[PATCH] usbserial: Regression in USB generic serial driver
[safe/jmp/linux-2.6] / drivers / char / drm / drm_fops.c
1 /**
2  * \file drm_fops.h 
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
40 static int drm_open_helper(struct inode *inode, struct file *filp, drm_device_t *dev);
41
42 static int drm_setup( drm_device_t *dev )
43 {
44         int i;
45         int ret;
46
47         if (dev->driver->presetup)
48         {
49                 ret=dev->driver->presetup(dev);
50                 if (ret!=0) 
51                         return ret;
52         }
53
54         atomic_set( &dev->ioctl_count, 0 );
55         atomic_set( &dev->vma_count, 0 );
56         dev->buf_use = 0;
57         atomic_set( &dev->buf_alloc, 0 );
58
59         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
60         {
61                 i = drm_dma_setup( dev );
62                 if ( i < 0 )
63                         return i;
64         }
65
66         for ( i = 0 ; i < DRM_ARRAY_SIZE(dev->counts) ; i++ )
67                 atomic_set( &dev->counts[i], 0 );
68
69         for ( i = 0 ; i < DRM_HASH_SIZE ; i++ ) {
70                 dev->magiclist[i].head = NULL;
71                 dev->magiclist[i].tail = NULL;
72         }
73
74         dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist),
75                                   DRM_MEM_CTXLIST);
76         if(dev->ctxlist == NULL) return -ENOMEM;
77         memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
78         INIT_LIST_HEAD(&dev->ctxlist->head);
79
80         dev->vmalist = NULL;
81         dev->sigdata.lock = dev->lock.hw_lock = NULL;
82         init_waitqueue_head( &dev->lock.lock_queue );
83         dev->queue_count = 0;
84         dev->queue_reserved = 0;
85         dev->queue_slots = 0;
86         dev->queuelist = NULL;
87         dev->irq_enabled = 0;
88         dev->context_flag = 0;
89         dev->interrupt_flag = 0;
90         dev->dma_flag = 0;
91         dev->last_context = 0;
92         dev->last_switch = 0;
93         dev->last_checked = 0;
94         init_waitqueue_head( &dev->context_wait );
95         dev->if_version = 0;
96
97         dev->ctx_start = 0;
98         dev->lck_start = 0;
99
100         dev->buf_rp = dev->buf;
101         dev->buf_wp = dev->buf;
102         dev->buf_end = dev->buf + DRM_BSZ;
103         dev->buf_async = NULL;
104         init_waitqueue_head( &dev->buf_readers );
105         init_waitqueue_head( &dev->buf_writers );
106
107         DRM_DEBUG( "\n" );
108
109         /*
110          * The kernel's context could be created here, but is now created
111          * in drm_dma_enqueue.  This is more resource-efficient for
112          * hardware that does not do DMA, but may mean that
113          * drm_select_queue fails between the time the interrupt is
114          * initialized and the time the queues are initialized.
115          */
116         if (dev->driver->postsetup)
117                 dev->driver->postsetup(dev);
118
119         return 0;
120 }
121
122 /**
123  * Open file.
124  * 
125  * \param inode device inode
126  * \param filp file pointer.
127  * \return zero on success or a negative number on failure.
128  *
129  * Searches the DRM device with the same minor number, calls open_helper(), and
130  * increments the device open count. If the open count was previous at zero,
131  * i.e., it's the first that the device is open, then calls setup().
132  */
133 int drm_open( struct inode *inode, struct file *filp )
134 {
135         drm_device_t *dev = NULL;
136         int minor = iminor(inode);
137         int retcode = 0;
138
139         if (!((minor >= 0) && (minor < drm_cards_limit)))
140                 return -ENODEV;
141                 
142         if (!drm_heads[minor])
143                 return -ENODEV;
144
145         if (!(dev = drm_heads[minor]->dev))
146                 return -ENODEV;
147         
148         retcode = drm_open_helper( inode, filp, dev );
149         if ( !retcode ) {
150                 atomic_inc( &dev->counts[_DRM_STAT_OPENS] );
151                 spin_lock( &dev->count_lock );
152                 if ( !dev->open_count++ ) {
153                         spin_unlock( &dev->count_lock );
154                         return drm_setup( dev );
155                 }
156                 spin_unlock( &dev->count_lock );
157         }
158
159         return retcode;
160 }
161 EXPORT_SYMBOL(drm_open);
162
163 /**
164  * Release file.
165  *
166  * \param inode device inode
167  * \param filp file pointer.
168  * \return zero on success or a negative number on failure.
