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 <drm/drmP.h>
38 #include <linux/poll.h>
39 #include <linux/slab.h>
40 #include <linux/module.h>
41 #include "drm_legacy.h"
42 #include "drm_internal.h"
43
44 /* from BKL pushdown */
45 DEFINE_MUTEX(drm_global_mutex);
46
47 static int drm_open_helper(struct file *filp, struct drm_minor *minor);
48
drm_setup(struct drm_device * dev)49 static int drm_setup(struct drm_device * dev)
50 {
51 int ret;
52
53 if (dev->driver->firstopen &&
54 !drm_core_check_feature(dev, DRIVER_MODESET)) {
55 ret = dev->driver->firstopen(dev);
56 if (ret != 0)
57 return ret;
58 }
59
60 ret = drm_legacy_dma_setup(dev);
61 if (ret < 0)
62 return ret;
63
64
65 DRM_DEBUG("\n");
66 return 0;
67 }
68
69 /**
70 * Open file.
71 *
72 * \param inode device inode
73 * \param filp file pointer.
74 * \return zero on success or a negative number on failure.
75 *
76 * Searches the DRM device with the same minor number, calls open_helper(), and
77 * increments the device open count. If the open count was previous at zero,
78 * i.e., it's the first that the device is open, then calls setup().
79 */
drm_open(struct inode * inode,struct file * filp)80 int drm_open(struct inode *inode, struct file *filp)
81 {
82 struct drm_device *dev;
83 struct drm_minor *minor;
84 int retcode;
85 int need_setup = 0;
86
87 minor = drm_minor_acquire(iminor(inode));
88 if (IS_ERR(minor))
89 return PTR_ERR(minor);
90
91 dev = minor->dev;
92 if (!dev->open_count++)
93 need_setup = 1;
94
95 /* share address_space across all char-devs of a single device */
96 filp->f_mapping = dev->anon_inode->i_mapping;
97
98 retcode = drm_open_helper(filp, minor);
99 if (retcode)
100 goto err_undo;
101 if (need_setup) {
102 retcode = drm_setup(dev);
103 if (retcode)
104 goto err_undo;
105 }
106 return 0;
107
108 err_undo:
109 dev->open_count--;
110 drm_minor_release(minor);
111 return retcode;
112 }
113 EXPORT_SYMBOL(drm_open);
114
115 /**
116 * Check whether DRI will run on this CPU.
117 *
118 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
119 */
drm_cpu_valid(void)120 static int drm_cpu_valid(void)
121 {
122 #if defined(__sparc__) && !defined(__sparc_v9__)
123 return 0; /* No cmpxchg before v9 sparc. */
124 #endif
125 return 1;
126 }
127
128 /**
129 * drm_new_set_master - Allocate a new master object and become master for the
130 * associated master realm.
131 *
132 * @dev: The associated device.
133 * @fpriv: File private identifying the client.
134 *
135 * This function must be called with dev::struct_mutex held.
136 * Returns negative error code on failure. Zero on success.
137 */
drm_new_set_master(struct drm_device * dev,struct drm_file * fpriv)138 int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv)
139 {
140 struct drm_master *old_master;
141 int ret;
142
143 lockdep_assert_held_once(&dev->master_mutex);
144
145 /* create a new master */
146 fpriv->minor->master = drm_master_create(fpriv->minor);
147 if (!fpriv->minor->master)
148 return -ENOMEM;
149
150 /* take another reference for the copy in the local file priv */
151 old_master = fpriv->master;
152 fpriv->master = drm_master_get(fpriv->minor->master);
153
154 if (dev->driver->master_create) {
155 ret = dev->driver->master_create(dev, fpriv->master);
156 if (ret)
157 goto out_err;
158 }
159 if (dev->driver->master_set) {
160 ret = dev->driver->master_set(dev, fpriv, true);
161 if (ret)
162 goto out_err;
163 }
164
165 fpriv->is_master = 1;
166 fpriv->allowed_master = 1;
167 fpriv->authenticated = 1;
168 if (old_master)
169 drm_master_put(&old_master);
170
171 return 0;
172
173 out_err:
174 /* drop both references and restore old master on failure */
175 drm_master_put(&fpriv->minor->master);
176 drm_master_put(&fpriv->master);
177 fpriv->master = old_master;
178
179 return ret;
180 }
181
182 /**
183 * Called whenever a process opens /dev/drm.
