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 <drm/drm_atomic.h>
12#include <drm/drm_atomic_helper.h>
13#include <drm/drm_drv.h>
14#include <drm/drm_fourcc.h>
15#include <drm/drm_framebuffer.h>
16#include <drm/drm_gem.h>
17#include <drm/drm_gem_atomic_helper.h>
18#include <drm/drm_gem_framebuffer_helper.h>
19#include <drm/drm_probe_helper.h>
20#include <drm/drm_vblank.h>
21
22#include "xen_drm_front.h"
23#include "xen_drm_front_conn.h"
24#include "xen_drm_front_kms.h"
25
26/*
27 * Timeout in ms to wait for frame done event from the backend:
28 * must be a bit more than IO time-out
29 */
30#define FRAME_DONE_TO_MS (XEN_DRM_FRONT_WAIT_BACK_MS + 100)
31
32static struct xen_drm_front_drm_pipeline *
33to_xen_drm_pipeline(struct drm_simple_display_pipe *pipe)
34{
35 return container_of(pipe, struct xen_drm_front_drm_pipeline, pipe);
36}
37
38static void fb_destroy(struct drm_framebuffer *fb)
39{
40 struct xen_drm_front_drm_info *drm_info = fb->dev->dev_private;
41 int idx;
42
43 if (drm_dev_enter(dev: fb->dev, idx: &idx)) {
44 xen_drm_front_fb_detach(front_info: drm_info->front_info,
45 fb_cookie: xen_drm_front_fb_to_cookie(fb));
46 drm_dev_exit(idx);
47 }
48 drm_gem_fb_destroy(fb);
49}
50
51static const struct drm_framebuffer_funcs fb_funcs = {
52 .destroy = fb_destroy,
53};
54
55static struct drm_framebuffer *
56fb_create(struct drm_device *dev, struct drm_file *filp,
57 const struct drm_mode_fb_cmd2 *mode_cmd)
58{
59 struct xen_drm_front_drm_info *drm_info = dev->dev_private;
60 struct drm_framebuffer *fb;
61 struct drm_gem_object *gem_obj;
62 int ret;
63
64 fb = drm_gem_fb_create_with_funcs(dev, file: filp, mode_cmd, funcs: &fb_funcs);
65 if (IS_ERR(ptr: fb))
66 return fb;
67
68 gem_obj = fb->obj[0];
69
70 ret = xen_drm_front_fb_attach(front_info: drm_info->front_info,
71 dbuf_cookie: xen_drm_front_dbuf_to_cookie(gem_obj),
72 fb_cookie: xen_drm_front_fb_to_cookie(fb),
73 width: fb->width, height: fb->height,
74 pixel_format: fb->format->format);
75 if (ret < 0) {
76 DRM_ERROR("Back failed to attach FB %p: %d\n", fb, ret);
77 goto fail;
78 }
79
80 return fb;
81
82fail:
83 drm_gem_fb_destroy(fb);
84 return ERR_PTR(error: ret);
85}
86
87static const struct drm_mode_config_funcs mode_config_funcs = {
88 .fb_create = fb_create,
89 .atomic_check = drm_atomic_helper_check,
90 .atomic_commit = drm_atomic_helper_commit,
91};
92
93static void send_pending_event(struct xen_drm_front_drm_pipeline *pipeline)
94{
95 struct drm_crtc *crtc = &pipeline->pipe.crtc;
96 struct drm_device *dev = crtc->dev;
97 unsigned long flags;
98
99 spin_lock_irqsave(&dev->event_lock, flags);
100 if (pipeline->pending_event)
101 drm_crtc_send_vblank_event(crtc, e: pipeline->pending_event);
102 pipeline->pending_event = NULL;
103 spin_unlock_irqrestore(lock: &dev->event_lock, flags);
104}
105
106static void display_enable(struct drm_simple_display_pipe *pipe,
107 struct drm_crtc_state *crtc_state,
108 struct drm_plane_state *plane_state)
109{
110 struct xen_drm_front_drm_pipeline *pipeline =
111 to_xen_drm_pipeline(pipe);
112 struct drm_crtc *crtc = &pipe->crtc;
113 struct drm_framebuffer *fb = plane_state->fb;
114 int ret, idx;
115
116 if (!drm_dev_enter(dev: pipe->crtc.dev, idx: &idx))
117 return;
118
119 ret = xen_drm_front_mode_set(pipeline, x: crtc->x, y: crtc->y,
120 width: fb->width, height: fb->height,
121 bpp: fb->format->cpp[0] * 8,
122 fb_cookie: xen_drm_front_fb_to_cookie(fb));
123
124 if (ret) {
125 DRM_ERROR("Failed to enable display: %d\n", ret);
126 pipeline->conn_connected = false;
127 }
128
