3733e36d135ed2700e221fb6609a0b8809c481c5
[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/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->open && (err = filp->f_op->open(inode, filp))) {
187                 fops_put(filp->f_op);
188                 filp->f_op = fops_get(old_fops);
189         }
190         fops_put(old_fops);
191
192 out:
193         unlock_kernel();
194         return err;
195 }
196
197 /**
198  * Check whether DRI will run on this CPU.
199  *
200  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
201  */
202 static int drm_cpu_valid(void)
203 {
204 #if defined(__i386__)
205         if (boot_cpu_data.x86 == 3)
206                 return 0;       /* No cmpxchg on a 386 */
207 #endif
208 #if defined(__sparc__) && !defined(__sparc_v9__)
209         return 0;               /* No cmpxchg before v9 sparc. */
210 #endif
211         return 1;
212 }
213
214 /**
215  * Called whenever a process opens /dev/drm.
216  *
217  * \param inode device inode.
218  * \param filp file pointer.
219  * \param dev device.
220  * \return zero on success or a negative number on failure.
221  *
222  * Creates and initializes a drm_file structure for the file private data in \p
223  * filp and add it into the double linked list in \p dev.
224  */
225 static int drm_open_helper(struct inode *inode, struct file *filp,
226                            struct drm_device * dev)
227 {
228         int minor_id = iminor(inode);
229         struct drm_file *priv;
230         int ret;
231
232         if (filp->f_flags & O_EXCL)
233                 return -EBUSY;  /* No exclusive opens */
234         if (!drm_cpu_valid())
235                 return -EINVAL;
236
237         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
238
239         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
240         if (!priv)
241                 return -ENOMEM;
242
243         memset(priv, 0, sizeof(*priv));
244         filp->private_data = priv;
245         priv->filp = filp;
246         priv->uid = current_euid();
247         priv->pid = task_pid_nr(current);
248         priv->minor = idr_find(&drm_minors_idr, minor_id);
249         priv->ioctl_count = 0;
250         /* for compatibility root is always authenticated */
251         priv->authenticated = capable(CAP_SYS_ADMIN);
252         priv->lock_count = 0;
253
254         INIT_LIST_HEAD(&priv->lhead);
255         INIT_LIST_HEAD(&priv->fbs);
256
257         if (dev->driver->driver_features & DRIVER_GEM)
258                 drm_gem_open(dev, priv);
259
260         if (dev->driver->open) {
261                 ret = dev->driver->open(dev, priv);
262                 if (ret < 0)
263                         goto out_free;
264         }
265
266
267         /* if there is no current master make this fd it */
268         mutex_lock(&dev->struct_mutex);
269         if (!priv->minor->master) {
270                 /* create a new master */
271                 priv->minor->master = drm_master_create(priv->minor);
272                 if (!priv->minor->master) {
273                         ret = -ENOMEM;
274                         goto out_free;
275                 }
276
277                 priv->is_master = 1;
278                 /* take another reference for the copy in the local file priv */
279                 priv->master = drm_master_get(priv->minor->master);
280
281                 priv->authenticated = 1;
282
283                 mutex_unlock(&dev->struct_mutex);
284                 if (dev->driver->master_create) {
285                         ret = dev->driver->master_create(dev, priv->master);
286                         if (ret) {
287                                 mutex_lock(&dev->struct_mutex);
288                                 /* drop both references if this fails */
289                                 drm_master_put(&priv->minor->master);
290                                 drm_master_put(&priv->master);
291                                 mutex_unlock(&dev->struct_mutex);
292                                 goto out_free;
293                         }
294                 }
295         } else {
296                 /* get a reference to the master */
297                 priv->master = drm_master_get(priv->minor->master);
298                 mutex_unlock(&dev->struct_mutex);
299         }
300
301         mutex_lock(&dev->struct_mutex);
302         list_add(&priv->lhead, &dev->filelist);
303         mutex_unlock(&dev->struct_mutex);
304
305 #ifdef __alpha__
306         /*
307          * Default the hose
308          */
309         if (!dev->hose) {
310                 struct pci_dev *pci_dev;
311                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
312                 if (pci_dev) {
313                         dev->hose = pci_dev->sysdata;
314                         pci_dev_put(pci_dev);
315                 }
316                 if (!dev->hose) {
317                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
318                         if (b)
319                                 dev->hose = b->sysdata;
320                 }
321         }
322 #endif
323
324         return 0;
325       out_free:
326         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
327         filp->private_data = NULL;
328         return ret;
329 }
330
331 /** No-op. */
332 int drm_fasync(int fd, struct file *filp, int on)
333 {
334         struct drm_file *priv = filp->private_data;
335         struct drm_device *dev = priv->minor->dev;
336         int retcode;
337
338         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
339                   (long)old_encode_dev(priv->minor->device));
340         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
341         if (retcode < 0)
342                 return retcode;
343         return 0;
344 }
345 EXPORT_SYMBOL(drm_fasync);
346
347 /*
348  * Reclaim locked buffers; note that this may be a bad idea if the current
349  * context doesn't have the hw lock...
350  */
351 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
352 {
353         struct drm_file *file_priv = f->private_data;
354
355         if (drm_i_have_hw_lock(dev, file_priv)) {
356                 dev->driver->reclaim_buffers_locked(dev, file_priv);
357         } else {
358                 unsigned long _end = jiffies + 3 * DRM_HZ;
359                 int locked = 0;
360
361                 drm_idlelock_take(&file_priv->master->lock);
362
363                 /*
364                  * Wait for a while.
