xref: /linux/drivers/gpu/drm/drm_drv.c (revision 7ec7fb394298c212c30e063c57e0aa895efe9439)
1 /**
2  * \file drm_drv.c
3  * Generic driver template
4  *
5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
6  * \author Gareth Hughes <gareth@valinux.com>
7  *
8  * To use this template, you must at least define the following (samples
9  * given for the MGA driver):
10  *
11  * \code
12  * #define DRIVER_AUTHOR	"VA Linux Systems, Inc."
13  *
14  * #define DRIVER_NAME		"mga"
15  * #define DRIVER_DESC		"Matrox G200/G400"
16  * #define DRIVER_DATE		"20001127"
17  *
18  * #define drm_x		mga_##x
19  * \endcode
20  */
21 
22 /*
23  * Created: Thu Nov 23 03:10:50 2000 by gareth@valinux.com
24  *
25  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
26  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
27  * All Rights Reserved.
28  *
29  * Permission is hereby granted, free of charge, to any person obtaining a
30  * copy of this software and associated documentation files (the "Software"),
31  * to deal in the Software without restriction, including without limitation
32  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
33  * and/or sell copies of the Software, and to permit persons to whom the
34  * Software is furnished to do so, subject to the following conditions:
35  *
36  * The above copyright notice and this permission notice (including the next
37  * paragraph) shall be included in all copies or substantial portions of the
38  * Software.
39  *
40  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
41  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
42  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
43  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
44  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
45  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
46  * OTHER DEALINGS IN THE SOFTWARE.
47  */
48 
49 #include "drmP.h"
50 #include "drm_core.h"
51 
52 static int drm_version(struct drm_device *dev, void *data,
53 		       struct drm_file *file_priv);
54 
55 /** Ioctl table */
56 static struct drm_ioctl_desc drm_ioctls[] = {
57 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, 0),
58 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
59 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
60 	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
61 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, 0),
62 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
63 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
64 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER|DRM_ROOT_ONLY),
65 
66 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
67 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
68 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
69 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
70 
71 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
72 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_rmmap_ioctl, DRM_AUTH),
73 
74 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
75 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_getsareactx, DRM_AUTH),
76 
77 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY),
78 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY),
79 
80 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_addctx, DRM_AUTH|DRM_ROOT_ONLY),
81 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
82 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_modctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
83 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_getctx, DRM_AUTH),
84 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
85 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
86 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_resctx, DRM_AUTH),
87 
88 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_adddraw, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
89 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_rmdraw, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
90 
91 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_lock, DRM_AUTH),
92 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_unlock, DRM_AUTH),
93 
94 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
95 
96 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
97 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
98 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_infobufs, DRM_AUTH),
99 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_mapbufs, DRM_AUTH),
100 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_freebufs, DRM_AUTH),
101 	/* The DRM_IOCTL_DMA ioctl should be defined by the driver. */
102 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, NULL, DRM_AUTH),
103 
104 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
105 
106 #if __OS_HAS_AGP
107 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
108 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
109 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
110 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
111 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
112 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
113 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
114 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
115 #endif
116 
117 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_sg_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
118 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
119 
120 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, 0),
121 
122 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
123 
124 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_update_drawable_info, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
125 
126 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, 0),
127 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH),
128 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH),
129 
130 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_MASTER|DRM_CONTROL_ALLOW),
131 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_MASTER|DRM_CONTROL_ALLOW),
132 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW),
133 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW),
134 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_MASTER),
135 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER),
136 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_MASTER|DRM_CONTROL_ALLOW),
137 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_MASTER|DRM_CONTROL_ALLOW),
138 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_mode_attachmode_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW),
139 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_mode_detachmode_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW),
140 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_MASTER | DRM_CONTROL_ALLOW),
141 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW),
142 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW),
143 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_MASTER|DRM_CONTROL_ALLOW),
144 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_MASTER|DRM_CONTROL_ALLOW),
145 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_MASTER|DRM_CONTROL_ALLOW),
146 };
147 
148 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
149 
150 /**
151  * Take down the DRM device.
152  *
153  * \param dev DRM device structure.
154  *
155  * Frees every resource in \p dev.
