summaryrefslogtreecommitdiffstats
path: root/drivers/char/drm/drm_irq.c
blob: b08608a9f02666da3a948373998919d58ee28a93 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
/**
 * \file drm_irq.c
 * IRQ support
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
 *
 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include "drmP.h"

#include <linux/interrupt.h>	/* For task queue support */

/**
 * Get interrupt from bus id.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_irq_busid structure.
 * \return zero on success or a negative number on failure.
 *
 * Finds the PCI device with the specified bus id and gets its IRQ number.
 * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
 * to that of the device that this DRM instance attached to.
 */
int drm_irq_by_busid(struct inode *inode, struct file *filp,
		     unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_irq_busid_t __user *argp = (void __user *)arg;
	drm_irq_busid_t p;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
		return -EINVAL;

	if (copy_from_user(&p, argp, sizeof(p)))
		return -EFAULT;

	if ((p.busnum >> 8) != drm_get_pci_domain(dev) ||
	    (p.busnum & 0xff) != dev->pdev->bus->number ||
	    p.devnum != PCI_SLOT(dev->pdev->devfn) || p.funcnum != PCI_FUNC(dev->pdev->devfn))
		return -EINVAL;

	p.irq = dev->irq;

	DRM_DEBUG("%d:%d:%d => IRQ %d\n", p.busnum, p.devnum, p.funcnum, p.irq);
	if (copy_to_user(argp, &p, sizeof(p)))
		return -EFAULT;
	return 0;
}

/**
 * Install IRQ handler.
 *
 * \param dev DRM device.
 * \param irq IRQ number.
 *
 * Initializes the IRQ related data, and setups drm_device::vbl_queue. Installs the handler, calling the driver
 * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
 * before and after the installation.
 */
static int drm_irq_install(drm_device_t * dev)
{
	int ret;
	unsigned long sh_flags = 0;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
		return -EINVAL;

	if (dev->irq == 0)
		return -EINVAL;

	mutex_lock(&dev->struct_mutex);

	/* Driver must have been initialized */
	if (!dev->dev_private) {
		mutex_unlock(&dev->struct_mutex);
		return -EINVAL;
	}

	if (dev->irq_enabled) {
		mutex_unlock(&dev->struct_mutex);
		return -EBUSY;
	}
	dev->irq_enabled = 1;
	mutex_unlock(&dev->struct_mutex);

	DRM_DEBUG("%s: irq=%d\n", __FUNCTION__, dev->irq);

	if (drm_core_check_feature(dev, DRIVER_IRQ_VBL)) {
		init_waitqueue_head(&dev->vbl_queue);

		spin_lock_init(&dev->vbl_lock);

		INIT_LIST_HEAD(&dev->vbl_sigs.head);
		INIT_LIST_HEAD(&dev->vbl_sigs2.head);

		dev->vbl_pending = 0;
	}

	/* Before installing handler */
	dev->driver->irq_preinstall(dev);

	/* Install handler */
	if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
		sh_flags = IRQF_SHARED;

	ret = request_irq(dev->irq, dev->driver->irq_handler,
			  sh_flags, dev->devname, dev);
	if (ret < 0) {
		mutex_lock(&dev->struct_mutex);
		dev->irq_enabled = 0;
		mutex_unlock(&dev->struct_mutex);
		return ret;
	}

	/* After installing handler */
	dev->driver->irq_postinstall(dev);

	return 0;
}

/**
 * Uninstall the IRQ handler.
 *
 * \param dev DRM device.
 *
 * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
 */
int drm_irq_uninstall(drm_device_t * dev)
{
	int irq_enabled;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
		return -EINVAL;

	mutex_lock(&dev->struct_mutex);
	irq_enabled = dev->irq_enabled;
	dev->irq_enabled = 0;
	mutex_unlock(&dev->struct_mutex);

	if (!irq_enabled)
		return -EINVAL;

	DRM_DEBUG("%s: irq=%d\n", __FUNCTION__, dev->irq);

	dev->driver->irq_uninstall(dev);

	free_irq(dev->irq, dev);

	dev->locked_tasklet_func = NULL;

	return 0;
}

EXPORT_SYMBOL(drm_irq_uninstall);

/**
 * IRQ control ioctl.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_control structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls irq_install() or irq_uninstall() according to \p arg.
 */
int drm_control(struct inode *inode, struct file *filp,
		unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_control_t ctl;

