[mirror_edk2.git] / MdeModulePkg / Core / Dxe / Mem / Pool.c

/** @file\r
  UEFI Memory pool management functions.\r
\r
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "DxeMain.h"\r
#include "Imem.h"\r
#include "HeapGuard.h"\r
\r
STATIC EFI_LOCK mPoolMemoryLock = EFI_INITIALIZE_LOCK_VARIABLE (TPL_NOTIFY);\r
\r
#define POOL_FREE_SIGNATURE   SIGNATURE_32('p','f','r','0')\r
typedef struct {\r
  UINT32          Signature;\r
  UINT32          Index;\r
  LIST_ENTRY      Link;\r
} POOL_FREE;\r
\r
\r
#define POOL_HEAD_SIGNATURE       SIGNATURE_32('p','h','d','0')\r
#define POOLPAGE_HEAD_SIGNATURE   SIGNATURE_32('p','h','d','1')\r
typedef struct {\r
  UINT32          Signature;\r
  UINT32          Reserved;\r
  EFI_MEMORY_TYPE Type;\r
  UINTN           Size;\r
  CHAR8           Data[1];\r
} POOL_HEAD;\r
\r
#define SIZE_OF_POOL_HEAD OFFSET_OF(POOL_HEAD,Data)\r
\r
#define POOL_TAIL_SIGNATURE   SIGNATURE_32('p','t','a','l')\r
typedef struct {\r
  UINT32      Signature;\r
  UINT32      Reserved;\r
  UINTN       Size;\r
} POOL_TAIL;\r
\r
#define POOL_OVERHEAD (SIZE_OF_POOL_HEAD + sizeof(POOL_TAIL))\r
\r
#define HEAD_TO_TAIL(a)   \\r
  ((POOL_TAIL *) (((CHAR8 *) (a)) + (a)->Size - sizeof(POOL_TAIL)));\r
\r
//\r
// Each element is the sum of the 2 previous ones: this allows us to migrate\r
// blocks between bins by splitting them up, while not wasting too much memory\r
// as we would in a strict power-of-2 sequence\r
//\r
STATIC CONST UINT16 mPoolSizeTable[] = {\r
  128, 256, 384, 640, 1024, 1664, 2688, 4352, 7040, 11392, 18432, 29824\r
};\r
\r
#define SIZE_TO_LIST(a)   (GetPoolIndexFromSize (a))\r
#define LIST_TO_SIZE(a)   (mPoolSizeTable [a])\r
\r
#define MAX_POOL_LIST     (ARRAY_SIZE (mPoolSizeTable))\r
\r
#define MAX_POOL_SIZE     (MAX_ADDRESS - POOL_OVERHEAD)\r
\r
//\r
// Globals\r
//\r
\r
#define POOL_SIGNATURE  SIGNATURE_32('p','l','s','t')\r
typedef struct {\r
    INTN             Signature;\r
    UINTN            Used;\r
    EFI_MEMORY_TYPE  MemoryType;\r
    LIST_ENTRY       FreeList[MAX_POOL_LIST];\r
    LIST_ENTRY       Link;\r
} POOL;\r
\r
//\r
// Pool header for each memory type.\r
//\r
POOL            mPoolHead[EfiMaxMemoryType];\r
\r
//\r
// List of pool header to search for the appropriate memory type.\r
//\r
LIST_ENTRY      mPoolHeadList = INITIALIZE_LIST_HEAD_VARIABLE (mPoolHeadList);\r
\r
/**\r
  Get pool size table index from the specified size.\r
\r
  @param  Size          The specified size to get index from pool table.\r
\r
  @return               The index of pool size table.\r
\r
**/\r
STATIC\r
UINTN\r
GetPoolIndexFromSize (\r
  UINTN   Size\r
  )\r
{\r
  UINTN   Index;\r
\r
  for (Index = 0; Index < MAX_POOL_LIST; Index++) {\r
    if (mPoolSizeTable [Index] >= Size) {\r
      return Index;\r
    }\r
  }\r
  return MAX_POOL_LIST;\r
}\r
\r
/**\r
  Called to initialize the pool.\r
\r
**/\r
VOID\r
CoreInitializePool (\r
  VOID\r
  )\r
{\r
  UINTN  Type;\r
  UINTN  Index;\r
\r
