compositor-drm: Add Support virtual output

Add support virtual output for streaming image to remote output by
remoting-plugin which will be added by the patch:
"Add remoting plugin for output streaming."
The gbm bo of virtual output is the linear format.

Virtual output is implemented based on a patch by Grigory Kletsko
<grigory.kletsko@cogentembedded.com>.
Signed-off-by: Tomohito Esaki <etom@igel.co.jp>

libweston/compositor-drm.c

@@ -74,6 +74,10 @@
 #define GBM_BO_USE_CURSOR GBM_BO_USE_CURSOR_64X64
 #endif
 
+#ifndef GBM_BO_USE_LINEAR
+#define GBM_BO_USE_LINEAR (1 << 4)
+#endif
+
 /**
  * A small wrapper to print information into the 'drm-backend' debug scope.
  *
@@ -547,6 +551,10 @@ struct drm_output {
 	struct wl_listener recorder_frame_listener;
 
 	struct wl_event_source *pageflip_timer;
+
+	bool virtual;
+
+	submit_frame_cb virtual_submit_frame;
 };
 
 static const char *const aspect_ratio_as_string[] = {
@@ -859,6 +867,9 @@ drm_output_update_msc(struct drm_output *output, unsigned int seq);
 static void
 drm_output_destroy(struct weston_output *output_base);
 
+static void
+drm_virtual_output_destroy(struct weston_output *output_base);
+
 /**
  * Returns true if the plane can be used on the given output for its current
  * repaint cycle.
@@ -868,6 +879,9 @@ drm_plane_is_available(struct drm_plane *plane, struct drm_output *output)
 {
 	assert(plane->state_cur);
 
+	if (output->virtual)
+		return false;
+
 	/* The plane still has a request not yet completed by the kernel. */
 	if (!plane->state_cur->complete)
 		return false;
@@ -2668,6 +2682,8 @@ drm_pending_state_apply_atomic(struct drm_pending_state *pending_state,
 	}
 
 	wl_list_for_each(output_state, &pending_state->output_list, link) {
+		if (output_state->output->virtual)
+			continue;
 		if (mode == DRM_STATE_APPLY_SYNC)
 			assert(output_state->dpms == WESTON_DPMS_OFF);
 		ret |= drm_output_apply_state_atomic(output_state, req, &flags);
@@ -2777,6 +2793,12 @@ drm_pending_state_apply(struct drm_pending_state *pending_state)
 		struct drm_output *output = output_state->output;
 		int ret;
 
+		if (output->virtual) {
+			drm_output_assign_state(output_state,
+						DRM_STATE_APPLY_ASYNC);
+			continue;
+		}
+
 		ret = drm_output_apply_state_legacy(output_state);
 		if (ret != 0) {
 			weston_log("Couldn't apply state for output %s\n",
@@ -2855,6 +2877,8 @@ drm_output_repaint(struct weston_output *output_base,
 	struct drm_output_state *state = NULL;
 	struct drm_plane_state *scanout_state;
 
+	assert(!output->virtual);
+
 	if (output->disable_pending || output->destroy_pending)
 		goto err;
 
@@ -3729,7 +3753,7 @@ drm_assign_planes(struct weston_output *output_base, void *repaint_data)
 	drm_debug(b, "\t[repaint] preparing state for output %s (%lu)\n",
 		  output_base->name, (unsigned long) output_base->id);
 
-	if (!b->sprites_are_broken) {
+	if (!b->sprites_are_broken && !output->virtual) {
 		state = drm_output_propose_state(output_base, pending_state,
 						 DRM_OUTPUT_PROPOSE_STATE_PLANES_ONLY);
 		if (!state) {
@@ -4448,6 +4472,63 @@ drm_plane_destroy(struct drm_plane *plane)
 	free(plane);
 }
 
