uefi/linaro-edk2/OvmfPkg/VirtioNetDxe/SnpStart.c

/** @file

  Implementation of the SNP.Start() function and its private helpers if any.

  Copyright (C) 2013, Red Hat, Inc.
  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>

  This program and the accompanying materials are licensed and made available
  under the terms and conditions of the BSD License which accompanies this
  distribution. The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include <Library/UefiBootServicesTableLib.h>

#include "VirtioNet.h"

/**
  Changes the state of a network interface from "stopped" to "started".

  @param  This Protocol instance pointer.

  @retval EFI_SUCCESS           The network interface was started.
  @retval EFI_ALREADY_STARTED   The network interface is already in the started
                                state.
  @retval EFI_INVALID_PARAMETER One or more of the parameters has an
                                unsupported value.
  @retval EFI_DEVICE_ERROR      The command could not be sent to the network
                                interface.
  @retval EFI_UNSUPPORTED       This function is not supported by the network
                                interface.
**/

EFI_STATUS
EFIAPI
VirtioNetStart (
  IN EFI_SIMPLE_NETWORK_PROTOCOL *This
  )
{
  VNET_DEV   *Dev;
  EFI_TPL    OldTpl;
  EFI_STATUS Status;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Dev = VIRTIO_NET_FROM_SNP (This);
  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  if (Dev->Snm.State != EfiSimpleNetworkStopped) {
    Status = EFI_ALREADY_STARTED;
  }
  else {
    Dev->Snm.State = EfiSimpleNetworkStarted;
    Status = EFI_SUCCESS;
  }

  gBS->RestoreTPL (OldTpl);
  return Status;
}