/** @file

  Routine procedures for memory allocate/free.

Copyright (c) 2007 - 2016, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "Ehci.h"

/**
  Allocate a block of memory to be used by the buffer pool.

  @param  Pool           The buffer pool to allocate memory for.
  @param  Pages          How many pages to allocate.

  @return The allocated memory block or NULL if failed.

**/
USBHC_MEM_BLOCK *
UsbHcAllocMemBlock (
  IN  USBHC_MEM_POOL  *Pool,
  IN  UINTN           Pages
  )
{
  USBHC_MEM_BLOCK       *Block;
  EFI_PCI_IO_PROTOCOL   *PciIo;
  VOID                  *BufHost;
  VOID                  *Mapping;
  EFI_PHYSICAL_ADDRESS  MappedAddr;
  UINTN                 Bytes;
  EFI_STATUS            Status;

  PciIo = Pool->PciIo;

  Block = AllocateZeroPool (sizeof (USBHC_MEM_BLOCK));
  if (Block == NULL) {
    return NULL;
  }

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

  Block->BufLen  = EFI_PAGES_TO_SIZE (Pages);
  Block->BitsLen = Block->BufLen / (USBHC_MEM_UNIT * 8);
  Block->Bits    = AllocateZeroPool (Block->BitsLen);

  if (Block->Bits == NULL) {
    gBS->FreePool (Block);
    return NULL;
  }

  //
  // Allocate the number of Pages of memory, then map it for
  // bus master read and write.
  //
  Status = PciIo->AllocateBuffer (
                    PciIo,
                    AllocateAnyPages,
                    EfiBootServicesData,
                    Pages,
                    &BufHost,
                    0
                    );

  if (EFI_ERROR (Status)) {
    goto FREE_BITARRAY;
  }

  Bytes  = EFI_PAGES_TO_SIZE (Pages);
  Status = PciIo->Map (
                    PciIo,
                    EfiPciIoOperationBusMasterCommonBuffer,
                    BufHost,
                    &Bytes,
                    &MappedAddr,
                    &Mapping
                    );

  if (EFI_ERROR (Status) || (Bytes != EFI_PAGES_TO_SIZE (Pages))) {
    goto FREE_BUFFER;
  }

  //
  // Check whether the data structure used by the host controller
  // should be restricted into the same 4G
  //
  if (Pool->Check4G && (Pool->Which4G != USB_HC_HIGH_32BIT (MappedAddr))) {
    PciIo->Unmap (PciIo, Mapping);
    goto FREE_BUFFER;
  }

  Block->BufHost = BufHost;
  Block->Buf     = (UINT8 *)((UINTN)MappedAddr);
  Block->Mapping = Mapping;

  return Block;

FREE_BUFFER:
  PciIo->FreeBuffer (PciIo, Pages, BufHost);

FREE_BITARRAY:
  gBS->FreePool (Block->Bits);
  gBS->FreePool (Block);
  return NULL;
}

/**
  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
UsbHcFreeMemBlock (
  IN USBHC_MEM_POOL   *Pool,
  IN USBHC_MEM_BLOCK  *Block
  )
{
  EFI_PCI_IO_PROTOCOL  *PciIo;

  ASSERT ((Pool != NULL) && (Block != NULL));

  PciIo = Pool->PciIo;

  //
  // Unmap the common buffer then free the structures
  //
  PciIo->Unmap (PciIo, Block->Mapping);
  PciIo->FreeBuffer (PciIo, EFI_SIZE_TO_PAGES (Block->BufLen), Block->BufHost);

  gBS->FreePool (Block->Bits);
  gBS->FreePool (Block);
}

/**
  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 *
UsbHcAllocMemFromBlock (
  IN  USBHC_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 (!USB_HC_BIT_IS_SET (Block->Bits[Byte], Bit)) {
      Available++;

      if (Available >= Units) {
        break;
      }

      NEXT_BIT (Byte, Bit);
    } else {
      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 (!USB_HC_BIT_IS_SET (Block->Bits[Byte], Bit));

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

  return Block->BufHost + (StartByte * 8 + StartBit) * USBHC_MEM_UNIT;
}

/**
  Calculate the corresponding pci bus address according to the Mem parameter.

  @param  Pool           The memory pool of the host controller.
  @param  Mem            The pointer to host memory.
  @param  Size           The size of the memory region.

  @return the pci memory address
**/
EFI_PHYSICAL_ADDRESS
UsbHcGetPciAddressForHostMem (
  IN USBHC_MEM_POOL  *Pool,
  IN VOID            *Mem,
  IN UINTN           Size
  )
{
  USBHC_MEM_BLOCK       *Head;
  USBHC_MEM_BLOCK       *Block;
  UINTN                 AllocSize;
  EFI_PHYSICAL_ADDRESS  PhyAddr;
  UINTN                 Offset;

  Head      = Pool->Head;
  AllocSize = USBHC_MEM_ROUND (Size);

  if (Mem == NULL) {
    return 0;
  }

  for (Block = Head; Block != NULL; Block = Block->Next) {
    //
    // scan the memory block list for the memory block that
    // completely contains the allocated memory.
    //
    if ((Block->BufHost <= (UINT8 *)Mem) && (((UINT8 *)Mem + AllocSize) <= (Block->BufHost + Block->BufLen))) {
      break;
    }
  }

  ASSERT ((Block != NULL));

  if (Block == NULL) {
    return 0;
  }

  //
  // calculate the pci memory address for host memory address.
  //
  Offset  = (UINT8 *)Mem - Block->BufHost;
  PhyAddr = (EFI_PHYSICAL_ADDRESS)(UINTN)(Block->Buf + Offset);
  return PhyAddr;
}

/**
  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
UsbHcInsertMemBlockToPool (
  IN USBHC_MEM_BLOCK  *Head,
  IN USBHC_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
UsbHcIsMemBlockEmpty (
  IN USBHC_MEM_BLOCK  *Block
  )
{
  UINTN  Index;

  for (Index = 0; Index < Block->BitsLen; Index++) {
    if (Block->Bits[Index] != 0) {
      return FALSE;
    }
  }

  return TRUE;
}

/**
  Unlink the memory block from the pool's list.