+/**
+ * Create a drm_plane for virtual output
+ *
+ * Call drm_virtual_plane_destroy to clean up the plane.
+ *
+ * @param b DRM compositor backend
+ * @param output Output to create internal plane for
+ */
+static struct drm_plane *
+drm_virtual_plane_create(struct drm_backend *b, struct drm_output *output)
+{
+	struct drm_plane *plane;
+
+	/* num of formats is one */
+	plane = zalloc(sizeof(*plane) + sizeof(plane->formats[0]));
+	if (!plane) {
+		weston_log("%s: out of memory\n", __func__);
+		return NULL;
+	}
+
+	plane->type = WDRM_PLANE_TYPE_PRIMARY;
+	plane->backend = b;
+	plane->state_cur = drm_plane_state_alloc(NULL, plane);
+	plane->state_cur->complete = true;
+	plane->formats[0].format = output->gbm_format;
+	plane->count_formats = 1;
+	if (output->gbm_bo_flags & GBM_BO_USE_LINEAR) {
+		uint64_t *modifiers = zalloc(sizeof *modifiers);
+		if (modifiers) {
+			*modifiers = DRM_FORMAT_MOD_LINEAR;
+			plane->formats[0].modifiers = modifiers;
+			plane->formats[0].count_modifiers = 1;
+		}
+	}
+
+	weston_plane_init(&plane->base, b->compositor, 0, 0);
+	wl_list_insert(&b->plane_list, &plane->link);
+
+	return plane;
+}
+
+/**
+ * Destroy one DRM plane
+ *
+ * @param plane Plane to deallocate (will be freed)
+ */
+static void
+drm_virtual_plane_destroy(struct drm_plane *plane)
+{
+	drm_plane_state_free(plane->state_cur, true);
+	weston_plane_release(&plane->base);
+	wl_list_remove(&plane->link);
+	if (plane->formats[0].modifiers)
+		free(plane->formats[0].modifiers);
+	free(plane);
+}
+
 /**
  * Initialise sprites (overlay planes)
  *
@@ -4681,6 +4762,8 @@ drm_output_init_backlight(struct drm_output *output)
  *
  * If we are called as part of repaint, we simply set the relevant bit in
  * state and return.
+ *
+ * This function is never called on a virtual output.
  */
 static void
 drm_set_dpms(struct weston_output *output_base, enum dpms_enum level)
@@ -4691,6 +4774,8 @@ drm_set_dpms(struct weston_output *output_base, enum dpms_enum level)
 	struct drm_output_state *state;
 	int ret;
 
+	assert(!output->virtual);
+
 	if (output->state_cur->dpms == level)
 		return;
 
@@ -5591,6 +5676,9 @@ drm_output_set_mode(struct weston_output *base,
 
 	struct drm_mode *current;
 
+	if (output->virtual)
+		return -1;
+
 	if (drm_output_update_modelist_from_heads(output) < 0)
 		return -1;
 
@@ -5948,6 +6036,8 @@ drm_output_enable(struct weston_output *base)
 	drmModeRes *resources;
 	int ret;
 
+	assert(!output->virtual);
+
 	resources = drmModeGetResources(b->drm.fd);
 	if (!resources) {
 		weston_log("drmModeGetResources failed\n");
@@ -6045,6 +6135,8 @@ drm_output_destroy(struct weston_output *base)
 	struct drm_output *output = to_drm_output(base);
 	struct drm_backend *b = to_drm_backend(base->compositor);
 
+	assert(!output->virtual);
+
 	if (output->page_flip_pending || output->vblank_pending ||
 	    output->atomic_complete_pending) {
 		output->destroy_pending = 1;
@@ -6073,6 +6165,8 @@ drm_output_disable(struct weston_output *base)
 {
 	struct drm_output *output = to_drm_output(base);
 
+	assert(!output->virtual);
+
 	if (output->page_flip_pending || output->vblank_pending ||
 	    output->atomic_complete_pending) {
 		output->disable_pending = 1;
@@ -6909,12 +7003,269 @@ renderer_switch_binding(struct weston_keyboard *keyboard,
 	switch_to_gl_renderer(b);
 }
 