156  *
157  * \sa drm_device
158  */
159 int drm_lastclose(struct drm_device * dev)
160 {
161 	struct drm_vma_entry *vma, *vma_temp;
162 	int i;
163 
164 	DRM_DEBUG("\n");
165 
166 	if (dev->driver->lastclose)
167 		dev->driver->lastclose(dev);
168 	DRM_DEBUG("driver lastclose completed\n");
169 
170 	if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
171 		drm_irq_uninstall(dev);
172 
173 	mutex_lock(&dev->struct_mutex);
174 
175 	/* Free drawable information memory */
176 	drm_drawable_free_all(dev);
177 	del_timer(&dev->timer);
178 
179 	/* Clear AGP information */
180 	if (drm_core_has_AGP(dev) && dev->agp &&
181 	    !drm_core_check_feature(dev, DRIVER_MODESET)) {
182 		struct drm_agp_mem *entry, *tempe;
183 
184 		/* Remove AGP resources, but leave dev->agp
185 		   intact until drv_cleanup is called. */
186 		list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
187 			if (entry->bound)
188 				drm_unbind_agp(entry->memory);
189 			drm_free_agp(entry->memory, entry->pages);
190 			drm_free(entry, sizeof(*entry), DRM_MEM_AGPLISTS);
191 		}
192 		INIT_LIST_HEAD(&dev->agp->memory);
193 
194 		if (dev->agp->acquired)
195 			drm_agp_release(dev);
196 
197 		dev->agp->acquired = 0;
198 		dev->agp->enabled = 0;
199 	}
200 	if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
201 	    !drm_core_check_feature(dev, DRIVER_MODESET)) {
202 		drm_sg_cleanup(dev->sg);
203 		dev->sg = NULL;
204 	}
205 
206 	/* Clear vma list (only built for debugging) */
207 	list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
208 		list_del(&vma->head);
209 		drm_free(vma, sizeof(*vma), DRM_MEM_VMAS);
210 	}
211 
212 	if (drm_core_check_feature(dev, DRIVER_DMA_QUEUE) && dev->queuelist) {
213 		for (i = 0; i < dev->queue_count; i++) {
214 			if (dev->queuelist[i]) {
215 				drm_free(dev->queuelist[i],
216 					 sizeof(*dev->queuelist[0]),
217 					 DRM_MEM_QUEUES);
218 				dev->queuelist[i] = NULL;
219 			}
220 		}
221 		drm_free(dev->queuelist,
222 			 dev->queue_slots * sizeof(*dev->queuelist),
223 			 DRM_MEM_QUEUES);
224 		dev->queuelist = NULL;
225 	}
226 	dev->queue_count = 0;
227 
228 	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
229 	    !drm_core_check_feature(dev, DRIVER_MODESET))
230 		drm_dma_takedown(dev);
231 
232 	dev->dev_mapping = NULL;
233 	mutex_unlock(&dev->struct_mutex);
234 
235 	DRM_DEBUG("lastclose completed\n");
236 	return 0;
237 }
238 
239 /**
240  * Module initialization. Called via init_module at module load time, or via
241  * linux/init/main.c (this is not currently supported).
242  *
243  * \return zero on success or a negative number on failure.
244  *
245  * Initializes an array of drm_device structures, and attempts to
246  * initialize all available devices, using consecutive minors, registering the
247  * stubs and initializing the AGP device.
248  *
249  * Expands the \c DRIVER_PREINIT and \c DRIVER_POST_INIT macros before and
250  * after the initialization for driver customization.
251  */
252 int drm_init(struct drm_driver *driver)
253 {
254 	struct pci_dev *pdev = NULL;
255 	struct pci_device_id *pid;
256 	int i;
257 
258 	DRM_DEBUG("\n");
259 
260 	INIT_LIST_HEAD(&driver->device_list);
261 
262 	for (i = 0; driver->pci_driver.id_table[i].vendor != 0; i++) {
263 		pid = (struct pci_device_id *)&driver->pci_driver.id_table[i];
264 
265 		/* Loop around setting up a DRM device for each PCI device
266 		 * matching our ID and device class.  If we had the internal
267 		 * function that pci_get_subsys and pci_get_class used, we'd
268 		 * be able to just pass pid in instead of doing a two-stage
269 		 * thing.
270 		 */
271 		pdev = NULL;
272 		while ((pdev =
273 			pci_get_subsys(pid->vendor, pid->device, pid->subvendor,
274 				       pid->subdevice, pdev)) != NULL) {
275 			if ((pdev->class & pid->class_mask) != pid->class)
276 				continue;
277 
278 			/* stealth mode requires a manual probe */
279 			pci_dev_get(pdev);
280 			drm_get_dev(pdev, pid, driver);
281 		}
282 	}
283 	return 0;
284 }
285 
286 EXPORT_SYMBOL(drm_init);
287 
288 /**
289  * Called via cleanup_module() at module unload time.
