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: stable/11/sys/dev/drm/drm_irq.c 331409 2018-03-23 02:33:30Z emaste $");
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
39int 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
58static irqreturn_t
59drm_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
68static 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
103void 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
124int 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
150err:
151	drm_vblank_cleanup(dev);
152	return ret;
153}
154
155int 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;
201err:
202	DRM_LOCK();
203	dev->irq_enabled = 0;
204	DRM_UNLOCK();
205
206	return retcode;
207}
208
209int 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
243int 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
271u32 drm_vblank_count(struct drm_device *dev, int crtc)
272{
273	return atomic_load_acq_32(&dev->vblank[crtc].count);
274}
275
276static 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
302int 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
329void 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
343int 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
393out:
394	return ret;
395}
396
397int 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
478done:
479	DRM_SPINLOCK(&dev->vbl_lock);
480	drm_vblank_put(dev, crtc);
481	DRM_SPINUNLOCK(&dev->vbl_lock);
482
483	return ret;
484}
485
486void 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