184 *
185 * \param filp file pointer.
186 * \param minor acquired minor-object.
187 * \return zero on success or a negative number on failure.
188 *
189 * Creates and initializes a drm_file structure for the file private data in \p
190 * filp and add it into the double linked list in \p dev.
191 */
drm_open_helper(struct file * filp,struct drm_minor * minor)192 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
193 {
194 struct drm_device *dev = minor->dev;
195 struct drm_file *priv;
196 int ret;
197
198 if (filp->f_flags & O_EXCL)
199 return -EBUSY; /* No exclusive opens */
200 if (!drm_cpu_valid())
201 return -EINVAL;
202 if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
203 return -EINVAL;
204
205 DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
206
207 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
208 if (!priv)
209 return -ENOMEM;
210
211 filp->private_data = priv;
212 priv->filp = filp;
213 priv->uid = current_euid();
214 priv->pid = get_pid(task_pid(current));
215 priv->minor = minor;
216
217 /* for compatibility root is always authenticated */
218 priv->authenticated = capable(CAP_SYS_ADMIN);
219 priv->lock_count = 0;
220
221 INIT_LIST_HEAD(&priv->lhead);
222 INIT_LIST_HEAD(&priv->fbs);
223 mutex_init(&priv->fbs_lock);
224 INIT_LIST_HEAD(&priv->blobs);
225 INIT_LIST_HEAD(&priv->event_list);
226 init_waitqueue_head(&priv->event_wait);
227 priv->event_space = 4096; /* set aside 4k for event buffer */
228
229 if (drm_core_check_feature(dev, DRIVER_GEM))
230 drm_gem_open(dev, priv);
231
232 if (drm_core_check_feature(dev, DRIVER_PRIME))
233 drm_prime_init_file_private(&priv->prime);
234
235 if (dev->driver->open) {
236 ret = dev->driver->open(dev, priv);
237 if (ret < 0)
238 goto out_prime_destroy;
239 }
240
241 /* if there is no current master make this fd it, but do not create
242 * any master object for render clients */
243 mutex_lock(&dev->master_mutex);
244 if (drm_is_primary_client(priv) && !priv->minor->master) {
245 /* create a new master */
246 ret = drm_new_set_master(dev, priv);
247 if (ret)
248 goto out_close;
249 } else if (drm_is_primary_client(priv)) {
250 /* get a reference to the master */
251 priv->master = drm_master_get(priv->minor->master);
252 }
253 mutex_unlock(&dev->master_mutex);
254
255 mutex_lock(&dev->struct_mutex);
256 list_add(&priv->lhead, &dev->filelist);
257 mutex_unlock(&dev->struct_mutex);
258
259 #ifdef __alpha__
260 /*
261 * Default the hose
262 */
263 if (!dev->hose) {
264 struct pci_dev *pci_dev;
265 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
266 if (pci_dev) {
267 dev->hose = pci_dev->sysdata;
268 pci_dev_put(pci_dev);
269 }
270 if (!dev->hose) {
271 struct pci_bus *b = list_entry(pci_root_buses.next,
272 struct pci_bus, node);
273 if (b)
274 dev->hose = b->sysdata;
275 }
276 }
277 #endif
278
279 return 0;
280
281 out_close:
282 mutex_unlock(&dev->master_mutex);
283 if (dev->driver->postclose)
284 dev->driver->postclose(dev, priv);
285 out_prime_destroy:
286 if (drm_core_check_feature(dev, DRIVER_PRIME))
287 drm_prime_destroy_file_private(&priv->prime);
288 if (drm_core_check_feature(dev, DRIVER_GEM))
289 drm_gem_release(dev, priv);
290 put_pid(priv->pid);
291 kfree(priv);
292 filp->private_data = NULL;
293 return ret;
294 }
295
drm_master_release(struct drm_device * dev,struct file * filp)296 static void drm_master_release(struct drm_device *dev, struct file *filp)
297 {
298 struct drm_file *file_priv = filp->private_data;
299
300 if (drm_legacy_i_have_hw_lock(dev, file_priv)) {
301 DRM_DEBUG("File %p released, freeing lock for context %d\n",
302 filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
303 drm_legacy_lock_free(&file_priv->master->lock,
304 _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
305 }
306 }
307
drm_events_release(struct drm_file * file_priv)308 static void drm_events_release(struct drm_file *file_priv)
309 {
310 struct drm_device *dev = file_priv->minor->dev;
311 struct drm_pending_event *e, *et;
312 struct drm_pending_vblank_event *v, *vt;
313 unsigned long flags;
314
315 spin_lock_irqsave(&dev->event_lock, flags);
316
317 /* Remove pending flips */
318 list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
319 if (v->base.file_priv == file_priv) {
320 list_del(&v->base.link);
321 drm_vblank_put(dev, v->pipe);
322 v->base.destroy(&v->base);
323 }
324
325 /* Remove unconsumed events */
326 list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
327 list_del(&e->link);
328 e->destroy(e);
329 }
330
331 spin_unlock_irqrestore(&dev->event_lock, flags);
332 }
333
334 /**
335 * drm_legacy_dev_reinit
336 *
337 * Reinitializes a legacy/ums drm device in it's lastclose function.
