICAL_ADDRESS  Memory;
 160
 161   if (Pages == 0) {
 162     return NULL;
 163   }
 164
 165   Status = gSmst->SmmAllocatePages (AllocateAnyPages, MemoryType, Pages, &Memory);
 166   if (EFI_ERROR (Status)) {
 167     return NULL;
 168   }
 169   return (VOID *) (UINTN) Memory;
 170 }
 171
 172 /**
 173   Allocates one or more 4KB pages of type EfiRuntimeServicesData.
 174
 175   Allocates the number of 4KB pages of type EfiRuntimeServicesData and returns a pointer
 176   to the allocated buffer.  The buffer returned is aligned on a 4KB boundary.  If
 177   Pages is 0, then NULL is returned.  If there is not enough memory remaining to
 178   satisfy the request, then NULL is returned.
 179
 180   @param  Pages                 The number of 4 KB pages to allocate.
 181
 182   @return A pointer to the allocated buffer or NULL if allocation fails.
 183
 184 **/
 185 VOID *
 186 EFIAPI
 187 AllocatePages (
 188   IN UINTN  Pages
 189   )
 190 {
 191   return InternalAllocatePages (EfiRuntimeServicesData, Pages);
 192 }
 193
 194 /**
 195   Allocates one or more 4KB pages of type EfiRuntimeServicesData.
 196
 197   Allocates the number of 4KB pages of type EfiRuntimeServicesData and returns a
 198   pointer to the allocated buffer.  The buffer returned is aligned on a 4KB boundary.
 199   If Pages is 0, then NULL is returned.  If there is not enough memory remaining
 200   to satisfy the request, then NULL is returned.
 201
 202   @param  Pages                 The number of 4 KB pages to allocate.
 203
 204   @return A pointer to the allocated buffer or NULL if allocation fails.
 205
 206 **/
 207 VOID *
 208 EFIAPI
 209 AllocateRuntimePages (
 210   IN UINTN  Pages
 211   )
 212 {
 213   return InternalAllocatePages (EfiRuntimeServicesData, Pages);
 214 }
 215
 216 /**
 217   Allocates one or more 4KB pages of type EfiReservedMemoryType.
 218
 219   Allocates the number of 4KB pages of type EfiReservedMemoryType and returns a
 220   pointer to the allocated buffer.  The buffer returned is aligned on a 4KB boundary.
 221   If Pages is 0, then NULL is returned.  If there is not enough memory remaining
 222   to satisfy the request, then NULL is returned.
 223
 224   @param  Pages                 The number of 4 KB pages to allocate.
 225
 226   @return A pointer to the allocated buffer or NULL if allocation fails.
 227
 228 **/
 229 VOID *
 230 EFIAPI
 231 AllocateReservedPages (
 232   IN UINTN  Pages
 233   )
 234 {
 235   return NULL;
 236 }
 237
 238 /**
 239   Frees one or more 4KB pages that were previously allocated with one of the page allocation
 240   functions in the Memory Allocation Library.
 241
 242   Frees the number of 4KB pages specified by Pages from the buffer specified by Buffer.
 243   Buffer must have been allocated on a previous call to the page allocation services
 244   of the Memory Allocation Library.  If it is not possible to free allocated pages,
 245   then this function will perform no actions.
 246
 247   If Buffer was not allocated with a page allocation function in the Memory Allocation
 248   Library, then ASSERT().
 249   If Pages is zero, then ASSERT().
 250
 251   @param  Buffer                The pointer to the buffer of pages to free.
 252   @param  Pages                 The number of 4 KB pages to free.
 253
 254 **/
 255 VOID
 256 EFIAPI
 257 FreePages (
 258   IN VOID   *Buffer,
 259   IN UINTN  Pages
 260   )
 261 {
 262   EFI_STATUS  Status;
 263
 264   ASSERT (Pages != 0);
 265   if (BufferInSmram (Buffer)) {
 266     //
 267     // When Buffer is in SMRAM range, it should be allocated by gSmst->SmmAllocatePages() service.
 268     // So, gSmst->SmmFreePages() service is used to free it.
 269     //
 270     Status = gSmst->SmmFreePages ((EFI_PHYSICAL_ADDRESS) (UINTN) Buffer, Pages);
 271   } else {
 272     //
 273     // When Buffer is out of SMRAM range, it should be allocated by gBS->AllocatePages() service.
