xref: /openbmc/linux/drivers/gpu/drm/drm_ioctl.c (revision 5534b673)
1 /*
2  * Created: Fri Jan  8 09:01:26 1999 by faith@valinux.com
3  *
4  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6  * All Rights Reserved.
7  *
8  * Author Rickard E. (Rik) Faith <faith@valinux.com>
9  * Author Gareth Hughes <gareth@valinux.com>
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining a
12  * copy of this software and associated documentation files (the "Software"),
13  * to deal in the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15  * and/or sell copies of the Software, and to permit persons to whom the
16  * Software is furnished to do so, subject to the following conditions:
17  *
18  * The above copyright notice and this permission notice (including the next
19  * paragraph) shall be included in all copies or substantial portions of the
20  * Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
25  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28  * OTHER DEALINGS IN THE SOFTWARE.
29  */
30 
31 #include <drm/drmP.h>
32 #include <drm/drm_core.h>
33 #include "drm_legacy.h"
34 
35 #include <linux/pci.h>
36 #include <linux/export.h>
37 #ifdef CONFIG_X86
38 #include <asm/mtrr.h>
39 #endif
40 
41 static int drm_version(struct drm_device *dev, void *data,
42 		       struct drm_file *file_priv);
43 
44 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \
45 	[DRM_IOCTL_NR(ioctl)] = {.cmd = ioctl, .func = _func, .flags = _flags, .cmd_drv = 0, .name = #ioctl}
46 
47 /** Ioctl table */
48 static const struct drm_ioctl_desc drm_ioctls[] = {
49 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_UNLOCKED|DRM_RENDER_ALLOW),
50 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
51 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
52 	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
53 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, DRM_UNLOCKED),
54 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
55 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
56 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
57 	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
58 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
59 
60 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
61 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
62 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
63 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_MASTER),
64 
65 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
66 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_rmmap_ioctl, DRM_AUTH),
67 
68 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
69 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
70 
71 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY),
72 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY),
73 
74 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
75 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
76 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
77 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
78 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
79 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
80 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
81 
82 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
83 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
84 
85 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_lock, DRM_AUTH),
86 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_unlock, DRM_AUTH),
87 
88 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
89 
90 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
91 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
92 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_infobufs, DRM_AUTH),
93 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_mapbufs, DRM_AUTH),
94 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_freebufs, DRM_AUTH),
95 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_dma_ioctl, DRM_AUTH),
96 
97 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
98 
99 #if __OS_HAS_AGP
100 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
101 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
102 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
103 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
104 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
105 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
106 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
107 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
108 #endif
109 
110 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
111 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
112 
113 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
114 
115 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
116 
117 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
118 
119 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
120 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
121 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
122 
123 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
124 
125 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
126 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
127 
128 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
129 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
130 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
131 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
132 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
133 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
134 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
135 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
136 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
137 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
138 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
139 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
140 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
141 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
142 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
143 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
144 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
145 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
146 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
147 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
148 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
149 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
150 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
151 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
152 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
153 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
154 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
155 };
156 
157 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
158 
159 /**
160  * Get the bus id.
161  *
162  * \param inode device inode.
163  * \param file_priv DRM file private.
164  * \param cmd command.
165  * \param arg user argument, pointing to a drm_unique structure.
166  * \return zero on success or a negative number on failure.
167  *
168  * Copies the bus id from drm_device::unique into user space.
169  */
170 int drm_getunique(struct drm_device *dev, void *data,
171 		  struct drm_file *file_priv)
172 {
173 	struct drm_unique *u = data;
174 	struct drm_master *master = file_priv->master;
175 
176 	if (u->unique_len >= master->unique_len) {
177 		if (copy_to_user(u->unique, master->unique, master->unique_len))
178 			return -EFAULT;
179 	}
180 	u->unique_len = master->unique_len;
181 
182 	return 0;
183 }
184 
185 static void
186 drm_unset_busid(struct drm_device *dev,
187 		struct drm_master *master)
188 {
189 	kfree(master->unique);
190 	master->unique = NULL;
191 	master->unique_len = 0;
192 	master->unique_size = 0;
193 }
194 
195 /**
196  * Set the bus id.