  for (Type=0; Type < EfiMaxMemoryType; Type++) {\r
    mPoolHead[Type].Signature  = 0;\r
    mPoolHead[Type].Used       = 0;\r
    mPoolHead[Type].MemoryType = (EFI_MEMORY_TYPE) Type;\r
    for (Index=0; Index < MAX_POOL_LIST; Index++) {\r
      InitializeListHead (&mPoolHead[Type].FreeList[Index]);\r
    }\r
  }\r
}\r
\r
\r
/**\r
  Look up pool head for specified memory type.\r
\r
  @param  MemoryType             Memory type of which pool head is looked for\r
\r
  @return Pointer of Corresponding pool head.\r
\r
**/\r
POOL *\r
LookupPoolHead (\r
  IN EFI_MEMORY_TYPE  MemoryType\r
  )\r
{\r
  LIST_ENTRY      *Link;\r
  POOL            *Pool;\r
  UINTN           Index;\r
\r
  if ((UINT32)MemoryType < EfiMaxMemoryType) {\r
    return &mPoolHead[MemoryType];\r
  }\r
\r
  //\r
  // MemoryType values in the range 0x80000000..0xFFFFFFFF are reserved for use by UEFI\r
  // OS loaders that are provided by operating system vendors.\r
  // MemoryType values in the range 0x70000000..0x7FFFFFFF are reserved for OEM use.\r
  //\r
  if ((UINT32) MemoryType >= MEMORY_TYPE_OEM_RESERVED_MIN) {\r
\r
    for (Link = mPoolHeadList.ForwardLink; Link != &mPoolHeadList; Link = Link->ForwardLink) {\r
      Pool = CR(Link, POOL, Link, POOL_SIGNATURE);\r
      if (Pool->MemoryType == MemoryType) {\r
        return Pool;\r
      }\r
    }\r
\r
    Pool = CoreAllocatePoolI (EfiBootServicesData, sizeof (POOL), FALSE);\r
    if (Pool == NULL) {\r
      return NULL;\r
    }\r
\r
    Pool->Signature = POOL_SIGNATURE;\r
    Pool->Used      = 0;\r
    Pool->MemoryType = MemoryType;\r
    for (Index=0; Index < MAX_POOL_LIST; Index++) {\r
      InitializeListHead (&Pool->FreeList[Index]);\r
    }\r
\r
    InsertHeadList (&mPoolHeadList, &Pool->Link);\r
\r
    return Pool;\r
  }\r
\r
  return NULL;\r
}\r
\r
\r
\r
/**\r
  Allocate pool of a particular type.\r
\r
  @param  PoolType               Type of pool to allocate\r
  @param  Size                   The amount of pool to allocate\r
  @param  Buffer                 The address to return a pointer to the allocated\r
                                 pool\r
\r
  @retval EFI_INVALID_PARAMETER  Buffer is NULL.\r
                                 PoolType is in the range EfiMaxMemoryType..0x6FFFFFFF.\r
                                 PoolType is EfiPersistentMemory.\r
  @retval EFI_OUT_OF_RESOURCES   Size exceeds max pool size or allocation failed.\r
  @retval EFI_SUCCESS            Pool successfully allocated.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
CoreInternalAllocatePool (\r
  IN EFI_MEMORY_TYPE  PoolType,\r
  IN UINTN            Size,\r
  OUT VOID            **Buffer\r
  )\r
{\r
  EFI_STATUS            Status;\r
  BOOLEAN               NeedGuard;\r
\r
  //\r
  // If it's not a valid type, fail it\r
  //\r
  if ((PoolType >= EfiMaxMemoryType && PoolType < MEMORY_TYPE_OEM_RESERVED_MIN) ||\r