129 drm_dev_exit(idx);
130}
131
132static void display_disable(struct drm_simple_display_pipe *pipe)
133{
134 struct xen_drm_front_drm_pipeline *pipeline =
135 to_xen_drm_pipeline(pipe);
136 int ret = 0, idx;
137
138 if (drm_dev_enter(dev: pipe->crtc.dev, idx: &idx)) {
139 ret = xen_drm_front_mode_set(pipeline, x: 0, y: 0, width: 0, height: 0, bpp: 0,
140 fb_cookie: xen_drm_front_fb_to_cookie(NULL));
141 drm_dev_exit(idx);
142 }
143 if (ret)
144 DRM_ERROR("Failed to disable display: %d\n", ret);
145
146 /* Make sure we can restart with enabled connector next time */
147 pipeline->conn_connected = true;
148
149 /* release stalled event if any */
150 send_pending_event(pipeline);
151}
152
153void xen_drm_front_kms_on_frame_done(struct xen_drm_front_drm_pipeline *pipeline,
154 u64 fb_cookie)
155{
156 /*
157 * This runs in interrupt context, e.g. under
158 * drm_info->front_info->io_lock, so we cannot call _sync version
159 * to cancel the work
160 */
161 cancel_delayed_work(dwork: &pipeline->pflip_to_worker);
162
163 send_pending_event(pipeline);
164}
165
166static void pflip_to_worker(struct work_struct *work)
167{
168 struct delayed_work *delayed_work = to_delayed_work(work);
169 struct xen_drm_front_drm_pipeline *pipeline =
170 container_of(delayed_work,
171 struct xen_drm_front_drm_pipeline,
172 pflip_to_worker);
173
174 DRM_ERROR("Frame done timed-out, releasing");
175 send_pending_event(pipeline);
176}
177
178static bool display_send_page_flip(struct drm_simple_display_pipe *pipe,
179 struct drm_plane_state *old_plane_state)
180{
181 struct drm_plane_state *plane_state =
182 drm_atomic_get_new_plane_state(state: old_plane_state->state,
183 plane: &pipe->plane);
184
185 /*
186 * If old_plane_state->fb is NULL and plane_state->fb is not,
187 * then this is an atomic commit which will enable display.
188 * If old_plane_state->fb is not NULL and plane_state->fb is,
189 * then this is an atomic commit which will disable display.
190 * Ignore these and do not send page flip as this framebuffer will be
191 * sent to the backend as a part of display_set_config call.
192 */
193 if (old_plane_state->fb && plane_state->fb) {
194 struct xen_drm_front_drm_pipeline *pipeline =
195 to_xen_drm_pipeline(pipe);
196 struct xen_drm_front_drm_info *drm_info = pipeline->drm_info;
197 int ret;
198
199 schedule_delayed_work(dwork: &pipeline->pflip_to_worker,
200 delay: msecs_to_jiffies(FRAME_DONE_TO_MS));
201
202 ret = xen_drm_front_page_flip(front_info: drm_info->front_info,
203 conn_idx: pipeline->index,
204 fb_cookie: xen_drm_front_fb_to_cookie(fb: plane_state->fb));
205 if (ret) {
206 DRM_ERROR("Failed to send page flip request to backend: %d\n", ret);
207
208 pipeline->conn_connected = false;
209 /*
210 * Report the flip not handled, so pending event is
211 * sent, unblocking user-space.
212 */
213 return false;
214 }
215 /*
216 * Signal that page flip was handled, pending event will be sent
217 * on frame done event from the backend.
218 */
219 return true;
220 }
221
222 return false;
223}
224
225static int display_check(struct drm_simple_display_pipe *pipe,
226 struct drm_plane_state *plane_state,
227 struct drm_crtc_state *crtc_state)
228{
229 /*
230 * Xen doesn't initialize vblanking via drm_vblank_init(), so
231 * DRM helpers assume that it doesn't handle vblanking and start
232 * sending out fake VBLANK events automatically.
233 *
234 * As xen contains it's own logic for sending out VBLANK events
235 * in send_pending_event(), disable no_vblank (i.e., the xen
236 * driver has vblanking support).