197  *
198  * \param inode device inode.
199  * \param file_priv DRM file private.
200  * \param cmd command.
201  * \param arg user argument, pointing to a drm_unique structure.
202  * \return zero on success or a negative number on failure.
203  *
204  * Copies the bus id from userspace into drm_device::unique, and verifies that
205  * it matches the device this DRM is attached to (EINVAL otherwise).  Deprecated
206  * in interface version 1.1 and will return EBUSY when setversion has requested
207  * version 1.1 or greater. Also note that KMS is all version 1.1 and later and
208  * UMS was only ever supported on pci devices.
209  */
210 int drm_setunique(struct drm_device *dev, void *data,
211 		  struct drm_file *file_priv)
212 {
213 	struct drm_unique *u = data;
214 	struct drm_master *master = file_priv->master;
215 	int ret;
216 
217 	if (master->unique_len || master->unique)
218 		return -EBUSY;
219 
220 	if (!u->unique_len || u->unique_len > 1024)
221 		return -EINVAL;
222 
223 	if (drm_core_check_feature(dev, DRIVER_MODESET))
224 		return 0;
225 
226 	if (WARN_ON(!dev->pdev))
227 		return -EINVAL;
228 
229 	ret = drm_pci_set_unique(dev, master, u);
230 	if (ret)
231 		goto err;
232 
233 	return 0;
234 
235 err:
236 	drm_unset_busid(dev, master);
237 	return ret;
238 }
239 
240 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
241 {
242 	struct drm_master *master = file_priv->master;
243 	int ret;
244 
245 	if (master->unique != NULL)
246 		drm_unset_busid(dev, master);
247 
248 	if (dev->driver->bus && dev->driver->bus->set_busid) {
249 		ret = dev->driver->bus->set_busid(dev, master);
250 		if (ret) {
251 			drm_unset_busid(dev, master);
252 			return ret;
253 		}
254 	} else {
255 		if (WARN(dev->unique == NULL,
256 			 "No drm_bus.set_busid() implementation provided by "
257 			 "%ps. Use drm_dev_set_unique() to set the unique "
258 			 "name explicitly.", dev->driver))
259 			return -EINVAL;
260 
261 		master->unique = kstrdup(dev->unique, GFP_KERNEL);
262 		if (master->unique)
263 			master->unique_len = strlen(dev->unique);
264 	}
265 
266 	return 0;
267 }
268 
269 /**
270  * Get a mapping information.
271  *
272  * \param inode device inode.
273  * \param file_priv DRM file private.
274  * \param cmd command.
275  * \param arg user argument, pointing to a drm_map structure.
276  *
277  * \return zero on success or a negative number on failure.
278  *
279  * Searches for the mapping with the specified offset and copies its information
280  * into userspace
281  */
282 int drm_getmap(struct drm_device *dev, void *data,
283 	       struct drm_file *file_priv)
284 {
285 	struct drm_map *map = data;
286 	struct drm_map_list *r_list = NULL;
287 	struct list_head *list;
288 	int idx;
289 	int i;
290 
291 	idx = map->offset;
292 	if (idx < 0)
293 		return -EINVAL;
294 
295 	i = 0;
296 	mutex_lock(&dev->struct_mutex);
297 	list_for_each(list, &dev->maplist) {
298 		if (i == idx) {
299 			r_list = list_entry(list, struct drm_map_list, head);
300 			break;
301 		}
302 		i++;
303 	}
304 	if (!r_list || !r_list->map) {
305 		mutex_unlock(&dev->struct_mutex);
306 		return -EINVAL;
307 	}
308 
309 	map->offset = r_list->map->offset;
310 	map->size = r_list->map->size;
311 	map->type = r_list->map->type;
312 	map->flags = r_list->map->flags;
313 	map->handle = (void *)(unsigned long) r_list->user_token;
314 
315 #ifdef CONFIG_X86
316 	/*
317 	 * There appears to be exactly one user of the mtrr index: dritest.
318 	 * It's easy enough to keep it working on non-PAT systems.
