drm: kill BKL from common code
[linux-2.6.git] / drivers / gpu / drm / drm_fops.c
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/smp_lock.h>
41
42 /* from BKL pushdown: note that nothing else serializes idr_find() */
43 DEFINE_MUTEX(drm_global_mutex);
44
45 static int drm_open_helper(struct inode *inode, struct file *filp,
46                            struct drm_device * dev);
47
48 static 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  */
121 int 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                 spin_lock(&dev->count_lock);
139                 if (!dev->open_count++) {
140                         spin_unlock(&dev->count_lock);
141                         retcode = drm_setup(dev);
142                         goto out;
143                 }
144                 spin_unlock(&dev->count_lock);
145         }
146 out:
147         if (!retcode) {
148                 mutex_lock(&dev->struct_mutex);
149                 if (minor->type == DRM_MINOR_LEGACY) {
150                         if (dev->dev_mapping == NULL)
151                                 dev->dev_mapping = inode->i_mapping;
152                         else if (dev->dev_mapping != inode->i_mapping)
153                                 retcode = -ENODEV;
154                 }
155                 mutex_unlock(&dev->struct_mutex);
156         }
157
158         return retcode;
159 }
160 EXPORT_SYMBOL(drm_open);
161
162 /**
163  * File \c open operation.
164  *
165  * \param inode device inode.
166  * \param filp file pointer.
167  *
168  * Puts the dev->fops corresponding to the device minor number into
169  * \p filp, call the \c open method, and restore the file operations.
170  */
171 int drm_stub_open(struct inode *inode, struct file *filp)
172 {
173         struct drm_device *dev = NULL;
174         struct drm_minor *minor;
175         int minor_id = iminor(inode);
176         int err = -ENODEV;
177         const struct file_operations *old_fops;
178
179         DRM_DEBUG("\n");
180
181         mutex_lock(&drm_global_mutex);
182         minor = idr_find(&drm_minors_idr, minor_id);
183         if (!minor)
184                 goto out;
185
186         if (!(dev = minor->dev))
187                 goto out;
188
189         old_fops = filp->f_op;
190         filp->f_op = fops_get(&dev->driver->fops);
191         if (filp->f_op == NULL) {
192                 filp->f_op = old_fops;
193                 goto out;
194         }
195         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
196                 fops_put(filp->f_op);
197                 filp->f_op = fops_get(old_fops);
198         }
199         fops_put(old_fops);
200
201 out:
202         mutex_unlock(&drm_global_mutex);
203         return err;
204 }
205
206 /**
207  * Check whether DRI will run on this CPU.
208  *
209  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
210  */
211 static int drm_cpu_valid(void)
212 {
213 #if defined(__i386__)
214         if (boot_cpu_data.x86 == 3)
215                 return 0;       /* No cmpxchg on a 386 */
216 #endif
217 #if defined(__sparc__) && !defined(__sparc_v9__)
218         return 0;               /* No cmpxchg before v9 sparc. */
219 #endif
220         return 1;
221 }
222
223 /**
224  * Called whenever a process opens /dev/drm.
225  *
226  * \param inode device inode.
227  * \param filp file pointer.
228  * \param dev device.
229  * \return zero on success or a negative number on failure.
230  *
231  * Creates and initializes a drm_file structure for the file private data in \p
232  * filp and add it into the double linked list in \p dev.