290  *
291  * Cleans up all DRM device, calling drm_lastclose().
292  *
293  * \sa drm_init
294  */
295 static void drm_cleanup(struct drm_device * dev)
296 {
297 	DRM_DEBUG("\n");
298 
299 	if (!dev) {
300 		DRM_ERROR("cleanup called no dev\n");
301 		return;
302 	}
303 
304 	drm_vblank_cleanup(dev);
305 
306 	drm_lastclose(dev);
307 
308 	if (drm_core_has_MTRR(dev) && drm_core_has_AGP(dev) &&
309 	    dev->agp && dev->agp->agp_mtrr >= 0) {
310 		int retval;
311 		retval = mtrr_del(dev->agp->agp_mtrr,
312 				  dev->agp->agp_info.aper_base,
313 				  dev->agp->agp_info.aper_size * 1024 * 1024);
314 		DRM_DEBUG("mtrr_del=%d\n", retval);
315 	}
316 
317 	if (drm_core_has_AGP(dev) && dev->agp) {
318 		drm_free(dev->agp, sizeof(*dev->agp), DRM_MEM_AGPLISTS);
319 		dev->agp = NULL;
320 	}
321 
322 	if (dev->driver->unload)
323 		dev->driver->unload(dev);
324 
325 	drm_ht_remove(&dev->map_hash);
326 	drm_ctxbitmap_cleanup(dev);
327 
328 	if (drm_core_check_feature(dev, DRIVER_MODESET))
329 		drm_put_minor(&dev->control);
330 
331 	if (dev->driver->driver_features & DRIVER_GEM)
332 		drm_gem_destroy(dev);
333 
334 	drm_put_minor(&dev->primary);
335 	if (drm_put_dev(dev))
336 		DRM_ERROR("Cannot unload module\n");
337 }
338 
339 void drm_exit(struct drm_driver *driver)
340 {
341 	struct drm_device *dev, *tmp;
342 	DRM_DEBUG("\n");
343 
344 	list_for_each_entry_safe(dev, tmp, &driver->device_list, driver_item)
345 		drm_cleanup(dev);
346 
347 	DRM_INFO("Module unloaded\n");
348 }
349 
350 EXPORT_SYMBOL(drm_exit);
351 
352 /** File operations structure */
353 static const struct file_operations drm_stub_fops = {
354 	.owner = THIS_MODULE,
355 	.open = drm_stub_open
356 };
357 
358 static int __init drm_core_init(void)
359 {
360 	int ret = -ENOMEM;
361 
362 	idr_init(&drm_minors_idr);
363 
364 	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
365 		goto err_p1;
366 
367 	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
368 	if (IS_ERR(drm_class)) {
369 		printk(KERN_ERR "DRM: Error creating drm class.\n");
370 		ret = PTR_ERR(drm_class);
371 		goto err_p2;
372 	}
373 
374 	drm_proc_root = proc_mkdir("dri", NULL);
375 	if (!drm_proc_root) {
376 		DRM_ERROR("Cannot create /proc/dri\n");
377 		ret = -1;
378 		goto err_p3;
379 	}
380 
381 	drm_mem_init();
382 
383 	DRM_INFO("Initialized %s %d.%d.%d %s\n",
384 		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
385 	return 0;
386 err_p3:
387 	drm_sysfs_destroy();
388 err_p2:
389 	unregister_chrdev(DRM_MAJOR, "drm");
390 
391 	idr_destroy(&drm_minors_idr);
392 err_p1:
393 	return ret;
394 }
395 
396 static void __exit drm_core_exit(void)
397 {
398 	remove_proc_entry("dri", NULL);
399 	drm_sysfs_destroy();
400 
401 	unregister_chrdev(DRM_MAJOR, "drm");
402 
403 	idr_destroy(&drm_minors_idr);
404 }
405 
406 module_init(drm_core_init);
407 module_exit(drm_core_exit);
408 
409 /**
410  * Get version information
411  *
412  * \param inode device inode.
413  * \param filp file pointer.
414  * \param cmd command.
415  * \param arg user argument, pointing to a drm_version structure.
416  * \return zero on success or negative number on failure.
417  *
418  * Fills in the version information in \p arg.
