source: vbox/trunk/src/VBox/Devices/EFI/Firmware/OvmfPkg/Library/LockBoxLib/LockBoxDxe.c

/** @file

  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>

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

**/

#include <Uefi.h>

#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Protocol/LockBox.h>
#include <LockBoxLib.h>

/**
  Allocate memory below 4G memory address.

  This function allocates memory below 4G memory address.

  @param  MemoryType   Memory type of memory to allocate.
  @param  Size         Size of memory to allocate.

  @return Allocated address for output.

**/
STATIC
VOID *
AllocateMemoryBelow4G (
  IN EFI_MEMORY_TYPE  MemoryType,
  IN UINTN            Size
  )
{
  UINTN                 Pages;
  EFI_PHYSICAL_ADDRESS  Address;
  EFI_STATUS            Status;
  VOID                  *Buffer;
  UINTN                 AllocRemaining;

  Pages   = EFI_SIZE_TO_PAGES (Size);
  Address = 0xffffffff;

  //
  // Since we need to use gBS->AllocatePages to get a buffer below
  // 4GB, there is a good chance that space will be wasted for very
  // small allocation. We keep track of unused portions of the page
  // allocations, and use these to allocate memory for small buffers.
  //
  ASSERT (mLockBoxGlobal->Signature == LOCK_BOX_GLOBAL_SIGNATURE);
  if ((UINTN)mLockBoxGlobal->SubPageRemaining >= Size) {
    Buffer                            = (VOID *)(UINTN)mLockBoxGlobal->SubPageBuffer;
    mLockBoxGlobal->SubPageBuffer    += (UINT32)Size;
    mLockBoxGlobal->SubPageRemaining -= (UINT32)Size;
    return Buffer;
  }

  Status = gBS->AllocatePages (
                  AllocateMaxAddress,
                  MemoryType,
                  Pages,
                  &Address
                  );
  if (EFI_ERROR (Status)) {
    return NULL;
  }

  Buffer = (VOID *)(UINTN)Address;
  ZeroMem (Buffer, EFI_PAGES_TO_SIZE (Pages));

  AllocRemaining = EFI_PAGES_TO_SIZE (Pages) - Size;
  if (AllocRemaining > (UINTN)mLockBoxGlobal->SubPageRemaining) {
    mLockBoxGlobal->SubPageBuffer    = (UINT32)(Address + Size);
    mLockBoxGlobal->SubPageRemaining = (UINT32)AllocRemaining;
  }

  return Buffer;
}

/**
  Allocates a buffer of type EfiACPIMemoryNVS.

  Allocates the number bytes specified by AllocationSize of type
  EfiACPIMemoryNVS and returns a pointer to the allocated buffer.
  If AllocationSize is 0, then a valid buffer of 0 size is
  returned.  If there is not enough memory remaining to satisfy
  the request, then NULL is returned.

  @param  AllocationSize        The number of bytes to allocate.

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

**/
VOID *
EFIAPI
AllocateAcpiNvsPool (
  IN UINTN  AllocationSize
  )
{
  return AllocateMemoryBelow4G (EfiACPIMemoryNVS, AllocationSize);
}

EFI_STATUS
EFIAPI
LockBoxDxeLibInitialize (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS  Status;
  VOID        *Interface;

  Status = LockBoxLibInitialize ();
  if (!EFI_ERROR (Status)) {
    if (PcdGetBool (PcdAcpiS3Enable)) {
      //
      // When S3 enabled, the first driver run with this library linked will
      // have this library constructor to install LockBox protocol on the
      // ImageHandle. As other drivers may have gEfiLockBoxProtocolGuid
      // dependency, the first driver should run before them.
      //
      Status = gBS->LocateProtocol (&gEfiLockBoxProtocolGuid, NULL, &Interface);
      if (EFI_ERROR (Status)) {
        Status = gBS->InstallProtocolInterface (
                        &ImageHandle,
                        &gEfiLockBoxProtocolGuid,
                        EFI_NATIVE_INTERFACE,
                        NULL
                        );
        ASSERT_EFI_ERROR (Status);
      }
    }
  }

  return Status;
}