CloverBootloader/MdeModulePkg/Library/CommonMemoryAllocationLib/AlignedPages.c

/** @file
  Common code for the Memory Allocation Library aligned page allocation code.

  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <Base.h>
#include <Uefi/UefiBaseType.h>
#include <Uefi/UefiSpec.h>

#include <Library/MemoryAllocationLib.h>
#include <Library/MemoryAllocationLibEx.h>

#include "AlignedPages.h"

/**
  Allocates one or more 4KB pages of a certain memory type at a specified alignment.

  Allocates the number of 4KB pages specified by Pages of a certain memory type with an alignment
  specified by Alignment.  The allocated buffer is returned.  If Pages is 0, then NULL is returned.
  If there is not enough memory at the specified alignment remaining to satisfy the request, then
  NULL is returned.
  If Alignment is not a power of two and Alignment is not zero, then ASSERT().
  If Pages plus EFI_SIZE_TO_PAGES (Alignment) overflows, then ASSERT().

  @param  MemoryType            The type of memory to allocate.
  @param  Pages                 The number of 4 KB pages to allocate.
  @param  Alignment             The requested alignment of the allocation.  Must be a power of two.
                                If Alignment is zero, then byte alignment is used.

  @return A pointer to the allocated buffer or NULL if allocation fails.

**/
VOID *
InternalAllocateAlignedPages (
  IN EFI_MEMORY_TYPE  MemoryType,
  IN UINTN            Pages,
  IN UINTN            Alignment
  )
{
  EFI_STATUS           Status;
  EFI_PHYSICAL_ADDRESS Memory;

  Status = AllocateAlignedPagesEx (
             AllocateAnyPages,
             MemoryType,
             Pages,
             Alignment,
             &Memory
             );
  if (EFI_ERROR (Status)) {
    return NULL;
  }

  return (VOID *)(UINTN)Memory;
}

/**
  Frees one or more 4KB pages that were previously allocated with one of the aligned page
  allocation functions in the Memory Allocation Library.

  Frees the number of 4KB pages specified by Pages from the buffer specified by Buffer.  Buffer
  must have been allocated on a previous call to the aligned page allocation services of the Memory
  Allocation Library.  If it is not possible to free allocated pages, then this function will
  perform no actions.

  If Buffer was not allocated with an aligned page allocation function in the Memory Allocation
  Library, then ASSERT().
  If Pages is zero, then ASSERT().

  @param  Buffer                Pointer to the buffer of pages to free.
  @param  Pages                 The number of 4 KB pages to free.

**/
VOID
InternalFreeAlignedPages (
  IN VOID   *Buffer,
  IN UINTN  Pages
  )
{
  FreePages (Buffer, Pages);
}