419  */
420 static int drm_version(struct drm_device *dev, void *data,
421 		       struct drm_file *file_priv)
422 {
423 	struct drm_version *version = data;
424 	int len;
425 
426 	version->version_major = dev->driver->major;
427 	version->version_minor = dev->driver->minor;
428 	version->version_patchlevel = dev->driver->patchlevel;
429 	DRM_COPY(version->name, dev->driver->name);
430 	DRM_COPY(version->date, dev->driver->date);
431 	DRM_COPY(version->desc, dev->driver->desc);
432 
433 	return 0;
434 }
435 
436 /**
437  * Called whenever a process performs an ioctl on /dev/drm.
438  *
439  * \param inode device inode.
440  * \param file_priv DRM file private.
441  * \param cmd command.
442  * \param arg user argument.
443  * \return zero on success or negative number on failure.
444  *
445  * Looks up the ioctl function in the ::ioctls table, checking for root
446  * previleges if so required, and dispatches to the respective function.
447  */
448 int drm_ioctl(struct inode *inode, struct file *filp,
449 	      unsigned int cmd, unsigned long arg)
450 {
451 	struct drm_file *file_priv = filp->private_data;
452 	struct drm_device *dev = file_priv->minor->dev;
453 	struct drm_ioctl_desc *ioctl;
454 	drm_ioctl_t *func;
455 	unsigned int nr = DRM_IOCTL_NR(cmd);
456 	int retcode = -EINVAL;
457 	char *kdata = NULL;
458 
459 	atomic_inc(&dev->ioctl_count);
460 	atomic_inc(&dev->counts[_DRM_STAT_IOCTLS]);
461 	++file_priv->ioctl_count;
462 
463 	DRM_DEBUG("pid=%d, cmd=0x%02x, nr=0x%02x, dev 0x%lx, auth=%d\n",
464 		  task_pid_nr(current), cmd, nr,
465 		  (long)old_encode_dev(file_priv->minor->device),
466 		  file_priv->authenticated);
467 
468 	if ((nr >= DRM_CORE_IOCTL_COUNT) &&
469 	    ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
470 		goto err_i1;
471 	if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
472 	    (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls))
473 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
474 	else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
475 		ioctl = &drm_ioctls[nr];
476 		cmd = ioctl->cmd;
477 	} else
478 		goto err_i1;
479 
480 	/* Do not trust userspace, use our own definition */
481 	func = ioctl->func;
482 	/* is there a local override? */
483 	if ((nr == DRM_IOCTL_NR(DRM_IOCTL_DMA)) && dev->driver->dma_ioctl)
484 		func = dev->driver->dma_ioctl;
485 
486 	if (!func) {
487 		DRM_DEBUG("no function\n");
488 		retcode = -EINVAL;
489 	} else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
490 		   ((ioctl->flags & DRM_AUTH) && !file_priv->authenticated) ||
491 		   ((ioctl->flags & DRM_MASTER) && !file_priv->is_master)) {
492 		retcode = -EACCES;
493 	} else {
494 		if (cmd & (IOC_IN | IOC_OUT)) {
495 			kdata = kmalloc(_IOC_SIZE(cmd), GFP_KERNEL);
496 			if (!kdata) {
497 				retcode = -ENOMEM;
498 				goto err_i1;
499 			}
500 		}
501 
502 		if (cmd & IOC_IN) {
503 			if (copy_from_user(kdata, (void __user *)arg,
504 					   _IOC_SIZE(cmd)) != 0) {
505 				retcode = -EFAULT;
506 				goto err_i1;
507 			}
508 		}
509 		retcode = func(dev, kdata, file_priv);
510 
511 		if ((retcode == 0) && (cmd & IOC_OUT)) {
512 			if (copy_to_user((void __user *)arg, kdata,
513 					 _IOC_SIZE(cmd)) != 0)
514 				retcode = -EFAULT;
515 		}
516 	}
517 
518       err_i1:
519 	if (kdata)
520 		kfree(kdata);
521 	atomic_dec(&dev->ioctl_count);
522 	if (retcode)
523 		DRM_DEBUG("ret = %x\n", retcode);
524 	return retcode;
525 }
526 
527 EXPORT_SYMBOL(drm_ioctl);
528 
529 drm_local_map_t *drm_getsarea(struct drm_device *dev)
530 {
531 	struct drm_map_list *entry;
532 
533 	list_for_each_entry(entry, &dev->maplist, head) {
534 		if (entry->map && entry->map->type == _DRM_SHM &&
535 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
536 			return entry->map;
537 		}
538 	}
539 	return NULL;
540 }
541 EXPORT_SYMBOL(drm_getsarea);
542