	/* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */

	if (copy_from_user(&ctl, (drm_control_t __user *) arg, sizeof(ctl)))
		return -EFAULT;

	switch (ctl.func) {
	case DRM_INST_HANDLER:
		if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
			return 0;
		if (dev->if_version < DRM_IF_VERSION(1, 2) &&
		    ctl.irq != dev->irq)
			return -EINVAL;
		return drm_irq_install(dev);
	case DRM_UNINST_HANDLER:
		if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
			return 0;
		return drm_irq_uninstall(dev);
	default:
		return -EINVAL;
	}
}

/**
 * Wait for VBLANK.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param data user argument, pointing to a drm_wait_vblank structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the IRQ is installed.
 *
 * If a signal is requested checks if this task has already scheduled the same signal
 * for the same vblank sequence number - nothing to be done in
 * that case. If the number of tasks waiting for the interrupt exceeds 100 the
 * function fails. Otherwise adds a new entry to drm_device::vbl_sigs for this
 * task.
 *
 * If a signal is not requested, then calls vblank_wait().
 */
int drm_wait_vblank(DRM_IOCTL_ARGS)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_wait_vblank_t __user *argp = (void __user *)data;
	drm_wait_vblank_t vblwait;
	struct timeval now;
	int ret = 0;
	unsigned int flags;
	atomic_t *seq;

	if (!dev->irq)
		return -EINVAL;

	if (copy_from_user(&vblwait, argp, sizeof(vblwait)))
		return -EFAULT;

	if (vblwait.request.type &
	    ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)) {
		DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
			  vblwait.request.type,
			  (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK));
		return -EINVAL;
	}

	flags = vblwait.request.type & _DRM_VBLANK_FLAGS_MASK;

	if (!drm_core_check_feature(dev, (flags & _DRM_VBLANK_SECONDARY) ?
				    DRIVER_IRQ_VBL2 : DRIVER_IRQ_VBL))
		return -EINVAL;

	seq = (flags & _DRM_VBLANK_SECONDARY) ? &dev->vbl_received2 :
	      &dev->vbl_received;

	switch (vblwait.request.type & _DRM_VBLANK_TYPES_MASK) {
	case _DRM_VBLANK_RELATIVE:
		vblwait.request.sequence += atomic_read(seq);
		vblwait.request.type &= ~_DRM_VBLANK_RELATIVE;
	case _DRM_VBLANK_ABSOLUTE:
		break;
	default:
		return -EINVAL;
	}

	if (flags & _DRM_VBLANK_SIGNAL) {
		unsigned long irqflags;
		drm_vbl_sig_t *vbl_sigs = (flags & _DRM_VBLANK_SECONDARY)
				      ? &dev->vbl_sigs2 : &dev->vbl_sigs;
		drm_vbl_sig_t *vbl_sig;

		vblwait.reply.sequence = atomic_read(seq);

		spin_lock_irqsave(&dev->vbl_lock, irqflags);

		/* Check if this task has already scheduled the same signal
		 * for the same vblank sequence number; nothing to be done in
		 * that case
		 */
		list_for_each_entry(vbl_sig, &vbl_sigs->head, head) {
			if (vbl_sig->sequence == vblwait.request.sequence
			    && vbl_sig->info.si_signo == vblwait.request.signal
			    && vbl_sig->task == current) {
				spin_unlock_irqrestore(&dev->vbl_lock,
						       irqflags);
				goto done;
			}
		}

		if (dev->vbl_pending >= 100) {
			spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
			return -EBUSY;
		}

		dev->vbl_pending++;

		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);

		if (!
		    (vbl_sig =
		     drm_alloc(sizeof(drm_vbl_sig_t), DRM_MEM_DRIVER))) {
			return -ENOMEM;
		}

		memset((void *)vbl_sig, 0, sizeof(*vbl_sig));

		vbl_sig->sequence = vblwait.request.sequence;
		vbl_sig->info.si_signo = vblwait.request.signal;
		vbl_sig->task = current;

		spin_lock_irqsave(&dev->vbl_lock, irqflags);

		list_add_tail((struct list_head *)vbl_sig, &vbl_sigs->head);

