/** @file

Copyright (c) 2016 - 2017, Intel Corporation. All rights reserved.<BR>

SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "EmmcBlockIoPei.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.

**/
EMMC_PEIM_MEM_BLOCK *
EmmcPeimAllocMemBlock (
  IN  UINTN  Pages
  )
{
  EMMC_PEIM_MEM_BLOCK   *Block;
  VOID                  *BufHost;
  VOID                  *Mapping;
  EFI_PHYSICAL_ADDRESS  MappedAddr;
  EFI_STATUS            Status;
  VOID                  *TempPtr;

  TempPtr = NULL;
  Block   = NULL;

  Status = PeiServicesAllocatePool (sizeof (EMMC_PEIM_MEM_BLOCK), &TempPtr);
  if (EFI_ERROR (Status)) {
    return NULL;
  }

  ZeroMem ((VOID *)(UINTN)TempPtr, sizeof (EMMC_PEIM_MEM_BLOCK));

  //
  // each bit in the bit array represents EMMC_PEIM_MEM_UNIT
  // bytes of memory in the memory block.
  //
  ASSERT (EMMC_PEIM_MEM_UNIT * 8 <= EFI_PAGE_SIZE);

  Block          = (EMMC_PEIM_MEM_BLOCK *)(UINTN)TempPtr;
  Block->BufLen  = EFI_PAGES_TO_SIZE (Pages);
  Block->BitsLen = Block->BufLen / (EMMC_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
EmmcPeimFreeMemBlock (
  IN EMMC_PEIM_MEM_POOL   *Pool,
  IN EMMC_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 *
EmmcPeimAllocMemFromBlock (
  IN  EMMC_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 consecutive number of zero bit.
    //
    if (!EMMC_PEIM_MEM_BIT_IS_SET (Block->Bits[Byte], Bit)) {
      Available++;

      if (Available >= Units) {
        break;
      }

      EMMC_PEIM_NEXT_BIT (Byte, Bit);
    } else {
      EMMC_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 (!EMMC_PEIM_MEM_BIT_IS_SET (Block->Bits[Byte], Bit));

    Block->Bits[Byte] = (UINT8)(Block->Bits[Byte] | (UINT8)EMMC_PEIM_MEM_BIT (Bit));
    EMMC_PEIM_NEXT_BIT (Byte, Bit);
  }

  return Block->Buf + (StartByte * 8 + StartBit) * EMMC_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
EmmcPeimInsertMemBlockToPool (
  IN EMMC_PEIM_MEM_BLOCK  *Head,
  IN EMMC_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
EmmcPeimIsMemBlockEmpty (
  IN EMMC_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 Emmc Peim driver private data.

  @retval EFI_SUCCESS           The memory pool is initialized.
  @retval Others                Fail to init the memory pool.

**/
EFI_STATUS
EmmcPeimInitMemPool (
  IN  EMMC_PEIM_HC_PRIVATE_DATA  *Private
  )
{
  EMMC_PEIM_MEM_POOL  *Pool;
  EFI_STATUS          Status;
  VOID                *TempPtr;

  TempPtr = NULL;
  Pool    = NULL;

  Status = PeiServicesAllocatePool (sizeof (EMMC_PEIM_MEM_POOL), &TempPtr);
  if (EFI_ERROR (Status)) {
    return EFI_OUT_OF_RESOURCES;
  }

  ZeroMem ((VOID *)(UINTN)TempPtr, sizeof (EMMC_PEIM_MEM_POOL));

  Pool = (EMMC_PEIM_MEM_POOL *)((UINTN)TempPtr);

  Pool->Head = EmmcPeimAllocMemBlock (EMMC_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
EmmcPeimFreeMemPool (
  IN EMMC_PEIM_MEM_POOL  *Pool
  )
{
  EMMC_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) {
    EmmcPeimFreeMemBlock (Pool, Block);
  }

  EmmcPeimFreeMemBlock (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 *
EmmcPeimAllocateMem (
  IN  EMMC_PEIM_MEM_POOL  *Pool,
  IN  UINTN               Size
  )
{
  EMMC_PEIM_MEM_BLOCK  *Head;
  EMMC_PEIM_MEM_BLOCK  *Block;
  EMMC_PEIM_MEM_BLOCK  *NewBlock;
  VOID                 *Mem;
  UINTN                AllocSize;
  UINTN                Pages;

  Mem       = NULL;
  AllocSize = EMMC_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 = EmmcPeimAllocMemFromBlock (Block, AllocSize / EMMC_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 (EMMC_PEIM_MEM_DEFAULT_PAGES)) {
    Pages = EFI_SIZE_TO_PAGES (AllocSize) + 1;
  } else {
    Pages = EMMC_PEIM_MEM_DEFAULT_PAGES;
  }

  NewBlock = EmmcPeimAllocMemBlock (Pages);
  if (NewBlock == NULL) {
    return NULL;
  }

  //
  // Add the new memory block to the pool, then allocate memory from it
  //
  EmmcPeimInsertMemBlockToPool (Head, NewBlock);
  Mem = EmmcPeimAllocMemFromBlock (NewBlock, AllocSize / EMMC_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
EmmcPeimFreeMem (
  IN EMMC_PEIM_MEM_POOL  *Pool,
  IN VOID                *Mem,
  IN UINTN               Size
  )
{
  EMMC_PEIM_MEM_BLOCK  *Head;
  EMMC_PEIM_MEM_BLOCK  *Block;
  UINT8                *ToFree;
  UINTN                AllocSize;
  UINTN                Byte;
  UINTN                Bit;
  UINTN                Count;

  Head      = Pool->Head;
  AllocSize = EMMC_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) / EMMC_PEIM_MEM_UNIT) / 8;
      Bit  = ((ToFree - Block->Buf) / EMMC_PEIM_MEM_UNIT) % 8;

      //
      // reset associated bits in bit array
      //
      for (Count = 0; Count < (AllocSize / EMMC_PEIM_MEM_UNIT); Count++) {
        ASSERT (EMMC_PEIM_MEM_BIT_IS_SET (Block->Bits[Byte], Bit));

        Block->Bits[Byte] = (UINT8)(Block->Bits[Byte] ^ EMMC_PEIM_MEM_BIT (Bit));
        EMMC_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) && EmmcPeimIsMemBlockEmpty (Block)) {
    EmmcPeimFreeMemBlock (Pool, Block);
  }

  return;
}
