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 #include "xen_drm_front_kms.h"
12 
13 #include <drm/drmP.h>
14 #include <drm/drm_atomic.h>
15 #include <drm/drm_atomic_helper.h>
16 #include <drm/drm_gem.h>
17 #include <drm/drm_gem_framebuffer_helper.h>
18 #include <drm/drm_probe_helper.h>
19 
20 #include "xen_drm_front.h"
21 #include "xen_drm_front_conn.h"
22 
23 /*
24  * Timeout in ms to wait for frame done event from the backend:
25  * must be a bit more than IO time-out
26  */
27 #define FRAME_DONE_TO_MS	(XEN_DRM_FRONT_WAIT_BACK_MS + 100)
28 
29 static struct xen_drm_front_drm_pipeline *
30 to_xen_drm_pipeline(struct drm_simple_display_pipe *pipe)
31 {
32 	return container_of(pipe, struct xen_drm_front_drm_pipeline, pipe);
33 }
34 
35 static void fb_destroy(struct drm_framebuffer *fb)
36 {
37 	struct xen_drm_front_drm_info *drm_info = fb->dev->dev_private;
38 	int idx;
39 
40 	if (drm_dev_enter(fb->dev, &idx)) {
41 		xen_drm_front_fb_detach(drm_info->front_info,
42 					xen_drm_front_fb_to_cookie(fb));
43 		drm_dev_exit(idx);
44 	}
45 	drm_gem_fb_destroy(fb);
46 }
47 
48 static struct drm_framebuffer_funcs fb_funcs = {
49 	.destroy = fb_destroy,
50 };
51 
52 static struct drm_framebuffer *
53 fb_create(struct drm_device *dev, struct drm_file *filp,
54 	  const struct drm_mode_fb_cmd2 *mode_cmd)
55 {
56 	struct xen_drm_front_drm_info *drm_info = dev->dev_private;
57 	struct drm_framebuffer *fb;
58 	struct drm_gem_object *gem_obj;
59 	int ret;
60 
61 	fb = drm_gem_fb_create_with_funcs(dev, filp, mode_cmd, &fb_funcs);
62 	if (IS_ERR_OR_NULL(fb))
63 		return fb;
64 
65 	gem_obj = drm_gem_object_lookup(filp, mode_cmd->handles[0]);
66 	if (!gem_obj) {
67 		DRM_ERROR("Failed to lookup GEM object\n");
68 		ret = -ENOENT;
69 		goto fail;
70 	}
71 
72 	drm_gem_object_put_unlocked(gem_obj);
73 
74 	ret = xen_drm_front_fb_attach(drm_info->front_info,
75 				      xen_drm_front_dbuf_to_cookie(gem_obj),
76 				      xen_drm_front_fb_to_cookie(fb),
77 				      fb->width, fb->height,
78 				      fb->format->format);
79 	if (ret < 0) {
80 		DRM_ERROR("Back failed to attach FB %p: %d\n", fb, ret);
81 		goto fail;
82 	}
83 
84 	return fb;
85 
86 fail:
87 	drm_gem_fb_destroy(fb);
88 	return ERR_PTR(ret);
89 }
90 
91 static const struct drm_mode_config_funcs mode_config_funcs = {
92 	.fb_create = fb_create,
93 	.atomic_check = drm_atomic_helper_check,
94 	.atomic_commit = drm_atomic_helper_commit,
95 };
96 
97 static void send_pending_event(struct xen_drm_front_drm_pipeline *pipeline)
98 {
99 	struct drm_crtc *crtc = &pipeline->pipe.crtc;
100 	struct drm_device *dev = crtc->dev;
101 	unsigned long flags;
102 
103 	spin_lock_irqsave(&dev->event_lock, flags);
104 	if (pipeline->pending_event)
105 		drm_crtc_send_vblank_event(crtc, pipeline->pending_event);
106 	pipeline->pending_event = NULL;
107 	spin_unlock_irqrestore(&dev->event_lock, flags);
108 }
109 
110 static void display_enable(struct drm_simple_display_pipe *pipe,
111 			   struct drm_crtc_state *crtc_state,
112 			   struct drm_plane_state *plane_state)
113 {
114 	struct xen_drm_front_drm_pipeline *pipeline =
115 			to_xen_drm_pipeline(pipe);
116 	struct drm_crtc *crtc = &pipe->crtc;
117 	struct drm_framebuffer *fb = plane_state->fb;
118 	int ret, idx;
119 
120 	if (!drm_dev_enter(pipe->crtc.dev, &idx))
121 		return;
122 
