xref: /freebsd-11-stable/sys/dev/drm/drm_irq.c (revision 5d863a302bba9f5e494478ae469b583da5a65043)
1 /*-
2  * Copyright 2003 Eric Anholt
3  * All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * ERIC ANHOLT BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
20  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22  *
23  * Authors:
24  *    Eric Anholt <anholt@FreeBSD.org>
25  *
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 /** @file drm_irq.c
32  * Support code for handling setup/teardown of interrupt handlers and
33  * handing interrupt handlers off to the drivers.
34  */
35 
36 #include "dev/drm/drmP.h"
37 #include "dev/drm/drm.h"
38 
drm_irq_by_busid(struct drm_device * dev,void * data,struct drm_file * file_priv)39 int drm_irq_by_busid(struct drm_device *dev, void *data,
40 		     struct drm_file *file_priv)
41 {
42 	struct drm_irq_busid *irq = data;
43 
44 	if ((irq->busnum >> 8) != dev->pci_domain ||
45 	    (irq->busnum & 0xff) != dev->pci_bus ||
46 	    irq->devnum != dev->pci_slot ||
47 	    irq->funcnum != dev->pci_func)
48 		return EINVAL;
49 
50 	irq->irq = dev->irq;
51 
52 	DRM_DEBUG("%d:%d:%d => IRQ %d\n",
53 	    irq->busnum, irq->devnum, irq->funcnum, irq->irq);
54 
55 	return 0;
56 }
57 
58 static irqreturn_t
drm_irq_handler_wrap(DRM_IRQ_ARGS)59 drm_irq_handler_wrap(DRM_IRQ_ARGS)
60 {
61 	struct drm_device *dev = arg;
62 
63 	DRM_SPINLOCK(&dev->irq_lock);
64 	dev->driver->irq_handler(arg);
65 	DRM_SPINUNLOCK(&dev->irq_lock);
66 }
67 
vblank_disable_fn(void * arg)68 static void vblank_disable_fn(void *arg)
69 {
70 	struct drm_device *dev = (struct drm_device *)arg;
71 	int i;
72 
73 	/* Make sure that we are called with the lock held */
74 	mtx_assert(&dev->vbl_lock, MA_OWNED);
75 
76 	if (callout_pending(&dev->vblank_disable_timer)) {
77 		/* callout was reset */
78 		return;
79 	}
80 	if (!callout_active(&dev->vblank_disable_timer)) {
81 		/* callout was stopped */
82 		return;
83 	}
84 	callout_deactivate(&dev->vblank_disable_timer);
85 
86 	DRM_DEBUG("vblank_disable: %s\n", dev->vblank_disable_allowed ?
87 		"allowed" : "denied");
88 	if (!dev->vblank_disable_allowed)
89 		return;
90 
91 	for (i = 0; i < dev->num_crtcs; i++) {
92 		if (dev->vblank[i].refcount == 0 &&
93 		    dev->vblank[i].enabled && !dev->vblank[i].inmodeset) {
94 			DRM_DEBUG("disabling vblank on crtc %d\n", i);
95 			dev->vblank[i].last =
96 			    dev->driver->get_vblank_counter(dev, i);
97 			dev->driver->disable_vblank(dev, i);
98 			dev->vblank[i].enabled = 0;
99 		}
100 	}
101 }
102 
drm_vblank_cleanup(struct drm_device * dev)103 void drm_vblank_cleanup(struct drm_device *dev)
104 {
105 	/* Bail if the driver didn't call drm_vblank_init() */
106 	if (dev->num_crtcs == 0)
107 		return;
108 
109 	DRM_SPINLOCK(&dev->vbl_lock);
110 	callout_stop(&dev->vblank_disable_timer);
111 	DRM_SPINUNLOCK(&dev->vbl_lock);
112 
113 	callout_drain(&dev->vblank_disable_timer);
114 
115 	DRM_SPINLOCK(&dev->vbl_lock);
116 	vblank_disable_fn((void *)dev);
117 	DRM_SPINUNLOCK(&dev->vbl_lock);
118 
119 	free(dev->vblank, DRM_MEM_DRIVER);
120 
121 	dev->num_crtcs = 0;
122 }
123 
drm_vblank_init(struct drm_device * dev,int num_crtcs)124 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
125 {
126 	int i, ret = ENOMEM;
127 
