text: /** @file
  
  Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved.<BR>
  
  SPDX-License-Identifier: BSD-2-Clause-Patent
  
  **/
  
  #include "UfsBlockIoPei.h"
  
  /**
    Allocate a block of memory to be used by the buffer pool.
  
    @param  Pages          How many pages to allocate.
  
    @return The allocated memory block or NULL if failed.
  
  **/
  UFS_PEIM_MEM_BLOCK *
  UfsPeimAllocMemBlock (
    IN  UINTN  Pages
    )
  {
    UFS_PEIM_MEM_BLOCK    *Block;
    VOID                  *BufHost;
    VOID                  *Mapping;
    EFI_PHYSICAL_ADDRESS  MappedAddr;
    EFI_STATUS            Status;
    VOID                  *TempPtr;
  
    TempPtr = NULL;
    Block   = NULL;
  
    Status = PeiServicesAllocatePool (sizeof (UFS_PEIM_MEM_BLOCK), &TempPtr);
    if (EFI_ERROR (Status)) {
      return NULL;
    }
  
    ZeroMem ((VOID *)(UINTN)TempPtr, sizeof (UFS_PEIM_MEM_BLOCK));
  
    //
    // each bit in the bit array represents UFS_PEIM_MEM_UNIT
    // bytes of memory in the memory block.
    //
    ASSERT (UFS_PEIM_MEM_UNIT * 8 <= EFI_PAGE_SIZE);
  
    Block          = (UFS_PEIM_MEM_BLOCK *)(UINTN)TempPtr;
    Block->BufLen  = EFI_PAGES_TO_SIZE (Pages);
    Block->BitsLen = Block->BufLen / (UFS_PEIM_MEM_UNIT * 8);
  
    Status = PeiServicesAllocatePool (Block->BitsLen, &TempPtr);
    if (EFI_ERROR (Status)) {
      return NULL;
    }
  
    ZeroMem ((VOID *)(UINTN)TempPtr, Block->BitsLen);
  
    Block->Bits = (UINT8 *)(UINTN)TempPtr;
  
    Status = IoMmuAllocateBuffer (
               Pages,
               &BufHost,
               &MappedAddr,
               &Mapping
               );
    if (EFI_ERROR (Status)) {
      return NULL;
    }
  
    ZeroMem ((VOID *)(UINTN)BufHost, EFI_PAGES_TO_SIZE (Pages));
  
    Block->BufHost = (UINT8 *)(UINTN)BufHost;
    Block->Buf     = (UINT8 *)(UINTN)MappedAddr;
    Block->Mapping = Mapping;
    Block->Next    = NULL;
  
    return Block;
  }
  
  /**
    Free the memory block from the memory pool.
  
    @param  Pool           The memory pool to free the block from.
    @param  Block          The memory block to free.
  
  **/
  VOID
  UfsPeimFreeMemBlock (
    IN UFS_PEIM_MEM_POOL   *Pool,
    IN UFS_PEIM_MEM_BLOCK  *Block
    )
  {
    ASSERT ((Pool != NULL) && (Block != NULL));
  
    IoMmuFreeBuffer (EFI_SIZE_TO_PAGES (Block->BufLen), Block->BufHost, Block->Mapping);
  }
  
  /**
    Alloc some memory from the block.
  
    @param  Block          The memory block to allocate memory from.
    @param  Units          Number of memory units to allocate.
  
    @return The pointer to the allocated memory. If couldn't allocate the needed memory,
            the return value is NULL.
  
  **/
  VOID *
  UfsPeimAllocMemFromBlock (
    IN  UFS_PEIM_MEM_BLOCK  *Block,
    IN  UINTN               Units
    )
  {
    UINTN  Byte;
    UINT8  Bit;
    UINTN  StartByte;
    UINT8  StartBit;
    UINTN  Available;
    UINTN  Count;
  
    ASSERT ((Block != 0) && (Units != 0));
  
    StartByte = 0;
    StartBit  = 0;
    Available = 0;
  
    for (Byte = 0, Bit = 0; Byte < Block->BitsLen;) {
      //
      // If current bit is zero, the corresponding memory unit is
      // available, otherwise we need to restart our searching.
      // Available counts the consective number of zero bit.
      //
      if (!UFS_PEIM_MEM_BIT_IS_SET (Block->Bits[Byte], Bit)) {
        Available++;
  
        if (Available >= Units) {
          break;
        }
  
        UFS_PEIM_NEXT_BIT (Byte, Bit);
      } else {
        UFS_PEIM_NEXT_BIT (Byte, Bit);
  