 274     // So, gBS->FreePages() service is used to free it.
 275     //
 276     Status = gBS->FreePages ((EFI_PHYSICAL_ADDRESS) (UINTN) Buffer, Pages);
 277   }
 278   ASSERT_EFI_ERROR (Status);
 279 }
 280
 281 /**
 282   Allocates one or more 4KB pages of a certain memory type at a specified alignment.
 283
 284   Allocates the number of 4KB pages specified by Pages of a certain memory type
 285   with an alignment specified by Alignment.  The allocated buffer is returned.
 286   If Pages is 0, then NULL is returned. If there is not enough memory at the
 287   specified alignment remaining to satisfy the request, then NULL is returned.
 288   If Alignment is not a power of two and Alignment is not zero, then ASSERT().
 289   If Pages plus EFI_SIZE_TO_PAGES (Alignment) overflows, then ASSERT().
 290
 291   @param  MemoryType            The type of memory to allocate.
 292   @param  Pages                 The number of 4 KB pages to allocate.
 293   @param  Alignment             The requested alignment of the allocation.
 294                                 Must be a power of two.
 295                                 If Alignment is zero, then byte alignment is used.
 296
 297   @return A pointer to the allocated buffer or NULL if allocation fails.
 298
 299 **/
 300 VOID *
 301 InternalAllocateAlignedPages (
 302   IN EFI_MEMORY_TYPE  MemoryType,
 303   IN UINTN            Pages,
 304   IN UINTN            Alignment
 305   )
 306 {
 307   EFI_STATUS            Status;
 308   EFI_PHYSICAL_ADDRESS  Memory;
 309   UINTN                 AlignedMemory;
 310   UINTN                 AlignmentMask;
 311   UINTN                 UnalignedPages;
 312   UINTN                 RealPages;
 313
 314   //
 315   // Alignment must be a power of two or zero.
 316   //
 317   ASSERT ((Alignment & (Alignment - 1)) == 0);
 318
 319   if (Pages == 0) {
 320     return NULL;
 321   }
 322   if (Alignment > EFI_PAGE_SIZE) {
 323     //
 324     // Calculate the total number of pages since alignment is larger than page size.
 325     //
 326     AlignmentMask  = Alignment - 1;
 327     RealPages      = Pages + EFI_SIZE_TO_PAGES (Alignment);
 328     //
 329     // Make sure that Pages plus EFI_SIZE_TO_PAGES (Alignment) does not overflow.
 330     //
 331     ASSERT (RealPages > Pages);
 332
 333     Status         = gSmst->SmmAllocatePages (AllocateAnyPages, MemoryType, RealPages, &Memory);
 334     if (EFI_ERROR (Status)) {
 335       return NULL;
 336     }
 337     AlignedMemory  = ((UINTN) Memory + AlignmentMask) & ~AlignmentMask;
 338     UnalignedPages = EFI_SIZE_TO_PAGES (AlignedMemory - (UINTN) Memory);
 339     if (UnalignedPages > 0) {
 340       //
 341       // Free first unaligned page(s).
 342       //
 343       Status = gSmst->SmmFreePages (Memory, UnalignedPages);
 344       ASSERT_EFI_ERROR (Status);
 345     }
 346     Memory         = AlignedMemory + EFI_PAGES_TO_SIZE (Pages);
 347     UnalignedPages = RealPages - Pages - UnalignedPages;
 348     if (UnalignedPages > 0) {
 349       //
 350       // Free last unaligned page(s).
 351       //
 352       Status = gSmst->SmmFreePages (Memory, UnalignedPages);
 353       ASSERT_EFI_ERROR (Status);
 354     }
 355   } else {
 356     //
 357     // Do not over-allocate pages in this case.
 358     //
 359     Status = gSmst->SmmAllocatePages (AllocateAnyPages, MemoryType, Pages, &Memory);
 360     if (EFI_ERROR (Status)) {
 361       return NULL;
 362     }
 363     AlignedMemory  = (UINTN) Memory;
 364   }
 365   return (VOID *) AlignedMemory;
 366 }
 367
 368 /**
 369   Allocates one or more 4KB pages of type EfiRuntimeServicesData at a specified alignment.
 370
 371   Allocates the number of 4KB pages specified by Pages of type EfiRuntimeServicesData
 372   with an alignment specified by Alignment.  The allocated buffer is returned.
