OvmfPkg/XenBusDxe/EventChannel.c

   1 /** @file
   2   Event Channel function implementation.
   3
   4   Event channel are use to notify of an event that happened in a shared
   5   structure for example.
   6
   7   Copyright (C) 2014, Citrix Ltd.
   8
   9   This program and the accompanying materials
  10   are licensed and made available under the terms and conditions of the BSD License
  11   which accompanies this distribution.  The full text of the license may be found at
  12   http://opensource.org/licenses/bsd-license.php
  13
  14   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  15   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  16
  17 **/
  18 #include "EventChannel.h"
  19
  20 #include <Library/XenHypercallLib.h>
  21
  22 UINT32
  23 XenEventChannelNotify (
  24   IN XENBUS_DEVICE *Dev,
  25   IN evtchn_port_t Port
  26   )
  27 {
  28   INTN ReturnCode;
  29   evtchn_send_t Send;
  30
  31   Send.port = Port;
  32   ReturnCode = XenHypercallEventChannelOp (EVTCHNOP_send, &Send);
  33   return (UINT32)ReturnCode;
  34 }
  35
  36 UINT32
  37 EFIAPI
  38 XenBusEventChannelAllocate (
  39   IN  XENBUS_PROTOCOL *This,
  40   IN  domid_t         DomainId,
  41   OUT evtchn_port_t   *Port
  42   )
  43 {
  44   evtchn_alloc_unbound_t Parameter;
  45   UINT32 ReturnCode;
  46
  47   Parameter.dom = DOMID_SELF;
  48   Parameter.remote_dom = DomainId;
  49   ReturnCode = (UINT32)XenHypercallEventChannelOp (
  50                                    EVTCHNOP_alloc_unbound,
  51                                    &Parameter);
  52   if (ReturnCode != 0) {
  53     DEBUG ((EFI_D_ERROR, "ERROR: alloc_unbound failed with rc=%d", ReturnCode));
  54     return ReturnCode;
  55   }
  56   *Port = Parameter.port;
  57   return ReturnCode;
  58 }
  59
  60 UINT32
  61 EFIAPI
  62 XenBusEventChannelNotify (
  63   IN XENBUS_PROTOCOL *This,
  64   IN evtchn_port_t   Port
  65   )
  66 {
  67   XENBUS_PRIVATE_DATA *Private;
  68
  69   Private = XENBUS_PRIVATE_DATA_FROM_THIS(This);
  70   return XenEventChannelNotify (Private->Dev, Port);
  71 }
  72
  73 UINT32
  74 EFIAPI
  75 XenBusEventChannelClose (
  76   IN XENBUS_PROTOCOL *This,
  77   IN evtchn_port_t   Port
  78   )
  79 {
  80   evtchn_close_t Close;
  81
  82   Close.port = Port;
  83   return (UINT32)XenHypercallEventChannelOp (EVTCHNOP_close, &Close);
  84 }