Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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_setup( drm_device_t *dev )
 41 {
 42         int i;
 43         int ret;
 44 
 45         if (dev->driver->presetup)
 46         {
 47                 ret=dev->driver->presetup(dev);
 48                 if (ret!=0) 
 49                         return ret;
 50         }
 51 
 52         atomic_set( &dev->ioctl_count, 0 );
 53         atomic_set( &dev->vma_count, 0 );
 54         dev->buf_use = 0;
 55         atomic_set( &dev->buf_alloc, 0 );
 56 
 57         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 58         {
 59                 i = drm_dma_setup( dev );
 60                 if ( i < 0 )
 61                         return i;
 62         }
 63 
 64         for ( i = 0 ; i < DRM_ARRAY_SIZE(dev->counts) ; i++ )
 65                 atomic_set( &dev->counts[i], 0 );
 66 
 67         for ( i = 0 ; i < DRM_HASH_SIZE ; i++ ) {
 68                 dev->magiclist[i].head = NULL;
 69                 dev->magiclist[i].tail = NULL;
 70         }
 71 
 72         dev->maplist = drm_alloc(sizeof(*dev->maplist),
 73                                   DRM_MEM_MAPS);
 74         if(dev->maplist == NULL) return -ENOMEM;
 75         memset(dev->maplist, 0, sizeof(*dev->maplist));
 76         INIT_LIST_HEAD(&dev->maplist->head);
 77 
 78         dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist),
 79                                   DRM_MEM_CTXLIST);
 80         if(dev->ctxlist == NULL) return -ENOMEM;
 81         memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
 82         INIT_LIST_HEAD(&dev->ctxlist->head);
 83 
 84         dev->vmalist = NULL;
 85         dev->sigdata.lock = dev->lock.hw_lock = NULL;
 86         init_waitqueue_head( &dev->lock.lock_queue );
 87         dev->queue_count = 0;
 88         dev->queue_reserved = 0;
 89         dev->queue_slots = 0;
 90         dev->queuelist = NULL;
 91         dev->irq_enabled = 0;
 92         dev->context_flag = 0;
 93         dev->interrupt_flag = 0;
 94         dev->dma_flag = 0;
 95         dev->last_context = 0;
 96         dev->last_switch = 0;
 97         dev->last_checked = 0;
 98         init_waitqueue_head( &dev->context_wait );
 99         dev->if_version = 0;
100 
101         dev->ctx_start = 0;
102         dev->lck_start = 0;
103 
104         dev->buf_rp = dev->buf;
105         dev->buf_wp = dev->buf;
106         dev->buf_end = dev->buf + DRM_BSZ;
107         dev->buf_async = NULL;
108         init_waitqueue_head( &dev->buf_readers );
109         init_waitqueue_head( &dev->buf_writers );
110 
111         DRM_DEBUG( "\n" );
112 
113         /*
114          * The kernel's context could be created here, but is now created
115          * in drm_dma_enqueue.  This is more resource-efficient for
116          * hardware that does not do DMA, but may mean that
117          * drm_select_queue fails between the time the interrupt is
118          * initialized and the time the queues are initialized.
119          */
120         if (dev->driver->postsetup)
121                 dev->driver->postsetup(dev);
122 
123         return 0;
124 }
125 
126 /**
127  * Open file.
128  * 
129  * \param inode device inode
130  * \param filp file pointer.
131  * \return zero on success or a negative number on failure.
132  *
133  * Searches the DRM device with the same minor number, calls open_helper(), and
134  * increments the device open count. If the open count was previous at zero,
135  * i.e., it's the first that the device is open, then calls setup().
136  */
137 int drm_open( struct inode *inode, struct file *filp )
138 {
139         drm_device_t *dev = NULL;
140         int minor = iminor(inode);
141         int retcode = 0;
142 
143         if (!((minor >= 0) && (minor < drm_cards_limit)))
144                 return -ENODEV;
145                 
146         dev = drm_minors[minor].dev;
147         if (!dev)
148                 return -ENODEV;
149         
150         retcode = drm_open_helper( inode, filp, dev );
151         if ( !retcode ) {
152                 atomic_inc( &dev->counts[_DRM_STAT_OPENS] );
153                 spin_lock( &dev->count_lock );
154                 if ( !dev->open_count++ ) {
155                         spin_unlock( &dev->count_lock );
156                         return drm_setup( dev );
157                 }
158                 spin_unlock( &dev->count_lock );
159         }
160 
161         return retcode;
162 }
163 EXPORT_SYMBOL(drm_open);
164 
165 /**
166  * Release file.
167  *
168  * \param inode device inode
169  * \param filp file pointer.
170  * \return zero on success or a negative number on failure.