 373   If Pages is 0, then NULL is returned.  If there is not enough memory at the
 374   specified alignment remaining to satisfy the request, then NULL is returned.
 375
 376   If Alignment is not a power of two and Alignment is not zero, then ASSERT().
 377   If Pages plus EFI_SIZE_TO_PAGES (Alignment) overflows, then ASSERT().
 378
 379   @param  Pages                 The number of 4 KB pages to allocate.
 380   @param  Alignment             The requested alignment of the allocation.
 381                                 Must be a power of two.
 382                                 If Alignment is zero, then byte alignment is used.
 383
 384   @return A pointer to the allocated buffer or NULL if allocation fails.
 385
 386 **/
 387 VOID *
 388 EFIAPI
 389 AllocateAlignedPages (
 390   IN UINTN  Pages,
 391   IN UINTN  Alignment
 392   )
 393 {
 394   return InternalAllocateAlignedPages (EfiRuntimeServicesData, Pages, Alignment);
 395 }
 396
 397 /**
 398   Allocates one or more 4KB pages of type EfiRuntimeServicesData at a specified alignment.
 399
 400   Allocates the number of 4KB pages specified by Pages of type EfiRuntimeServicesData
 401   with an alignment specified by Alignment.  The allocated buffer is returned.
 402   If Pages is 0, then NULL is returned.  If there is not enough memory at the
 403   specified alignment remaining to satisfy the request, then NULL is returned.
 404
 405   If Alignment is not a power of two and Alignment is not zero, then ASSERT().
 406   If Pages plus EFI_SIZE_TO_PAGES (Alignment) overflows, then ASSERT().
 407
 408   @param  Pages                 The number of 4 KB pages to allocate.
 409   @param  Alignment             The requested alignment of the allocation.
 410                                 Must be a power of two.
 411                                 If Alignment is zero, then byte alignment is used.
 412
 413   @return A pointer to the allocated buffer or NULL if allocation fails.
 414
 415 **/
 416 VOID *
 417 EFIAPI
 418 AllocateAlignedRuntimePages (
 419   IN UINTN  Pages,
 420   IN UINTN  Alignment
 421   )
 422 {
 423   return InternalAllocateAlignedPages (EfiRuntimeServicesData, Pages, Alignment);
 424 }
 425
 426 /**
 427   Allocates one or more 4KB pages of type EfiReservedMemoryType at a specified alignment.
 428
 429   Allocates the number of 4KB pages specified by Pages of type EfiReservedMemoryType
 430   with an alignment specified by Alignment.  The allocated buffer is returned.
 431   If Pages is 0, then NULL is returned.  If there is not enough memory at the
 432   specified alignment remaining to satisfy the request, then NULL is returned.
 433
 434   If Alignment is not a power of two and Alignment is not zero, then ASSERT().
 435   If Pages plus EFI_SIZE_TO_PAGES (Alignment) overflows, then ASSERT().
 436
 437   @param  Pages                 The number of 4 KB pages to allocate.
 438   @param  Alignment             The requested alignment of the allocation.
 439                                 Must be a power of two.
 440                                 If Alignment is zero, then byte alignment is used.
 441
 442   @return A pointer to the allocated buffer or NULL if allocation fails.
 443
 444 **/
 445 VOID *
 446 EFIAPI
 447 AllocateAlignedReservedPages (
 448   IN UINTN  Pages,
 449   IN UINTN  Alignment
 450   )
 451 {
 452   return NULL;
 453 }
 454
 455 /**
 456   Frees one or more 4KB pages that were previously allocated with one of the aligned page
 457   allocation functions in the Memory Allocation Library.
 458
 459   Frees the number of 4KB pages specified by Pages from the buffer specified by
 460   Buffer.  Buffer must have been allocated on a previous call to the aligned page
 461   allocation services of the Memory Allocation Library.  If it is not possible to
 462   free allocated pages, then this function will perform no actions.
 463
 464   If Buffer was not allocated with an aligned page allocation function in the
 465   Memory Allocation Library, then ASSERT().
 466   If Pages is zero, then ASSERT().
 467
 468   @param  Buffer                The pointer to the buffer of pages to free.