        Available = 0;
        StartByte = Byte;
        StartBit  = Bit;
      }
    }
  
    if (Available < Units) {
      return NULL;
    }
  
    //
    // Mark the memory as allocated
    //
    Byte = StartByte;
    Bit  = StartBit;
  
    for (Count = 0; Count < Units; Count++) {
      ASSERT (!UFS_PEIM_MEM_BIT_IS_SET (Block->Bits[Byte], Bit));
  
      Block->Bits[Byte] = (UINT8)(Block->Bits[Byte] | (UINT8)UFS_PEIM_MEM_BIT (Bit));
      UFS_PEIM_NEXT_BIT (Byte, Bit);
    }
  
    return Block->Buf + (StartByte * 8 + StartBit) * UFS_PEIM_MEM_UNIT;
  }
  
  /**
    Insert the memory block to the pool's list of the blocks.
  
    @param  Head           The head of the memory pool's block list.
    @param  Block          The memory block to insert.
  
  **/
  VOID
  UfsPeimInsertMemBlockToPool (
    IN UFS_PEIM_MEM_BLOCK  *Head,
    IN UFS_PEIM_MEM_BLOCK  *Block
    )
  {
    ASSERT ((Head != NULL) && (Block != NULL));
    Block->Next = Head->Next;
    Head->Next  = Block;
  }
  
  /**
    Is the memory block empty?
  
    @param  Block   The memory block to check.
  
    @retval TRUE    The memory block is empty.
    @retval FALSE   The memory block isn't empty.
  
  **/
  BOOLEAN
  UfsPeimIsMemBlockEmpty (
    IN UFS_PEIM_MEM_BLOCK  *Block
    )
  {
    UINTN  Index;
  
    for (Index = 0; Index < Block->BitsLen; Index++) {
      if (Block->Bits[Index] != 0) {
        return FALSE;
      }
    }
  
    return TRUE;
  }
  
  /**
    Initialize the memory management pool for the host controller.
  
    @param  Private               The Ufs Peim driver private data.
  
    @retval EFI_SUCCESS           The memory pool is initialized.
    @retval Others                Fail to init the memory pool.
  
  **/
  EFI_STATUS
  UfsPeimInitMemPool (
    IN  UFS_PEIM_HC_PRIVATE_DATA  *Private
    )
  {
    UFS_PEIM_MEM_POOL  *Pool;
    EFI_STATUS         Status;
    VOID               *TempPtr;
  
    TempPtr = NULL;
    Pool    = NULL;
  
    Status = PeiServicesAllocatePool (sizeof (UFS_PEIM_MEM_POOL), &TempPtr);
    if (EFI_ERROR (Status)) {
      return EFI_OUT_OF_RESOURCES;
    }
  
    ZeroMem ((VOID *)(UINTN)TempPtr, sizeof (UFS_PEIM_MEM_POOL));
  
    Pool = (UFS_PEIM_MEM_POOL *)((UINTN)TempPtr);
  
    Pool->Head = UfsPeimAllocMemBlock (UFS_PEIM_MEM_DEFAULT_PAGES);
  
    if (Pool->Head == NULL) {
      return EFI_OUT_OF_RESOURCES;
    }
  
    Private->Pool = Pool;
    return EFI_SUCCESS;
  }
  
  /**
    Release the memory management pool.
  
    @param  Pool                  The memory pool to free.
  
    @retval EFI_DEVICE_ERROR      Fail to free the memory pool.
    @retval EFI_SUCCESS           The memory pool is freed.
  
  **/
  EFI_STATUS
  UfsPeimFreeMemPool (
    IN UFS_PEIM_MEM_POOL  *Pool
    )
  {
    UFS_PEIM_MEM_BLOCK  *Block;
  
    ASSERT (Pool->Head != NULL);
  
    //
    // Unlink all the memory blocks from the pool, then free them.
    //
    for (Block = Pool->Head->Next; Block != NULL; Block = Pool->Head->Next) {
      UfsPeimFreeMemBlock (Pool, Block);
    }
  
    UfsPeimFreeMemBlock (Pool, Pool->Head);
  
    return EFI_SUCCESS;
  }
  
  /**
    Allocate some memory from the host controller's memory pool
    which can be used to communicate with host controller.
  
    @param  Pool      The host controller's memory pool.
    @param  Size      Size of the memory to allocate.
  
    @return The allocated memory or NULL.
  
