Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[linux-2.6] / 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/smp_lock.h>
40
41 static int drm_open_helper(struct inode *inode, struct file *filp,
42                            struct drm_device * dev);
43
44 static int drm_setup(struct drm_device * dev)
45 {
46         int i;
47         int ret;
48
49         if (dev->driver->firstopen) {
50                 ret = dev->driver->firstopen(dev);
51                 if (ret != 0)
52                         return ret;
53         }
54
55         atomic_set(&dev->ioctl_count, 0);
56         atomic_set(&dev->vma_count, 0);
57
58         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
59             !drm_core_check_feature(dev, DRIVER_MODESET)) {
60                 dev->buf_use = 0;
61                 atomic_set(&dev->buf_alloc, 0);
62
63                 i = drm_dma_setup(dev);
64                 if (i < 0)
65                         return i;
66         }
67
68         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
69                 atomic_set(&dev->counts[i], 0);
70
71         dev->sigdata.lock = NULL;
72
73         dev->queue_count = 0;
74         dev->queue_reserved = 0;
75         dev->queue_slots = 0;
76         dev->queuelist = NULL;
77         dev->context_flag = 0;
78         dev->interrupt_flag = 0;
79         dev->dma_flag = 0;
80         dev->last_context = 0;
81         dev->last_switch = 0;
82         dev->last_checked = 0;
83         init_waitqueue_head(&dev->context_wait);
84         dev->if_version = 0;
85
86         dev->ctx_start = 0;
87         dev->lck_start = 0;
88
89         dev->buf_async = NULL;
90         init_waitqueue_head(&dev->buf_readers);
91         init_waitqueue_head(&dev->buf_writers);
92
93         DRM_DEBUG("\n");
94
95         /*
96          * The kernel's context could be created here, but is now created
97          * in drm_dma_enqueue.  This is more resource-efficient for
98          * hardware that does not do DMA, but may mean that
99          * drm_select_queue fails between the time the interrupt is
100          * initialized and the time the queues are initialized.
101          */
102
103         return 0;
104 }
105
106 /**
107  * Open file.
108  *
109  * \param inode device inode
110  * \param filp file pointer.
111  * \return zero on success or a negative number on failure.
112  *
113  * Searches the DRM device with the same minor number, calls open_helper(), and
114  * increments the device open count. If the open count was previous at zero,
115  * i.e., it's the first that the device is open, then calls setup().
116  */
117 int drm_open(struct inode *inode, struct file *filp)
118 {
119         struct drm_device *dev = NULL;
120         int minor_id = iminor(inode);
121         struct drm_minor *minor;
122         int retcode = 0;
123
124         minor = idr_find(&drm_minors_idr, minor_id);
125         if (!minor)
126                 return -ENODEV;
127
128         if (!(dev = minor->dev))
129                 return -ENODEV;
130
131         retcode = drm_open_helper(inode, filp, dev);
132         if (!retcode) {
133                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
134                 spin_lock(&dev->count_lock);
135                 if (!dev->open_count++) {
136                         spin_unlock(&dev->count_lock);
137                         retcode = drm_setup(dev);
138                         goto out;
139                 }
140                 spin_unlock(&dev->count_lock);
141         }
142 out:
143         mutex_lock(&dev->struct_mutex);
144         if (minor->type == DRM_MINOR_LEGACY) {
145                 BUG_ON((dev->dev_mapping != NULL) &&
146                         (dev->dev_mapping != inode->i_mapping));
147                 if (dev->dev_mapping == NULL)
148                         dev->dev_mapping = inode->i_mapping;
149         }
150         mutex_unlock(&dev->struct_mutex);
151
152         return retcode;
153 }
154 EXPORT_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  */
165 int 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         /* BKL pushdown: note that nothing else serializes idr_find() */
176         lock_kernel();
177         minor = idr_find(&drm_minors_idr, minor_id);
178         if (!minor)
179                 goto out;
180
181         if (!(dev = minor->dev))
182                 goto out;
183
184         old_fops = filp->f_op;
185         filp->f_op = fops_get(&dev->driver->fops);
186         if (filp->f_op == NULL) {
187                 filp->f_op = old_fops;
188                 goto out;
189         }
190         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
191                 fops_put(filp->f_op);
192                 filp->f_op = fops_get(old_fops);
193         }
194         fops_put(old_fops);
195
196 out:
197         unlock_kernel();
198         return err;
199 }
200
201 /**
202  * Check whether DRI will run on this CPU.
203  *
204  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
205  */
206 static int drm_cpu_valid(void)
207 {
208 #if defined(__i386__)
209         if (boot_cpu_data.x86 == 3)
210                 return 0;       /* No cmpxchg on a 386 */
211 #endif
212 #if defined(__sparc__) && !defined(__sparc_v9__)
213         return 0;               /* No cmpxchg before v9 sparc. */
214 #endif
215         return 1;
216 }
217
218 /**
219  * Called whenever a process opens /dev/drm.
220  *
221  * \param inode device inode.
222  * \param filp file pointer.
223  * \param dev device.