 469   @param  Pages                 The number of 4 KB pages to free.
 470
 471 **/
 472 VOID
 473 EFIAPI
 474 FreeAlignedPages (
 475   IN VOID   *Buffer,
 476   IN UINTN  Pages
 477   )
 478 {
 479   EFI_STATUS  Status;
 480
 481   ASSERT (Pages != 0);
 482   if (BufferInSmram (Buffer)) {
 483     //
 484     // When Buffer is in SMRAM range, it should be allocated by gSmst->SmmAllocatePages() service.
 485     // So, gSmst->SmmFreePages() service is used to free it.
 486     //
 487     Status = gSmst->SmmFreePages ((EFI_PHYSICAL_ADDRESS) (UINTN) Buffer, Pages);
 488   } else {
 489     //
 490     // When Buffer is out of SMRAM range, it should be allocated by gBS->AllocatePages() service.
 491     // So, gBS->FreePages() service is used to free it.
 492     //
 493     Status = gBS->FreePages ((EFI_PHYSICAL_ADDRESS) (UINTN) Buffer, Pages);
 494   }
 495   ASSERT_EFI_ERROR (Status);
 496 }
 497
 498 /**
 499   Allocates a buffer of a certain pool type.
 500
 501   Allocates the number bytes specified by AllocationSize of a certain pool type
 502   and returns a pointer to the allocated buffer.  If AllocationSize is 0, then a
 503   valid buffer of 0 size is returned.  If there is not enough memory remaining to
 504   satisfy the request, then NULL is returned.
 505
 506   @param  MemoryType            The type of memory to allocate.
 507   @param  AllocationSize        The number of bytes to allocate.
 508
 509   @return A pointer to the allocated buffer or NULL if allocation fails.
 510
 511 **/
 512 VOID *
 513 InternalAllocatePool (
 514   IN EFI_MEMORY_TYPE  MemoryType,
 515   IN UINTN            AllocationSize
 516   )
 517 {
 518   EFI_STATUS  Status;
 519   VOID        *Memory;
 520
 521   Status = gSmst->SmmAllocatePool (MemoryType, AllocationSize, &Memory);
 522   if (EFI_ERROR (Status)) {
 523     Memory = NULL;
 524   }
 525   return Memory;
 526 }
 527
 528 /**
 529   Allocates a buffer of type EfiRuntimeServicesData.
 530
 531   Allocates the number bytes specified by AllocationSize of type EfiRuntimeServicesData
 532   and returns a pointer to the allocated buffer.  If AllocationSize is 0, then a
 533   valid buffer of 0 size is returned.  If there is not enough memory remaining to
 534   satisfy the request, then NULL is returned.
 535
 536   @param  AllocationSize        The number of bytes to allocate.
 537
 538   @return A pointer to the allocated buffer or NULL if allocation fails.
 539
 540 **/
 541 VOID *
 542 EFIAPI
 543 AllocatePool (
 544   IN UINTN  AllocationSize
 545   )
 546 {
 547   return InternalAllocatePool (EfiRuntimeServicesData, AllocationSize);
 548 }
 549
 550 /**
 551   Allocates a buffer of type EfiRuntimeServicesData.
 552
 553   Allocates the number bytes specified by AllocationSize of type EfiRuntimeServicesData
 554   and returns a pointer to the allocated buffer.  If AllocationSize is 0, then a
 555   valid buffer of 0 size is returned.  If there is not enough memory remaining to
 556   satisfy the request, then NULL is returned.
 557
 558   @param  AllocationSize        The number of bytes to allocate.
 559
 560   @return A pointer to the allocated buffer or NULL if allocation fails.
 561
 562 **/
 563 VOID *
 564 EFIAPI
 565 AllocateRuntimePool (
 566   IN UINTN  AllocationSize
 567   )
 568 {
 569   return InternalAllocatePool (EfiRuntimeServicesData, AllocationSize);
 570 }
 571
 572 /**
 573   Allocates a buffer of type EfiReservedMemoryType.
 574
 575   Allocates the number bytes specified by AllocationSize of type EfiReservedMemoryType
 576   and returns a pointer to the allocated buffer.  If AllocationSize is 0, then a
 577   valid buffer of 0 size is returned.  If there is not enough memory remaining to
 578   satisfy the request, then NULL is returned.