128 	callout_init_mtx(&dev->vblank_disable_timer, &dev->vbl_lock, 0);
129 	dev->num_crtcs = num_crtcs;
130 
131 	dev->vblank = malloc(sizeof(struct drm_vblank_info) * num_crtcs,
132 	    DRM_MEM_DRIVER, M_NOWAIT | M_ZERO);
133 	if (!dev->vblank)
134 	    goto err;
135 
136 	DRM_DEBUG("\n");
137 
138 	/* Zero per-crtc vblank stuff */
139 	DRM_SPINLOCK(&dev->vbl_lock);
140 	for (i = 0; i < num_crtcs; i++) {
141 		DRM_INIT_WAITQUEUE(&dev->vblank[i].queue);
142 		dev->vblank[i].refcount = 0;
143 		atomic_store_rel_32(&dev->vblank[i].count, 0);
144 	}
145 	dev->vblank_disable_allowed = 0;
146 	DRM_SPINUNLOCK(&dev->vbl_lock);
147 
148 	return 0;
149 
150 err:
151 	drm_vblank_cleanup(dev);
152 	return ret;
153 }
154 
drm_irq_install(struct drm_device * dev)155 int drm_irq_install(struct drm_device *dev)
156 {
157 	int crtc, retcode;
158 
159 	if (dev->irq == 0 || dev->dev_private == NULL)
160 		return EINVAL;
161 
162 	DRM_DEBUG("irq=%d\n", dev->irq);
163 
164 	DRM_LOCK();
165 	if (dev->irq_enabled) {
166 		DRM_UNLOCK();
167 		return EBUSY;
168 	}
169 	dev->irq_enabled = 1;
170 
171 	dev->context_flag = 0;
172 
173 	/* Before installing handler */
174 	dev->driver->irq_preinstall(dev);
175 	DRM_UNLOCK();
176 
177 	/* Install handler */
178 	retcode = bus_setup_intr(dev->device, dev->irqr,
179 				 INTR_TYPE_TTY | INTR_MPSAFE,
180 				 NULL, drm_irq_handler_wrap, dev, &dev->irqh);
181 	if (retcode != 0)
182 		goto err;
183 
184 	/* After installing handler */
185 	DRM_LOCK();
186 	dev->driver->irq_postinstall(dev);
187 	DRM_UNLOCK();
188 	if (dev->driver->enable_vblank) {
189 		DRM_SPINLOCK(&dev->vbl_lock);
190 		for( crtc = 0 ; crtc < dev->num_crtcs ; crtc++) {
191 			if (dev->driver->enable_vblank(dev, crtc) == 0) {
192 				dev->vblank[crtc].enabled = 1;
193 			}
194 		}
195 		callout_reset(&dev->vblank_disable_timer, 5 * DRM_HZ,
196 		    (timeout_t *)vblank_disable_fn, (void *)dev);
197 		DRM_SPINUNLOCK(&dev->vbl_lock);
198 	}
199 
200 	return 0;
201 err:
202 	DRM_LOCK();
203 	dev->irq_enabled = 0;
204 	DRM_UNLOCK();
205 
206 	return retcode;
207 }
208 
drm_irq_uninstall(struct drm_device * dev)209 int drm_irq_uninstall(struct drm_device *dev)
210 {
211 	int crtc;
212 
213 	if (!dev->irq_enabled)
214 		return EINVAL;
215 
216 	dev->irq_enabled = 0;
217 
218 	/*
219 	* Wake up any waiters so they don't hang.
220 	*/
221 	DRM_SPINLOCK(&dev->vbl_lock);
222 	for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
223 		if (dev->vblank[crtc].enabled) {
224 			DRM_WAKEUP(&dev->vblank[crtc].queue);
225 			dev->vblank[crtc].last =
226 			    dev->driver->get_vblank_counter(dev, crtc);
227 			dev->vblank[crtc].enabled = 0;
228 		}
229 	}
230 	DRM_SPINUNLOCK(&dev->vbl_lock);
231 
232 	DRM_DEBUG("irq=%d\n", dev->irq);
233 
234 	dev->driver->irq_uninstall(dev);
235 
236 	DRM_UNLOCK();
237 	bus_teardown_intr(dev->device, dev->irqr, dev->irqh);
238 	DRM_LOCK();
239 
240 	return 0;
241 }
242 
drm_control(struct drm_device * dev,void * data,struct drm_file * file_priv)243 int drm_control(struct drm_device *dev, void *data, struct drm_file *file_priv)
244 {
245 	struct drm_control *ctl = data;
246 	int err;
247 
248 	switch (ctl->func) {
249 	case DRM_INST_HANDLER:
250 		/* Handle drivers whose DRM used to require IRQ setup but the
251 		 * no longer does.
