xref: /openbmc/linux/drivers/gpu/drm/drm_drv.c (revision 483eb062)
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|DRM_RENDER_ALLOW),
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_CLIENT_CAP, drm_setclientcap, 0),
73 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
74 
75 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
76 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
77 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
78 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_MASTER),
79 
80 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
81 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_rmmap_ioctl, DRM_AUTH),
82 
83 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
84 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_getsareactx, DRM_AUTH),
85 
86 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY),
87 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY),
88 
89 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_addctx, DRM_AUTH|DRM_ROOT_ONLY),
90 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
91 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
92 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_getctx, DRM_AUTH),
93 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
94 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
95 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_resctx, DRM_AUTH),
96 
97 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
98 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
99 
100 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_lock, DRM_AUTH),
101 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_unlock, DRM_AUTH),
102 
103 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
104 
105 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
106 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
107 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_infobufs, DRM_AUTH),
108 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_mapbufs, DRM_AUTH),
109 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_freebufs, DRM_AUTH),
110 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_dma_ioctl, 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, 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|DRM_RENDER_ALLOW),
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|DRM_RENDER_ALLOW),
141 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
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 /** File operations structure */
175 static const struct file_operations drm_stub_fops = {
176 	.owner = THIS_MODULE,
177 	.open = drm_stub_open,
178 	.llseek = noop_llseek,
179 };
180 
181 static int __init drm_core_init(void)
182 {
183 	int ret = -ENOMEM;
184 
185 	drm_global_init();
186 	drm_connector_ida_init();
187 	idr_init(&drm_minors_idr);
188 
189 	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
190 		goto err_p1;
191 
192 	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
193 	if (IS_ERR(drm_class)) {
194 		printk(KERN_ERR "DRM: Error creating drm class.\n");
195 		ret = PTR_ERR(drm_class);
196 		goto err_p2;
197 	}
198 
199 	drm_debugfs_root = debugfs_create_dir("dri", NULL);
200 	if (!drm_debugfs_root) {
201 		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
202 		ret = -1;
203 		goto err_p3;
204 	}
205 
206 	DRM_INFO("Initialized %s %d.%d.%d %s\n",
207 		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
208 	return 0;
209 err_p3:
210 	drm_sysfs_destroy();
211 err_p2:
212 	unregister_chrdev(DRM_MAJOR, "drm");
213 
214 	idr_destroy(&drm_minors_idr);
215 err_p1:
216 	return ret;
217 }
218 
219 static void __exit drm_core_exit(void)
220 {
221 	debugfs_remove(drm_debugfs_root);
222 	drm_sysfs_destroy();
223 
224 	unregister_chrdev(DRM_MAJOR, "drm");
225 
226 	drm_connector_ida_destroy();
227 	idr_destroy(&drm_minors_idr);
228 }
229 
230 module_init(drm_core_init);
231 module_exit(drm_core_exit);
232 
233 /**
234  * Copy and IOCTL return string to user space
235  */
236 static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
237 {
238 	int len;
239 
240 	/* don't overflow userbuf */
241 	len = strlen(value);
242 	if (len > *buf_len)
243 		len = *buf_len;
244 
245 	/* let userspace know exact length of driver value (which could be
246 	 * larger than the userspace-supplied buffer) */
247 	*buf_len = strlen(value);
248 
249 	/* finally, try filling in the userbuf */
250 	if (len && buf)
251 		if (copy_to_user(buf, value, len))
252 			return -EFAULT;
253 	return 0;
254 }
255 
256 /**
257  * Get version information
258  *
259  * \param inode device inode.
260  * \param filp file pointer.
261  * \param cmd command.
262  * \param arg user argument, pointing to a drm_version structure.
263  * \return zero on success or negative number on failure.
264  *
265  * Fills in the version information in \p arg.
266  */
267 static int drm_version(struct drm_device *dev, void *data,
268 		       struct drm_file *file_priv)
269 {
270 	struct drm_version *version = data;
271 	int err;
272 
273 	version->version_major = dev->driver->major;
274 	version->version_minor = dev->driver->minor;
275 	version->version_patchlevel = dev->driver->patchlevel;
276 	err = drm_copy_field(version->name, &version->name_len,
277 			dev->driver->name);
278 	if (!err)
279 		err = drm_copy_field(version->date, &version->date_len,
280 				dev->driver->date);
281 	if (!err)
282 		err = drm_copy_field(version->desc, &version->desc_len,
283 				dev->driver->desc);
284 
285 	return err;
286 }
287 
288 /**
289  * Called whenever a process performs an ioctl on /dev/drm.