 579
 580   @param  AllocationSize        The number of bytes to allocate.
 581
 582   @return A pointer to the allocated buffer or NULL if allocation fails.
 583
 584 **/
 585 VOID *
 586 EFIAPI
 587 AllocateReservedPool (
 588   IN UINTN  AllocationSize
 589   )
 590 {
 591   return NULL;
 592 }
 593
 594 /**
 595   Allocates and zeros a buffer of a certain pool type.
 596
 597   Allocates the number bytes specified by AllocationSize of a certain pool type,
 598   clears the buffer with zeros, and returns a pointer to the allocated buffer.
 599   If AllocationSize is 0, then a valid buffer of 0 size is returned.  If there is
 600   not enough memory remaining to satisfy the request, then NULL is returned.
 601
 602   @param  PoolType              The type of memory to allocate.
 603   @param  AllocationSize        The number of bytes to allocate and zero.
 604
 605   @return A pointer to the allocated buffer or NULL if allocation fails.
 606
 607 **/
 608 VOID *
 609 InternalAllocateZeroPool (
 610   IN EFI_MEMORY_TYPE  PoolType,
 611   IN UINTN            AllocationSize
 612   )
 613 {
 614   VOID  *Memory;
 615
 616   Memory = InternalAllocatePool (PoolType, AllocationSize);
 617   if (Memory != NULL) {
 618     Memory = ZeroMem (Memory, AllocationSize);
 619   }
 620   return Memory;
 621 }
 622
 623 /**
 624   Allocates and zeros a buffer of type EfiRuntimeServicesData.
 625
 626   Allocates the number bytes specified by AllocationSize of type EfiRuntimeServicesData,
 627   clears the buffer with zeros, and returns a pointer to the allocated buffer.
 628   If AllocationSize is 0, then a valid buffer of 0 size is returned.  If there is
 629   not enough memory remaining to satisfy the request, then NULL is returned.
 630
 631   @param  AllocationSize        The number of bytes to allocate and zero.
 632
 633   @return A pointer to the allocated buffer or NULL if allocation fails.
 634
 635 **/
 636 VOID *
 637 EFIAPI
 638 AllocateZeroPool (
 639   IN UINTN  AllocationSize
 640   )
 641 {
 642   return InternalAllocateZeroPool (EfiRuntimeServicesData, AllocationSize);
 643 }
 644
 645 /**
 646   Allocates and zeros a buffer of type EfiRuntimeServicesData.
 647
 648   Allocates the number bytes specified by AllocationSize of type EfiRuntimeServicesData,
 649   clears the buffer with zeros, and returns a pointer to the allocated buffer.
 650   If AllocationSize is 0, then a valid buffer of 0 size is returned.  If there is
 651   not enough memory remaining to satisfy the request, then NULL is returned.
 652
 653   @param  AllocationSize        The number of bytes to allocate and zero.
 654
 655   @return A pointer to the allocated buffer or NULL if allocation fails.
 656
 657 **/
 658 VOID *
 659 EFIAPI
 660 AllocateRuntimeZeroPool (
 661   IN UINTN  AllocationSize
 662   )
 663 {
 664   return InternalAllocateZeroPool (EfiRuntimeServicesData, AllocationSize);
 665 }
 666
 667 /**
 668   Allocates and zeros a buffer of type EfiReservedMemoryType.
 669
 670   Allocates the number bytes specified by AllocationSize of type EfiReservedMemoryType,
 671   clears the   buffer with zeros, and returns a pointer to the allocated buffer.
 672   If AllocationSize is 0, then a valid buffer of 0 size is returned.  If there is
 673   not enough memory remaining to satisfy the request, then NULL is returned.
 674
 675   @param  AllocationSize        The number of bytes to allocate and zero.
 676
 677   @return A pointer to the allocated buffer or NULL if allocation fails.