237 */
238 crtc_state->no_vblank = false;
239
240 return 0;
241}
242
243static void display_update(struct drm_simple_display_pipe *pipe,
244 struct drm_plane_state *old_plane_state)
245{
246 struct xen_drm_front_drm_pipeline *pipeline =
247 to_xen_drm_pipeline(pipe);
248 struct drm_crtc *crtc = &pipe->crtc;
249 struct drm_pending_vblank_event *event;
250 int idx;
251
252 event = crtc->state->event;
253 if (event) {
254 struct drm_device *dev = crtc->dev;
255 unsigned long flags;
256
257 WARN_ON(pipeline->pending_event);
258
259 spin_lock_irqsave(&dev->event_lock, flags);
260 crtc->state->event = NULL;
261
262 pipeline->pending_event = event;
263 spin_unlock_irqrestore(lock: &dev->event_lock, flags);
264 }
265
266 if (!drm_dev_enter(dev: pipe->crtc.dev, idx: &idx)) {
267 send_pending_event(pipeline);
268 return;
269 }
270
271 /*
272 * Send page flip request to the backend *after* we have event cached
273 * above, so on page flip done event from the backend we can
274 * deliver it and there is no race condition between this code and
275 * event from the backend.
276 * If this is not a page flip, e.g. no flip done event from the backend
277 * is expected, then send now.
278 */
279 if (!display_send_page_flip(pipe, old_plane_state))
280 send_pending_event(pipeline);
281
282 drm_dev_exit(idx);
283}
284
285static enum drm_mode_status
286display_mode_valid(struct drm_simple_display_pipe *pipe,
287 const struct drm_display_mode *mode)
288{
289 struct xen_drm_front_drm_pipeline *pipeline =
290 container_of(pipe, struct xen_drm_front_drm_pipeline,
291 pipe);
292
293 if (mode->hdisplay != pipeline->width)
294 return MODE_ERROR;
295
296 if (mode->vdisplay != pipeline->height)
297 return MODE_ERROR;
298
299 return MODE_OK;
300}
301
302static const struct drm_simple_display_pipe_funcs display_funcs = {
303 .mode_valid = display_mode_valid,
304 .enable = display_enable,
305 .disable = display_disable,
306 .check = display_check,
307 .update = display_update,
308};
309
310static int display_pipe_init(struct xen_drm_front_drm_info *drm_info,
311 int index, struct xen_drm_front_cfg_connector *cfg,
312 struct xen_drm_front_drm_pipeline *pipeline)
313{
314 struct drm_device *dev = drm_info->drm_dev;
315 const u32 *formats;
316 int format_count;
317 int ret;
318
319 pipeline->drm_info = drm_info;
320 pipeline->index = index;
321 pipeline->height = cfg->height;
322 pipeline->width = cfg->width;
323
324 INIT_DELAYED_WORK(&pipeline->pflip_to_worker, pflip_to_worker);
325
326 ret = xen_drm_front_conn_init(drm_info, connector: &pipeline->conn);
327 if (ret)
328 return ret;
329
330 formats = xen_drm_front_conn_get_formats(format_count: &format_count);
331
332 return drm_simple_display_pipe_init(dev, pipe: &pipeline->pipe,
333 funcs: &display_funcs, formats,
334 format_count, NULL,
335 connector: &pipeline->conn);
336}
337
338int xen_drm_front_kms_init(struct xen_drm_front_drm_info *drm_info)
339{
340 struct drm_device *dev = drm_info->drm_dev;
341 int i, ret;
342
343 drm_mode_config_init(dev);
344
345 dev->mode_config.min_width = 0;
346 dev->mode_config.min_height = 0;
347 dev->mode_config.max_width = 4095;
348 dev->mode_config.max_height = 2047;
349 dev->mode_config.funcs = &mode_config_funcs;
350
351 for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) {
352 struct xen_drm_front_cfg_connector *cfg =
353 &drm_info->front_info->cfg.connectors[i];
354 struct xen_drm_front_drm_pipeline *pipeline =
355 &drm_info->pipeline[i];
356
357 ret = display_pipe_init(drm_info, index: i, cfg, pipeline);
358 if (ret) {
359 drm_mode_config_cleanup(dev);
360 return ret;
361 }
362 }
363
364 drm_mode_config_reset(dev);
365 drm_kms_helper_poll_init(dev);
366 return 0;
367}
368
369void xen_drm_front_kms_fini(struct xen_drm_front_drm_info *drm_info)
370{
371 int i;
372
373 for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) {
374 struct xen_drm_front_drm_pipeline *pipeline =
375 &drm_info->pipeline[i];
376
377 cancel_delayed_work_sync(dwork: &pipeline->pflip_to_worker);
378
379 send_pending_event(pipeline);
380 }
381}
382

source code of linux/drivers/gpu/drm/xen/xen_drm_front_kms.c