233  */
234 static int drm_open_helper(struct inode *inode, struct file *filp,
235                            struct drm_device * dev)
236 {
237         int minor_id = iminor(inode);
238         struct drm_file *priv;
239         int ret;
240
241         if (filp->f_flags & O_EXCL)
242                 return -EBUSY;  /* No exclusive opens */
243         if (!drm_cpu_valid())
244                 return -EINVAL;
245
246         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
247
248         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
249         if (!priv)
250                 return -ENOMEM;
251
252         filp->private_data = priv;
253         priv->filp = filp;
254         priv->uid = current_euid();
255         priv->pid = task_pid_nr(current);
256         priv->minor = idr_find(&drm_minors_idr, minor_id);
257         priv->ioctl_count = 0;
258         /* for compatibility root is always authenticated */
259         priv->authenticated = capable(CAP_SYS_ADMIN);
260         priv->lock_count = 0;
261
262         INIT_LIST_HEAD(&priv->lhead);
263         INIT_LIST_HEAD(&priv->fbs);
264         INIT_LIST_HEAD(&priv->event_list);
265         init_waitqueue_head(&priv->event_wait);
266         priv->event_space = 4096; /* set aside 4k for event buffer */
267
268         if (dev->driver->driver_features & DRIVER_GEM)
269                 drm_gem_open(dev, priv);
270
271         if (dev->driver->open) {
272                 ret = dev->driver->open(dev, priv);
273                 if (ret < 0)
274                         goto out_free;
275         }
276
277
278         /* if there is no current master make this fd it */
279         mutex_lock(&dev->struct_mutex);
280         if (!priv->minor->master) {
281                 /* create a new master */
282                 priv->minor->master = drm_master_create(priv->minor);
283                 if (!priv->minor->master) {
284                         mutex_unlock(&dev->struct_mutex);
285                         ret = -ENOMEM;
286                         goto out_free;
287                 }
288
289                 priv->is_master = 1;
290                 /* take another reference for the copy in the local file priv */
291                 priv->master = drm_master_get(priv->minor->master);
292
293                 priv->authenticated = 1;
294
295                 mutex_unlock(&dev->struct_mutex);
296                 if (dev->driver->master_create) {
297                         ret = dev->driver->master_create(dev, priv->master);
298                         if (ret) {
299                                 mutex_lock(&dev->struct_mutex);
300                                 /* drop both references if this fails */
301                                 drm_master_put(&priv->minor->master);
302                                 drm_master_put(&priv->master);
303                                 mutex_unlock(&dev->struct_mutex);
304                                 goto out_free;
305                         }
306                 }
307                 mutex_lock(&dev->struct_mutex);
308                 if (dev->driver->master_set) {
309                         ret = dev->driver->master_set(dev, priv, true);
310                         if (ret) {
311                                 /* drop both references if this fails */
312                                 drm_master_put(&priv->minor->master);
313                                 drm_master_put(&priv->master);
314                                 mutex_unlock(&dev->struct_mutex);
315                                 goto out_free;
316                         }
317                 }
318                 mutex_unlock(&dev->struct_mutex);
319         } else {
320                 /* get a reference to the master */
321                 priv->master = drm_master_get(priv->minor->master);
322                 mutex_unlock(&dev->struct_mutex);
323         }
324
325         mutex_lock(&dev->struct_mutex);
326         list_add(&priv->lhead, &dev->filelist);
327         mutex_unlock(&dev->struct_mutex);
328
329 #ifdef __alpha__
330         /*
331          * Default the hose
332          */
333         if (!dev->hose) {
334                 struct pci_dev *pci_dev;
335                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
336                 if (pci_dev) {
337                         dev->hose = pci_dev->sysdata;
338                         pci_dev_put(pci_dev);
339                 }
340                 if (!dev->hose) {
341                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
342                         if (b)
343                                 dev->hose = b->sysdata;
344                 }
345         }
346 #endif
347
348         return 0;
349       out_free:
350         kfree(priv);
351         filp->private_data = NULL;
352         return ret;
353 }
354
355 /** No-op. */
356 int drm_fasync(int fd, struct file *filp, int on)
357 {
358         struct drm_file *priv = filp->private_data;
359         struct drm_device *dev = priv->minor->dev;
360
361         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
362                   (long)old_encode_dev(priv->minor->device));
363         return fasync_helper(fd, filp, on, &dev->buf_async);
364 }
365 EXPORT_SYMBOL(drm_fasync);
366
367 /*
368  * Reclaim locked buffers; note that this may be a bad idea if the current
369  * context doesn't have the hw lock...
370  */
371 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
372 {
373         struct drm_file *file_priv = f->private_data;
374
375         if (drm_i_have_hw_lock(dev, file_priv)) {
376                 dev->driver->reclaim_buffers_locked(dev, file_priv);
377         } else {
378                 unsigned long _end = jiffies + 3 * DRM_HZ;
379                 int locked = 0;
380
381                 drm_idlelock_take(&file_priv->master->lock);
382
383                 /*
384                  * Wait for a while.