 678
 679 **/
 680 VOID *
 681 EFIAPI
 682 AllocateReservedZeroPool (
 683   IN UINTN  AllocationSize
 684   )
 685 {
 686   return NULL;
 687 }
 688
 689 /**
 690   Copies a buffer to an allocated buffer of a certain pool type.
 691
 692   Allocates the number bytes specified by AllocationSize of a certain pool type,
 693   copies AllocationSize bytes from Buffer to the newly allocated buffer, and returns
 694   a pointer to the allocated buffer.  If AllocationSize is 0, then a valid buffer
 695   of 0 size is returned.  If there is not enough memory remaining to satisfy the
 696   request, then NULL is returned. If Buffer is NULL, then ASSERT().
 697   If AllocationSize is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
 698
 699   @param  PoolType              The type of pool to allocate.
 700   @param  AllocationSize        The number of bytes to allocate and zero.
 701   @param  Buffer                The buffer to copy to the allocated buffer.
 702
 703   @return A pointer to the allocated buffer or NULL if allocation fails.
 704
 705 **/
 706 VOID *
 707 InternalAllocateCopyPool (
 708   IN EFI_MEMORY_TYPE  PoolType,
 709   IN UINTN            AllocationSize,
 710   IN CONST VOID       *Buffer
 711   )
 712 {
 713   VOID  *Memory;
 714
 715   ASSERT (Buffer != NULL);
 716   ASSERT (AllocationSize <= (MAX_ADDRESS - (UINTN) Buffer + 1));
 717
 718   Memory = InternalAllocatePool (PoolType, AllocationSize);
 719   if (Memory != NULL) {
 720      Memory = CopyMem (Memory, Buffer, AllocationSize);
 721   }
 722   return Memory;
 723 }
 724
 725 /**
 726   Copies a buffer to an allocated buffer of type EfiRuntimeServicesData.
 727
 728   Allocates the number bytes specified by AllocationSize of type EfiRuntimeServicesData,
 729   copies AllocationSize bytes from Buffer to the newly allocated buffer, and returns
 730   a pointer to the allocated buffer.  If AllocationSize is 0, then a valid buffer
 731   of 0 size is returned.  If there is not enough memory remaining to satisfy the
 732   request, then NULL is returned.
 733
 734   If Buffer is NULL, then ASSERT().
 735   If AllocationSize is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
 736
 737   @param  AllocationSize        The number of bytes to allocate and zero.
 738   @param  Buffer                The buffer to copy to the allocated buffer.
 739
 740   @return A pointer to the allocated buffer or NULL if allocation fails.
 741
 742 **/
 743 VOID *
 744 EFIAPI
 745 AllocateCopyPool (
 746   IN UINTN       AllocationSize,
 747   IN CONST VOID  *Buffer
 748   )
 749 {
 750   return InternalAllocateCopyPool (EfiRuntimeServicesData, AllocationSize, Buffer);
 751 }
 752
 753 /**
 754   Copies a buffer to an allocated buffer of type EfiRuntimeServicesData.
 755
 756   Allocates the number bytes specified by AllocationSize of type EfiRuntimeServicesData,
 757   copies AllocationSize bytes from Buffer to the newly allocated buffer, and returns
 758   a pointer to the allocated buffer.  If AllocationSize is 0, then a valid buffer
 759   of 0 size is returned.  If there is not enough memory remaining to satisfy the
 760   request, then NULL is returned.
 761
 762   If Buffer is NULL, then ASSERT().
 763   If AllocationSize is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
 764
 765   @param  AllocationSize        The number of bytes to allocate and zero.
 766   @param  Buffer                The buffer to copy to the allocated buffer.
 767
 768   @return A pointer to the allocated buffer or NULL if allocation fails.
 769
 770 **/
 771 VOID *
 772 EFIAPI
 773 AllocateRuntimeCopyPool (
 774   IN UINTN       AllocationSize,
 775   IN CONST VOID  *Buffer
 776   )
 777 {
 778   return InternalAllocateCopyPool (EfiRuntimeServicesData, AllocationSize, Buffer);
 779 }
 780
 781 /**
 782   Copies a buffer to an allocated buffer of type EfiReservedMemoryType.
 783
 784   Allocates the number bytes specified by AllocationSize of type EfiReservedMemoryType,
 785   copies AllocationSize bytes from Buffer to the newly allocated buffer, and returns
 786   a pointer to the allocated buffer.  If AllocationSize is 0, then a valid buffer
 787   of 0 size is returned.  If there is not enough memory remaining to satisfy the
 788   request, then NULL is returned.