252 		 */
253 		if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
254 			return 0;
255 		if (dev->if_version < DRM_IF_VERSION(1, 2) &&
256 		    ctl->irq != dev->irq)
257 			return EINVAL;
258 		return drm_irq_install(dev);
259 	case DRM_UNINST_HANDLER:
260 		if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
261 			return 0;
262 		DRM_LOCK();
263 		err = drm_irq_uninstall(dev);
264 		DRM_UNLOCK();
265 		return err;
266 	default:
267 		return EINVAL;
268 	}
269 }
270 
drm_vblank_count(struct drm_device * dev,int crtc)271 u32 drm_vblank_count(struct drm_device *dev, int crtc)
272 {
273 	return atomic_load_acq_32(&dev->vblank[crtc].count);
274 }
275 
drm_update_vblank_count(struct drm_device * dev,int crtc)276 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
277 {
278 	u32 cur_vblank, diff;
279 
280 	/*
281 	 * Interrupts were disabled prior to this call, so deal with counter
282 	 * wrap if needed.
283 	 * NOTE!  It's possible we lost a full dev->max_vblank_count events
284 	 * here if the register is small or we had vblank interrupts off for
285 	 * a long time.
286 	 */
287 	cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
288 	diff = cur_vblank - dev->vblank[crtc].last;
289 	if (cur_vblank < dev->vblank[crtc].last) {
290 		diff += dev->max_vblank_count;
291 
292 		DRM_DEBUG("vblank[%d].last=0x%x, cur_vblank=0x%x => diff=0x%x\n",
293 		    crtc, dev->vblank[crtc].last, cur_vblank, diff);
294 	}
295 
296 	DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
297 	    crtc, diff);
298 
299 	atomic_add_rel_32(&dev->vblank[crtc].count, diff);
300 }
301 
drm_vblank_get(struct drm_device * dev,int crtc)302 int drm_vblank_get(struct drm_device *dev, int crtc)
303 {
304 	int ret = 0;
305 
306 	/* Make sure that we are called with the lock held */
307 	mtx_assert(&dev->vbl_lock, MA_OWNED);
308 
309 	/* Going from 0->1 means we have to enable interrupts again */
310 	if (++dev->vblank[crtc].refcount == 1 &&
311 	    !dev->vblank[crtc].enabled) {
312 		ret = dev->driver->enable_vblank(dev, crtc);
313 		DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
314 		if (ret)
315 			--dev->vblank[crtc].refcount;
316 		else {
317 			dev->vblank[crtc].enabled = 1;
318 			drm_update_vblank_count(dev, crtc);
319 		}
320 	}
321 
322 	if (dev->vblank[crtc].enabled)
323 		dev->vblank[crtc].last =
324 		    dev->driver->get_vblank_counter(dev, crtc);
325 
326 	return ret;
327 }
328 
drm_vblank_put(struct drm_device * dev,int crtc)329 void drm_vblank_put(struct drm_device *dev, int crtc)
330 {
331 	/* Make sure that we are called with the lock held */
332 	mtx_assert(&dev->vbl_lock, MA_OWNED);
333 
334 	KASSERT(dev->vblank[crtc].refcount > 0,
335 	    ("invalid refcount"));
336 
337 	/* Last user schedules interrupt disable */
338 	if (--dev->vblank[crtc].refcount == 0)
339 	    callout_reset(&dev->vblank_disable_timer, 5 * DRM_HZ,
340 		(timeout_t *)vblank_disable_fn, (void *)dev);
341 }
342 
drm_modeset_ctl(struct drm_device * dev,void * data,struct drm_file * file_priv)343 int drm_modeset_ctl(struct drm_device *dev, void *data,
344 		    struct drm_file *file_priv)
345 {
346 	struct drm_modeset_ctl *modeset = data;
347 	int crtc, ret = 0;
348 
349 	/* If drm_vblank_init() hasn't been called yet, just no-op */
350 	if (!dev->num_crtcs)
351 		goto out;
352 
353 	crtc = modeset->crtc;
354 	if (crtc < 0 || crtc >= dev->num_crtcs) {
355 		ret = EINVAL;
356 		goto out;
357 	}
358 
359 	/*
360 	 * To avoid all the problems that might happen if interrupts
361 	 * were enabled/disabled around or between these calls, we just
362 	 * have the kernel take a reference on the CRTC (just once though
363 	 * to avoid corrupting the count if multiple, mismatch calls occur),
364 	 * so that interrupts remain enabled in the interim.
