1 /**
2 * \file drm_fops.c
3 * File operations for DRM
4 *
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Daryll Strauss <daryll@valinux.com>
7 * \author Gareth Hughes <gareth@valinux.com>
8 */
9
10 /*
11 * Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com
12 *
13 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
14 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
15 * All Rights Reserved.
16 *
17 * Permission is hereby granted, free of charge, to any person obtaining a
18 * copy of this software and associated documentation files (the "Software"),
19 * to deal in the Software without restriction, including without limitation
20 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
21 * and/or sell copies of the Software, and to permit persons to whom the
22 * Software is furnished to do so, subject to the following conditions:
23 *
24 * The above copyright notice and this permission notice (including the next
25 * paragraph) shall be included in all copies or substantial portions of the
26 * Software.
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
29 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
30 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
31 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
32 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
33 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
34 * OTHER DEALINGS IN THE SOFTWARE.
35 */
36
37 #include "drmP.h"
38 #include <linux/poll.h>
39 #include <linux/slab.h>
40 #include <linux/module.h>
41
42 /* from BKL pushdown: note that nothing else serializes idr_find() */
43 DEFINE_MUTEX(drm_global_mutex);
44 EXPORT_SYMBOL(drm_global_mutex);
45
46 static int drm_open_helper(struct inode *inode, struct file *filp,
47 struct drm_device * dev);
48
drm_setup(struct drm_device * dev)49 static int drm_setup(struct drm_device * dev)
50 {
51 int i;
52 int ret;
53
54 if (dev->driver->firstopen) {
55 ret = dev->driver->firstopen(dev);
56 if (ret != 0)
57 return ret;
58 }
59
60 atomic_set(&dev->ioctl_count, 0);
61 atomic_set(&dev->vma_count, 0);
62
63 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
64 !drm_core_check_feature(dev, DRIVER_MODESET)) {
65 dev->buf_use = 0;
66 atomic_set(&dev->buf_alloc, 0);
67
68 i = drm_dma_setup(dev);
69 if (i < 0)
70 return i;
71 }
72
73 for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
74 atomic_set(&dev->counts[i], 0);
75
76 dev->sigdata.lock = NULL;
77
78 dev->queue_count = 0;
79 dev->queue_reserved = 0;
80 dev->queue_slots = 0;
81 dev->queuelist = NULL;
82 dev->context_flag = 0;
83 dev->interrupt_flag = 0;
84 dev->dma_flag = 0;
85 dev->last_context = 0;
86 dev->last_switch = 0;
87 dev->last_checked = 0;
88 init_waitqueue_head(&dev->context_wait);
89 dev->if_version = 0;
90
91 dev->ctx_start = 0;
92 dev->lck_start = 0;
93
94 dev->buf_async = NULL;
95 init_waitqueue_head(&dev->buf_readers);
96 init_waitqueue_head(&dev->buf_writers);
97
98 DRM_DEBUG("\n");
99
100 /*
101 * The kernel's context could be created here, but is now created
102 * in drm_dma_enqueue. This is more resource-efficient for
103 * hardware that does not do DMA, but may mean that
104 * drm_select_queue fails between the time the interrupt is
105 * initialized and the time the queues are initialized.
106 */
107
108 return 0;
109 }
110
111 /**
112 * Open file.
113 *
114 * \param inode device inode
115 * \param filp file pointer.
116 * \return zero on success or a negative number on failure.
117 *
118 * Searches the DRM device with the same minor number, calls open_helper(), and
119 * increments the device open count. If the open count was previous at zero,
120 * i.e., it's the first that the device is open, then calls setup().
121 */
drm_open(struct inode * inode,struct file * filp)122 int drm_open(struct inode *inode, struct file *filp)
123 {
124 struct drm_device *dev = NULL;
125 int minor_id = iminor(inode);
126 struct drm_minor *minor;
127 int retcode = 0;
128
129 minor = idr_find(&drm_minors_idr, minor_id);
130 if (!minor)
131 return -ENODEV;
132
133 if (!(dev = minor->dev))
134 return -ENODEV;
135
136 if (drm_device_is_unplugged(dev))
137 return -ENODEV;
138
139 retcode = drm_open_helper(inode, filp, dev);
140 if (!retcode) {
141 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
142 if (!dev->open_count++) {
143 retcode = drm_setup(dev);
144 if (retcode)
145 dev->open_count--;
146 }
147 }
148 if (!retcode) {
149 mutex_lock(&dev->struct_mutex);
150 if (minor->type == DRM_MINOR_LEGACY) {
151 if (dev->dev_mapping == NULL)
152 dev->dev_mapping = inode->i_mapping;
153 else if (dev->dev_mapping != inode->i_mapping)
154 retcode = -ENODEV;
155 }
156 mutex_unlock(&dev->struct_mutex);
157 }
158
159 return retcode;
160 }
161 EXPORT_SYMBOL(drm_open);
162
163 /**
164 * File \c open operation.
