pool.c

来自「EFI BIOS是Intel提出的下一代的BIOS标准。这里上传的Edk源代码是」· C语言 代码 · 共 614 行

/*++

Copyright (c) 2004 - 2006, Intel Corporation                                                         
All rights reserved. This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

Module Name:

  pool.c

Abstract:

  EFI Memory pool management

Revision History

--*/

#include "imem.h"

#define POOL_FREE_SIGNATURE   EFI_SIGNATURE_32('p','f','r','0')
typedef struct {
  UINT32          Signature;
  UINT32          Index;
  EFI_LIST_ENTRY  Link;
} POOL_FREE;


#define POOL_HEAD_SIGNATURE   EFI_SIGNATURE_32('p','h','d','0')
typedef struct {
  UINT32          Signature;
  UINT32          Size;
  EFI_MEMORY_TYPE Type;
  UINTN           Reserved;
  CHAR8           Data[1];
} POOL_HEAD;

#define SIZE_OF_POOL_HEAD EFI_FIELD_OFFSET(POOL_HEAD,Data)

#define POOL_TAIL_SIGNATURE   EFI_SIGNATURE_32('p','t','a','l')
typedef struct {
  UINT32      Signature;
  UINT32      Size;
} POOL_TAIL;


#define POOL_SHIFT  7

#define POOL_OVERHEAD (SIZE_OF_POOL_HEAD + sizeof(POOL_TAIL))

#define HEAD_TO_TAIL(a)   \
  ((POOL_TAIL *) (((CHAR8 *) (a)) + (a)->Size - sizeof(POOL_TAIL)));


#define SIZE_TO_LIST(a)   ((a) >> POOL_SHIFT)
#define LIST_TO_SIZE(a)   ((a+1) << POOL_SHIFT)

#define MAX_POOL_LIST       SIZE_TO_LIST(DEFAULT_PAGE_ALLOCATION)
#define MAX_POOL_SIZE       (EFI_MAX_ADDRESS - POOL_OVERHEAD)

//
// Globals
//

#define POOL_SIGNATURE  EFI_SIGNATURE_32('p','l','s','t')
typedef struct {
    INTN             Signature;
    UINTN            Used;
    EFI_MEMORY_TYPE  MemoryType;
    EFI_LIST_ENTRY   FreeList[MAX_POOL_LIST];
    EFI_LIST_ENTRY   Link;
} POOL; 


POOL            PoolHead[EfiMaxMemoryType];
EFI_LIST_ENTRY  PoolHeadList;

//
//
//

VOID
CoreInitializePool (
  VOID
  )
/*++

Routine Description:

  Called to initialize the pool.

Arguments:

  None

Returns:

  None

--*/
{
  UINTN  Type;
  UINTN  Index;

  for (Type=0; Type < EfiMaxMemoryType; Type++) {
    PoolHead[Type].Signature  = 0;
    PoolHead[Type].Used       = 0;
    PoolHead[Type].MemoryType = Type;
    for (Index=0; Index < MAX_POOL_LIST; Index++) {
        InitializeListHead (&PoolHead[Type].FreeList[Index]);
    }
  }
  InitializeListHead (&PoolHeadList);
}


POOL *
LookupPoolHead (
  IN EFI_MEMORY_TYPE  MemoryType
  )
/*++

Routine Description:

  Look up pool head for specified memory type.

Arguments:

  MemoryType      - Memory type of which pool head is looked for

Returns:

  Pointer of Corresponding pool head.

--*/
{
  EFI_LIST_ENTRY  *Link;
  POOL            *Pool;
  UINTN           Index;

  if (MemoryType >= 0 && MemoryType < EfiMaxMemoryType) {
    return &PoolHead[MemoryType];
  }

  if (MemoryType < 0) {

    for (Link = PoolHeadList.ForwardLink; Link != &PoolHeadList; Link = Link->ForwardLink) {
      Pool = CR(Link, POOL, Link, POOL_SIGNATURE);
      if (Pool->MemoryType == MemoryType) {
        return Pool;
      }
    }

    Pool = CoreAllocatePoolI (EfiBootServicesData, sizeof (POOL));
    if (Pool == NULL) {
      return NULL;
    }

    Pool->Signature = POOL_SIGNATURE;
    Pool->Used      = 0;
    Pool->MemoryType = MemoryType;
    for (Index=0; Index < MAX_POOL_LIST; Index++) {
      InitializeListHead (&Pool->FreeList[Index]);
    }

    InsertHeadList (&PoolHeadList, &Pool->Link);

    return Pool;
  }

  return NULL;
}

 
EFI_BOOTSERVICE
EFI_STATUS
EFIAPI
CoreAllocatePool (
  IN EFI_MEMORY_TYPE  PoolType,
  IN UINTN            Size,
  OUT VOID            **Buffer
  )
/*++

Routine Description:

  Allocate pool of a particular type.

