xref: /openbmc/linux/drivers/gpu/drm/drm_drv.c (revision 5bd8e16d)
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|DRM_RENDER_ALLOW),
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_noop, 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 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_dma_ioctl, DRM_AUTH),
110 
111 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
112 
113 #if __OS_HAS_AGP
114 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
115 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
116 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
117 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
118 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
119 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
120 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
121 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
122 #endif
123 
124 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
125 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
126 
127 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
128 
129 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
130 
131 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
132 
133 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
134 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
135 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
136 
137 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
138 
139 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
140 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
141 
142 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
143 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
144 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
145 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
146 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
147 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
148 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
149 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
150 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
151 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
152 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
153 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
154 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
155 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
156 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
157 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
158 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
159 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
160 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
161 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
162 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
163 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
164 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
165 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
166 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
167 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
168 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
169 };
170 
171 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
172 
173 /**
174  * drm_legacy_dev_reinit
175  *
176  * Reinitializes a legacy/ums drm device in it's lastclose function.
177  */
178 static void drm_legacy_dev_reinit(struct drm_device *dev)
179 {
180 	int i;
181 
182 	if (drm_core_check_feature(dev, DRIVER_MODESET))
183 		return;
184 
185 	atomic_set(&dev->ioctl_count, 0);
186 	atomic_set(&dev->vma_count, 0);
187 
188 	for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
189 		atomic_set(&dev->counts[i], 0);
190 
191 	dev->sigdata.lock = NULL;
192 
193 	dev->context_flag = 0;
194 	dev->last_context = 0;
195 	dev->if_version = 0;
196 }
197 
198 /**
199  * Take down the DRM device.
200  *
201  * \param dev DRM device structure.
202  *
203  * Frees every resource in \p dev.
204  *
205  * \sa drm_device
206  */
207 int drm_lastclose(struct drm_device * dev)
208 {
209 	struct drm_vma_entry *vma, *vma_temp;
210 
211 	DRM_DEBUG("\n");
212 
213 	if (dev->driver->lastclose)
214 		dev->driver->lastclose(dev);
215 	DRM_DEBUG("driver lastclose completed\n");
216 
217 	if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
218 		drm_irq_uninstall(dev);
219 
220 	mutex_lock(&dev->struct_mutex);
221 
222 	drm_agp_clear(dev);
223 
224 	drm_legacy_sg_cleanup(dev);
225 
226 	/* Clear vma list (only built for debugging) */
227 	list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
228 		list_del(&vma->head);
229 		kfree(vma);
230 	}
231 
232 	drm_legacy_dma_takedown(dev);
233 
234 	dev->dev_mapping = NULL;
235 	mutex_unlock(&dev->struct_mutex);
236 
237 	drm_legacy_dev_reinit(dev);
238 
239 	DRM_DEBUG("lastclose completed\n");
240 	return 0;
241 }
242 
243 /** File operations structure */
244 static const struct file_operations drm_stub_fops = {
245 	.owner = THIS_MODULE,
246 	.open = drm_stub_open,
247 	.llseek = noop_llseek,
248 };
249 
250 static int __init drm_core_init(void)
251 {
252 	int ret = -ENOMEM;
253 
254 	drm_global_init();
255 	drm_connector_ida_init();
256 	idr_init(&drm_minors_idr);
257 
258 	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
259 		goto err_p1;
260 
261 	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
262 	if (IS_ERR(drm_class)) {
263 		printk(KERN_ERR "DRM: Error creating drm class.\n");
264 		ret = PTR_ERR(drm_class);
265 		goto err_p2;
266 	}
267 
268 	drm_debugfs_root = debugfs_create_dir("dri", NULL);
269 	if (!drm_debugfs_root) {
270 		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
271 		ret = -1;
272 		goto err_p3;
273 	}
274 
275 	DRM_INFO("Initialized %s %d.%d.%d %s\n",
276 		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
277 	return 0;
278 err_p3:
279 	drm_sysfs_destroy();
280 err_p2:
281 	unregister_chrdev(DRM_MAJOR, "drm");
282 
283 	idr_destroy(&drm_minors_idr);
284 err_p1:
285 	return ret;
286 }
287 
288 static void __exit drm_core_exit(void)
289 {
290 	debugfs_remove(drm_debugfs_root);
291 	drm_sysfs_destroy();
292 
293 	unregister_chrdev(DRM_MAJOR, "drm");
294 
295 	drm_connector_ida_destroy();
296 	idr_destroy(&drm_minors_idr);
297 }
298 
299 module_init(drm_core_init);
300 module_exit(drm_core_exit);
301 
302 /**
303  * Copy and IOCTL return string to user space
304  */
305 static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
306 {
307 	int len;
308 
309 	/* don't overflow userbuf */
310 	len = strlen(value);
311 	if (len > *buf_len)
312 		len = *buf_len;
313 
314 	/* let userspace know exact length of driver value (which could be
315 	 * larger than the userspace-supplied buffer) */
316 	*buf_len = strlen(value);
317 
318 	/* finally, try filling in the userbuf */
319 	if (len && buf)
320 		if (copy_to_user(buf, value, len))
321 			return -EFAULT;
322 	return 0;
323 }
324 
325 /**
326  * Get version information
327  *
328  * \param inode device inode.
329  * \param filp file pointer.
330  * \param cmd command.
331  * \param arg user argument, pointing to a drm_version structure.
332  * \return zero on success or negative number on failure.