224  * \return zero on success or a negative number on failure.
225  *
226  * Creates and initializes a drm_file structure for the file private data in \p
227  * filp and add it into the double linked list in \p dev.
228  */
229 static int drm_open_helper(struct inode *inode, struct file *filp,
230                            struct drm_device * dev)
231 {
232         int minor_id = iminor(inode);
233         struct drm_file *priv;
234         int ret;
235
236         if (filp->f_flags & O_EXCL)
237                 return -EBUSY;  /* No exclusive opens */
238         if (!drm_cpu_valid())
239                 return -EINVAL;
240
241         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
242
243         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
244         if (!priv)
245                 return -ENOMEM;
246
247         memset(priv, 0, sizeof(*priv));
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
261         if (dev->driver->driver_features & DRIVER_GEM)
262                 drm_gem_open(dev, priv);
263
264         if (dev->driver->open) {
265                 ret = dev->driver->open(dev, priv);
266                 if (ret < 0)
267                         goto out_free;
268         }
269
270
271         /* if there is no current master make this fd it */
272         mutex_lock(&dev->struct_mutex);
273         if (!priv->minor->master) {
274                 /* create a new master */
275                 priv->minor->master = drm_master_create(priv->minor);
276                 if (!priv->minor->master) {
277                         mutex_unlock(&dev->struct_mutex);
278                         ret = -ENOMEM;
279                         goto out_free;
280                 }
281
282                 priv->is_master = 1;
283                 /* take another reference for the copy in the local file priv */
284                 priv->master = drm_master_get(priv->minor->master);
285
286                 priv->authenticated = 1;
287
288                 mutex_unlock(&dev->struct_mutex);
289                 if (dev->driver->master_create) {
290                         ret = dev->driver->master_create(dev, priv->master);
291                         if (ret) {
292                                 mutex_lock(&dev->struct_mutex);
293                                 /* drop both references if this fails */
294                                 drm_master_put(&priv->minor->master);
295                                 drm_master_put(&priv->master);
296                                 mutex_unlock(&dev->struct_mutex);
297                                 goto out_free;
298                         }
299                 }
300         } else {
301                 /* get a reference to the master */
302                 priv->master = drm_master_get(priv->minor->master);
303                 mutex_unlock(&dev->struct_mutex);
304         }
305
306         mutex_lock(&dev->struct_mutex);
307         list_add(&priv->lhead, &dev->filelist);
308         mutex_unlock(&dev->struct_mutex);
309
310 #ifdef __alpha__
311         /*
312          * Default the hose
313          */
314         if (!dev->hose) {
315                 struct pci_dev *pci_dev;
316                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
317                 if (pci_dev) {
318                         dev->hose = pci_dev->sysdata;
319                         pci_dev_put(pci_dev);
320                 }
321                 if (!dev->hose) {
322                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
323                         if (b)
324                                 dev->hose = b->sysdata;
325                 }
326         }
327 #endif
328
329         return 0;
330       out_free:
331         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
332         filp->private_data = NULL;
333         return ret;
334 }
335
336 /** No-op. */
337 int drm_fasync(int fd, struct file *filp, int on)
338 {
339         struct drm_file *priv = filp->private_data;
340         struct drm_device *dev = priv->minor->dev;
341
342         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
343                   (long)old_encode_dev(priv->minor->device));
344         return fasync_helper(fd, filp, on, &dev->buf_async);
345 }
346 EXPORT_SYMBOL(drm_fasync);
347
348 /*
349  * Reclaim locked buffers; note that this may be a bad idea if the current
350  * context doesn't have the hw lock...
351  */
352 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
353 {
354         struct drm_file *file_priv = f->private_data;
355
356         if (drm_i_have_hw_lock(dev, file_priv)) {
357                 dev->driver->reclaim_buffers_locked(dev, file_priv);
358         } else {
359                 unsigned long _end = jiffies + 3 * DRM_HZ;
360                 int locked = 0;
361
362                 drm_idlelock_take(&file_priv->master->lock);
363
364                 /*
365                  * Wait for a while.
366                  */
367                 do {
368                         spin_lock_bh(&file_priv->master->lock.spinlock);
369                         locked = file_priv->master->lock.idle_has_lock;
370                         spin_unlock_bh(&file_priv->master->lock.spinlock);
371                         if (locked)
372                                 break;
373                         schedule();
374                 } while (!time_after_eq(jiffies, _end));
375
376                 if (!locked) {
377                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
378                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
379                                   "\tI will go on reclaiming the buffers anyway.\n");
380                 }
381
382                 dev->driver->reclaim_buffers_locked(dev, file_priv);
383                 drm_idlelock_release(&file_priv->master->lock);
384         }
385 }
386
387 static void drm_master_release(struct drm_device *dev, struct file *filp)
388 {
389         struct drm_file *file_priv = filp->private_data;
390
391         if (dev->driver->reclaim_buffers_locked &&
392             file_priv->master->lock.hw_lock)
393                 drm_reclaim_locked_buffers(dev, filp);
394
395         if (dev->driver->reclaim_buffers_idlelocked &&
396             file_priv->master->lock.hw_lock) {
397                 drm_idlelock_take(&file_priv->master->lock);
398                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
399                 drm_idlelock_release(&file_priv->master->lock);
400         }
401
402
403         if (drm_i_have_hw_lock(dev, file_priv)) {
404                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
405                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
406                 drm_lock_free(&file_priv->master->lock,
407                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
408         }
409
410         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
411             !dev->driver->reclaim_buffers_locked) {
412                 dev->driver->reclaim_buffers(dev, file_priv);
413         }
414 }
415
416 /**
417  * Release file.