165 *
166 * \param inode device inode.
167 * \param filp file pointer.
168 *
169 * Puts the dev->fops corresponding to the device minor number into
170 * \p filp, call the \c open method, and restore the file operations.
171 */
drm_stub_open(struct inode * inode,struct file * filp)172 int drm_stub_open(struct inode *inode, struct file *filp)
173 {
174 struct drm_device *dev = NULL;
175 struct drm_minor *minor;
176 int minor_id = iminor(inode);
177 int err = -ENODEV;
178 const struct file_operations *old_fops;
179
180 DRM_DEBUG("\n");
181
182 mutex_lock(&drm_global_mutex);
183 minor = idr_find(&drm_minors_idr, minor_id);
184 if (!minor)
185 goto out;
186
187 if (!(dev = minor->dev))
188 goto out;
189
190 if (drm_device_is_unplugged(dev))
191 goto out;
192
193 old_fops = filp->f_op;
194 filp->f_op = fops_get(dev->driver->fops);
195 if (filp->f_op == NULL) {
196 filp->f_op = old_fops;
197 goto out;
198 }
199 if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
200 fops_put(filp->f_op);
201 filp->f_op = fops_get(old_fops);
202 }
203 fops_put(old_fops);
204
205 out:
206 mutex_unlock(&drm_global_mutex);
207 return err;
208 }
209
210 /**
211 * Check whether DRI will run on this CPU.
212 *
213 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
214 */
drm_cpu_valid(void)215 static int drm_cpu_valid(void)
216 {
217 #if defined(__i386__)
218 if (boot_cpu_data.x86 == 3)
219 return 0; /* No cmpxchg on a 386 */
220 #endif
221 #if defined(__sparc__) && !defined(__sparc_v9__)
222 return 0; /* No cmpxchg before v9 sparc. */
223 #endif
224 return 1;
225 }
226
227 /**
228 * Called whenever a process opens /dev/drm.
229 *
230 * \param inode device inode.
231 * \param filp file pointer.
232 * \param dev device.
233 * \return zero on success or a negative number on failure.
234 *
235 * Creates and initializes a drm_file structure for the file private data in \p
236 * filp and add it into the double linked list in \p dev.
237 */
drm_open_helper(struct inode * inode,struct file * filp,struct drm_device * dev)238 static int drm_open_helper(struct inode *inode, struct file *filp,
239 struct drm_device * dev)
240 {
241 int minor_id = iminor(inode);
242 struct drm_file *priv;
243 int ret;
244
245 if (filp->f_flags & O_EXCL)
246 return -EBUSY; /* No exclusive opens */
247 if (!drm_cpu_valid())
248 return -EINVAL;
249 if (dev->switch_power_state != DRM_SWITCH_POWER_ON)
250 return -EINVAL;
251
252 DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
253
254 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
255 if (!priv)
256 return -ENOMEM;
257
258 filp->private_data = priv;
259 priv->filp = filp;
260 priv->uid = current_euid();
261 priv->pid = task_pid_nr(current);
262 priv->minor = idr_find(&drm_minors_idr, minor_id);
263 priv->ioctl_count = 0;
264 /* for compatibility root is always authenticated */
265 priv->authenticated = capable(CAP_SYS_ADMIN);
266 priv->lock_count = 0;
267
268 INIT_LIST_HEAD(&priv->lhead);
269 INIT_LIST_HEAD(&priv->fbs);
270 INIT_LIST_HEAD(&priv->event_list);
271 init_waitqueue_head(&priv->event_wait);
272 priv->event_space = 4096; /* set aside 4k for event buffer */
273
274 if (dev->driver->driver_features & DRIVER_GEM)
275 drm_gem_open(dev, priv);
276
277 if (drm_core_check_feature(dev, DRIVER_PRIME))
