1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xen/xen_drm_front_evtchnl.h b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.h
new file mode 100644
index 000000000000..b0af6994332b
--- /dev/null
+++ b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ *  Xen para-virtual DRM device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ */
+
+#ifndef __XEN_DRM_FRONT_EVTCHNL_H_
+#define __XEN_DRM_FRONT_EVTCHNL_H_
+
+#include <linux/completion.h>
+#include <linux/types.h>
+
+#include <xen/interface/io/ring.h>
+#include <xen/interface/io/displif.h>
+
+/*
+ * All operations which are not connector oriented use this ctrl event channel,
+ * e.g. fb_attach/destroy which belong to a DRM device, not to a CRTC.
+ */
+#define GENERIC_OP_EVT_CHNL	0
+
+enum xen_drm_front_evtchnl_state {
+	EVTCHNL_STATE_DISCONNECTED,
+	EVTCHNL_STATE_CONNECTED,
+};
+
+enum xen_drm_front_evtchnl_type {
+	EVTCHNL_TYPE_REQ,
+	EVTCHNL_TYPE_EVT,
+};
+
+struct xen_drm_front_drm_info;
+
+struct xen_drm_front_evtchnl {
+	struct xen_drm_front_info *front_info;
+	int gref;
+	int port;
+	int irq;
+	int index;
+	enum xen_drm_front_evtchnl_state state;
+	enum xen_drm_front_evtchnl_type type;
+	/* either response id or incoming event id */
+	u16 evt_id;
+	/* next request id or next expected event id */
+	u16 evt_next_id;
+	union {
+		struct {
+			struct xen_displif_front_ring ring;
+			struct completion completion;
+			/* latest response status */
+			int resp_status;
+			/* serializer for backend IO: request/response */
+			struct mutex req_io_lock;
+		} req;
+		struct {
+			struct xendispl_event_page *page;
+		} evt;
+	} u;
+};
+
+struct xen_drm_front_evtchnl_pair {
+	struct xen_drm_front_evtchnl req;
+	struct xen_drm_front_evtchnl evt;
+};
+
+int xen_drm_front_evtchnl_create_all(struct xen_drm_front_info *front_info);
+
+int xen_drm_front_evtchnl_publish_all(struct xen_drm_front_info *front_info);
+
+void xen_drm_front_evtchnl_flush(struct xen_drm_front_evtchnl *evtchnl);
+
+void xen_drm_front_evtchnl_set_state(struct xen_drm_front_info *front_info,
+				     enum xen_drm_front_evtchnl_state state);
+
+void xen_drm_front_evtchnl_free_all(struct xen_drm_front_info *front_info);
+
+#endif /* __XEN_DRM_FRONT_EVTCHNL_H_ */