171  *
172  * If the hardware lock is held then free it, and take it again for the kernel
173  * context since it's necessary to reclaim buffers. Unlink the file private
174  * data from its list and free it. Decreases the open count and if it reaches
175  * zero calls takedown().
176  */
177 int drm_release( struct inode *inode, struct file *filp )
178 {
179         drm_file_t *priv = filp->private_data;
180         drm_device_t *dev;
181         int retcode = 0;
182 
183         lock_kernel();
184         dev = priv->dev;
185 
186         DRM_DEBUG( "open_count = %d\n", dev->open_count );
187 
188         if (dev->driver->prerelease)
189                 dev->driver->prerelease(dev, filp);
190 
191         /* ========================================================
192          * Begin inline drm_release
193          */
194 
195         DRM_DEBUG( "pid = %d, device = 0x%lx, open_count = %d\n",
196                    current->pid, (long)old_encode_dev(dev->device), dev->open_count );
197 
198         if ( priv->lock_count && dev->lock.hw_lock &&
199              _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
200              dev->lock.filp == filp ) {
201                 DRM_DEBUG( "File %p released, freeing lock for context %d\n",
202                         filp,
203                         _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock) );
204                 
205                 if (dev->driver->release)
206                         dev->driver->release(dev, filp);
207 
208                 drm_lock_free( dev, &dev->lock.hw_lock->lock,
209                                 _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock) );
210 
211                                 /* FIXME: may require heavy-handed reset of
212                                    hardware at this point, possibly
213                                    processed via a callback to the X
214                                    server. */
215         }
216         else if ( dev->driver->release && priv->lock_count && dev->lock.hw_lock ) {
217                 /* The lock is required to reclaim buffers */
218                 DECLARE_WAITQUEUE( entry, current );
219 
220                 add_wait_queue( &dev->lock.lock_queue, &entry );
221                 for (;;) {
222                         __set_current_state(TASK_INTERRUPTIBLE);
223                         if ( !dev->lock.hw_lock ) {
224                                 /* Device has been unregistered */
225                                 retcode = -EINTR;
226                                 break;
227                         }
228                         if ( drm_lock_take( &dev->lock.hw_lock->lock,
229                                              DRM_KERNEL_CONTEXT ) ) {
230                                 dev->lock.filp      = filp;
231                                 dev->lock.lock_time = jiffies;
232                                 atomic_inc( &dev->counts[_DRM_STAT_LOCKS] );
233                                 break;  /* Got lock */
234                         }
235                                 /* Contention */
236                         schedule();
237                         if ( signal_pending( current ) ) {
238                                 retcode = -ERESTARTSYS;
239                                 break;
240                         }
241                 }
242                 __set_current_state(TASK_RUNNING);
243                 remove_wait_queue( &dev->lock.lock_queue, &entry );
244                 if( !retcode ) {
245                         if (dev->driver->release)
246                                 dev->driver->release(dev, filp);
247                         drm_lock_free( dev, &dev->lock.hw_lock->lock,
248                                         DRM_KERNEL_CONTEXT );
249                 }
250         }
251         
252         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
253         {
254                 dev->driver->reclaim_buffers(dev, filp);
255         }
256 
257         drm_fasync( -1, filp, 0 );
258 
259         down( &dev->ctxlist_sem );
260         if ( !list_empty( &dev->ctxlist->head ) ) {
261                 drm_ctx_list_t *pos, *n;
262 
263                 list_for_each_entry_safe( pos, n, &dev->ctxlist->head, head ) {
264                         if ( pos->tag == priv &&
265                              pos->handle != DRM_KERNEL_CONTEXT ) {
266                                 if (dev->driver->context_dtor)
267                                         dev->driver->context_dtor(dev, pos->handle);
268 
269                                 drm_ctxbitmap_free( dev, pos->handle );
270 
271                                 list_del( &pos->head );
272                                 drm_free( pos, sizeof(*pos), DRM_MEM_CTXLIST );
273                                 --dev->ctx_count;
274                         }
275                 }
276         }
277         up( &dev->ctxlist_sem );
278 
279         down( &dev->struct_sem );
280         if ( priv->remove_auth_on_close == 1 ) {
281                 drm_file_t *temp = dev->file_first;
282                 while ( temp ) {
283                         temp->authenticated = 0;
284                         temp = temp->next;
285                 }
286         }
287         if ( priv->prev ) {
288                 priv->prev->next = priv->next;
289         } else {
290                 dev->file_first  = priv->next;
291         }
292         if ( priv->next ) {
293                 priv->next->prev = priv->prev;
294         } else {
295                 dev->file_last   = priv->prev;
296         }
297         up( &dev->struct_sem );
298         
299         if (dev->driver->free_filp_priv)
300                 dev->driver->free_filp_priv(dev, priv);
301 
302         drm_free( priv, sizeof(*priv), DRM_MEM_FILES );
303 
304         /* ========================================================
305          * End inline drm_release
306          */
307 
308         atomic_inc( &dev->counts[_DRM_STAT_CLOSES] );
309         spin_lock( &dev->count_lock );
310         if ( !--dev->open_count ) {
311                 if ( atomic_read( &dev->ioctl_count ) || dev->blocked ) {
312                         DRM_ERROR( "Device busy: %d %d\n",
313                                    atomic_read( &dev->ioctl_count ),
314                                    dev->blocked );
315                         spin_unlock( &dev->count_lock );
316                         unlock_kernel();
317                         return -EBUSY;
318                 }
319                 spin_unlock( &dev->count_lock );
320                 unlock_kernel();
321                 return drm_takedown( dev );
322         }
323         spin_unlock( &dev->count_lock );
324 
325         unlock_kernel();
326 
327         return retcode;
328 }
329 EXPORT_SYMBOL(drm_release);
330 
331 /**
332  * Called whenever a process opens /dev/drm. 