169  *
170  * If the hardware lock is held then free it, and take it again for the kernel
171  * context since it's necessary to reclaim buffers. Unlink the file private
172  * data from its list and free it. Decreases the open count and if it reaches
173  * zero calls takedown().
174  */
175 int drm_release( struct inode *inode, struct file *filp )
176 {
177         drm_file_t *priv = filp->private_data;
178         drm_device_t *dev;
179         int retcode = 0;
180
181         lock_kernel();
182         dev = priv->head->dev;
183
184         DRM_DEBUG( "open_count = %d\n", dev->open_count );
185
186         if (dev->driver->prerelease)
187                 dev->driver->prerelease(dev, filp);
188
189         /* ========================================================
190          * Begin inline drm_release
191          */
192
193         DRM_DEBUG( "pid = %d, device = 0x%lx, open_count = %d\n",
194                    current->pid, (long)old_encode_dev(priv->head->device), dev->open_count );
195
196         if ( priv->lock_count && dev->lock.hw_lock &&
197              _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
198              dev->lock.filp == filp ) {
199                 DRM_DEBUG( "File %p released, freeing lock for context %d\n",
200                         filp,
201                         _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock) );
202                 
203                 if (dev->driver->release)
204                         dev->driver->release(dev, filp);
205
206                 drm_lock_free( dev, &dev->lock.hw_lock->lock,
207                                 _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock) );
208
209                                 /* FIXME: may require heavy-handed reset of
210                                    hardware at this point, possibly
211                                    processed via a callback to the X
212                                    server. */
213         }
214         else if ( dev->driver->release && priv->lock_count && dev->lock.hw_lock ) {
215                 /* The lock is required to reclaim buffers */
216                 DECLARE_WAITQUEUE( entry, current );
217
218                 add_wait_queue( &dev->lock.lock_queue, &entry );
219                 for (;;) {
220                         __set_current_state(TASK_INTERRUPTIBLE);
221                         if ( !dev->lock.hw_lock ) {
222                                 /* Device has been unregistered */
223                                 retcode = -EINTR;
224                                 break;
225                         }
226                         if ( drm_lock_take( &dev->lock.hw_lock->lock,
227                                              DRM_KERNEL_CONTEXT ) ) {
228                                 dev->lock.filp      = filp;
229                                 dev->lock.lock_time = jiffies;
230                                 atomic_inc( &dev->counts[_DRM_STAT_LOCKS] );
231                                 break;  /* Got lock */
232                         }
233                                 /* Contention */
234                         schedule();
235                         if ( signal_pending( current ) ) {
236                                 retcode = -ERESTARTSYS;
237                                 break;
238                         }
239                 }
240                 __set_current_state(TASK_RUNNING);
241                 remove_wait_queue( &dev->lock.lock_queue, &entry );
242                 if( !retcode ) {
243                         if (dev->driver->release)
244                                 dev->driver->release(dev, filp);
245                         drm_lock_free( dev, &dev->lock.hw_lock->lock,
246                                         DRM_KERNEL_CONTEXT );
247                 }
248         }
249         
250         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) && !dev->driver->release)
251         {
252                 dev->driver->reclaim_buffers(dev, filp);
253         }
254
255         drm_fasync( -1, filp, 0 );
256
257         down( &dev->ctxlist_sem );
258         if ( dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
259                 drm_ctx_list_t *pos, *n;
260
261                 list_for_each_entry_safe( pos, n, &dev->ctxlist->head, head ) {
262                         if ( pos->tag == priv &&
263                              pos->handle != DRM_KERNEL_CONTEXT ) {
264                                 if (dev->driver->context_dtor)
265                                         dev->driver->context_dtor(dev, pos->handle);
266
267                                 drm_ctxbitmap_free( dev, pos->handle );
268
269                                 list_del( &pos->head );
270                                 drm_free( pos, sizeof(*pos), DRM_MEM_CTXLIST );
271                                 --dev->ctx_count;
272                         }
273                 }
274         }
275         up( &dev->ctxlist_sem );
276
277         down( &dev->struct_sem );
278         if ( priv->remove_auth_on_close == 1 ) {
279                 drm_file_t *temp = dev->file_first;
280                 while ( temp ) {
281                         temp->authenticated = 0;
282                         temp = temp->next;
283                 }
284         }
285         if ( priv->prev ) {
286                 priv->prev->next = priv->next;
287         } else {
288                 dev->file_first  = priv->next;
289         }
290         if ( priv->next ) {
291                 priv->next->prev = priv->prev;
292         } else {
293                 dev->file_last   = priv->prev;
294         }
295         up( &dev->struct_sem );
296         
297         if (dev->driver->free_filp_priv)
298                 dev->driver->free_filp_priv(dev, priv);
299
300         drm_free( priv, sizeof(*priv), DRM_MEM_FILES );
301
302         /* ========================================================
303          * End inline drm_release
304          */
305
306         atomic_inc( &dev->counts[_DRM_STAT_CLOSES] );
307         spin_lock( &dev->count_lock );
308         if ( !--dev->open_count ) {
309                 if ( atomic_read( &dev->ioctl_count ) || dev->blocked ) {
310                         DRM_ERROR( "Device busy: %d %d\n",
311                                    atomic_read( &dev->ioctl_count ),
312                                    dev->blocked );
313                         spin_unlock( &dev->count_lock );
314                         unlock_kernel();
315                         return -EBUSY;
316                 }
317                 spin_unlock( &dev->count_lock );
318                 unlock_kernel();
319                 return drm_takedown( dev );
320         }
321         spin_unlock( &dev->count_lock );
322
323         unlock_kernel();
324
325         return retcode;
326 }
327 EXPORT_SYMBOL(drm_release);
328
329 /**
330  * Called whenever a process opens /dev/drm. 