365 	 */
366 	switch (modeset->cmd) {
367 	case _DRM_PRE_MODESET:
368 		DRM_DEBUG("pre-modeset, crtc %d\n", crtc);
369 		DRM_SPINLOCK(&dev->vbl_lock);
370 		if (!dev->vblank[crtc].inmodeset) {
371 			dev->vblank[crtc].inmodeset = 0x1;
372 			if (drm_vblank_get(dev, crtc) == 0)
373 				dev->vblank[crtc].inmodeset |= 0x2;
374 		}
375 		DRM_SPINUNLOCK(&dev->vbl_lock);
376 		break;
377 	case _DRM_POST_MODESET:
378 		DRM_DEBUG("post-modeset, crtc %d\n", crtc);
379 		DRM_SPINLOCK(&dev->vbl_lock);
380 		if (dev->vblank[crtc].inmodeset) {
381 			if (dev->vblank[crtc].inmodeset & 0x2)
382 				drm_vblank_put(dev, crtc);
383 			dev->vblank[crtc].inmodeset = 0;
384 		}
385 		dev->vblank_disable_allowed = 1;
386 		DRM_SPINUNLOCK(&dev->vbl_lock);
387 		break;
388 	default:
389 		ret = EINVAL;
390 		break;
391 	}
392 
393 out:
394 	return ret;
395 }
396 
drm_wait_vblank(struct drm_device * dev,void * data,struct drm_file * file_priv)397 int drm_wait_vblank(struct drm_device *dev, void *data, struct drm_file *file_priv)
398 {
399 	union drm_wait_vblank *vblwait = data;
400 	unsigned int flags, seq, crtc;
401 	int ret = 0;
402 
403 	if (!dev->irq_enabled)
404 		return EINVAL;
405 
406 	if (vblwait->request.type &
407 	    ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)) {
408 		DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
409 		    vblwait->request.type,
410 		    (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK));
411 		return EINVAL;
412 	}
413 
414 	flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
415 	crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
416 
417 	if (crtc >= dev->num_crtcs)
418 		return EINVAL;
419 
420 	DRM_SPINLOCK(&dev->vbl_lock);
421 	ret = drm_vblank_get(dev, crtc);
422 	DRM_SPINUNLOCK(&dev->vbl_lock);
423 	if (ret) {
424 		DRM_ERROR("failed to acquire vblank counter, %d\n", ret);
425 		return ret;
426 	}
427 	seq = drm_vblank_count(dev, crtc);
428 
429 	switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
430 	case _DRM_VBLANK_RELATIVE:
431 		vblwait->request.sequence += seq;
432 		vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
433 	case _DRM_VBLANK_ABSOLUTE:
434 		break;
435 	default:
436 		ret = EINVAL;
437 		goto done;
438 	}
439 
440 	if ((flags & _DRM_VBLANK_NEXTONMISS) &&
441 	    (seq - vblwait->request.sequence) <= (1<<23)) {
442 		vblwait->request.sequence = seq + 1;
443 	}
444 
445 	if (flags & _DRM_VBLANK_SIGNAL) {
446 		/* There have never been any consumers */
447 		ret = EINVAL;
448 	} else {
449 		DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
450 		    vblwait->request.sequence, crtc);
451 		for ( ret = 0 ; !ret && !(((drm_vblank_count(dev, crtc) -
452 		    vblwait->request.sequence) <= (1 << 23)) ||
453 		    !dev->irq_enabled) ; ) {
454 			mtx_lock(&dev->irq_lock);
455 			if (!(((drm_vblank_count(dev, crtc) -
456 			    vblwait->request.sequence) <= (1 << 23)) ||
457 			    !dev->irq_enabled))
458 				ret = mtx_sleep(&dev->vblank[crtc].queue,
459 				    &dev->irq_lock, PCATCH, "vblwtq",
460 				    DRM_HZ);
461 			mtx_unlock(&dev->irq_lock);
462 		}
463 
464 		if (ret != EINTR && ret != ERESTART) {
465 			struct timeval now;
466 
467 			microtime(&now);
468 			vblwait->reply.tval_sec = now.tv_sec;
469 			vblwait->reply.tval_usec = now.tv_usec;
470 			vblwait->reply.sequence = drm_vblank_count(dev, crtc);
471 			DRM_DEBUG("returning %d to client, irq_enabled %d\n",
472 			    vblwait->reply.sequence, dev->irq_enabled);
473 		} else {
474 			DRM_DEBUG("vblank wait interrupted by signal\n");
475 		}
476 	}
477 
478 done:
479 	DRM_SPINLOCK(&dev->vbl_lock);
480 	drm_vblank_put(dev, crtc);
481 	DRM_SPINUNLOCK(&dev->vbl_lock);
482 
483 	return ret;
484 }
485 
drm_handle_vblank(struct drm_device * dev,int crtc)486 void drm_handle_vblank(struct drm_device *dev, int crtc)
487 {
488 	atomic_add_rel_32(&dev->vblank[crtc].count, 1);
489 	DRM_WAKEUP(&dev->vblank[crtc].queue);
490 }
491 
492