Arguments:

  PoolType    - Type of pool to allocate

  Size        - The amount of pool to allocate

  Buffer      - The address to return a pointer to the allocated pool

Returns:

  EFI_INVALID_PARAMETER     - PoolType not valid
  
  EFI_OUT_OF_RESOURCES      - Size exceeds max pool size or allocation failed.  
  
  EFI_SUCCESS               - Pool successfully allocated.

--*/
{
  EFI_STATUS    Status;

  //
  // If it's not a valid type, fail it
  //
  if ((PoolType >= EfiMaxMemoryType && PoolType <= 0x7fffffff) ||
       PoolType == EfiConventionalMemory) {
    return EFI_INVALID_PARAMETER;
  }
  
  *Buffer = NULL;
  //
  // As we need to reserve memory for other resources, we can't expect to allocate 
  // all memory( EFI_MAX_ADDRESS - POOL_OVERHEAD + 1) using this function, 
  // the following check operation is only used to make sure the allocated pool size will 
  // not rool over from a very large number to a very small number.
  //
  if (Size > MAX_POOL_SIZE) {
    return EFI_OUT_OF_RESOURCES;
  }

  //
  // Acquire the memory lock and make the allocation
  //
  Status = CoreAcquireLockOrFail (&gMemoryLock);
  if (EFI_ERROR (Status)) {
    return EFI_OUT_OF_RESOURCES;
  }

  *Buffer = CoreAllocatePoolI (PoolType, Size);
  CoreReleaseMemoryLock ();
  return (*Buffer != NULL) ? EFI_SUCCESS : EFI_OUT_OF_RESOURCES;
}


VOID *
CoreAllocatePoolI (
  IN EFI_MEMORY_TYPE  PoolType,
  IN UINTN            Size
  )
/*++

Routine Description:

  Internal function to allocate pool of a particular type.

  N.B. Caller must have the memory lock held


Arguments:

  PoolType    - Type of pool to allocate

  Size        - The amount of pool to allocate

Returns:

  The allocate pool, or NULL

--*/
{
  POOL        *Pool;
  POOL_FREE   *Free;
  POOL_HEAD   *Head;
  POOL_TAIL   *Tail;
  CHAR8       *NewPage;
  VOID        *Buffer;
  UINTN       Index;
  UINTN       FSize;
  UINTN       offset;
  UINTN       Adjustment;
  UINTN       NoPages;

  ASSERT_LOCKED (&gMemoryLock);

  //
  // Adjust the size by the pool header & tail overhead
  //
  
  //
  // Adjusting the Size to be of proper alignment so that
  // we don't get an unaligned access fault later when
  // pool_Tail is being initialized
  //
  ALIGN_VARIABLE (Size, Adjustment);

  Size += POOL_OVERHEAD;
  Index = SIZE_TO_LIST(Size);
  Pool = LookupPoolHead (PoolType);
  if (Pool== NULL) {
    return NULL;
  }
  Head = NULL;

  //
  // If allocation is over max size, just allocate pages for the request
  // (slow)
  //
  if (Index >= MAX_POOL_LIST) {
    NoPages = EFI_SIZE_TO_PAGES(Size) + EFI_SIZE_TO_PAGES (DEFAULT_PAGE_ALLOCATION) - 1;
    NoPages &= ~(EFI_SIZE_TO_PAGES (DEFAULT_PAGE_ALLOCATION) - 1);
    Head = CoreAllocatePoolPages (PoolType, NoPages, DEFAULT_PAGE_ALLOCATION);
    goto Done;
  }

  //
  // If there's no free pool in the proper list size, go get some more pages
  //
  if (IsListEmpty (&Pool->FreeList[Index])) {