+static void
+drm_virtual_output_start_repaint_loop(struct weston_output *output_base)
+{
+	weston_output_finish_frame(output_base, NULL,
+				   WP_PRESENTATION_FEEDBACK_INVALID);
+}
+
+static int
+drm_virtual_output_submit_frame(struct drm_output *output,
+				struct drm_fb *fb)
+{
+	struct drm_backend *b = to_drm_backend(output->base.compositor);
+	int fd, ret;
+
+	assert(fb->num_planes == 1);
+	ret = drmPrimeHandleToFD(b->drm.fd, fb->handles[0], DRM_CLOEXEC, &fd);
+	if (ret) {
+		weston_log("drmPrimeHandleFD failed, errno=%d\n", errno);
+		return -1;
+	}
+
+	drm_fb_ref(fb);
+	ret = output->virtual_submit_frame(&output->base, fd, fb->strides[0],
+					   fb);
+	if (ret < 0) {
+		drm_fb_unref(fb);
+		close(fd);
+	}
+	return ret;
+}
+
+static int
+drm_virtual_output_repaint(struct weston_output *output_base,
+			   pixman_region32_t *damage,
+			   void *repaint_data)
+{
+	struct drm_pending_state *pending_state = repaint_data;
+	struct drm_output_state *state = NULL;
+	struct drm_output *output = to_drm_output(output_base);
+	struct drm_plane *scanout_plane = output->scanout_plane;
+	struct drm_plane_state *scanout_state;
+
+	assert(output->virtual);
+
+	if (output->disable_pending || output->destroy_pending)
+		goto err;
+
+	/* Drop frame if there isn't free buffers */
+	if (!gbm_surface_has_free_buffers(output->gbm_surface)) {
+		weston_log("%s: Drop frame!!\n", __func__);
+		return -1;
+	}
+
+	assert(!output->state_last);
+
+	/* If planes have been disabled in the core, we might not have
+	 * hit assign_planes at all, so might not have valid output state
+	 * here. */
+	state = drm_pending_state_get_output(pending_state, output);
+	if (!state)
+		state = drm_output_state_duplicate(output->state_cur,
+						   pending_state,
+						   DRM_OUTPUT_STATE_CLEAR_PLANES);
+
+	drm_output_render(state, damage);
+	scanout_state = drm_output_state_get_plane(state, scanout_plane);
+	if (!scanout_state || !scanout_state->fb)
+		goto err;
+
+	if (drm_virtual_output_submit_frame(output, scanout_state->fb) < 0)
+		goto err;
+
+	return 0;
+
+err:
+	drm_output_state_free(state);
+	return -1;
+}
+
+static void
+drm_virtual_output_deinit(struct weston_output *base)
+{
+	struct drm_output *output = to_drm_output(base);
+
+	drm_output_fini_egl(output);
+
+	drm_virtual_plane_destroy(output->scanout_plane);
+}
+
+static void
+drm_virtual_output_destroy(struct weston_output *base)
+{
+	struct drm_output *output = to_drm_output(base);
+
+	assert(output->virtual);
+
+	if (output->base.enabled)
+		drm_virtual_output_deinit(&output->base);
+
+	weston_output_release(&output->base);
+
+	drm_output_state_free(output->state_cur);
+
+	free(output);
+}
+
+static int
+drm_virtual_output_enable(struct weston_output *output_base)
+{
+	struct drm_output *output = to_drm_output(output_base);
+	struct drm_backend *b = to_drm_backend(output_base->compositor);
+
+	assert(output->virtual);
+
+	if (b->use_pixman) {
+		weston_log("Not support pixman renderer on Virtual output\n");
+		goto err;
+	}
+
+	if (!output->virtual_submit_frame) {
+		weston_log("The virtual_submit_frame hook is not set\n");
+		goto err;
+	}
+
+	output->scanout_plane = drm_virtual_plane_create(b, output);
+	if (!output->scanout_plane) {