278 drm_prime_init_file_private(&priv->prime);
279
280 if (dev->driver->open) {
281 ret = dev->driver->open(dev, priv);
282 if (ret < 0)
283 goto out_free;
284 }
285
286
287 /* if there is no current master make this fd it */
288 mutex_lock(&dev->struct_mutex);
289 if (!priv->minor->master) {
290 /* create a new master */
291 priv->minor->master = drm_master_create(priv->minor);
292 if (!priv->minor->master) {
293 mutex_unlock(&dev->struct_mutex);
294 ret = -ENOMEM;
295 goto out_free;
296 }
297
298 priv->is_master = 1;
299 /* take another reference for the copy in the local file priv */
300 priv->master = drm_master_get(priv->minor->master);
301
302 priv->authenticated = 1;
303
304 mutex_unlock(&dev->struct_mutex);
305 if (dev->driver->master_create) {
306 ret = dev->driver->master_create(dev, priv->master);
307 if (ret) {
308 mutex_lock(&dev->struct_mutex);
309 /* drop both references if this fails */
310 drm_master_put(&priv->minor->master);
311 drm_master_put(&priv->master);
312 mutex_unlock(&dev->struct_mutex);
313 goto out_free;
314 }
315 }
316 mutex_lock(&dev->struct_mutex);
317 if (dev->driver->master_set) {
318 ret = dev->driver->master_set(dev, priv, true);
319 if (ret) {
320 /* drop both references if this fails */
321 drm_master_put(&priv->minor->master);
322 drm_master_put(&priv->master);
323 mutex_unlock(&dev->struct_mutex);
324 goto out_free;
325 }
326 }
327 mutex_unlock(&dev->struct_mutex);
328 } else {
329 /* get a reference to the master */
330 priv->master = drm_master_get(priv->minor->master);
331 mutex_unlock(&dev->struct_mutex);
332 }
333
334 mutex_lock(&dev->struct_mutex);
335 list_add(&priv->lhead, &dev->filelist);
336 mutex_unlock(&dev->struct_mutex);
337
338 #ifdef __alpha__
339 /*
340 * Default the hose
341 */
342 if (!dev->hose) {
343 struct pci_dev *pci_dev;
344 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
345 if (pci_dev) {
346 dev->hose = pci_dev->sysdata;
347 pci_dev_put(pci_dev);
348 }
349 if (!dev->hose) {
350 struct pci_bus *b = pci_bus_b(pci_root_buses.next);
351 if (b)
352 dev->hose = b->sysdata;
353 }
354 }
355 #endif
356
357 return 0;
358 out_free:
359 kfree(priv);
360 filp->private_data = NULL;
361 return ret;
362 }
363
364 /** No-op. */
drm_fasync(int fd,struct file * filp,int on)365 int drm_fasync(int fd, struct file *filp, int on)
366 {
367 struct drm_file *priv = filp->private_data;
368 struct drm_device *dev = priv->minor->dev;
369
370 DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
371 (long)old_encode_dev(priv->minor->device));
372 return fasync_helper(fd, filp, on, &dev->buf_async);
373 }
374 EXPORT_SYMBOL(drm_fasync);
375
376 /*
377 * Reclaim locked buffers; note that this may be a bad idea if the current
378 * context doesn't have the hw lock...
379 */
drm_reclaim_locked_buffers(struct drm_device * dev,struct file * f)380 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
381 {
382 struct drm_file *file_priv = f->private_data;
383
384 if (drm_i_have_hw_lock(dev, file_priv)) {
385 dev->driver->reclaim_buffers_locked(dev, file_priv);
386 } else {
387 unsigned long _end = jiffies + 3 * DRM_HZ;
388 int locked = 0;
389
390 drm_idlelock_take(&file_priv->master->lock);
391
392 /*
393 * Wait for a while.
