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

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