OvmfPkg/XenBusDxe/EventChannel.c

/** @file
  Event Channel function implementation.

  Event channel are use to notify of an event that happened in a shared
  structure for example.

  Copyright (C) 2014, Citrix Ltd.

  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 "EventChannel.h"

#include <Library/XenHypercallLib.h>

UINT32
XenEventChannelNotify (
  IN XENBUS_DEVICE *Dev,
  IN evtchn_port_t Port
  )
{
  INTN ReturnCode;
  evtchn_send_t Send;

  Send.port = Port;
  ReturnCode = XenHypercallEventChannelOp (EVTCHNOP_send, &Send);
  return (UINT32)ReturnCode;
}

UINT32
EFIAPI
XenBusEventChannelAllocate (
  IN  XENBUS_PROTOCOL *This,
  IN  domid_t         DomainId,
  OUT evtchn_port_t   *Port
  )
{
  evtchn_alloc_unbound_t Parameter;
  UINT32 ReturnCode;

  Parameter.dom = DOMID_SELF;
  Parameter.remote_dom = DomainId;
  ReturnCode = (UINT32)XenHypercallEventChannelOp (
                                   EVTCHNOP_alloc_unbound,
                                   &Parameter);
  if (ReturnCode != 0) {
    DEBUG ((EFI_D_ERROR, "ERROR: alloc_unbound failed with rc=%d", ReturnCode));
    return ReturnCode;
  }
  *Port = Parameter.port;
  return ReturnCode;
}

UINT32
EFIAPI
XenBusEventChannelNotify (
  IN XENBUS_PROTOCOL *This,
  IN evtchn_port_t   Port
  )
{
  XENBUS_PRIVATE_DATA *Private;

  Private = XENBUS_PRIVATE_DATA_FROM_THIS(This);
  return XenEventChannelNotify (Private->Dev, Port);
}

UINT32
EFIAPI
XenBusEventChannelClose (
  IN XENBUS_PROTOCOL *This,
  IN evtchn_port_t   Port
  )
{
  evtchn_close_t Close;

  Close.port = Port;
  return (UINT32)XenHypercallEventChannelOp (EVTCHNOP_close, &Close);
}