drivers/gpu/drm/xen/xen_drm_front_evtchnl.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
   2
   3 /*
   4  *  Xen para-virtual DRM device
   5  *
   6  * Copyright (C) 2016-2018 EPAM Systems Inc.
   7  *
   8  * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
   9  */
  10
  11 #ifndef __XEN_DRM_FRONT_EVTCHNL_H_
  12 #define __XEN_DRM_FRONT_EVTCHNL_H_
  13
  14 #include <linux/completion.h>
  15 #include <linux/types.h>
  16
  17 #include <xen/interface/io/ring.h>
  18 #include <xen/interface/io/displif.h>
  19
  20 /*
  21  * All operations which are not connector oriented use this ctrl event channel,
  22  * e.g. fb_attach/destroy which belong to a DRM device, not to a CRTC.
  23  */
  24 #define GENERIC_OP_EVT_CHNL     0
  25
  26 enum xen_drm_front_evtchnl_state {
  27         EVTCHNL_STATE_DISCONNECTED,
  28         EVTCHNL_STATE_CONNECTED,
  29 };
  30
  31 enum xen_drm_front_evtchnl_type {
  32         EVTCHNL_TYPE_REQ,
  33         EVTCHNL_TYPE_EVT,
  34 };
  35
  36 struct xen_drm_front_drm_info;
  37
  38 struct xen_drm_front_evtchnl {
  39         struct xen_drm_front_info *front_info;
  40         int gref;
  41         int port;
  42         int irq;
  43         int index;
  44         enum xen_drm_front_evtchnl_state state;
  45         enum xen_drm_front_evtchnl_type type;
  46         /* either response id or incoming event id */
  47         u16 evt_id;
  48         /* next request id or next expected event id */
  49         u16 evt_next_id;
  50         union {
  51                 struct {
  52                         struct xen_displif_front_ring ring;
  53                         struct completion completion;
  54                         /* latest response status */
  55                         int resp_status;
  56                         /* serializer for backend IO: request/response */
  57                         struct mutex req_io_lock;
  58                 } req;
  59                 struct {
  60                         struct xendispl_event_page *page;
  61                 } evt;
  62         } u;
  63 };
  64
  65 struct xen_drm_front_evtchnl_pair {
  66         struct xen_drm_front_evtchnl req;
  67         struct xen_drm_front_evtchnl evt;
  68 };
  69
  70 int xen_drm_front_evtchnl_create_all(struct xen_drm_front_info *front_info);
  71
  72 int xen_drm_front_evtchnl_publish_all(struct xen_drm_front_info *front_info);
  73
  74 void xen_drm_front_evtchnl_flush(struct xen_drm_front_evtchnl *evtchnl);
  75
  76 void xen_drm_front_evtchnl_set_state(struct xen_drm_front_info *front_info,
  77                                      enum xen_drm_front_evtchnl_state state);
  78
  79 void xen_drm_front_evtchnl_free_all(struct xen_drm_front_info *front_info);
  80
  81 #endif /* __XEN_DRM_FRONT_EVTCHNL_H_ */