       (PoolType == EfiConventionalMemory) || (PoolType == EfiPersistentMemory)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (Buffer == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  *Buffer = NULL;\r
\r
  //\r
  // If size is too large, fail it\r
  // Base on the EFI spec, return status of EFI_OUT_OF_RESOURCES\r
  //\r
  if (Size > MAX_POOL_SIZE) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  NeedGuard = IsPoolTypeToGuard (PoolType) && !mOnGuarding;\r
\r
  //\r
  // Acquire the memory lock and make the allocation\r
  //\r
  Status = CoreAcquireLockOrFail (&mPoolMemoryLock);\r
  if (EFI_ERROR (Status)) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  *Buffer = CoreAllocatePoolI (PoolType, Size, NeedGuard);\r
  CoreReleaseLock (&mPoolMemoryLock);\r
  return (*Buffer != NULL) ? EFI_SUCCESS : EFI_OUT_OF_RESOURCES;\r
}\r
\r
/**\r
  Allocate pool of a particular type.\r
\r
  @param  PoolType               Type of pool to allocate\r
  @param  Size                   The amount of pool to allocate\r
  @param  Buffer                 The address to return a pointer to the allocated\r
                                 pool\r
\r
  @retval EFI_INVALID_PARAMETER  Buffer is NULL.\r
                                 PoolType is in the range EfiMaxMemoryType..0x6FFFFFFF.\r
                                 PoolType is EfiPersistentMemory.\r
  @retval EFI_OUT_OF_RESOURCES   Size exceeds max pool size or allocation failed.\r
  @retval EFI_SUCCESS            Pool successfully allocated.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
CoreAllocatePool (\r
  IN EFI_MEMORY_TYPE  PoolType,\r
  IN UINTN            Size,\r
  OUT VOID            **Buffer\r
  )\r
{\r
  EFI_STATUS  Status;\r
\r
  Status = CoreInternalAllocatePool (PoolType, Size, Buffer);\r
  if (!EFI_ERROR (Status)) {\r
    CoreUpdateProfile (\r
      (EFI_PHYSICAL_ADDRESS) (UINTN) RETURN_ADDRESS (0),\r
      MemoryProfileActionAllocatePool,\r
      PoolType,\r
      Size,\r
      *Buffer,\r
      NULL\r
      );\r
    InstallMemoryAttributesTableOnMemoryAllocation (PoolType);\r
  }\r
  return Status;\r
}\r
\r
/**\r
  Internal function.  Used by the pool functions to allocate pages\r
  to back pool allocation requests.\r
\r
  @param  PoolType               The type of memory for the new pool pages\r
  @param  NoPages                No of pages to allocate\r
  @param  Granularity            Bits to align.\r
  @param  NeedGuard              Flag to indicate Guard page is needed or not\r
\r
  @return The allocated memory, or NULL\r
\r
**/\r
STATIC\r
VOID *\r
CoreAllocatePoolPagesI (\r
  IN EFI_MEMORY_TYPE    PoolType,\r
  IN UINTN              NoPages,\r
  IN UINTN              Granularity,\r
  IN BOOLEAN            NeedGuard\r
  )\r
{\r
  VOID        *Buffer;\r
  EFI_STATUS  Status;\r
\r
  Status = CoreAcquireLockOrFail (&gMemoryLock);\r
  if (EFI_ERROR (Status)) {\r
    return NULL;\r
  }\r
\r
  Buffer = CoreAllocatePoolPages (PoolType, NoPages, Granularity, NeedGuard);\r
  CoreReleaseMemoryLock ();\r
\r
  if (Buffer != NULL) {\r