    //
    // Get another page
    //
    NewPage = CoreAllocatePoolPages(PoolType, EFI_SIZE_TO_PAGES (DEFAULT_PAGE_ALLOCATION), DEFAULT_PAGE_ALLOCATION);
    if (NewPage == NULL) {
      goto Done;
    }

    //
    // Carve up new page into free pool blocks
    //
    offset = 0;
    while (offset < DEFAULT_PAGE_ALLOCATION) {
      ASSERT (Index < MAX_POOL_LIST);
      FSize = LIST_TO_SIZE(Index);

      while (offset + FSize <= DEFAULT_PAGE_ALLOCATION) {
        Free = (POOL_FREE *) &NewPage[offset];          
        Free->Signature = POOL_FREE_SIGNATURE;
        Free->Index     = (UINT32)Index;
        InsertHeadList (&Pool->FreeList[Index], &Free->Link);
        offset += FSize;
      }

      Index -= 1;
    }

    ASSERT (offset == DEFAULT_PAGE_ALLOCATION);
    Index = SIZE_TO_LIST(Size);
  }

  //
  // Remove entry from free pool list
  //
  Free = CR (Pool->FreeList[Index].ForwardLink, POOL_FREE, Link, POOL_FREE_SIGNATURE);
  RemoveEntryList (&Free->Link);

  Head = (POOL_HEAD *) Free;

Done:
  Buffer = NULL;

  if (Head != NULL) {
    
    //
    // If we have a pool buffer, fill in the header & tail info
    //
    Head->Signature = POOL_HEAD_SIGNATURE;
    Head->Size      = (UINT32) Size;
    Head->Type      = (EFI_MEMORY_TYPE) PoolType;
    Tail            = HEAD_TO_TAIL (Head);
    Tail->Signature = POOL_TAIL_SIGNATURE;
    Tail->Size      = (UINT32) Size;
    Buffer          = Head->Data;
    DEBUG_SET_MEMORY (Buffer, Size - POOL_OVERHEAD);

    DEBUG (
      (EFI_D_POOL,
      "AllcocatePoolI: Type %x, Addr %x (len %x) %,d\n",
       (UINTN)PoolType, 
       Buffer, 
       Size - POOL_OVERHEAD, 
      Pool->Used)
      );

    //
    // Account the allocation
    //
    Pool->Used += Size;

  } else {
    DEBUG ((EFI_D_ERROR | EFI_D_POOL, "AllocatePool: failed to allocate %d bytes\n", Size));
  }

  return Buffer;
}
  

EFI_BOOTSERVICE
EFI_STATUS
EFIAPI
CoreFreePool (
  IN VOID        *Buffer
  )
/*++

Routine Description:

  Frees pool.

Arguments:

  Buffer      - The allocated pool entry to free

Returns:

  EFI_INVALID_PARAMETER   - Buffer is not a valid value.
  
  EFI_SUCCESS             - Pool successfully freed.

--*/
{
  EFI_STATUS Status;

  if (NULL == Buffer) {
    return EFI_INVALID_PARAMETER;
  }

  CoreAcquireMemoryLock ();
  Status = CoreFreePoolI (Buffer);
  CoreReleaseMemoryLock ();
  return Status;
}


EFI_STATUS
CoreFreePoolI (
  IN VOID       *Buffer
  )
/*++

Routine Description:

  Internal function to free a pool entry.

  N.B. Caller must have the memory lock held


Arguments:

  Buffer      - The allocated pool entry to free

Returns:

  EFI_INVALID_PARAMETER     - Buffer not valid
  
  EFI_SUCCESS               - Buffer successfully freed.

--*/
{
  POOL        *Pool;
  POOL_HEAD   *Head;
  POOL_TAIL   *Tail;
  POOL_FREE   *Free;
  UINTN       Index;
  UINTN       NoPages;
  UINTN       Size;
  CHAR8       *NewPage;
  UINTN       FSize;
  UINTN       offset;
  BOOLEAN     AllFree;

  ASSERT(NULL != Buffer);
  //
  // Get the head & tail of the pool entry
  //
  Head = CR (Buffer, POOL_HEAD, Data, POOL_HEAD_SIGNATURE);
  ASSERT(NULL != Head);

  if (Head->Signature != POOL_HEAD_SIGNATURE) {
    return EFI_INVALID_PARAMETER;
  }