  **/
  VOID *
  UfsPeimAllocateMem (
    IN  UFS_PEIM_MEM_POOL  *Pool,
    IN  UINTN              Size
    )
  {
    UFS_PEIM_MEM_BLOCK  *Head;
    UFS_PEIM_MEM_BLOCK  *Block;
    UFS_PEIM_MEM_BLOCK  *NewBlock;
    VOID                *Mem;
    UINTN               AllocSize;
    UINTN               Pages;
  
    Mem       = NULL;
    AllocSize = UFS_PEIM_MEM_ROUND (Size);
    Head      = Pool->Head;
    ASSERT (Head != NULL);
  
    //
    // First check whether current memory blocks can satisfy the allocation.
    //
    for (Block = Head; Block != NULL; Block = Block->Next) {
      Mem = UfsPeimAllocMemFromBlock (Block, AllocSize / UFS_PEIM_MEM_UNIT);
  
      if (Mem != NULL) {
        ZeroMem (Mem, Size);
        break;
      }
    }
  
    if (Mem != NULL) {
      return Mem;
    }
  
    //
    // Create a new memory block if there is not enough memory
    // in the pool. If the allocation size is larger than the
    // default page number, just allocate a large enough memory
    // block. Otherwise allocate default pages.
    //
    if (AllocSize > EFI_PAGES_TO_SIZE (UFS_PEIM_MEM_DEFAULT_PAGES)) {
      Pages = EFI_SIZE_TO_PAGES (AllocSize) + 1;
    } else {
      Pages = UFS_PEIM_MEM_DEFAULT_PAGES;
    }
  
    NewBlock = UfsPeimAllocMemBlock (Pages);
    if (NewBlock == NULL) {
      return NULL;
    }
  
    //
    // Add the new memory block to the pool, then allocate memory from it
    //
    UfsPeimInsertMemBlockToPool (Head, NewBlock);
    Mem = UfsPeimAllocMemFromBlock (NewBlock, AllocSize / UFS_PEIM_MEM_UNIT);
  
    if (Mem != NULL) {
      ZeroMem (Mem, Size);
    }
  
    return Mem;
  }
  
  /**
    Free the allocated memory back to the memory pool.
  
    @param  Pool           The memory pool of the host controller.
    @param  Mem            The memory to free.
    @param  Size           The size of the memory to free.
  
  **/
  VOID
  UfsPeimFreeMem (
    IN UFS_PEIM_MEM_POOL  *Pool,
    IN VOID               *Mem,
    IN UINTN              Size
    )
  {
    UFS_PEIM_MEM_BLOCK  *Head;
    UFS_PEIM_MEM_BLOCK  *Block;
    UINT8               *ToFree;
    UINTN               AllocSize;
    UINTN               Byte;
    UINTN               Bit;
    UINTN               Count;
  
    Head      = Pool->Head;
    AllocSize = UFS_PEIM_MEM_ROUND (Size);
    ToFree    = (UINT8 *)Mem;
  
    for (Block = Head; Block != NULL; Block = Block->Next) {
      //
      // scan the memory block list for the memory block that
      // completely contains the memory to free.
      //
      if ((Block->Buf <= ToFree) && ((ToFree + AllocSize) <= (Block->Buf + Block->BufLen))) {
        //
        // compute the start byte and bit in the bit array
        //
        Byte = ((ToFree - Block->Buf) / UFS_PEIM_MEM_UNIT) / 8;
        Bit  = ((ToFree - Block->Buf) / UFS_PEIM_MEM_UNIT) % 8;
  
        //
        // reset associated bits in bit array
        //
        for (Count = 0; Count < (AllocSize / UFS_PEIM_MEM_UNIT); Count++) {
          ASSERT (UFS_PEIM_MEM_BIT_IS_SET (Block->Bits[Byte], Bit));
  
          Block->Bits[Byte] = (UINT8)(Block->Bits[Byte] ^ UFS_PEIM_MEM_BIT (Bit));
          UFS_PEIM_NEXT_BIT (Byte, Bit);
        }
  
        break;
      }
    }
  
    //
    // If Block == NULL, it means that the current memory isn't
    // in the host controller's pool. This is critical because
    // the caller has passed in a wrong memory point
    //
    ASSERT (Block != NULL);
  
    //
    // Release the current memory block if it is empty and not the head
    //
    if ((Block != Head) && UfsPeimIsMemBlockEmpty (Block)) {
      UfsPeimFreeMemBlock (Pool, Block);
    }
  
    return;
  }
  