331  *
332  * \param inode device inode.
333  * \param filp file pointer.
334  * \param dev device.
335  * \return zero on success or a negative number on failure.
336  * 
337  * Creates and initializes a drm_file structure for the file private data in \p
338  * filp and add it into the double linked list in \p dev.
339  */
340 static int drm_open_helper(struct inode *inode, struct file *filp, drm_device_t *dev)
341 {
342         int          minor = iminor(inode);
343         drm_file_t   *priv;
344         int ret;
345
346         if (filp->f_flags & O_EXCL)   return -EBUSY; /* No exclusive opens */
347         if (!drm_cpu_valid())        return -EINVAL;
348
349         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
350
351         priv                = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
352         if(!priv) return -ENOMEM;
353
354         memset(priv, 0, sizeof(*priv));
355         filp->private_data  = priv;
356         priv->uid           = current->euid;
357         priv->pid           = current->pid;
358         priv->minor         = minor;
359         priv->head          = drm_heads[minor];
360         priv->ioctl_count   = 0;
361         priv->authenticated = capable(CAP_SYS_ADMIN);
362         priv->lock_count    = 0;
363
364         if (dev->driver->open_helper) {
365                 ret=dev->driver->open_helper(dev, priv);
366                 if (ret < 0)
367                         goto out_free;
368         }
369
370         down(&dev->struct_sem);
371         if (!dev->file_last) {
372                 priv->next      = NULL;
373                 priv->prev      = NULL;
374                 dev->file_first = priv;
375                 dev->file_last  = priv;
376         } else {
377                 priv->next           = NULL;
378                 priv->prev           = dev->file_last;
379                 dev->file_last->next = priv;
380                 dev->file_last       = priv;
381         }
382         up(&dev->struct_sem);
383
384 #ifdef __alpha__
385         /*
386          * Default the hose
387          */
388         if (!dev->hose) {
389                 struct pci_dev *pci_dev;
390                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
391                 if (pci_dev) {
392                         dev->hose = pci_dev->sysdata;
393                         pci_dev_put(pci_dev);
394                 }
395                 if (!dev->hose) {
396                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
397                         if (b) dev->hose = b->sysdata;
398                 }
399         }
400 #endif
401
402         return 0;
403 out_free:
404         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
405         filp->private_data=NULL;
406         return ret;
407 }
408
409 /** No-op. */
410 int drm_flush(struct file *filp)
411 {
412         drm_file_t    *priv   = filp->private_data;
413         drm_device_t  *dev    = priv->head->dev;
414
415         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
416                   current->pid, (long)old_encode_dev(priv->head->device), dev->open_count);
417         return 0;
418 }
419 EXPORT_SYMBOL(drm_flush);
420
421 /** No-op. */
422 int drm_fasync(int fd, struct file *filp, int on)
423 {
424         drm_file_t    *priv   = filp->private_data;
425         drm_device_t  *dev    = priv->head->dev;
426         int           retcode;
427
428         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd, (long)old_encode_dev(priv->head->device));
429         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
430         if (retcode < 0) return retcode;
431         return 0;
432 }
433 EXPORT_SYMBOL(drm_fasync);
434
435 /** No-op. */
436 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
437 {
438         return 0;
439 }
440 EXPORT_SYMBOL(drm_poll);
441