    if (NeedGuard) {\r
      SetGuardForMemory ((EFI_PHYSICAL_ADDRESS)(UINTN)Buffer, NoPages);\r
    }\r
    ApplyMemoryProtectionPolicy(EfiConventionalMemory, PoolType,\r
      (EFI_PHYSICAL_ADDRESS)(UINTN)Buffer, EFI_PAGES_TO_SIZE (NoPages));\r
  }\r
  return Buffer;\r
}\r
\r
/**\r
  Internal function to allocate pool of a particular type.\r
  Caller must have the memory lock held\r
\r
  @param  PoolType               Type of pool to allocate\r
  @param  Size                   The amount of pool to allocate\r
  @param  NeedGuard              Flag to indicate Guard page is needed or not\r
\r
  @return The allocate pool, or NULL\r
\r
**/\r
VOID *\r
CoreAllocatePoolI (\r
  IN EFI_MEMORY_TYPE  PoolType,\r
  IN UINTN            Size,\r
  IN BOOLEAN          NeedGuard\r
  )\r
{\r
  POOL        *Pool;\r
  POOL_FREE   *Free;\r
  POOL_HEAD   *Head;\r
  POOL_TAIL   *Tail;\r
  CHAR8       *NewPage;\r
  VOID        *Buffer;\r
  UINTN       Index;\r
  UINTN       FSize;\r
  UINTN       Offset, MaxOffset;\r
  UINTN       NoPages;\r
  UINTN       Granularity;\r
  BOOLEAN     HasPoolTail;\r
  BOOLEAN     PageAsPool;\r
\r
  ASSERT_LOCKED (&mPoolMemoryLock);\r
\r
  if  (PoolType == EfiACPIReclaimMemory   ||\r
       PoolType == EfiACPIMemoryNVS       ||\r
       PoolType == EfiRuntimeServicesCode ||\r
       PoolType == EfiRuntimeServicesData) {\r
\r
    Granularity = RUNTIME_PAGE_ALLOCATION_GRANULARITY;\r
  } else {\r
    Granularity = DEFAULT_PAGE_ALLOCATION_GRANULARITY;\r
  }\r
\r
  //\r
  // Adjust the size by the pool header & tail overhead\r
  //\r
\r
  HasPoolTail  = !(NeedGuard &&\r
                   ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) == 0));\r
  PageAsPool = (IsHeapGuardEnabled (GUARD_HEAP_TYPE_FREED) && !mOnGuarding);\r
\r
  //\r
  // Adjusting the Size to be of proper alignment so that\r
  // we don't get an unaligned access fault later when\r
  // pool_Tail is being initialized\r
  //\r
  Size = ALIGN_VARIABLE (Size);\r
\r
  Size += POOL_OVERHEAD;\r
  Index = SIZE_TO_LIST(Size);\r
  Pool = LookupPoolHead (PoolType);\r
  if (Pool== NULL) {\r
    return NULL;\r
  }\r
  Head = NULL;\r
\r
  //\r
  // If allocation is over max size, just allocate pages for the request\r
  // (slow)\r
  //\r
  if (Index >= SIZE_TO_LIST (Granularity) || NeedGuard || PageAsPool) {\r
    if (!HasPoolTail) {\r
      Size -= sizeof (POOL_TAIL);\r
    }\r
    NoPages = EFI_SIZE_TO_PAGES (Size) + EFI_SIZE_TO_PAGES (Granularity) - 1;\r
    NoPages &= ~(UINTN)(EFI_SIZE_TO_PAGES (Granularity) - 1);\r
    Head = CoreAllocatePoolPagesI (PoolType, NoPages, Granularity, NeedGuard);\r
    if (NeedGuard) {\r
      Head = AdjustPoolHeadA ((EFI_PHYSICAL_ADDRESS)(UINTN)Head, NoPages, Size);\r
    }\r
    goto Done;\r
  }\r
\r
  //\r
  // If there's no free pool in the proper list size, go get some more pages\r
  //\r
  if (IsListEmpty (&Pool->FreeList[Index])) {\r
\r
    Offset = LIST_TO_SIZE (Index);\r
    MaxOffset = Granularity;\r
