xref: /openbmc/linux/drivers/gpu/drm/drm_drv.c (revision 5104d265)
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 <linux/debugfs.h>
50 #include <linux/slab.h>
51 #include <linux/export.h>
52 #include <drm/drmP.h>
53 #include <drm/drm_core.h>
54 
55 
56 static int drm_version(struct drm_device *dev, void *data,
57 		       struct drm_file *file_priv);
58 
59 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \
60 	[DRM_IOCTL_NR(ioctl)] = {.cmd = ioctl, .func = _func, .flags = _flags, .cmd_drv = 0, .name = #ioctl}
61 
62 /** Ioctl table */
63 static const struct drm_ioctl_desc drm_ioctls[] = {
64 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_UNLOCKED),
65 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
66 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
67 	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
68 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, DRM_UNLOCKED),
69 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
70 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
71 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED),
72 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
73 
74 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
75 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
76 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
77 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_MASTER),
78 
79 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
80 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_rmmap_ioctl, DRM_AUTH),
81 
82 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
83 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_getsareactx, DRM_AUTH),
84 
85 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY),
86 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY),
87 
88 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_addctx, DRM_AUTH|DRM_ROOT_ONLY),
89 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
90 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_modctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
91 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_getctx, DRM_AUTH),
92 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
93 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
94 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_resctx, DRM_AUTH),
95 
96 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
97 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
98 
99 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_lock, DRM_AUTH),
100 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_unlock, DRM_AUTH),
101 
102 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
103 
104 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
105 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
106 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_infobufs, DRM_AUTH),
107 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_mapbufs, DRM_AUTH),
108 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_freebufs, DRM_AUTH),
109 	/* The DRM_IOCTL_DMA ioctl should be defined by the driver. */
110 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, NULL, DRM_AUTH),
111 
112 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
113 
114 #if __OS_HAS_AGP
115 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
116 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
117 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
118 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
119 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
120 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
121 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
122 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
123 #endif
124 
125 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_sg_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
126 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
127 
128 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
129 
130 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
131 
132 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
133 
134 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED),
135 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
136 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
137 
138 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
139 
140 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED),
141 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED),
142 
143 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
144 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
145 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
146 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
147 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
148 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
149 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
150 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
151 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
152 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
153 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
154 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
155 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
156 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
157 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
158 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
159 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
160 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
161 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
162 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
163 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
164 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
165 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