  @param  Head           The block list head of the memory's pool.
  @param  BlockToUnlink  The memory block to unlink.

**/
VOID
UsbHcUnlinkMemBlock (
  IN USBHC_MEM_BLOCK  *Head,
  IN USBHC_MEM_BLOCK  *BlockToUnlink
  )
{
  USBHC_MEM_BLOCK  *Block;

  ASSERT ((Head != NULL) && (BlockToUnlink != NULL));

  for (Block = Head; Block != NULL; Block = Block->Next) {
    if (Block->Next == BlockToUnlink) {
      Block->Next         = BlockToUnlink->Next;
      BlockToUnlink->Next = NULL;
      break;
    }
  }
}

/**
  Initialize the memory management pool for the host controller.

  @param  PciIo                The PciIo that can be used to access the host controller.
  @param  Check4G              Whether the host controller requires allocated memory
                               from one 4G address space.
  @param  Which4G              The 4G memory area each memory allocated should be from.

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

**/
USBHC_MEM_POOL *
UsbHcInitMemPool (
  IN EFI_PCI_IO_PROTOCOL  *PciIo,
  IN BOOLEAN              Check4G,
  IN UINT32               Which4G
  )
{
  USBHC_MEM_POOL  *Pool;

  Pool = AllocatePool (sizeof (USBHC_MEM_POOL));

  if (Pool == NULL) {
    return Pool;
  }

  Pool->PciIo   = PciIo;
  Pool->Check4G = Check4G;
  Pool->Which4G = Which4G;
  Pool->Head    = UsbHcAllocMemBlock (Pool, USBHC_MEM_DEFAULT_PAGES);

  if (Pool->Head == NULL) {
    gBS->FreePool (Pool);
    Pool = NULL;
  }

  return Pool;
}

/**
  Release the memory management pool.

  @param  Pool              The USB memory pool to free.

  @retval EFI_SUCCESS       The memory pool is freed.
  @retval EFI_DEVICE_ERROR  Failed to free the memory pool.

**/
EFI_STATUS
UsbHcFreeMemPool (
  IN USBHC_MEM_POOL  *Pool
  )
{
  USBHC_MEM_BLOCK  *Block;

  ASSERT (Pool->Head != NULL);

  //
  // Unlink all the memory blocks from the pool, then free them.
  // UsbHcUnlinkMemBlock can't be used to unlink and free the
  // first block.
  //
  for (Block = Pool->Head->Next; Block != NULL; Block = Pool->Head->Next) {
    UsbHcUnlinkMemBlock (Pool->Head, Block);
    UsbHcFreeMemBlock (Pool, Block);
  }

  UsbHcFreeMemBlock (Pool, Pool->Head);
  gBS->FreePool (Pool);
  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 *
UsbHcAllocateMem (
  IN  USBHC_MEM_POOL  *Pool,
  IN  UINTN           Size
  )
{
  USBHC_MEM_BLOCK  *Head;
  USBHC_MEM_BLOCK  *Block;
  USBHC_MEM_BLOCK  *NewBlock;
  VOID             *Mem;
  UINTN            AllocSize;
  UINTN            Pages;

  Mem       = NULL;
  AllocSize = USBHC_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 = UsbHcAllocMemFromBlock (Block, AllocSize / USBHC_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 (USBHC_MEM_DEFAULT_PAGES)) {
    Pages = EFI_SIZE_TO_PAGES (AllocSize) + 1;
  } else {
    Pages = USBHC_MEM_DEFAULT_PAGES;
  }

  NewBlock = UsbHcAllocMemBlock (Pool, Pages);

  if (NewBlock == NULL) {
    DEBUG ((DEBUG_ERROR, "UsbHcAllocateMem: failed to allocate block\n"));
    return NULL;
  }

  //
  // Add the new memory block to the pool, then allocate memory from it
  //
  UsbHcInsertMemBlockToPool (Head, NewBlock);
  Mem = UsbHcAllocMemFromBlock (NewBlock, AllocSize / USBHC_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
UsbHcFreeMem (
  IN USBHC_MEM_POOL  *Pool,
  IN VOID            *Mem,
  IN UINTN           Size
  )
{
  USBHC_MEM_BLOCK  *Head;
  USBHC_MEM_BLOCK  *Block;
  UINT8            *ToFree;
  UINTN            AllocSize;
  UINTN            Byte;
  UINTN            Bit;
  UINTN            Count;

  Head      = Pool->Head;
  AllocSize = USBHC_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->BufHost <= ToFree) && ((ToFree + AllocSize) <= (Block->BufHost + Block->BufLen))) {
      //
      // compute the start byte and bit in the bit array
      //
      Byte = ((ToFree - Block->BufHost) / USBHC_MEM_UNIT) / 8;
      Bit  = ((ToFree - Block->BufHost) / USBHC_MEM_UNIT) % 8;

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

        Block->Bits[Byte] = (UINT8)(Block->Bits[Byte] ^ USB_HC_BIT (Bit));
        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);

  if (Block == NULL) {
    return;
  }

  //
  // Release the current memory block if it is empty and not the head
  //
  if ((Block != Head) && UsbHcIsMemBlockEmpty (Block)) {
    UsbHcUnlinkMemBlock (Head, Block);
    UsbHcFreeMemBlock (Pool, Block);
  }

  return;
}