\r
    //\r
    // Check the bins holding larger blocks, and carve one up if needed\r
    //\r
    while (++Index < SIZE_TO_LIST (Granularity)) {\r
      if (!IsListEmpty (&Pool->FreeList[Index])) {\r
        Free = CR (Pool->FreeList[Index].ForwardLink, POOL_FREE, Link, POOL_FREE_SIGNATURE);\r
        RemoveEntryList (&Free->Link);\r
        NewPage = (VOID *) Free;\r
        MaxOffset = LIST_TO_SIZE (Index);\r
        goto Carve;\r
      }\r
    }\r
\r
    //\r
    // Get another page\r
    //\r
    NewPage = CoreAllocatePoolPagesI (PoolType, EFI_SIZE_TO_PAGES (Granularity),\r
                                      Granularity, NeedGuard);\r
    if (NewPage == NULL) {\r
      goto Done;\r
    }\r
\r
    //\r
    // Serve the allocation request from the head of the allocated block\r
    //\r
Carve:\r
    Head = (POOL_HEAD *) NewPage;\r
\r
    //\r
    // Carve up remaining space into free pool blocks\r
    //\r
    Index--;\r
    while (Offset < MaxOffset) {\r
      ASSERT (Index < MAX_POOL_LIST);\r
      FSize = LIST_TO_SIZE(Index);\r
\r
      while (Offset + FSize <= MaxOffset) {\r
        Free = (POOL_FREE *) &NewPage[Offset];\r
        Free->Signature = POOL_FREE_SIGNATURE;\r
        Free->Index     = (UINT32)Index;\r
        InsertHeadList (&Pool->FreeList[Index], &Free->Link);\r
        Offset += FSize;\r
      }\r
      Index -= 1;\r
    }\r
\r
    ASSERT (Offset == MaxOffset);\r
    goto Done;\r
  }\r
\r
  //\r
  // Remove entry from free pool list\r
  //\r
  Free = CR (Pool->FreeList[Index].ForwardLink, POOL_FREE, Link, POOL_FREE_SIGNATURE);\r
  RemoveEntryList (&Free->Link);\r
\r
  Head = (POOL_HEAD *) Free;\r
\r
Done:\r
  Buffer = NULL;\r
\r
  if (Head != NULL) {\r
\r
    //\r
    // Account the allocation\r
    //\r
    Pool->Used += Size;\r
\r
    //\r
    // If we have a pool buffer, fill in the header & tail info\r
    //\r
    Head->Signature = (PageAsPool) ? POOLPAGE_HEAD_SIGNATURE : POOL_HEAD_SIGNATURE;\r
    Head->Size      = Size;\r
    Head->Type      = (EFI_MEMORY_TYPE) PoolType;\r
    Buffer          = Head->Data;\r
\r
    if (HasPoolTail) {\r
      Tail            = HEAD_TO_TAIL (Head);\r
      Tail->Signature = POOL_TAIL_SIGNATURE;\r
      Tail->Size      = Size;\r
\r
      Size -= POOL_OVERHEAD;\r
    } else {\r
      Size -= SIZE_OF_POOL_HEAD;\r
    }\r
\r
    DEBUG_CLEAR_MEMORY (Buffer, Size);\r
\r
    DEBUG ((\r
      DEBUG_POOL,\r
      "AllocatePoolI: Type %x, Addr %p (len %lx) %,ld\n", PoolType,\r
      Buffer,\r
      (UINT64)Size,\r
      (UINT64) Pool->Used\r
      ));\r
\r
\r
  } else {\r
    DEBUG ((DEBUG_ERROR | DEBUG_POOL, "AllocatePool: failed to allocate %ld bytes\n", (UINT64) Size));\r
  }\r
\r
  return Buffer;\r
}\r
\r
\r
\r
/**\r
  Frees pool.\r
\r
  @param  Buffer                 The allocated pool entry to free\r
  @param  PoolType               Pointer to pool type\r
\r
  @retval EFI_INVALID_PARAMETER  Buffer is not a valid value.\r