  Tail = HEAD_TO_TAIL (Head);
  ASSERT(NULL != Tail);

  //
  // Debug
  //
  ASSERT (Tail->Signature == POOL_TAIL_SIGNATURE);
  ASSERT (Head->Size == Tail->Size);
  ASSERT_LOCKED (&gMemoryLock);

  if (Tail->Signature != POOL_TAIL_SIGNATURE) {
    return EFI_INVALID_PARAMETER;
  }

  if (Head->Size != Tail->Size) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Determine the pool type and account for it
  //
  Size = Head->Size;
  Pool = LookupPoolHead (Head->Type);
  if (Pool == NULL) {
    return EFI_INVALID_PARAMETER;
  }
  Pool->Used -= Size;
  DEBUG ((EFI_D_POOL, "FreePool: %x (len %x) %,d\n", Head->Data, (UINTN)Head->Size - POOL_OVERHEAD, Pool->Used));

  //
  // Determine the pool list 
  //
  Index = SIZE_TO_LIST(Size);
  DEBUG_SET_MEMORY (Head, Size);

  //
  // If it's not on the list, it must be pool pages
  //
  if (Index >= MAX_POOL_LIST) {

    //
    // Return the memory pages back to free memory
    //
    NoPages = EFI_SIZE_TO_PAGES(Size) + EFI_SIZE_TO_PAGES (DEFAULT_PAGE_ALLOCATION) - 1;
    NoPages &= ~(EFI_SIZE_TO_PAGES (DEFAULT_PAGE_ALLOCATION) - 1);
    CoreFreePoolPages ((EFI_PHYSICAL_ADDRESS) (UINTN) Head, NoPages);

  } else {

    //
    // Put the pool entry onto the free pool list
    //
    Free = (POOL_FREE *) Head;
    ASSERT(NULL != Free);
    Free->Signature = POOL_FREE_SIGNATURE;
    Free->Index     = (UINT32)Index;
    InsertHeadList (&Pool->FreeList[Index], &Free->Link);

    //
    // See if all the pool entries in the same page as Free are freed pool 
    // entries
    //
    NewPage = (CHAR8 *)((UINTN)Free & ~((DEFAULT_PAGE_ALLOCATION) -1));
    Free = (POOL_FREE *) &NewPage[0];
    ASSERT(NULL != Free);

    if (Free->Signature == POOL_FREE_SIGNATURE) {

      Index = Free->Index;

      AllFree = TRUE;
      offset = 0;
      
      while ((offset < DEFAULT_PAGE_ALLOCATION) && (AllFree)) {
        FSize = LIST_TO_SIZE(Index);
        while (offset + FSize <= DEFAULT_PAGE_ALLOCATION) {
          Free = (POOL_FREE *) &NewPage[offset];
          ASSERT(NULL != Free);
          if (Free->Signature != POOL_FREE_SIGNATURE) {
            AllFree = FALSE;
          }
          offset += FSize;
        }
        Index -= 1;
      }

      if (AllFree) {

        //
        // All of the pool entries in the same page as Free are free pool 
        // entries
        // Remove all of these pool entries from the free loop lists.
        //
        Free = (POOL_FREE *) &NewPage[0];
        ASSERT(NULL != Free);
        Index = Free->Index;
        offset = 0;
        
        while (offset < DEFAULT_PAGE_ALLOCATION) {
          FSize = LIST_TO_SIZE(Index);
          while (offset + FSize <= DEFAULT_PAGE_ALLOCATION) {
            Free = (POOL_FREE *) &NewPage[offset];
            ASSERT(NULL != Free);
            RemoveEntryList (&Free->Link);
            offset += FSize;
          }
          Index -= 1;
        }

        //
        // Free the page
        //
        CoreFreePoolPages ((EFI_PHYSICAL_ADDRESS) (UINTN)NewPage, EFI_SIZE_TO_PAGES (DEFAULT_PAGE_ALLOCATION));
      }
    }
  }

  //
  // If this is an OS specific memory type, then check to see if the last 
  // portion of that memory type has been freed.  If it has, then free the
  // list entry for that memory type
  //
  if (Pool->MemoryType < 0 && Pool->Used == 0) {
    RemoveEntryList (&Pool->Link);
    CoreFreePoolI (Pool);
  }

  return EFI_SUCCESS;
}