 789
 790   If Buffer is NULL, then ASSERT().
 791   If AllocationSize is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
 792
 793   @param  AllocationSize        The number of bytes to allocate and zero.
 794   @param  Buffer                The buffer to copy to the allocated buffer.
 795
 796   @return A pointer to the allocated buffer or NULL if allocation fails.
 797
 798 **/
 799 VOID *
 800 EFIAPI
 801 AllocateReservedCopyPool (
 802   IN UINTN       AllocationSize,
 803   IN CONST VOID  *Buffer
 804   )
 805 {
 806   return NULL;
 807 }
 808
 809 /**
 810   Reallocates a buffer of a specified memory type.
 811
 812   Allocates and zeros the number bytes specified by NewSize from memory of the type
 813   specified by PoolType.  If OldBuffer is not NULL, then the smaller of OldSize and
 814   NewSize bytes are copied from OldBuffer to the newly allocated buffer, and
 815   OldBuffer is freed.  A pointer to the newly allocated buffer is returned.
 816   If NewSize is 0, then a valid buffer of 0 size is  returned.  If there is not
 817   enough memory remaining to satisfy the request, then NULL is returned.
 818
 819   If the allocation of the new buffer is successful and the smaller of NewSize
 820   and OldSize is greater than (MAX_ADDRESS - OldBuffer + 1), then ASSERT().
 821
 822   @param  PoolType       The type of pool to allocate.
 823   @param  OldSize        The size, in bytes, of OldBuffer.
 824   @param  NewSize        The size, in bytes, of the buffer to reallocate.
 825   @param  OldBuffer      The buffer to copy to the allocated buffer.  This is an
 826                          optional parameter that may be NULL.
 827
 828   @return A pointer to the allocated buffer or NULL if allocation fails.
 829
 830 **/
 831 VOID *
 832 InternalReallocatePool (
 833   IN EFI_MEMORY_TYPE  PoolType,
 834   IN UINTN            OldSize,
 835   IN UINTN            NewSize,
 836   IN VOID             *OldBuffer  OPTIONAL
 837   )
 838 {
 839   VOID  *NewBuffer;
 840
 841   NewBuffer = InternalAllocateZeroPool (PoolType, NewSize);
 842   if (NewBuffer != NULL && OldBuffer != NULL) {
 843     CopyMem (NewBuffer, OldBuffer, MIN (OldSize, NewSize));
 844     FreePool (OldBuffer);
 845   }
 846   return NewBuffer;
 847 }
 848
 849 /**
 850   Reallocates a buffer of type EfiRuntimeServicesData.
 851
 852   Allocates and zeros the number bytes specified by NewSize from memory of type
 853   EfiRuntimeServicesData.  If OldBuffer is not NULL, then the smaller of OldSize and
 854   NewSize bytes are copied from OldBuffer to the newly allocated buffer, and
 855   OldBuffer is freed.  A pointer to the newly allocated buffer is returned.
 856   If NewSize is 0, then a valid buffer of 0 size is  returned.  If there is not
 857   enough memory remaining to satisfy the request, then NULL is returned.
 858
 859   If the allocation of the new buffer is successful and the smaller of NewSize
 860   and OldSize is greater than (MAX_ADDRESS - OldBuffer + 1), then ASSERT().
 861
 862   @param  OldSize        The size, in bytes, of OldBuffer.
 863   @param  NewSize        The size, in bytes, of the buffer to reallocate.
 864   @param  OldBuffer      The buffer to copy to the allocated buffer.  This is an
 865                          optional parameter that may be NULL.
 866
 867   @return A pointer to the allocated buffer or NULL if allocation fails.
 868
 869 **/
 870 VOID *
 871 EFIAPI
 872 ReallocatePool (
 873   IN UINTN  OldSize,
 874   IN UINTN  NewSize,
 875   IN VOID   *OldBuffer  OPTIONAL
 876   )
 877 {
 878   return InternalReallocatePool (EfiRuntimeServicesData, OldSize, NewSize, OldBuffer);
 879 }
 880
 881 /**
 882   Reallocates a buffer of type EfiRuntimeServicesData.
 883
 884   Allocates and zeros the number bytes specified by NewSize from memory of type
 885   EfiRuntimeServicesData.  If OldBuffer is not NULL, then the smaller of OldSize
 886   and NewSize bytes are copied from OldBuffer to the newly allocated buffer, and
 887   OldBuffer is freed.  A pointer to the newly allocated buffer is returned.
 888   If NewSize is 0, then a valid buffer of 0 size is  returned.  If there is not
 889   enough memory remaining to satisfy the request, then NULL is returned.