		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
	} else {
		if (flags & _DRM_VBLANK_SECONDARY) {
			if (dev->driver->vblank_wait2)
				ret = dev->driver->vblank_wait2(dev, &vblwait.request.sequence);
		} else if (dev->driver->vblank_wait)
			ret =
			    dev->driver->vblank_wait(dev,
						     &vblwait.request.sequence);

		do_gettimeofday(&now);
		vblwait.reply.tval_sec = now.tv_sec;
		vblwait.reply.tval_usec = now.tv_usec;
	}

      done:
	if (copy_to_user(argp, &vblwait, sizeof(vblwait)))
		return -EFAULT;

	return ret;
}

/**
 * Send the VBLANK signals.
 *
 * \param dev DRM device.
 *
 * Sends a signal for each task in drm_device::vbl_sigs and empties the list.
 *
 * If a signal is not requested, then calls vblank_wait().
 */
void drm_vbl_send_signals(drm_device_t * dev)
{
	unsigned long flags;
	int i;

	spin_lock_irqsave(&dev->vbl_lock, flags);

	for (i = 0; i < 2; i++) {
		struct list_head *list, *tmp;
		drm_vbl_sig_t *vbl_sig;
		drm_vbl_sig_t *vbl_sigs = i ? &dev->vbl_sigs2 : &dev->vbl_sigs;
		unsigned int vbl_seq = atomic_read(i ? &dev->vbl_received2 :
						   &dev->vbl_received);

		list_for_each_safe(list, tmp, &vbl_sigs->head) {
			vbl_sig = list_entry(list, drm_vbl_sig_t, head);
			if ((vbl_seq - vbl_sig->sequence) <= (1 << 23)) {
				vbl_sig->info.si_code = vbl_seq;
				send_sig_info(vbl_sig->info.si_signo,
					      &vbl_sig->info, vbl_sig->task);

				list_del(list);

				drm_free(vbl_sig, sizeof(*vbl_sig),
					 DRM_MEM_DRIVER);

				dev->vbl_pending--;
			}
		}
	}

	spin_unlock_irqrestore(&dev->vbl_lock, flags);
}

EXPORT_SYMBOL(drm_vbl_send_signals);

/**
 * Tasklet wrapper function.
 *
 * \param data DRM device in disguise.
 *
 * Attempts to grab the HW lock and calls the driver callback on success. On
 * failure, leave the lock marked as contended so the callback can be called
 * from drm_unlock().
 */
static void drm_locked_tasklet_func(unsigned long data)
{
	drm_device_t *dev = (drm_device_t*)data;
	unsigned long irqflags;

	spin_lock_irqsave(&dev->tasklet_lock, irqflags);

	if (!dev->locked_tasklet_func ||
	    !drm_lock_take(&dev->lock.hw_lock->lock,
			   DRM_KERNEL_CONTEXT)) {
		spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
		return;
	}

	dev->lock.lock_time = jiffies;
	atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);

	dev->locked_tasklet_func(dev);

	drm_lock_free(dev, &dev->lock.hw_lock->lock,
		      DRM_KERNEL_CONTEXT);

	dev->locked_tasklet_func = NULL;

	spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
}

/**
 * Schedule a tasklet to call back a driver hook with the HW lock held.
 *
 * \param dev DRM device.
 * \param func Driver callback.
 *
 * This is intended for triggering actions that require the HW lock from an
 * interrupt handler. The lock will be grabbed ASAP after the interrupt handler
 * completes. Note that the callback may be called from interrupt or process
 * context, it must not make any assumptions about this. Also, the HW lock will
 * be held with the kernel context or any client context.
 */
void drm_locked_tasklet(drm_device_t *dev, void (*func)(drm_device_t*))
{
	unsigned long irqflags;
	static DECLARE_TASKLET(drm_tasklet, drm_locked_tasklet_func, 0);

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ) ||
	    test_bit(TASKLET_STATE_SCHED, &drm_tasklet.state))
		return;

	spin_lock_irqsave(&dev->tasklet_lock, irqflags);

	if (dev->locked_tasklet_func) {
		spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
		return;
	}

	dev->locked_tasklet_func = func;

	spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);

	drm_tasklet.data = (unsigned long)dev;

	tasklet_hi_schedule(&drm_tasklet);
}
EXPORT_SYMBOL(drm_locked_tasklet);
OpenPOWER on IntegriCloud