  @retval EFI_SUCCESS            Pool successfully freed.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
CoreInternalFreePool (\r
  IN VOID               *Buffer,\r
  OUT EFI_MEMORY_TYPE   *PoolType OPTIONAL\r
  )\r
{\r
  EFI_STATUS Status;\r
\r
  if (Buffer == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  CoreAcquireLock (&mPoolMemoryLock);\r
  Status = CoreFreePoolI (Buffer, PoolType);\r
  CoreReleaseLock (&mPoolMemoryLock);\r
  return Status;\r
}\r
\r
/**\r
  Frees pool.\r
\r
  @param  Buffer                 The allocated pool entry to free\r
\r
  @retval EFI_INVALID_PARAMETER  Buffer is not a valid value.\r
  @retval EFI_SUCCESS            Pool successfully freed.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
CoreFreePool (\r
  IN VOID  *Buffer\r
  )\r
{\r
  EFI_STATUS        Status;\r
  EFI_MEMORY_TYPE   PoolType;\r
\r
  Status = CoreInternalFreePool (Buffer, &PoolType);\r
  if (!EFI_ERROR (Status)) {\r
    CoreUpdateProfile (\r
      (EFI_PHYSICAL_ADDRESS) (UINTN) RETURN_ADDRESS (0),\r
      MemoryProfileActionFreePool,\r
      PoolType,\r
      0,\r
      Buffer,\r
      NULL\r
      );\r
    InstallMemoryAttributesTableOnMemoryAllocation (PoolType);\r
  }\r
  return Status;\r
}\r
\r
/**\r
  Internal function.  Frees pool pages allocated via CoreAllocatePoolPagesI().\r
\r
  @param  PoolType               The type of memory for the pool pages\r
  @param  Memory                 The base address to free\r
  @param  NoPages                The number of pages to free\r
\r
**/\r
STATIC\r
VOID\r
CoreFreePoolPagesI (\r
  IN EFI_MEMORY_TYPE        PoolType,\r
  IN EFI_PHYSICAL_ADDRESS   Memory,\r
  IN UINTN                  NoPages\r
  )\r
{\r
  CoreAcquireMemoryLock ();\r
  CoreFreePoolPages (Memory, NoPages);\r
  CoreReleaseMemoryLock ();\r
\r
  GuardFreedPagesChecked (Memory, NoPages);\r
  ApplyMemoryProtectionPolicy (PoolType, EfiConventionalMemory,\r
    (EFI_PHYSICAL_ADDRESS)(UINTN)Memory, EFI_PAGES_TO_SIZE (NoPages));\r
}\r
\r
/**\r
  Internal function.  Frees guarded pool pages.\r
\r
  @param  PoolType               The type of memory for the pool pages\r
  @param  Memory                 The base address to free\r
  @param  NoPages                The number of pages to free\r
\r
**/\r
STATIC\r
VOID\r
CoreFreePoolPagesWithGuard (\r
  IN EFI_MEMORY_TYPE        PoolType,\r
  IN EFI_PHYSICAL_ADDRESS   Memory,\r
  IN UINTN                  NoPages\r
  )\r
{\r
  EFI_PHYSICAL_ADDRESS    MemoryGuarded;\r
  UINTN                   NoPagesGuarded;\r
\r
  MemoryGuarded  = Memory;\r
  NoPagesGuarded = NoPages;\r
\r
  AdjustMemoryF (&Memory, &NoPages);\r
  //\r
  // It's safe to unset Guard page inside memory lock because there should\r
  // be no memory allocation occurred in updating memory page attribute at\r
  // this point. And unsetting Guard page before free will prevent Guard\r
  // page just freed back to pool from being allocated right away before\r
  // marking it usable (from non-present to present).\r