+		weston_log("Failed to find primary plane for output %s\n",
+			   output->base.name);
+		return -1;
+	}
+
+	if (drm_output_init_egl(output, b) < 0) {
+		weston_log("Failed to init output gl state\n");
+		goto err;
+	}
+
+	output->base.start_repaint_loop = drm_virtual_output_start_repaint_loop;
+	output->base.repaint = drm_virtual_output_repaint;
+	output->base.assign_planes = drm_assign_planes;
+	output->base.set_dpms = NULL;
+	output->base.switch_mode = NULL;
+	output->base.gamma_size = 0;
+	output->base.set_gamma = NULL;
+
+	weston_compositor_stack_plane(b->compositor,
+				      &output->scanout_plane->base,
+				      &b->compositor->primary_plane);
+
+	return 0;
+err:
+	return -1;
+}
+
+static int
+drm_virtual_output_disable(struct weston_output *base)
+{
+	struct drm_output *output = to_drm_output(base);
+
+	assert(output->virtual);
+
+	if (output->base.enabled)
+		drm_virtual_output_deinit(&output->base);
+
+	return 0;
+}
+
+static struct weston_output *
+drm_virtual_output_create(struct weston_compositor *c, char *name)
+{
+	struct drm_output *output;
+
+	output = zalloc(sizeof *output);
+	if (!output)
+		return NULL;
+
+	output->virtual = true;
+	output->gbm_bo_flags = GBM_BO_USE_LINEAR | GBM_BO_USE_RENDERING;
+
+	weston_output_init(&output->base, c, name);
+
+	output->base.enable = drm_virtual_output_enable;
+	output->base.destroy = drm_virtual_output_destroy;
+	output->base.disable = drm_virtual_output_disable;
+	output->base.attach_head = NULL;
+
+	output->state_cur = drm_output_state_alloc(output, NULL);
+
+	weston_compositor_add_pending_output(&output->base, c);
+
+	return &output->base;
+}
+
+static uint32_t
+drm_virtual_output_set_gbm_format(struct weston_output *base,
+				  const char *gbm_format)
+{
+	struct drm_output *output = to_drm_output(base);
+	struct drm_backend *b = to_drm_backend(base->compositor);
+
+	if (parse_gbm_format(gbm_format, b->gbm_format, &output->gbm_format) == -1)
+		output->gbm_format = b->gbm_format;
+
+	return output->gbm_format;
+}
+
+static void
+drm_virtual_output_set_submit_frame_cb(struct weston_output *output_base,
+				       submit_frame_cb cb)
+{
+	struct drm_output *output = to_drm_output(output_base);
+
+	output->virtual_submit_frame = cb;
+}
+
+static int
+drm_virtual_output_get_fence_fd(struct weston_output *output_base)
+{
+	return gl_renderer->create_fence_fd(output_base);
+}
+
+static void
+drm_virtual_output_buffer_released(struct drm_fb *fb)
+{
+	drm_fb_unref(fb);
+}
+
+static void
+drm_virtual_output_finish_frame(struct weston_output *output_base,
+				struct timespec *stamp,
+				uint32_t presented_flags)
+{
+	struct drm_output *output = to_drm_output(output_base);
+	struct drm_plane_state *ps;
+
+	wl_list_for_each(ps, &output->state_cur->plane_list, link)
+		ps->complete = true;
+
+	drm_output_state_free(output->state_last);
+	output->state_last = NULL;
+
+	weston_output_finish_frame(&output->base, stamp, presented_flags);
+
+	/* We can't call this from frame_notify, because the output's
+	 * repaint needed flag is cleared just after that */
+	if (output->recorder)
+		weston_output_schedule_repaint(&output->base);
+}
+
 static const struct weston_drm_output_api api = {
 	drm_output_set_mode,
 	drm_output_set_gbm_format,
 	drm_output_set_seat,
 };
 
