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   SPDX-License-Identifier: BSD-2-Clause-Patent
  10
  11 **/
  12 #include "EventChannel.h"
  13
  14 #include <Library/XenHypercallLib.h>
  15
  16 UINT32
  17 XenEventChannelNotify (
  18   IN XENBUS_DEVICE  *Dev,
  19   IN evtchn_port_t  Port
  20   )
  21 {
  22   INTN           ReturnCode;
  23   evtchn_send_t  Send;
  24
  25   Send.port  = Port;
  26   ReturnCode = XenHypercallEventChannelOp (EVTCHNOP_send, &Send);
  27   return (UINT32)ReturnCode;
  28 }
  29
  30 UINT32
  31 EFIAPI
  32 XenBusEventChannelAllocate (
  33   IN  XENBUS_PROTOCOL  *This,
  34   IN  domid_t          DomainId,
  35   OUT evtchn_port_t    *Port
  36   )
  37 {
  38   evtchn_alloc_unbound_t  Parameter;
  39   UINT32                  ReturnCode;
  40
  41   Parameter.dom        = DOMID_SELF;
  42   Parameter.remote_dom = DomainId;
  43   ReturnCode           = (UINT32)XenHypercallEventChannelOp (
  44                                    EVTCHNOP_alloc_unbound,
  45                                    &Parameter
  46                                    );
  47   if (ReturnCode != 0) {
  48     DEBUG ((DEBUG_ERROR, "ERROR: alloc_unbound failed with rc=%d", ReturnCode));
  49     return ReturnCode;
  50   }
  51
  52   *Port = Parameter.port;
  53   return ReturnCode;
  54 }
  55
  56 UINT32
  57 EFIAPI
  58 XenBusEventChannelNotify (
  59   IN XENBUS_PROTOCOL  *This,
  60   IN evtchn_port_t    Port
  61   )
  62 {
  63   XENBUS_PRIVATE_DATA  *Private;
  64
  65   Private = XENBUS_PRIVATE_DATA_FROM_THIS (This);
  66   return XenEventChannelNotify (Private->Dev, Port);
  67 }
  68
  69 UINT32
  70 EFIAPI
  71 XenBusEventChannelClose (
  72   IN XENBUS_PROTOCOL  *This,
  73   IN evtchn_port_t    Port
  74   )
  75 {
  76   evtchn_close_t  Close;
  77
  78   Close.port = Port;
  79   return (UINT32)XenHypercallEventChannelOp (EVTCHNOP_close, &Close);
  80 }