  //\r
  UnsetGuardForMemory (MemoryGuarded, NoPagesGuarded);\r
  if (NoPages > 0) {\r
    CoreFreePoolPagesI (PoolType, Memory, NoPages);\r
  }\r
}\r
\r
/**\r
  Internal function to free a pool entry.\r
  Caller must have the memory lock held\r
\r
  @param  Buffer                 The allocated pool entry to free\r
  @param  PoolType               Pointer to pool type\r
\r
  @retval EFI_INVALID_PARAMETER  Buffer not valid\r
  @retval EFI_SUCCESS            Buffer successfully freed.\r
\r
**/\r
EFI_STATUS\r
CoreFreePoolI (\r
  IN VOID               *Buffer,\r
  OUT EFI_MEMORY_TYPE   *PoolType OPTIONAL\r
  )\r
{\r
  POOL        *Pool;\r
  POOL_HEAD   *Head;\r
  POOL_TAIL   *Tail;\r
  POOL_FREE   *Free;\r
  UINTN       Index;\r
  UINTN       NoPages;\r
  UINTN       Size;\r
  CHAR8       *NewPage;\r
  UINTN       Offset;\r
  BOOLEAN     AllFree;\r
  UINTN       Granularity;\r
  BOOLEAN     IsGuarded;\r
  BOOLEAN     HasPoolTail;\r
  BOOLEAN     PageAsPool;\r
\r
  ASSERT(Buffer != NULL);\r
  //\r
  // Get the head & tail of the pool entry\r
  //\r
  Head = BASE_CR (Buffer, POOL_HEAD, Data);\r
  ASSERT(Head != NULL);\r
\r
  if (Head->Signature != POOL_HEAD_SIGNATURE &&\r
      Head->Signature != POOLPAGE_HEAD_SIGNATURE) {\r
    ASSERT (Head->Signature == POOL_HEAD_SIGNATURE ||\r
            Head->Signature == POOLPAGE_HEAD_SIGNATURE);\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  IsGuarded   = IsPoolTypeToGuard (Head->Type) &&\r
                IsMemoryGuarded ((EFI_PHYSICAL_ADDRESS)(UINTN)Head);\r
  HasPoolTail = !(IsGuarded &&\r
                  ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) == 0));\r
  PageAsPool = (Head->Signature == POOLPAGE_HEAD_SIGNATURE);\r
\r
  if (HasPoolTail) {\r
    Tail = HEAD_TO_TAIL (Head);\r
    ASSERT (Tail != NULL);\r
\r
    //\r
    // Debug\r
    //\r
    ASSERT (Tail->Signature == POOL_TAIL_SIGNATURE);\r
    ASSERT (Head->Size == Tail->Size);\r
\r
    if (Tail->Signature != POOL_TAIL_SIGNATURE) {\r
      return EFI_INVALID_PARAMETER;\r
    }\r
\r
    if (Head->Size != Tail->Size) {\r
      return EFI_INVALID_PARAMETER;\r
    }\r
  }\r
\r
  ASSERT_LOCKED (&mPoolMemoryLock);\r
\r
  //\r
  // Determine the pool type and account for it\r
  //\r
  Size = Head->Size;\r
  Pool = LookupPoolHead (Head->Type);\r
  if (Pool == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
  Pool->Used -= Size;\r
  DEBUG ((DEBUG_POOL, "FreePool: %p (len %lx) %,ld\n", Head->Data, (UINT64)(Head->Size - POOL_OVERHEAD), (UINT64) Pool->Used));\r
\r
  if  (Head->Type == EfiACPIReclaimMemory   ||\r
       Head->Type == EfiACPIMemoryNVS       ||\r
       Head->Type == EfiRuntimeServicesCode ||\r
       Head->Type == EfiRuntimeServicesData) {\r
\r
    Granularity = RUNTIME_PAGE_ALLOCATION_GRANULARITY;\r
  } else {\r
    Granularity = DEFAULT_PAGE_ALLOCATION_GRANULARITY;\r
  }\r
\r
  if (PoolType != NULL) {\r
    *PoolType = Head->Type;\r
  }\r
\r
  //\r
  // Determine the pool list\r