385                  */
386                 do {
387                         spin_lock_bh(&file_priv->master->lock.spinlock);
388                         locked = file_priv->master->lock.idle_has_lock;
389                         spin_unlock_bh(&file_priv->master->lock.spinlock);
390                         if (locked)
391                                 break;
392                         schedule();
393                 } while (!time_after_eq(jiffies, _end));
394
395                 if (!locked) {
396                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
397                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
398                                   "\tI will go on reclaiming the buffers anyway.\n");
399                 }
400
401                 dev->driver->reclaim_buffers_locked(dev, file_priv);
402                 drm_idlelock_release(&file_priv->master->lock);
403         }
404 }
405
406 static void drm_master_release(struct drm_device *dev, struct file *filp)
407 {
408         struct drm_file *file_priv = filp->private_data;
409
410         if (dev->driver->reclaim_buffers_locked &&
411             file_priv->master->lock.hw_lock)
412                 drm_reclaim_locked_buffers(dev, filp);
413
414         if (dev->driver->reclaim_buffers_idlelocked &&
415             file_priv->master->lock.hw_lock) {
416                 drm_idlelock_take(&file_priv->master->lock);
417                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
418                 drm_idlelock_release(&file_priv->master->lock);
419         }
420
421
422         if (drm_i_have_hw_lock(dev, file_priv)) {
423                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
424                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
425                 drm_lock_free(&file_priv->master->lock,
426                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
427         }
428
429         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
430             !dev->driver->reclaim_buffers_locked) {
431                 dev->driver->reclaim_buffers(dev, file_priv);
432         }
433 }
434
435 static void drm_events_release(struct drm_file *file_priv)
436 {
437         struct drm_device *dev = file_priv->minor->dev;
438         struct drm_pending_event *e, *et;
439         struct drm_pending_vblank_event *v, *vt;
440         unsigned long flags;
441
442         spin_lock_irqsave(&dev->event_lock, flags);
443
444         /* Remove pending flips */
445         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
446                 if (v->base.file_priv == file_priv) {
447                         list_del(&v->base.link);
448                         drm_vblank_put(dev, v->pipe);
449                         v->base.destroy(&v->base);
450                 }
451
452         /* Remove unconsumed events */
453         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
454                 e->destroy(e);
455
456         spin_unlock_irqrestore(&dev->event_lock, flags);
457 }
458
459 /**
460  * Release file.
461  *
462  * \param inode device inode
463  * \param file_priv DRM file private.
464  * \return zero on success or a negative number on failure.
465  *
466  * If the hardware lock is held then free it, and take it again for the kernel
467  * context since it's necessary to reclaim buffers. Unlink the file private
468  * data from its list and free it. Decreases the open count and if it reaches
469  * zero calls drm_lastclose().
470  */
471 int drm_release(struct inode *inode, struct file *filp)
472 {
473         struct drm_file *file_priv = filp->private_data;
474         struct drm_device *dev = file_priv->minor->dev;
475         int retcode = 0;
476
477         mutex_lock(&drm_global_mutex);
478
479         DRM_DEBUG("open_count = %d\n", dev->open_count);
480
481         if (dev->driver->preclose)
482                 dev->driver->preclose(dev, file_priv);
483
484         /* ========================================================
485          * Begin inline drm_release
486          */
487
488         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
489                   task_pid_nr(current),
490                   (long)old_encode_dev(file_priv->minor->device),
491                   dev->open_count);
492
493         /* if the master has gone away we can't do anything with the lock */
494         if (file_priv->minor->master)
495                 drm_master_release(dev, filp);
496
497         drm_events_release(file_priv);
498
499         if (dev->driver->driver_features & DRIVER_GEM)
500                 drm_gem_release(dev, file_priv);
501
502         if (dev->driver->driver_features & DRIVER_MODESET)
503                 drm_fb_release(file_priv);
504
505         mutex_lock(&dev->ctxlist_mutex);
506         if (!list_empty(&dev->ctxlist)) {
507                 struct drm_ctx_list *pos, *n;
508
509                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
510                         if (pos->tag == file_priv &&
511                             pos->handle != DRM_KERNEL_CONTEXT) {
512                                 if (dev->driver->context_dtor)
513                                         dev->driver->context_dtor(dev,
514                                                                   pos->handle);
515
516                                 drm_ctxbitmap_free(dev, pos->handle);
517
518                                 list_del(&pos->head);
519                                 kfree(pos);
520                                 --dev->ctx_count;
521                         }
522                 }
523         }
524         mutex_unlock(&dev->ctxlist_mutex);
525
526         mutex_lock(&dev->struct_mutex);
527
528         if (file_priv->is_master) {
529                 struct drm_master *master = file_priv->master;
530                 struct drm_file *temp;
531                 list_for_each_entry(temp, &dev->filelist, lhead) {
532                         if ((temp->master == file_priv->master) &&
533                             (temp != file_priv))
534                                 temp->authenticated = 0;
535                 }
536
537                 /**
538                  * Since the master is disappearing, so is the
539                  * possibility to lock.