418  *
419  * \param inode device inode
420  * \param file_priv DRM file private.
421  * \return zero on success or a negative number on failure.
422  *
423  * If the hardware lock is held then free it, and take it again for the kernel
424  * context since it's necessary to reclaim buffers. Unlink the file private
425  * data from its list and free it. Decreases the open count and if it reaches
426  * zero calls drm_lastclose().
427  */
428 int drm_release(struct inode *inode, struct file *filp)
429 {
430         struct drm_file *file_priv = filp->private_data;
431         struct drm_device *dev = file_priv->minor->dev;
432         int retcode = 0;
433
434         lock_kernel();
435
436         DRM_DEBUG("open_count = %d\n", dev->open_count);
437
438         if (dev->driver->preclose)
439                 dev->driver->preclose(dev, file_priv);
440
441         /* ========================================================
442          * Begin inline drm_release
443          */
444
445         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
446                   task_pid_nr(current),
447                   (long)old_encode_dev(file_priv->minor->device),
448                   dev->open_count);
449
450         /* if the master has gone away we can't do anything with the lock */
451         if (file_priv->minor->master)
452                 drm_master_release(dev, filp);
453
454         if (dev->driver->driver_features & DRIVER_GEM)
455                 drm_gem_release(dev, file_priv);
456
457         if (dev->driver->driver_features & DRIVER_MODESET)
458                 drm_fb_release(file_priv);
459
460         mutex_lock(&dev->ctxlist_mutex);
461         if (!list_empty(&dev->ctxlist)) {
462                 struct drm_ctx_list *pos, *n;
463
464                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
465                         if (pos->tag == file_priv &&
466                             pos->handle != DRM_KERNEL_CONTEXT) {
467                                 if (dev->driver->context_dtor)
468                                         dev->driver->context_dtor(dev,
469                                                                   pos->handle);
470
471                                 drm_ctxbitmap_free(dev, pos->handle);
472
473                                 list_del(&pos->head);
474                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
475                                 --dev->ctx_count;
476                         }
477                 }
478         }
479         mutex_unlock(&dev->ctxlist_mutex);
480
481         mutex_lock(&dev->struct_mutex);
482
483         if (file_priv->is_master) {
484                 struct drm_master *master = file_priv->master;
485                 struct drm_file *temp;
486                 list_for_each_entry(temp, &dev->filelist, lhead) {
487                         if ((temp->master == file_priv->master) &&
488                             (temp != file_priv))
489                                 temp->authenticated = 0;
490                 }
491
492                 /**
493                  * Since the master is disappearing, so is the
494                  * possibility to lock.
495                  */
496
497                 if (master->lock.hw_lock) {
498                         if (dev->sigdata.lock == master->lock.hw_lock)
499                                 dev->sigdata.lock = NULL;
500                         master->lock.hw_lock = NULL;
501                         master->lock.file_priv = NULL;
502                         wake_up_interruptible_all(&master->lock.lock_queue);
503                 }
504
505                 if (file_priv->minor->master == file_priv->master) {
506                         /* drop the reference held my the minor */
507                         drm_master_put(&file_priv->minor->master);
508                 }
509         }
510
511         /* drop the reference held my the file priv */
512         drm_master_put(&file_priv->master);
513         file_priv->is_master = 0;
514         list_del(&file_priv->lhead);
515         mutex_unlock(&dev->struct_mutex);
516
517         if (dev->driver->postclose)
518                 dev->driver->postclose(dev, file_priv);
519         drm_free(file_priv, sizeof(*file_priv), DRM_MEM_FILES);
520
521         /* ========================================================
522          * End inline drm_release
523          */
524
525         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
526         spin_lock(&dev->count_lock);
527         if (!--dev->open_count) {
528                 if (atomic_read(&dev->ioctl_count)) {
529                         DRM_ERROR("Device busy: %d\n",
530                                   atomic_read(&dev->ioctl_count));
531                         spin_unlock(&dev->count_lock);
532                         unlock_kernel();
533                         return -EBUSY;
534                 }
535                 spin_unlock(&dev->count_lock);
536                 unlock_kernel();
537                 return drm_lastclose(dev);
538         }
539         spin_unlock(&dev->count_lock);
540
541         unlock_kernel();
542
543         return retcode;
544 }
545 EXPORT_SYMBOL(drm_release);
546
547 /** No-op. */
548 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
549 {
550         return 0;
551 }
552 EXPORT_SYMBOL(drm_poll);