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