 890
 891   If the allocation of the new buffer is successful and the smaller of NewSize
 892   and OldSize is greater than (MAX_ADDRESS - OldBuffer + 1), then ASSERT().
 893
 894   @param  OldSize        The size, in bytes, of OldBuffer.
 895   @param  NewSize        The size, in bytes, of the buffer to reallocate.
 896   @param  OldBuffer      The buffer to copy to the allocated buffer.  This is an
 897                          optional parameter that may be NULL.
 898
 899   @return A pointer to the allocated buffer or NULL if allocation fails.
 900
 901 **/
 902 VOID *
 903 EFIAPI
 904 ReallocateRuntimePool (
 905   IN UINTN  OldSize,
 906   IN UINTN  NewSize,
 907   IN VOID   *OldBuffer  OPTIONAL
 908   )
 909 {
 910   return InternalReallocatePool (EfiRuntimeServicesData, OldSize, NewSize, OldBuffer);
 911 }
 912
 913 /**
 914   Reallocates a buffer of type EfiReservedMemoryType.
 915
 916   Allocates and zeros the number bytes specified by NewSize from memory of type
 917   EfiReservedMemoryType.  If OldBuffer is not NULL, then the smaller of OldSize
 918   and NewSize bytes are copied from OldBuffer to the newly allocated buffer, and
 919   OldBuffer is freed.  A pointer to the newly allocated buffer is returned.
 920   If NewSize is 0, then a valid buffer of 0 size is  returned.  If there is not
 921   enough memory remaining to satisfy the request, then NULL is returned.
 922
 923   If the allocation of the new buffer is successful and the smaller of NewSize
 924   and OldSize is greater than (MAX_ADDRESS - OldBuffer + 1), then ASSERT().
 925
 926   @param  OldSize        The size, in bytes, of OldBuffer.
 927   @param  NewSize        The size, in bytes, of the buffer to reallocate.
 928   @param  OldBuffer      The buffer to copy to the allocated buffer.  This is an
 929                          optional parameter that may be NULL.
 930
 931   @return A pointer to the allocated buffer or NULL if allocation fails.
 932
 933 **/
 934 VOID *
 935 EFIAPI
 936 ReallocateReservedPool (
 937   IN UINTN  OldSize,
 938   IN UINTN  NewSize,
 939   IN VOID   *OldBuffer  OPTIONAL
 940   )
 941 {
 942   return NULL;
 943 }
 944
 945 /**
 946   Frees a buffer that was previously allocated with one of the pool allocation
 947   functions in the Memory Allocation Library.
 948
 949   Frees the buffer specified by Buffer.  Buffer must have been allocated on a
 950   previous call to the pool allocation services of the Memory Allocation Library.
 951   If it is not possible to free pool resources, then this function will perform
 952   no actions.
 953
 954   If Buffer was not allocated with a pool allocation function in the Memory
 955   Allocation Library, then ASSERT().
 956
 957   @param  Buffer                The pointer to the buffer to free.
 958
 959 **/
 960 VOID
 961 EFIAPI
 962 FreePool (
 963   IN VOID   *Buffer
 964   )
 965 {
 966   EFI_STATUS    Status;
 967
 968   if (BufferInSmram (Buffer)) {
 969     //
 970     // When Buffer is in SMRAM range, it should be allocated by gSmst->SmmAllocatePool() service.
 971     // So, gSmst->SmmFreePool() service is used to free it.
 972     //
 973     Status = gSmst->SmmFreePool (Buffer);
 974   } else {
 975     //
 976     // When Buffer is out of SMRAM range, it should be allocated by gBS->AllocatePool() service.
 977     // So, gBS->FreePool() service is used to free it.
 978     //
 979     Status = gBS->FreePool (Buffer);
 980   }
 981   ASSERT_EFI_ERROR (Status);
 982 }