166 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
167 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
168 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
169 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
170 };
171 
172 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
173 
174 /**
175  * Take down the DRM device.
176  *
177  * \param dev DRM device structure.
178  *
179  * Frees every resource in \p dev.
180  *
181  * \sa drm_device
182  */
183 int drm_lastclose(struct drm_device * dev)
184 {
185 	struct drm_vma_entry *vma, *vma_temp;
186 
187 	DRM_DEBUG("\n");
188 
189 	if (dev->driver->lastclose)
190 		dev->driver->lastclose(dev);
191 	DRM_DEBUG("driver lastclose completed\n");
192 
193 	if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
194 		drm_irq_uninstall(dev);
195 
196 	mutex_lock(&dev->struct_mutex);
197 
198 	/* Clear AGP information */
199 	if (drm_core_has_AGP(dev) && dev->agp &&
200 			!drm_core_check_feature(dev, DRIVER_MODESET)) {
201 		struct drm_agp_mem *entry, *tempe;
202 
203 		/* Remove AGP resources, but leave dev->agp
204 		   intact until drv_cleanup is called. */
205 		list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
206 			if (entry->bound)
207 				drm_unbind_agp(entry->memory);
208 			drm_free_agp(entry->memory, entry->pages);
209 			kfree(entry);
210 		}
211 		INIT_LIST_HEAD(&dev->agp->memory);
212 
213 		if (dev->agp->acquired)
214 			drm_agp_release(dev);
215 
216 		dev->agp->acquired = 0;
217 		dev->agp->enabled = 0;
218 	}
219 	if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
220 	    !drm_core_check_feature(dev, DRIVER_MODESET)) {
221 		drm_sg_cleanup(dev->sg);
222 		dev->sg = NULL;
223 	}
224 
225 	/* Clear vma list (only built for debugging) */
226 	list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
227 		list_del(&vma->head);
228 		kfree(vma);
229 	}
230 
231 	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
232 	    !drm_core_check_feature(dev, DRIVER_MODESET))
233 		drm_dma_takedown(dev);
234 
235 	dev->dev_mapping = NULL;
236 	mutex_unlock(&dev->struct_mutex);
237 
238 	DRM_DEBUG("lastclose completed\n");
239 	return 0;
240 }
241 
242 /** File operations structure */
243 static const struct file_operations drm_stub_fops = {
244 	.owner = THIS_MODULE,
245 	.open = drm_stub_open,
246 	.llseek = noop_llseek,
247 };
248 
249 static int __init drm_core_init(void)
250 {
251 	int ret = -ENOMEM;
252 
253 	drm_global_init();
254 	idr_init(&drm_minors_idr);
255 
256 	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
257 		goto err_p1;
258 
259 	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
260 	if (IS_ERR(drm_class)) {
261 		printk(KERN_ERR "DRM: Error creating drm class.\n");
262 		ret = PTR_ERR(drm_class);
263 		goto err_p2;
264 	}
265 
266 	drm_proc_root = proc_mkdir("dri", NULL);
267 	if (!drm_proc_root) {
268 		DRM_ERROR("Cannot create /proc/dri\n");
269 		ret = -1;
270 		goto err_p3;
271 	}
272 
273 	drm_debugfs_root = debugfs_create_dir("dri", NULL);
274 	if (!drm_debugfs_root) {
275 		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
276 		ret = -1;
277 		goto err_p3;
278 	}
279 
280 	DRM_INFO("Initialized %s %d.%d.%d %s\n",
281 		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
282 	return 0;
283 err_p3:
284 	drm_sysfs_destroy();
285 err_p2:
286 	unregister_chrdev(DRM_MAJOR, "drm");
287 
288 	idr_destroy(&drm_minors_idr);
289 err_p1:
290 	return ret;
291 }
292 
293 static void __exit drm_core_exit(void)
294 {
295 	remove_proc_entry("dri", NULL);
296 	debugfs_remove(drm_debugfs_root);
297 	drm_sysfs_destroy();
298 
299 	unregister_chrdev(DRM_MAJOR, "drm");
300 
301 	idr_destroy(&drm_minors_idr);
302 }
303 
304 module_init(drm_core_init);
305 module_exit(drm_core_exit);
306 
307 /**
308  * Copy and IOCTL return string to user space
309  */
310 static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
311 {
312 	int len;
313 
314 	/* don't overflow userbuf */
315 	len = strlen(value);
316 	if (len > *buf_len)
317 		len = *buf_len;
318 
319 	/* let userspace know exact length of driver value (which could be
320 	 * larger than the userspace-supplied buffer) */
321 	*buf_len = strlen(value);
322 
323 	/* finally, try filling in the userbuf */
324 	if (len && buf)
325 		if (copy_to_user(buf, value, len))
326 			return -EFAULT;
327 	return 0;
328 }
329 
330 /**
331  * Get version information
332  *
333  * \param inode device inode.
334  * \param filp file pointer.
335  * \param cmd command.
336  * \param arg user argument, pointing to a drm_version structure.
337  * \return zero on success or negative number on failure.
338  *
339  * Fills in the version information in \p arg.
340  */
341 static int drm_version(struct drm_device *dev, void *data,
342 		       struct drm_file *file_priv)
343 {
344 	struct drm_version *version = data;
345 	int err;
346 
347 	version->version_major = dev->driver->major;
348 	version->version_minor = dev->driver->minor;
349 	version->version_patchlevel = dev->driver->patchlevel;
350 	err = drm_copy_field(version->name, &version->name_len,
351 			dev->driver->name);
352 	if (!err)
353 		err = drm_copy_field(version->date, &version->date_len,
354 				dev->driver->date);
355 	if (!err)
356 		err = drm_copy_field(version->desc, &version->desc_len,
357 				dev->driver->desc);
358 
359 	return err;
360 }
361 
362 /**
363  * Called whenever a process performs an ioctl on /dev/drm.
364  *
365  * \param inode device inode.
366  * \param file_priv DRM file private.
367  * \param cmd command.
368  * \param arg user argument.
369  * \return zero on success or negative number on failure.
370  *
371  * Looks up the ioctl function in the ::ioctls table, checking for root
372  * previleges if so required, and dispatches to the respective function.