290  *
291  * \param inode device inode.
292  * \param file_priv DRM file private.
293  * \param cmd command.
294  * \param arg user argument.
295  * \return zero on success or negative number on failure.
296  *
297  * Looks up the ioctl function in the ::ioctls table, checking for root
298  * previleges if so required, and dispatches to the respective function.
299  */
300 long drm_ioctl(struct file *filp,
301 	      unsigned int cmd, unsigned long arg)
302 {
303 	struct drm_file *file_priv = filp->private_data;
304 	struct drm_device *dev;
305 	const struct drm_ioctl_desc *ioctl = NULL;
306 	drm_ioctl_t *func;
307 	unsigned int nr = DRM_IOCTL_NR(cmd);
308 	int retcode = -EINVAL;
309 	char stack_kdata[128];
310 	char *kdata = NULL;
311 	unsigned int usize, asize;
312 
313 	dev = file_priv->minor->dev;
314 
315 	if (drm_device_is_unplugged(dev))
316 		return -ENODEV;
317 
318 	if ((nr >= DRM_CORE_IOCTL_COUNT) &&
319 	    ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
320 		goto err_i1;
321 	if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
322 	    (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls)) {
323 		u32 drv_size;
324 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
325 		drv_size = _IOC_SIZE(ioctl->cmd_drv);
326 		usize = asize = _IOC_SIZE(cmd);
327 		if (drv_size > asize)
328 			asize = drv_size;
329 		cmd = ioctl->cmd_drv;
330 	}
331 	else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
332 		u32 drv_size;
333 
334 		ioctl = &drm_ioctls[nr];
335 
336 		drv_size = _IOC_SIZE(ioctl->cmd);
337 		usize = asize = _IOC_SIZE(cmd);
338 		if (drv_size > asize)
339 			asize = drv_size;
340 
341 		cmd = ioctl->cmd;
342 	} else
343 		goto err_i1;
344 
345 	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
346 		  task_pid_nr(current),
347 		  (long)old_encode_dev(file_priv->minor->device),
348 		  file_priv->authenticated, ioctl->name);
349 
350 	/* Do not trust userspace, use our own definition */
351 	func = ioctl->func;
352 
353 	if (!func) {
354 		DRM_DEBUG("no function\n");
355 		retcode = -EINVAL;
356 	} else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
357 		   ((ioctl->flags & DRM_AUTH) && !drm_is_render_client(file_priv) && !file_priv->authenticated) ||
358 		   ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) ||
359 		   (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL)) ||
360 		   (!(ioctl->flags & DRM_RENDER_ALLOW) && drm_is_render_client(file_priv))) {
361 		retcode = -EACCES;
362 	} else {
363 		if (cmd & (IOC_IN | IOC_OUT)) {
364 			if (asize <= sizeof(stack_kdata)) {
365 				kdata = stack_kdata;
366 			} else {
367 				kdata = kmalloc(asize, GFP_KERNEL);
368 				if (!kdata) {
369 					retcode = -ENOMEM;
370 					goto err_i1;
371 				}
372 			}
373 			if (asize > usize)
374 				memset(kdata + usize, 0, asize - usize);
375 		}
376 
377 		if (cmd & IOC_IN) {
378 			if (copy_from_user(kdata, (void __user *)arg,
379 					   usize) != 0) {
380 				retcode = -EFAULT;
381 				goto err_i1;
382 			}
383 		} else
384 			memset(kdata, 0, usize);
385 
386 		if (ioctl->flags & DRM_UNLOCKED)
387 			retcode = func(dev, kdata, file_priv);
388 		else {
389 			mutex_lock(&drm_global_mutex);
390 			retcode = func(dev, kdata, file_priv);
391 			mutex_unlock(&drm_global_mutex);
392 		}
393 
394 		if (cmd & IOC_OUT) {
395 			if (copy_to_user((void __user *)arg, kdata,
396 					 usize) != 0)
397 				retcode = -EFAULT;
398 		}
399 	}
400 
401       err_i1:
402 	if (!ioctl)
403 		DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
404 			  task_pid_nr(current),
405 			  (long)old_encode_dev(file_priv->minor->device),
406 			  file_priv->authenticated, cmd, nr);
407 
408 	if (kdata != stack_kdata)
409 		kfree(kdata);
410 	if (retcode)
411 		DRM_DEBUG("ret = %d\n", retcode);
412 	return retcode;
413 }
414 EXPORT_SYMBOL(drm_ioctl);
415