333  *
334  * Fills in the version information in \p arg.
335  */
336 static int drm_version(struct drm_device *dev, void *data,
337 		       struct drm_file *file_priv)
338 {
339 	struct drm_version *version = data;
340 	int err;
341 
342 	version->version_major = dev->driver->major;
343 	version->version_minor = dev->driver->minor;
344 	version->version_patchlevel = dev->driver->patchlevel;
345 	err = drm_copy_field(version->name, &version->name_len,
346 			dev->driver->name);
347 	if (!err)
348 		err = drm_copy_field(version->date, &version->date_len,
349 				dev->driver->date);
350 	if (!err)
351 		err = drm_copy_field(version->desc, &version->desc_len,
352 				dev->driver->desc);
353 
354 	return err;
355 }
356 
357 /**
358  * Called whenever a process performs an ioctl on /dev/drm.
359  *
360  * \param inode device inode.
361  * \param file_priv DRM file private.
362  * \param cmd command.
363  * \param arg user argument.
364  * \return zero on success or negative number on failure.
365  *
366  * Looks up the ioctl function in the ::ioctls table, checking for root
367  * previleges if so required, and dispatches to the respective function.
368  */
369 long drm_ioctl(struct file *filp,
370 	      unsigned int cmd, unsigned long arg)
371 {
372 	struct drm_file *file_priv = filp->private_data;
373 	struct drm_device *dev;
374 	const struct drm_ioctl_desc *ioctl = NULL;
375 	drm_ioctl_t *func;
376 	unsigned int nr = DRM_IOCTL_NR(cmd);
377 	int retcode = -EINVAL;
378 	char stack_kdata[128];
379 	char *kdata = NULL;
380 	unsigned int usize, asize;
381 
382 	dev = file_priv->minor->dev;
383 
384 	if (drm_device_is_unplugged(dev))
385 		return -ENODEV;
386 
387 	atomic_inc(&dev->ioctl_count);
388 	atomic_inc(&dev->counts[_DRM_STAT_IOCTLS]);
389 	++file_priv->ioctl_count;
390 
391 	if ((nr >= DRM_CORE_IOCTL_COUNT) &&
392 	    ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
393 		goto err_i1;
394 	if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
395 	    (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls)) {
396 		u32 drv_size;
397 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
398 		drv_size = _IOC_SIZE(ioctl->cmd_drv);
399 		usize = asize = _IOC_SIZE(cmd);
400 		if (drv_size > asize)
401 			asize = drv_size;
402 		cmd = ioctl->cmd_drv;
403 	}
404 	else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
405 		ioctl = &drm_ioctls[nr];
406 		cmd = ioctl->cmd;
407 		usize = asize = _IOC_SIZE(cmd);
408 	} else
409 		goto err_i1;
410 
411 	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
412 		  task_pid_nr(current),
413 		  (long)old_encode_dev(file_priv->minor->device),
414 		  file_priv->authenticated, ioctl->name);
415 
416 	/* Do not trust userspace, use our own definition */
417 	func = ioctl->func;
418 
419 	if (!func) {
420 		DRM_DEBUG("no function\n");
421 		retcode = -EINVAL;
422 	} else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
423 		   ((ioctl->flags & DRM_AUTH) && !drm_is_render_client(file_priv) && !file_priv->authenticated) ||
424 		   ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) ||
425 		   (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL)) ||
426 		   (!(ioctl->flags & DRM_RENDER_ALLOW) && drm_is_render_client(file_priv))) {
427 		retcode = -EACCES;
428 	} else {
429 		if (cmd & (IOC_IN | IOC_OUT)) {
430 			if (asize <= sizeof(stack_kdata)) {
431 				kdata = stack_kdata;
432 			} else {
433 				kdata = kmalloc(asize, GFP_KERNEL);
434 				if (!kdata) {
435 					retcode = -ENOMEM;
436 					goto err_i1;
437 				}
438 			}
439 			if (asize > usize)
440 				memset(kdata + usize, 0, asize - usize);
441 		}
442 
443 		if (cmd & IOC_IN) {
444 			if (copy_from_user(kdata, (void __user *)arg,
445 					   usize) != 0) {
446 				retcode = -EFAULT;
447 				goto err_i1;
448 			}
449 		} else
450 			memset(kdata, 0, usize);
451 
452 		if (ioctl->flags & DRM_UNLOCKED)
453 			retcode = func(dev, kdata, file_priv);
454 		else {
455 			mutex_lock(&drm_global_mutex);
456 			retcode = func(dev, kdata, file_priv);
457 			mutex_unlock(&drm_global_mutex);
458 		}
459 
460 		if (cmd & IOC_OUT) {
461 			if (copy_to_user((void __user *)arg, kdata,
462 					 usize) != 0)
463 				retcode = -EFAULT;
464 		}
465 	}
466 
467       err_i1:
468 	if (!ioctl)
469 		DRM_DEBUG("invalid iotcl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
470 			  task_pid_nr(current),
471 			  (long)old_encode_dev(file_priv->minor->device),
472 			  file_priv->authenticated, cmd, nr);
473 
474 	if (kdata != stack_kdata)
475 		kfree(kdata);
476 	atomic_dec(&dev->ioctl_count);
477 	if (retcode)
478 		DRM_DEBUG("ret = %d\n", retcode);
479 	return retcode;
480 }
481 EXPORT_SYMBOL(drm_ioctl);
482