540                  */
541
542                 if (master->lock.hw_lock) {
543                         if (dev->sigdata.lock == master->lock.hw_lock)
544                                 dev->sigdata.lock = NULL;
545                         master->lock.hw_lock = NULL;
546                         master->lock.file_priv = NULL;
547                         wake_up_interruptible_all(&master->lock.lock_queue);
548                 }
549
550                 if (file_priv->minor->master == file_priv->master) {
551                         /* drop the reference held my the minor */
552                         if (dev->driver->master_drop)
553                                 dev->driver->master_drop(dev, file_priv, true);
554                         drm_master_put(&file_priv->minor->master);
555                 }
556         }
557
558         /* drop the reference held my the file priv */
559         drm_master_put(&file_priv->master);
560         file_priv->is_master = 0;
561         list_del(&file_priv->lhead);
562         mutex_unlock(&dev->struct_mutex);
563
564         if (dev->driver->postclose)
565                 dev->driver->postclose(dev, file_priv);
566         kfree(file_priv);
567
568         /* ========================================================
569          * End inline drm_release
570          */
571
572         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
573         spin_lock(&dev->count_lock);
574         if (!--dev->open_count) {
575                 if (atomic_read(&dev->ioctl_count)) {
576                         DRM_ERROR("Device busy: %d\n",
577                                   atomic_read(&dev->ioctl_count));
578                         retcode = -EBUSY;
579                         goto out;
580                 }
581                 retcode = drm_lastclose(dev);
582         }
583 out:
584         spin_unlock(&dev->count_lock);
585         mutex_unlock(&drm_global_mutex);
586
587         return retcode;
588 }
589 EXPORT_SYMBOL(drm_release);
590
591 static bool
592 drm_dequeue_event(struct drm_file *file_priv,
593                   size_t total, size_t max, struct drm_pending_event **out)
594 {
595         struct drm_device *dev = file_priv->minor->dev;
596         struct drm_pending_event *e;
597         unsigned long flags;
598         bool ret = false;
599
600         spin_lock_irqsave(&dev->event_lock, flags);
601
602         *out = NULL;
603         if (list_empty(&file_priv->event_list))
604                 goto out;
605         e = list_first_entry(&file_priv->event_list,
606                              struct drm_pending_event, link);
607         if (e->event->length + total > max)
608                 goto out;
609
610         file_priv->event_space += e->event->length;
611         list_del(&e->link);
612         *out = e;
613         ret = true;
614
615 out:
616         spin_unlock_irqrestore(&dev->event_lock, flags);
617         return ret;
618 }
619
620 ssize_t drm_read(struct file *filp, char __user *buffer,
621                  size_t count, loff_t *offset)
622 {
623         struct drm_file *file_priv = filp->private_data;
624         struct drm_pending_event *e;
625         size_t total;
626         ssize_t ret;
627
628         ret = wait_event_interruptible(file_priv->event_wait,
629                                        !list_empty(&file_priv->event_list));
630         if (ret < 0)
631                 return ret;
632
633         total = 0;
634         while (drm_dequeue_event(file_priv, total, count, &e)) {
635                 if (copy_to_user(buffer + total,
636                                  e->event, e->event->length)) {
637                         total = -EFAULT;
638                         break;
639                 }
640
641                 total += e->event->length;
642                 e->destroy(e);
643         }
644
645         return total;
646 }
647 EXPORT_SYMBOL(drm_read);
648
649 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
650 {
651         struct drm_file *file_priv = filp->private_data;
652         unsigned int mask = 0;
653
654         poll_wait(filp, &file_priv->event_wait, wait);
655
656         if (!list_empty(&file_priv->event_list))
657                 mask |= POLLIN | POLLRDNORM;
658
659         return mask;
660 }
661 EXPORT_SYMBOL(drm_poll);