338 */
drm_legacy_dev_reinit(struct drm_device * dev)339 static void drm_legacy_dev_reinit(struct drm_device *dev)
340 {
341 if (drm_core_check_feature(dev, DRIVER_MODESET))
342 return;
343
344 dev->sigdata.lock = NULL;
345
346 dev->context_flag = 0;
347 dev->last_context = 0;
348 dev->if_version = 0;
349 }
350
351 /**
352 * Take down the DRM device.
353 *
354 * \param dev DRM device structure.
355 *
356 * Frees every resource in \p dev.
357 *
358 * \sa drm_device
359 */
drm_lastclose(struct drm_device * dev)360 int drm_lastclose(struct drm_device * dev)
361 {
362 DRM_DEBUG("\n");
363
364 if (dev->driver->lastclose)
365 dev->driver->lastclose(dev);
366 DRM_DEBUG("driver lastclose completed\n");
367
368 if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
369 drm_irq_uninstall(dev);
370
371 mutex_lock(&dev->struct_mutex);
372
373 drm_agp_clear(dev);
374
375 drm_legacy_sg_cleanup(dev);
376 drm_legacy_vma_flush(dev);
377 drm_legacy_dma_takedown(dev);
378
379 mutex_unlock(&dev->struct_mutex);
380
381 drm_legacy_dev_reinit(dev);
382
383 DRM_DEBUG("lastclose completed\n");
384 return 0;
385 }
386
387 /**
388 * Release file.
389 *
390 * \param inode device inode
391 * \param file_priv DRM file private.
392 * \return zero on success or a negative number on failure.
393 *
394 * If the hardware lock is held then free it, and take it again for the kernel
395 * context since it's necessary to reclaim buffers. Unlink the file private
396 * data from its list and free it. Decreases the open count and if it reaches
397 * zero calls drm_lastclose().
398 */
drm_release(struct inode * inode,struct file * filp)399 int drm_release(struct inode *inode, struct file *filp)
400 {
401 struct drm_file *file_priv = filp->private_data;
402 struct drm_minor *minor = file_priv->minor;
403 struct drm_device *dev = minor->dev;
404 int retcode = 0;
405
406 mutex_lock(&drm_global_mutex);
407
408 DRM_DEBUG("open_count = %d\n", dev->open_count);
409
410 mutex_lock(&dev->struct_mutex);
411 list_del(&file_priv->lhead);
412 if (file_priv->magic)
413 idr_remove(&file_priv->master->magic_map, file_priv->magic);
414 mutex_unlock(&dev->struct_mutex);
415
416 if (dev->driver->preclose)
417 dev->driver->preclose(dev, file_priv);
418
419 /* ========================================================
420 * Begin inline drm_release
421 */
422
423 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
424 task_pid_nr(current),
425 (long)old_encode_dev(file_priv->minor->kdev->devt),
426 dev->open_count);
427
428 /* if the master has gone away we can't do anything with the lock */
429 if (file_priv->minor->master)
430 drm_master_release(dev, filp);
431
432 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
433 drm_legacy_reclaim_buffers(dev, file_priv);
434
435 drm_events_release(file_priv);
436
437 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
438 drm_fb_release(file_priv);
439 drm_property_destroy_user_blobs(dev, file_priv);
440 }
441
442 if (drm_core_check_feature(dev, DRIVER_GEM))
443 drm_gem_release(dev, file_priv);
444
445 drm_legacy_ctxbitmap_flush(dev, file_priv);
446
447 mutex_lock(&dev->master_mutex);
448
449 if (file_priv->is_master) {
450 struct drm_master *master = file_priv->master;
451
452 /**
453 * Since the master is disappearing, so is the
454 * possibility to lock.