319 	 */
320 	map->mtrr = phys_wc_to_mtrr_index(r_list->map->mtrr);
321 #else
322 	map->mtrr = -1;
323 #endif
324 
325 	mutex_unlock(&dev->struct_mutex);
326 
327 	return 0;
328 }
329 
330 /**
331  * Get client information.
332  *
333  * \param inode device inode.
334  * \param file_priv DRM file private.
335  * \param cmd command.
336  * \param arg user argument, pointing to a drm_client structure.
337  *
338  * \return zero on success or a negative number on failure.
339  *
340  * Searches for the client with the specified index and copies its information
341  * into userspace
342  */
343 int drm_getclient(struct drm_device *dev, void *data,
344 		  struct drm_file *file_priv)
345 {
346 	struct drm_client *client = data;
347 
348 	/*
349 	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
350 	 * not breaking completely. Userspace tools stop enumerating one they
351 	 * get -EINVAL, hence this is the return value we need to hand back for
352 	 * no clients tracked.
353 	 *
354 	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
355 	 * attempt to figure out whether they're authenticated or not. Since
356 	 * that's the only thing they care about, give it to the directly
357 	 * instead of walking one giant list.
358 	 */
359 	if (client->idx == 0) {
360 		client->auth = file_priv->authenticated;
361 		client->pid = pid_vnr(file_priv->pid);
362 		client->uid = from_kuid_munged(current_user_ns(),
363 					       file_priv->uid);
364 		client->magic = 0;
365 		client->iocs = 0;
366 
367 		return 0;
368 	} else {
369 		return -EINVAL;
370 	}
371 }
372 
373 /**
374  * Get statistics information.
375  *
376  * \param inode device inode.
377  * \param file_priv DRM file private.
378  * \param cmd command.
379  * \param arg user argument, pointing to a drm_stats structure.
380  *
381  * \return zero on success or a negative number on failure.
382  */
383 int drm_getstats(struct drm_device *dev, void *data,
384 		 struct drm_file *file_priv)
385 {
386 	struct drm_stats *stats = data;
387 
388 	/* Clear stats to prevent userspace from eating its stack garbage. */
389 	memset(stats, 0, sizeof(*stats));
390 
391 	return 0;
392 }
393 
394 /**
395  * Get device/driver capabilities
396  */
397 int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
398 {
399 	struct drm_get_cap *req = data;
400 
401 	req->value = 0;
402 	switch (req->capability) {
403 	case DRM_CAP_DUMB_BUFFER:
404 		if (dev->driver->dumb_create)
405 			req->value = 1;
406 		break;
407 	case DRM_CAP_VBLANK_HIGH_CRTC:
408 		req->value = 1;
409 		break;
410 	case DRM_CAP_DUMB_PREFERRED_DEPTH:
411 		req->value = dev->mode_config.preferred_depth;
412 		break;
413 	case DRM_CAP_DUMB_PREFER_SHADOW:
414 		req->value = dev->mode_config.prefer_shadow;
415 		break;
416 	case DRM_CAP_PRIME:
417 		req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
418 		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
419 		break;
420 	case DRM_CAP_TIMESTAMP_MONOTONIC:
421 		req->value = drm_timestamp_monotonic;
422 		break;
423 	case DRM_CAP_ASYNC_PAGE_FLIP:
424 		req->value = dev->mode_config.async_page_flip;
425 		break;
426 	case DRM_CAP_CURSOR_WIDTH:
427 		if (dev->mode_config.cursor_width)
428 			req->value = dev->mode_config.cursor_width;
429 		else
430 			req->value = 64;
431 		break;
432 	case DRM_CAP_CURSOR_HEIGHT:
433 		if (dev->mode_config.cursor_height)
434 			req->value = dev->mode_config.cursor_height;
435 		else
436 			req->value = 64;
437 		break;
438 	default:
439 		return -EINVAL;
440 	}
441 	return 0;
442 }
443 
444 /**
445  * Set device/driver capabilities
446  */
447 int
448 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
449 {
450 	struct drm_set_client_cap *req = data;
451 
452 	switch (req->capability) {
453 	case DRM_CLIENT_CAP_STEREO_3D:
454 		if (req->value > 1)
455 			return -EINVAL;
456 		file_priv->stereo_allowed = req->value;
457 		break;
458 	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
459 		if (req->value > 1)
460 			return -EINVAL;
461 		file_priv->universal_planes = req->value;
462 		break;
463 	default:
464 		return -EINVAL;
465 	}
466 
467 	return 0;
468 }
469 
470 /**
471  * Setversion ioctl.