333  *
334  * \param inode device inode.
335  * \param filp file pointer.
336  * \param dev device.
337  * \return zero on success or a negative number on failure.
338  * 
339  * Creates and initializes a drm_file structure for the file private data in \p
340  * filp and add it into the double linked list in \p dev.
341  */
342 int drm_open_helper(struct inode *inode, struct file *filp, drm_device_t *dev)
343 {
344         int          minor = iminor(inode);
345         drm_file_t   *priv;
346         int ret;
347 
348         if (filp->f_flags & O_EXCL)   return -EBUSY; /* No exclusive opens */
349         if (!drm_cpu_valid())        return -EINVAL;
350 
351         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
352 
353         priv                = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
354         if(!priv) return -ENOMEM;
355 
356         memset(priv, 0, sizeof(*priv));
357         filp->private_data  = priv;
358         priv->uid           = current->euid;
359         priv->pid           = current->pid;
360         priv->minor         = minor;
361         priv->dev           = dev;
362         priv->ioctl_count   = 0;
363         priv->authenticated = capable(CAP_SYS_ADMIN);
364         priv->lock_count    = 0;
365 
366         if (dev->driver->open_helper) {
367                 ret=dev->driver->open_helper(dev, priv);
368                 if (ret < 0)
369                         goto out_free;
370         }
371 
372         down(&dev->struct_sem);
373         if (!dev->file_last) {
374                 priv->next      = NULL;
375                 priv->prev      = NULL;
376                 dev->file_first = priv;
377                 dev->file_last  = priv;
378         } else {
379                 priv->next           = NULL;
380                 priv->prev           = dev->file_last;
381                 dev->file_last->next = priv;
382                 dev->file_last       = priv;
383         }
384         up(&dev->struct_sem);
385 
386 #ifdef __alpha__
387         /*
388          * Default the hose
389          */
390         if (!dev->hose) {
391                 struct pci_dev *pci_dev;
392                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
393                 if (pci_dev) {
394                         dev->hose = pci_dev->sysdata;
395                         pci_dev_put(pci_dev);
396                 }
397                 if (!dev->hose) {
398                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
399                         if (b) dev->hose = b->sysdata;
400                 }
401         }
402 #endif
403 
404         return 0;
405 out_free:
406         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
407         filp->private_data=NULL;
408         return ret;
409 }
410 
411 /** No-op. */
412 int drm_flush(struct file *filp)
413 {
414         drm_file_t    *priv   = filp->private_data;
415         drm_device_t  *dev    = priv->dev;
416 
417         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
418                   current->pid, (long)old_encode_dev(dev->device), dev->open_count);
419         return 0;
420 }
421 EXPORT_SYMBOL(drm_flush);
422 
423 /** No-op. */
424 int drm_fasync(int fd, struct file *filp, int on)
425 {
426         drm_file_t    *priv   = filp->private_data;
427         drm_device_t  *dev    = priv->dev;
428         int           retcode;
429 
430         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd, (long)old_encode_dev(dev->device));
431         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
432         if (retcode < 0) return retcode;
433         return 0;
434 }
435 EXPORT_SYMBOL(drm_fasync);
436 
437 /** No-op. */
438 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
439 {
440         return 0;
441 }
442 EXPORT_SYMBOL(drm_poll);
443 
444 
445 /** No-op. */
446 ssize_t drm_read(struct file *filp, char __user *buf, size_t count, loff_t *off)
447 {
448         return 0;
449 }
450 
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