+static const struct weston_drm_virtual_output_api virt_api = {
+	drm_virtual_output_create,
+	drm_virtual_output_set_gbm_format,
+	drm_virtual_output_set_submit_frame_cb,
+	drm_virtual_output_get_fence_fd,
+	drm_virtual_output_buffer_released,
+	drm_virtual_output_finish_frame
+};
+
 static struct drm_backend *
 drm_backend_create(struct weston_compositor *compositor,
 		   struct weston_drm_backend_config *config)
@@ -7079,6 +7430,14 @@ drm_backend_create(struct weston_compositor *compositor,
 		goto err_udev_monitor;
 	}
 
+	ret = weston_plugin_api_register(compositor,
+					 WESTON_DRM_VIRTUAL_OUTPUT_API_NAME,
+					 &virt_api, sizeof(virt_api));
+	if (ret < 0) {
+		weston_log("Failed to register virtual output API.\n");
+		goto err_udev_monitor;
+	}
+
 	return b;
 
 err_udev_monitor:

libweston/compositor-drm.h

@@ -90,6 +90,79 @@ weston_drm_output_get_api(struct weston_compositor *compositor)
 	return (const struct weston_drm_output_api *)api;
 }
 
+#define WESTON_DRM_VIRTUAL_OUTPUT_API_NAME "weston_drm_virtual_output_api_v1"
+
+struct drm_fb;
+typedef int (*submit_frame_cb)(struct weston_output *output, int fd,
+			       int stride, struct drm_fb *buffer);
+
+struct weston_drm_virtual_output_api {
+	/** Create virtual output.
+	 * This is a low-level function, where the caller is expected to wrap
+	 * the weston_output function pointers as necessary to make the virtual
+	 * output useful. The caller must set up output make, model, serial,
+	 * physical size, the mode list and current mode.
+	 *
+	 * Returns output on success, NULL on failure.
+	 */
+	struct weston_output* (*create_output)(struct weston_compositor *c,
+					       char *name);
+
+	/** Set pixel format same as drm_output set_gbm_format().
+	 *
+	 * Returns the set format.
+	 */
+	uint32_t (*set_gbm_format)(struct weston_output *output,
+				   const char *gbm_format);
+
+	/** Set a callback to be called when the DRM-backend has drawn a new
+	 * frame and submits it for display.
+	 * The callback will deliver a buffer to the virtual output's the
+	 * owner and assumes the buffer is now reserved for the owner. The
+	 * callback is called in virtual output repaint function.
+	 * The caller must call buffer_released() and finish_frame().
+	 *
+	 * The callback parameters are output, FD and stride (bytes) of dmabuf,
+	 * and buffer (drm_fb) pointer.
+	 * The callback returns 0 on success, -1 on failure.
+	 *
+	 * The submit_frame_cb callback hook is responsible for closing the fd
+	 * if it returns success. One needs to call the buffer release and
+	 * finish frame functions if and only if this hook returns success.
+	 */
+	void (*set_submit_frame_cb)(struct weston_output *output,
+				    submit_frame_cb cb);
+
+	/** Get fd for renderer fence.
+	 * The returned fence signals when the renderer job has completed and
+	 * the buffer is fully drawn.
+	 *
+	 * Returns fd on success, -1 on failure.
+	 */
+	int (*get_fence_sync_fd)(struct weston_output *output);
+
+	/** Notify that the caller has finished using buffer */
+	void (*buffer_released)(struct drm_fb *fb);
+
+	/** Notify finish frame
+	 * This function allows the output repainting mechanism to advance to
+	 * the next frame.
+	 */
+	void (*finish_frame)(struct weston_output *output,
+			     struct timespec *stamp,
+			     uint32_t presented_flags);
+};
+
+static inline const struct weston_drm_virtual_output_api *
+weston_drm_virtual_output_get_api(struct weston_compositor *compositor)
+{
+	const void *api;
+	api = weston_plugin_api_get(compositor,
+				    WESTON_DRM_VIRTUAL_OUTPUT_API_NAME,
+				    sizeof(struct weston_drm_virtual_output_api));
+	return (const struct weston_drm_virtual_output_api *)api;
+}
+
 /** The backend configuration struct.
  *
  * weston_drm_backend_config contains the configuration used by a DRM