123 	ret = xen_drm_front_mode_set(pipeline, crtc->x, crtc->y,
124 				     fb->width, fb->height,
125 				     fb->format->cpp[0] * 8,
126 				     xen_drm_front_fb_to_cookie(fb));
127 
128 	if (ret) {
129 		DRM_ERROR("Failed to enable display: %d\n", ret);
130 		pipeline->conn_connected = false;
131 	}
132 
133 	drm_dev_exit(idx);
134 }
135 
136 static void display_disable(struct drm_simple_display_pipe *pipe)
137 {
138 	struct xen_drm_front_drm_pipeline *pipeline =
139 			to_xen_drm_pipeline(pipe);
140 	int ret = 0, idx;
141 
142 	if (drm_dev_enter(pipe->crtc.dev, &idx)) {
143 		ret = xen_drm_front_mode_set(pipeline, 0, 0, 0, 0, 0,
144 					     xen_drm_front_fb_to_cookie(NULL));
145 		drm_dev_exit(idx);
146 	}
147 	if (ret)
148 		DRM_ERROR("Failed to disable display: %d\n", ret);
149 
150 	/* Make sure we can restart with enabled connector next time */
151 	pipeline->conn_connected = true;
152 
153 	/* release stalled event if any */
154 	send_pending_event(pipeline);
155 }
156 
157 void xen_drm_front_kms_on_frame_done(struct xen_drm_front_drm_pipeline *pipeline,
158 				     u64 fb_cookie)
159 {
160 	/*
161 	 * This runs in interrupt context, e.g. under
162 	 * drm_info->front_info->io_lock, so we cannot call _sync version
163 	 * to cancel the work
164 	 */
165 	cancel_delayed_work(&pipeline->pflip_to_worker);
166 
167 	send_pending_event(pipeline);
168 }
169 
170 static void pflip_to_worker(struct work_struct *work)
171 {
172 	struct delayed_work *delayed_work = to_delayed_work(work);
173 	struct xen_drm_front_drm_pipeline *pipeline =
174 			container_of(delayed_work,
175 				     struct xen_drm_front_drm_pipeline,
176 				     pflip_to_worker);
177 
178 	DRM_ERROR("Frame done timed-out, releasing");
179 	send_pending_event(pipeline);
180 }
181 
182 static bool display_send_page_flip(struct drm_simple_display_pipe *pipe,
183 				   struct drm_plane_state *old_plane_state)
184 {
185 	struct drm_plane_state *plane_state =
186 			drm_atomic_get_new_plane_state(old_plane_state->state,
187 						       &pipe->plane);
188 
189 	/*
190 	 * If old_plane_state->fb is NULL and plane_state->fb is not,
191 	 * then this is an atomic commit which will enable display.
192 	 * If old_plane_state->fb is not NULL and plane_state->fb is,
193 	 * then this is an atomic commit which will disable display.
194 	 * Ignore these and do not send page flip as this framebuffer will be
195 	 * sent to the backend as a part of display_set_config call.
196 	 */
197 	if (old_plane_state->fb && plane_state->fb) {
198 		struct xen_drm_front_drm_pipeline *pipeline =
199 				to_xen_drm_pipeline(pipe);
200 		struct xen_drm_front_drm_info *drm_info = pipeline->drm_info;
201 		int ret;
202 
203 		schedule_delayed_work(&pipeline->pflip_to_worker,
204 				      msecs_to_jiffies(FRAME_DONE_TO_MS));
205 
206 		ret = xen_drm_front_page_flip(drm_info->front_info,
207 					      pipeline->index,
208 					      xen_drm_front_fb_to_cookie(plane_state->fb));
209 		if (ret) {
210 			DRM_ERROR("Failed to send page flip request to backend: %d\n", ret);
211 
212 			pipeline->conn_connected = false;
213 			/*
214 			 * Report the flip not handled, so pending event is
215 			 * sent, unblocking user-space.
216 			 */
217 			return false;
218 		}
219 		/*
220 		 * Signal that page flip was handled, pending event will be sent
221 		 * on frame done event from the backend.
