drm_drv.c revision f336ab76008f66f6153573d1479aeed388d7b08a
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
56static 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 */
63static 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_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),
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),
140	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED),
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 */
178static 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 */
207int 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 */
244static const struct file_operations drm_stub_fops = {
245	.owner = THIS_MODULE,
246	.open = drm_stub_open,
247	.llseek = noop_llseek,
248};
249
250static 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;
278err_p3:
279	drm_sysfs_destroy();
280err_p2:
281	unregister_chrdev(DRM_MAJOR, "drm");
282
283	idr_destroy(&drm_minors_idr);
284err_p1:
285	return ret;
286}
287
288static 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
299module_init(drm_core_init);
300module_exit(drm_core_exit);
301
302/**
303 * Copy and IOCTL return string to user space
304 */
305static 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 */
336static 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 */
369long 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) && !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		retcode = -EACCES;
427	} else {
428		if (cmd & (IOC_IN | IOC_OUT)) {
429			if (asize <= sizeof(stack_kdata)) {
430				kdata = stack_kdata;
431			} else {
432				kdata = kmalloc(asize, GFP_KERNEL);
433				if (!kdata) {
434					retcode = -ENOMEM;
435					goto err_i1;
436				}
437			}
438			if (asize > usize)
439				memset(kdata + usize, 0, asize - usize);
440		}
441
442		if (cmd & IOC_IN) {
443			if (copy_from_user(kdata, (void __user *)arg,
444					   usize) != 0) {
445				retcode = -EFAULT;
446				goto err_i1;
447			}
448		} else
449			memset(kdata, 0, usize);
450
451		if (ioctl->flags & DRM_UNLOCKED)
452			retcode = func(dev, kdata, file_priv);
453		else {
454			mutex_lock(&drm_global_mutex);
455			retcode = func(dev, kdata, file_priv);
456			mutex_unlock(&drm_global_mutex);
457		}
458
459		if (cmd & IOC_OUT) {
460			if (copy_to_user((void __user *)arg, kdata,
461					 usize) != 0)
462				retcode = -EFAULT;
463		}
464	}
465
466      err_i1:
467	if (!ioctl)
468		DRM_DEBUG("invalid iotcl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
469			  task_pid_nr(current),
470			  (long)old_encode_dev(file_priv->minor->device),
471			  file_priv->authenticated, cmd, nr);
472
473	if (kdata != stack_kdata)
474		kfree(kdata);
475	atomic_dec(&dev->ioctl_count);
476	if (retcode)
477		DRM_DEBUG("ret = %d\n", retcode);
478	return retcode;
479}
480EXPORT_SYMBOL(drm_ioctl);
481