394 */
395 do {
396 spin_lock_bh(&file_priv->master->lock.spinlock);
397 locked = file_priv->master->lock.idle_has_lock;
398 spin_unlock_bh(&file_priv->master->lock.spinlock);
399 if (locked)
400 break;
401 schedule();
402 } while (!time_after_eq(jiffies, _end));
403
404 if (!locked) {
405 DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
406 "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
407 "\tI will go on reclaiming the buffers anyway.\n");
408 }
409
410 dev->driver->reclaim_buffers_locked(dev, file_priv);
411 drm_idlelock_release(&file_priv->master->lock);
412 }
413 }
414
drm_master_release(struct drm_device * dev,struct file * filp)415 static void drm_master_release(struct drm_device *dev, struct file *filp)
416 {
417 struct drm_file *file_priv = filp->private_data;
418
419 if (dev->driver->reclaim_buffers_locked &&
420 file_priv->master->lock.hw_lock)
421 drm_reclaim_locked_buffers(dev, filp);
422
423 if (dev->driver->reclaim_buffers_idlelocked &&
424 file_priv->master->lock.hw_lock) {
425 drm_idlelock_take(&file_priv->master->lock);
426 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
427 drm_idlelock_release(&file_priv->master->lock);
428 }
429
430
431 if (drm_i_have_hw_lock(dev, file_priv)) {
432 DRM_DEBUG("File %p released, freeing lock for context %d\n",
433 filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
434 drm_lock_free(&file_priv->master->lock,
435 _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
436 }
437
438 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
439 !dev->driver->reclaim_buffers_locked) {
440 dev->driver->reclaim_buffers(dev, file_priv);
441 }
442 }
443
drm_events_release(struct drm_file * file_priv)444 static void drm_events_release(struct drm_file *file_priv)
445 {
446 struct drm_device *dev = file_priv->minor->dev;
447 struct drm_pending_event *e, *et;
448 struct drm_pending_vblank_event *v, *vt;
449 unsigned long flags;
450
451 spin_lock_irqsave(&dev->event_lock, flags);
452
453 /* Remove pending flips */
454 list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
455 if (v->base.file_priv == file_priv) {
456 list_del(&v->base.link);
457 drm_vblank_put(dev, v->pipe);
458 v->base.destroy(&v->base);
459 }
460
461 /* Remove unconsumed events */
462 list_for_each_entry_safe(e, et, &file_priv->event_list, link)
463 e->destroy(e);
464
465 spin_unlock_irqrestore(&dev->event_lock, flags);
466 }
467
468 /**
469 * Release file.
470 *
471 * \param inode device inode
472 * \param file_priv DRM file private.
473 * \return zero on success or a negative number on failure.
474 *
475 * If the hardware lock is held then free it, and take it again for the kernel
476 * context since it's necessary to reclaim buffers. Unlink the file private
477 * data from its list and free it. Decreases the open count and if it reaches
478 * zero calls drm_lastclose().
479 */
drm_release(struct inode * inode,struct file * filp)480 int drm_release(struct inode *inode, struct file *filp)
481 {
482 struct drm_file *file_priv = filp->private_data;
483 struct drm_device *dev = file_priv->minor->dev;
484 int retcode = 0;
485
486 mutex_lock(&drm_global_mutex);
487
488 DRM_DEBUG("open_count = %d\n", dev->open_count);
489
490 if (dev->driver->preclose)
491 dev->driver->preclose(dev, file_priv);
492
493 /* ========================================================
494 * Begin inline drm_release
495 */
496
497 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
498 task_pid_nr(current),
499 (long)old_encode_dev(file_priv->minor->device),
500 dev->open_count);
501
502 /* Release any auth tokens that might point to this file_priv,
503 (do that under the drm_global_mutex) */
504 if (file_priv->magic)
505 (void) drm_remove_magic(file_priv->master, file_priv->magic);
506
507 /* if the master has gone away we can't do anything with the lock */
508 if (file_priv->minor->master)
509 drm_master_release(dev, filp);
510
511 drm_events_release(file_priv);
512
513 if (dev->driver->driver_features & DRIVER_MODESET)
514 drm_fb_release(file_priv);
515
516 if (dev->driver->driver_features & DRIVER_GEM)
517 drm_gem_release(dev, file_priv);
518
519 mutex_lock(&dev->ctxlist_mutex);
520 if (!list_empty(&dev->ctxlist)) {
521 struct drm_ctx_list *pos, *n;
522
523 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
524 if (pos->tag == file_priv &&
525 pos->handle != DRM_KERNEL_CONTEXT) {
526 if (dev->driver->context_dtor)
527 dev->driver->context_dtor(dev,
528 pos->handle);
529
530 drm_ctxbitmap_free(dev, pos->handle);
531
532 list_del(&pos->head);
533 kfree(pos);
534 --dev->ctx_count;
535 }
536 }
537 }
538 mutex_unlock(&dev->ctxlist_mutex);
539
540 mutex_lock(&dev->struct_mutex);
541
542 if (file_priv->is_master) {
543 struct drm_master *master = file_priv->master;
544 struct drm_file *temp;
545 list_for_each_entry(temp, &dev->filelist, lhead) {
546 if ((temp->master == file_priv->master) &&
547 (temp != file_priv))
548 temp->authenticated = 0;
549 }
550
551 /**
552 * Since the master is disappearing, so is the
553 * possibility to lock.