365                  */
366                 do {
367                         spin_lock_bh(&file_priv->master->lock.spinlock);
368                         locked = file_priv->master->lock.idle_has_lock;
369                         spin_unlock_bh(&file_priv->master->lock.spinlock);
370                         if (locked)
371                                 break;
372                         schedule();
373                 } while (!time_after_eq(jiffies, _end));
374
375                 if (!locked) {
376                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
377                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
378                                   "\tI will go on reclaiming the buffers anyway.\n");
379                 }
380
381                 dev->driver->reclaim_buffers_locked(dev, file_priv);
382                 drm_idlelock_release(&file_priv->master->lock);
383         }
384 }
385
386 static void drm_master_release(struct drm_device *dev, struct file *filp)
387 {
388         struct drm_file *file_priv = filp->private_data;
389
390         if (dev->driver->reclaim_buffers_locked &&
391             file_priv->master->lock.hw_lock)
392                 drm_reclaim_locked_buffers(dev, filp);
393
394         if (dev->driver->reclaim_buffers_idlelocked &&
395             file_priv->master->lock.hw_lock) {
396                 drm_idlelock_take(&file_priv->master->lock);
397                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
398                 drm_idlelock_release(&file_priv->master->lock);
399         }
400
401
402         if (drm_i_have_hw_lock(dev, file_priv)) {
403                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
404                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
405                 drm_lock_free(&file_priv->master->lock,
406                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
407         }
408
409         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
410             !dev->driver->reclaim_buffers_locked) {
411                 dev->driver->reclaim_buffers(dev, file_priv);
412         }
413 }
414
415 /**
416  * Release file.
417  *
418  * \param inode device inode
419  * \param file_priv DRM file private.
420  * \return zero on success or a negative number on failure.
421  *
422  * If the hardware lock is held then free it, and take it again for the kernel
423  * context since it's necessary to reclaim buffers. Unlink the file private
424  * data from its list and free it. Decreases the open count and if it reaches
425  * zero calls drm_lastclose().
426  */
427 int drm_release(struct inode *inode, struct file *filp)
428 {
429         struct drm_file *file_priv = filp->private_data;
430         struct drm_device *dev = file_priv->minor->dev;
431         int retcode = 0;
432
433         lock_kernel();
434
435         DRM_DEBUG("open_count = %d\n", dev->open_count);
436
437         if (dev->driver->preclose)
438                 dev->driver->preclose(dev, file_priv);
439
440         /* ========================================================
441          * Begin inline drm_release
442          */
443
444         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
445                   task_pid_nr(current),
446                   (long)old_encode_dev(file_priv->minor->device),
447                   dev->open_count);
448
449         /* if the master has gone away we can't do anything with the lock */
450         if (file_priv->minor->master)
451                 drm_master_release(dev, filp);
452
453         if (dev->driver->driver_features & DRIVER_GEM)
454                 drm_gem_release(dev, file_priv);
455
456         mutex_lock(&dev->ctxlist_mutex);
457         if (!list_empty(&dev->ctxlist)) {
458                 struct drm_ctx_list *pos, *n;
459
460                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
461                         if (pos->tag == file_priv &&
462                             pos->handle != DRM_KERNEL_CONTEXT) {
463                                 if (dev->driver->context_dtor)
464                                         dev->driver->context_dtor(dev,
465                                                                   pos->handle);
466
467                                 drm_ctxbitmap_free(dev, pos->handle);
468
469                                 list_del(&pos->head);
470                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
471                                 --dev->ctx_count;
472                         }
473                 }
474         }
475         mutex_unlock(&dev->ctxlist_mutex);
476
477         mutex_lock(&dev->struct_mutex);
478
479         if (file_priv->is_master) {
480                 struct drm_file *temp;
481                 list_for_each_entry(temp, &dev->filelist, lhead) {
482                         if ((temp->master == file_priv->master) &&
483                             (temp != file_priv))
484                                 temp->authenticated = 0;
485                 }
486
487                 if (file_priv->minor->master == file_priv->master) {
488                         /* drop the reference held my the minor */
489                         drm_master_put(&file_priv->minor->master);
490                 }
491         }
492
493         /* drop the reference held my the file priv */
494         drm_master_put(&file_priv->master);
495         file_priv->is_master = 0;
496         list_del(&file_priv->lhead);
497         mutex_unlock(&dev->struct_mutex);
498
499         if (dev->driver->postclose)
500                 dev->driver->postclose(dev, file_priv);
501         drm_free(file_priv, sizeof(*file_priv), DRM_MEM_FILES);
502
503         /* ========================================================
504          * End inline drm_release
505          */
506
507         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
508         spin_lock(&dev->count_lock);
509         if (!--dev->open_count) {
510                 if (atomic_read(&dev->ioctl_count)) {
511                         DRM_ERROR("Device busy: %d\n",
512                                   atomic_read(&dev->ioctl_count));
513                         spin_unlock(&dev->count_lock);
514                         unlock_kernel();
515                         return -EBUSY;
516                 }
517                 spin_unlock(&dev->count_lock);
518                 unlock_kernel();
519                 return drm_lastclose(dev);
520         }
521         spin_unlock(&dev->count_lock);
522
523         unlock_kernel();
524
525         return retcode;
526 }
527 EXPORT_SYMBOL(drm_release);
528
529 /** No-op. */
530 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
531 {
532         return 0;
533 }
534 EXPORT_SYMBOL(drm_poll);