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   if (ReturnCode != 0) {
  47     DEBUG ((EFI_D_ERROR, "ERROR: alloc_unbound failed with rc=%d", ReturnCode));
  48     return ReturnCode;
  49   }
  50   *Port = Parameter.port;
  51   return ReturnCode;
  52 }
  53
  54 UINT32
  55 EFIAPI
  56 XenBusEventChannelNotify (
  57   IN XENBUS_PROTOCOL *This,
  58   IN evtchn_port_t   Port
  59   )
  60 {
  61   XENBUS_PRIVATE_DATA *Private;
  62
  63   Private = XENBUS_PRIVATE_DATA_FROM_THIS(This);
  64   return XenEventChannelNotify (Private->Dev, Port);
  65 }
  66
  67 UINT32
  68 EFIAPI
  69 XenBusEventChannelClose (
  70   IN XENBUS_PROTOCOL *This,
  71   IN evtchn_port_t   Port
  72   )
  73 {
  74   evtchn_close_t Close;
  75
  76   Close.port = Port;
  77   return (UINT32)XenHypercallEventChannelOp (EVTCHNOP_close, &Close);
  78 }