554 */
555
556 if (master->lock.hw_lock) {
557 if (dev->sigdata.lock == master->lock.hw_lock)
558 dev->sigdata.lock = NULL;
559 master->lock.hw_lock = NULL;
560 master->lock.file_priv = NULL;
561 wake_up_interruptible_all(&master->lock.lock_queue);
562 }
563
564 if (file_priv->minor->master == file_priv->master) {
565 /* drop the reference held my the minor */
566 if (dev->driver->master_drop)
567 dev->driver->master_drop(dev, file_priv, true);
568 drm_master_put(&file_priv->minor->master);
569 }
570 }
571
572 /* drop the reference held my the file priv */
573 drm_master_put(&file_priv->master);
574 file_priv->is_master = 0;
575 list_del(&file_priv->lhead);
576 mutex_unlock(&dev->struct_mutex);
577
578 if (dev->driver->postclose)
579 dev->driver->postclose(dev, file_priv);
580
581 if (drm_core_check_feature(dev, DRIVER_PRIME))
582 drm_prime_destroy_file_private(&file_priv->prime);
583
584 kfree(file_priv);
585
586 /* ========================================================
587 * End inline drm_release
588 */
589
590 atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
591 if (!--dev->open_count) {
592 if (atomic_read(&dev->ioctl_count)) {
593 DRM_ERROR("Device busy: %d\n",
594 atomic_read(&dev->ioctl_count));
595 retcode = -EBUSY;
596 } else
597 retcode = drm_lastclose(dev);
598 if (drm_device_is_unplugged(dev))
599 drm_put_dev(dev);
600 }
601 mutex_unlock(&drm_global_mutex);
602
603 return retcode;
604 }
605 EXPORT_SYMBOL(drm_release);
606
607 static bool
drm_dequeue_event(struct drm_file * file_priv,size_t total,size_t max,struct drm_pending_event ** out)608 drm_dequeue_event(struct drm_file *file_priv,
609 size_t total, size_t max, struct drm_pending_event **out)
610 {
611 struct drm_device *dev = file_priv->minor->dev;
612 struct drm_pending_event *e;
613 unsigned long flags;
614 bool ret = false;
615
616 spin_lock_irqsave(&dev->event_lock, flags);
617
618 *out = NULL;
619 if (list_empty(&file_priv->event_list))
620 goto out;
621 e = list_first_entry(&file_priv->event_list,
622 struct drm_pending_event, link);
623 if (e->event->length + total > max)
624 goto out;
625
626 file_priv->event_space += e->event->length;
627 list_del(&e->link);
628 *out = e;
629 ret = true;
630
631 out:
632 spin_unlock_irqrestore(&dev->event_lock, flags);
633 return ret;
634 }
635
drm_read(struct file * filp,char __user * buffer,size_t count,loff_t * offset)636 ssize_t drm_read(struct file *filp, char __user *buffer,
637 size_t count, loff_t *offset)
638 {
639 struct drm_file *file_priv = filp->private_data;
640 struct drm_pending_event *e;
641 size_t total;
642 ssize_t ret;
643
644 ret = wait_event_interruptible(file_priv->event_wait,
645 !list_empty(&file_priv->event_list));
646 if (ret < 0)
647 return ret;
648
649 total = 0;
650 while (drm_dequeue_event(file_priv, total, count, &e)) {
651 if (copy_to_user(buffer + total,
652 e->event, e->event->length)) {
653 total = -EFAULT;
654 break;
655 }
656
657 total += e->event->length;
658 e->destroy(e);
659 }
660
661 return total;
662 }
663 EXPORT_SYMBOL(drm_read);
664
drm_poll(struct file * filp,struct poll_table_struct * wait)665 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
666 {
667 struct drm_file *file_priv = filp->private_data;
668 unsigned int mask = 0;
669
670 poll_wait(filp, &file_priv->event_wait, wait);
671
672 if (!list_empty(&file_priv->event_list))
673 mask |= POLLIN | POLLRDNORM;
674
675 return mask;
676 }
677 EXPORT_SYMBOL(drm_poll);
678