  //\r
  Index = SIZE_TO_LIST(Size);\r
  DEBUG_CLEAR_MEMORY (Head, Size);\r
\r
  //\r
  // If it's not on the list, it must be pool pages\r
  //\r
  if (Index >= SIZE_TO_LIST (Granularity) || IsGuarded || PageAsPool) {\r
\r
    //\r
    // Return the memory pages back to free memory\r
    //\r
    NoPages = EFI_SIZE_TO_PAGES (Size) + EFI_SIZE_TO_PAGES (Granularity) - 1;\r
    NoPages &= ~(UINTN)(EFI_SIZE_TO_PAGES (Granularity) - 1);\r
    if (IsGuarded) {\r
      Head = AdjustPoolHeadF ((EFI_PHYSICAL_ADDRESS)(UINTN)Head);\r
      CoreFreePoolPagesWithGuard (\r
        Pool->MemoryType,\r
        (EFI_PHYSICAL_ADDRESS)(UINTN)Head,\r
        NoPages\r
        );\r
    } else {\r
      CoreFreePoolPagesI (\r
        Pool->MemoryType,\r
        (EFI_PHYSICAL_ADDRESS)(UINTN)Head,\r
        NoPages\r
        );\r
    }\r
\r
  } else {\r
\r
    //\r
    // Put the pool entry onto the free pool list\r
    //\r
    Free = (POOL_FREE *) Head;\r
    ASSERT(Free != NULL);\r
    Free->Signature = POOL_FREE_SIGNATURE;\r
    Free->Index     = (UINT32)Index;\r
    InsertHeadList (&Pool->FreeList[Index], &Free->Link);\r
\r
    //\r
    // See if all the pool entries in the same page as Free are freed pool\r
    // entries\r
    //\r
    NewPage = (CHAR8 *)((UINTN)Free & ~(Granularity - 1));\r
    Free = (POOL_FREE *) &NewPage[0];\r
    ASSERT(Free != NULL);\r
\r
    if (Free->Signature == POOL_FREE_SIGNATURE) {\r
\r
      AllFree = TRUE;\r
      Offset = 0;\r
\r
      while ((Offset < Granularity) && (AllFree)) {\r
        Free = (POOL_FREE *) &NewPage[Offset];\r
        ASSERT(Free != NULL);\r
        if (Free->Signature != POOL_FREE_SIGNATURE) {\r
          AllFree = FALSE;\r
        }\r
        Offset += LIST_TO_SIZE(Free->Index);\r
      }\r
\r
      if (AllFree) {\r
\r
        //\r
        // All of the pool entries in the same page as Free are free pool\r
        // entries\r
        // Remove all of these pool entries from the free loop lists.\r
        //\r
        Free = (POOL_FREE *) &NewPage[0];\r
        ASSERT(Free != NULL);\r
        Offset = 0;\r
\r
        while (Offset < Granularity) {\r
          Free = (POOL_FREE *) &NewPage[Offset];\r
          ASSERT(Free != NULL);\r
          RemoveEntryList (&Free->Link);\r
          Offset += LIST_TO_SIZE(Free->Index);\r
        }\r
\r
        //\r
        // Free the page\r
        //\r
        CoreFreePoolPagesI (Pool->MemoryType, (EFI_PHYSICAL_ADDRESS) (UINTN)NewPage,\r
          EFI_SIZE_TO_PAGES (Granularity));\r
      }\r
    }\r
  }\r
\r
  //\r
  // If this is an OS/OEM specific memory type, then check to see if the last\r
  // portion of that memory type has been freed.  If it has, then free the\r
  // list entry for that memory type\r
  //\r
  if (((UINT32) Pool->MemoryType >= MEMORY_TYPE_OEM_RESERVED_MIN) && Pool->Used == 0) {\r
    RemoveEntryList (&Pool->Link);\r
    CoreFreePoolI (Pool, NULL);\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r