455 */
456 mutex_lock(&dev->struct_mutex);
457 if (master->lock.hw_lock) {
458 if (dev->sigdata.lock == master->lock.hw_lock)
459 dev->sigdata.lock = NULL;
460 master->lock.hw_lock = NULL;
461 master->lock.file_priv = NULL;
462 wake_up_interruptible_all(&master->lock.lock_queue);
463 }
464 mutex_unlock(&dev->struct_mutex);
465
466 if (file_priv->minor->master == file_priv->master) {
467 /* drop the reference held my the minor */
468 if (dev->driver->master_drop)
469 dev->driver->master_drop(dev, file_priv, true);
470 drm_master_put(&file_priv->minor->master);
471 }
472 }
473
474 /* drop the master reference held by the file priv */
475 if (file_priv->master)
476 drm_master_put(&file_priv->master);
477 file_priv->is_master = 0;
478 mutex_unlock(&dev->master_mutex);
479
480 if (dev->driver->postclose)
481 dev->driver->postclose(dev, file_priv);
482
483
484 if (drm_core_check_feature(dev, DRIVER_PRIME))
485 drm_prime_destroy_file_private(&file_priv->prime);
486
487 WARN_ON(!list_empty(&file_priv->event_list));
488
489 put_pid(file_priv->pid);
490 kfree(file_priv);
491
492 /* ========================================================
493 * End inline drm_release
494 */
495
496 if (!--dev->open_count) {
497 retcode = drm_lastclose(dev);
498 if (drm_device_is_unplugged(dev))
499 drm_put_dev(dev);
500 }
501 mutex_unlock(&drm_global_mutex);
502
503 drm_minor_release(minor);
504
505 return retcode;
506 }
507 EXPORT_SYMBOL(drm_release);
508
drm_read(struct file * filp,char __user * buffer,size_t count,loff_t * offset)509 ssize_t drm_read(struct file *filp, char __user *buffer,
510 size_t count, loff_t *offset)
511 {
512 struct drm_file *file_priv = filp->private_data;
513 struct drm_device *dev = file_priv->minor->dev;
514 ssize_t ret = 0;
515
516 if (!access_ok(VERIFY_WRITE, buffer, count))
517 return -EFAULT;
518
519 spin_lock_irq(&dev->event_lock);
520 for (;;) {
521 if (list_empty(&file_priv->event_list)) {
522 if (ret)
523 break;
524
525 if (filp->f_flags & O_NONBLOCK) {
526 ret = -EAGAIN;
527 break;
528 }
529
530 spin_unlock_irq(&dev->event_lock);
531 ret = wait_event_interruptible(file_priv->event_wait,
532 !list_empty(&file_priv->event_list));
533 spin_lock_irq(&dev->event_lock);
534 if (ret < 0)
535 break;
536
537 ret = 0;
538 } else {
539 struct drm_pending_event *e;
540
541 e = list_first_entry(&file_priv->event_list,
542 struct drm_pending_event, link);
543 if (e->event->length + ret > count)
544 break;
545
546 if (__copy_to_user_inatomic(buffer + ret,
547 e->event, e->event->length)) {
548 if (ret == 0)
549 ret = -EFAULT;
550 break;
551 }
552
553 file_priv->event_space += e->event->length;
554 ret += e->event->length;
555 list_del(&e->link);
556 e->destroy(e);
557 }
558 }
559 spin_unlock_irq(&dev->event_lock);
560
561 return ret;
562 }
563 EXPORT_SYMBOL(drm_read);
564
drm_poll(struct file * filp,struct poll_table_struct * wait)565 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
566 {
567 struct drm_file *file_priv = filp->private_data;
568 unsigned int mask = 0;
569
570 poll_wait(filp, &file_priv->event_wait, wait);
571
572 if (!list_empty(&file_priv->event_list))
573 mask |= POLLIN | POLLRDNORM;
574
575 return mask;
576 }
577 EXPORT_SYMBOL(drm_poll);
578