373  */
374 long drm_ioctl(struct file *filp,
375 	      unsigned int cmd, unsigned long arg)
376 {
377 	struct drm_file *file_priv = filp->private_data;
378 	struct drm_device *dev;
379 	const struct drm_ioctl_desc *ioctl = NULL;
380 	drm_ioctl_t *func;
381 	unsigned int nr = DRM_IOCTL_NR(cmd);
382 	int retcode = -EINVAL;
383 	char stack_kdata[128];
384 	char *kdata = NULL;
385 	unsigned int usize, asize;
386 
387 	dev = file_priv->minor->dev;
388 
389 	if (drm_device_is_unplugged(dev))
390 		return -ENODEV;
391 
392 	atomic_inc(&dev->ioctl_count);
393 	atomic_inc(&dev->counts[_DRM_STAT_IOCTLS]);
394 	++file_priv->ioctl_count;
395 
396 	if ((nr >= DRM_CORE_IOCTL_COUNT) &&
397 	    ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
398 		goto err_i1;
399 	if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
400 	    (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls)) {
401 		u32 drv_size;
402 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
403 		drv_size = _IOC_SIZE(ioctl->cmd_drv);
404 		usize = asize = _IOC_SIZE(cmd);
405 		if (drv_size > asize)
406 			asize = drv_size;
407 		cmd = ioctl->cmd_drv;
408 	}
409 	else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
410 		ioctl = &drm_ioctls[nr];
411 		cmd = ioctl->cmd;
412 		usize = asize = _IOC_SIZE(cmd);
413 	} else
414 		goto err_i1;
415 
416 	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
417 		  task_pid_nr(current),
418 		  (long)old_encode_dev(file_priv->minor->device),
419 		  file_priv->authenticated, ioctl->name);
420 
421 	/* Do not trust userspace, use our own definition */
422 	func = ioctl->func;
423 	/* is there a local override? */
424 	if ((nr == DRM_IOCTL_NR(DRM_IOCTL_DMA)) && dev->driver->dma_ioctl)
425 		func = dev->driver->dma_ioctl;
426 
427 	if (!func) {
428 		DRM_DEBUG("no function\n");
429 		retcode = -EINVAL;
430 	} else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
431 		   ((ioctl->flags & DRM_AUTH) && !file_priv->authenticated) ||
432 		   ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) ||
433 		   (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL))) {
434 		retcode = -EACCES;
435 	} else {
436 		if (cmd & (IOC_IN | IOC_OUT)) {
437 			if (asize <= sizeof(stack_kdata)) {
438 				kdata = stack_kdata;
439 			} else {
440 				kdata = kmalloc(asize, GFP_KERNEL);
441 				if (!kdata) {
442 					retcode = -ENOMEM;
443 					goto err_i1;
444 				}
445 			}
446 			if (asize > usize)
447 				memset(kdata + usize, 0, asize - usize);
448 		}
449 
450 		if (cmd & IOC_IN) {
451 			if (copy_from_user(kdata, (void __user *)arg,
452 					   usize) != 0) {
453 				retcode = -EFAULT;
454 				goto err_i1;
455 			}
456 		} else
457 			memset(kdata, 0, usize);
458 
459 		if (ioctl->flags & DRM_UNLOCKED)
460 			retcode = func(dev, kdata, file_priv);
461 		else {
462 			mutex_lock(&drm_global_mutex);
463 			retcode = func(dev, kdata, file_priv);
464 			mutex_unlock(&drm_global_mutex);
465 		}
466 
467 		if (cmd & IOC_OUT) {
468 			if (copy_to_user((void __user *)arg, kdata,
469 					 usize) != 0)
470 				retcode = -EFAULT;
471 		}
472 	}
473 
474       err_i1:
475 	if (!ioctl)
476 		DRM_DEBUG("invalid iotcl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
477 			  task_pid_nr(current),
478 			  (long)old_encode_dev(file_priv->minor->device),
479 			  file_priv->authenticated, cmd, nr);
480 
481 	if (kdata != stack_kdata)
482 		kfree(kdata);
483 	atomic_dec(&dev->ioctl_count);
484 	if (retcode)
485 		DRM_DEBUG("ret = %d\n", retcode);
486 	return retcode;
487 }
488 
489 EXPORT_SYMBOL(drm_ioctl);
490 
491 struct drm_local_map *drm_getsarea(struct drm_device *dev)
492 {
493 	struct drm_map_list *entry;
494 
495 	list_for_each_entry(entry, &dev->maplist, head) {
496 		if (entry->map && entry->map->type == _DRM_SHM &&
497 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
498 			return entry->map;
499 		}
500 	}
501 	return NULL;
502 }
503 EXPORT_SYMBOL(drm_getsarea);
504