222 		 */
223 		return true;
224 	}
225 
226 	return false;
227 }
228 
229 static void display_update(struct drm_simple_display_pipe *pipe,
230 			   struct drm_plane_state *old_plane_state)
231 {
232 	struct xen_drm_front_drm_pipeline *pipeline =
233 			to_xen_drm_pipeline(pipe);
234 	struct drm_crtc *crtc = &pipe->crtc;
235 	struct drm_pending_vblank_event *event;
236 	int idx;
237 
238 	event = crtc->state->event;
239 	if (event) {
240 		struct drm_device *dev = crtc->dev;
241 		unsigned long flags;
242 
243 		WARN_ON(pipeline->pending_event);
244 
245 		spin_lock_irqsave(&dev->event_lock, flags);
246 		crtc->state->event = NULL;
247 
248 		pipeline->pending_event = event;
249 		spin_unlock_irqrestore(&dev->event_lock, flags);
250 	}
251 
252 	if (!drm_dev_enter(pipe->crtc.dev, &idx)) {
253 		send_pending_event(pipeline);
254 		return;
255 	}
256 
257 	/*
258 	 * Send page flip request to the backend *after* we have event cached
259 	 * above, so on page flip done event from the backend we can
260 	 * deliver it and there is no race condition between this code and
261 	 * event from the backend.
262 	 * If this is not a page flip, e.g. no flip done event from the backend
263 	 * is expected, then send now.
264 	 */
265 	if (!display_send_page_flip(pipe, old_plane_state))
266 		send_pending_event(pipeline);
267 
268 	drm_dev_exit(idx);
269 }
270 
271 static enum drm_mode_status
272 display_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode *mode)
273 {
274 	struct xen_drm_front_drm_pipeline *pipeline =
275 			container_of(crtc, struct xen_drm_front_drm_pipeline,
276 				     pipe.crtc);
277 
278 	if (mode->hdisplay != pipeline->width)
279 		return MODE_ERROR;
280 
281 	if (mode->vdisplay != pipeline->height)
282 		return MODE_ERROR;
283 
284 	return MODE_OK;
285 }
286 
287 static const struct drm_simple_display_pipe_funcs display_funcs = {
288 	.mode_valid = display_mode_valid,
289 	.enable = display_enable,
290 	.disable = display_disable,
291 	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
292 	.update = display_update,
293 };
294 
295 static int display_pipe_init(struct xen_drm_front_drm_info *drm_info,
296 			     int index, struct xen_drm_front_cfg_connector *cfg,
297 			     struct xen_drm_front_drm_pipeline *pipeline)
298 {
299 	struct drm_device *dev = drm_info->drm_dev;
300 	const u32 *formats;
301 	int format_count;
302 	int ret;
303 
304 	pipeline->drm_info = drm_info;
305 	pipeline->index = index;
306 	pipeline->height = cfg->height;
307 	pipeline->width = cfg->width;
308 
309 	INIT_DELAYED_WORK(&pipeline->pflip_to_worker, pflip_to_worker);
310 
311 	ret = xen_drm_front_conn_init(drm_info, &pipeline->conn);
312 	if (ret)
313 		return ret;
314 
315 	formats = xen_drm_front_conn_get_formats(&format_count);
316 
317 	return drm_simple_display_pipe_init(dev, &pipeline->pipe,
318 					    &display_funcs, formats,
319 					    format_count, NULL,
320 					    &pipeline->conn);
321 }
322 
323 int xen_drm_front_kms_init(struct xen_drm_front_drm_info *drm_info)
324 {
325 	struct drm_device *dev = drm_info->drm_dev;
326 	int i, ret;
327 
328 	drm_mode_config_init(dev);
329 
330 	dev->mode_config.min_width = 0;
331 	dev->mode_config.min_height = 0;
332 	dev->mode_config.max_width = 4095;
333 	dev->mode_config.max_height = 2047;
334 	dev->mode_config.funcs = &mode_config_funcs;
335 
336 	for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) {
337 		struct xen_drm_front_cfg_connector *cfg =
338 				&drm_info->front_info->cfg.connectors[i];
339 		struct xen_drm_front_drm_pipeline *pipeline =
340 				&drm_info->pipeline[i];
341 
342 		ret = display_pipe_init(drm_info, i, cfg, pipeline);
343 		if (ret) {
344 			drm_mode_config_cleanup(dev);
345 			return ret;
346 		}
347 	}
348 
349 	drm_mode_config_reset(dev);
350 	drm_kms_helper_poll_init(dev);
351 	return 0;
352 }
353 
354 void xen_drm_front_kms_fini(struct xen_drm_front_drm_info *drm_info)
355 {
356 	int i;
357 
358 	for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) {
359 		struct xen_drm_front_drm_pipeline *pipeline =
360 				&drm_info->pipeline[i];
361 
362 		cancel_delayed_work_sync(&pipeline->pflip_to_worker);
363 
364 		send_pending_event(pipeline);
365 	}
366 }
367