472  *
473  * \param inode device inode.
474  * \param file_priv DRM file private.
475  * \param cmd command.
476  * \param arg user argument, pointing to a drm_lock structure.
477  * \return zero on success or negative number on failure.
478  *
479  * Sets the requested interface version
480  */
481 int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
482 {
483 	struct drm_set_version *sv = data;
484 	int if_version, retcode = 0;
485 
486 	if (sv->drm_di_major != -1) {
487 		if (sv->drm_di_major != DRM_IF_MAJOR ||
488 		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
489 			retcode = -EINVAL;
490 			goto done;
491 		}
492 		if_version = DRM_IF_VERSION(sv->drm_di_major,
493 					    sv->drm_di_minor);
494 		dev->if_version = max(if_version, dev->if_version);
495 		if (sv->drm_di_minor >= 1) {
496 			/*
497 			 * Version 1.1 includes tying of DRM to specific device
498 			 * Version 1.4 has proper PCI domain support
499 			 */
500 			retcode = drm_set_busid(dev, file_priv);
501 			if (retcode)
502 				goto done;
503 		}
504 	}
505 
506 	if (sv->drm_dd_major != -1) {
507 		if (sv->drm_dd_major != dev->driver->major ||
508 		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
509 		    dev->driver->minor) {
510 			retcode = -EINVAL;
511 			goto done;
512 		}
513 	}
514 
515 done:
516 	sv->drm_di_major = DRM_IF_MAJOR;
517 	sv->drm_di_minor = DRM_IF_MINOR;
518 	sv->drm_dd_major = dev->driver->major;
519 	sv->drm_dd_minor = dev->driver->minor;
520 
521 	return retcode;
522 }
523 
524 /** No-op ioctl. */
525 int drm_noop(struct drm_device *dev, void *data,
526 	     struct drm_file *file_priv)
527 {
528 	DRM_DEBUG("\n");
529 	return 0;
530 }
531 EXPORT_SYMBOL(drm_noop);
532 
533 /**
534  * Copy and IOCTL return string to user space
535  */
536 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
537 {
538 	int len;
539 
540 	/* don't overflow userbuf */
541 	len = strlen(value);
542 	if (len > *buf_len)
543 		len = *buf_len;
544 
545 	/* let userspace know exact length of driver value (which could be
546 	 * larger than the userspace-supplied buffer) */
547 	*buf_len = strlen(value);
548 
549 	/* finally, try filling in the userbuf */
550 	if (len && buf)
551 		if (copy_to_user(buf, value, len))
552 			return -EFAULT;
553 	return 0;
554 }
555 
556 /**
557  * Get version information
558  *
559  * \param inode device inode.
560  * \param filp file pointer.
561  * \param cmd command.
562  * \param arg user argument, pointing to a drm_version structure.
563  * \return zero on success or negative number on failure.
564  *
565  * Fills in the version information in \p arg.
566  */
567 static int drm_version(struct drm_device *dev, void *data,
568 		       struct drm_file *file_priv)
569 {
570 	struct drm_version *version = data;
571 	int err;
572 
573 	version->version_major = dev->driver->major;
574 	version->version_minor = dev->driver->minor;
575 	version->version_patchlevel = dev->driver->patchlevel;
576 	err = drm_copy_field(version->name, &version->name_len,
577 			dev->driver->name);
578 	if (!err)
579 		err = drm_copy_field(version->date, &version->date_len,
580 				dev->driver->date);
581 	if (!err)
582 		err = drm_copy_field(version->desc, &version->desc_len,
583 				dev->driver->desc);
584 
585 	return err;
586 }
587 
588 /**
589  * drm_ioctl_permit - Check ioctl permissions against caller
590  *
591  * @flags: ioctl permission flags.
592  * @file_priv: Pointer to struct drm_file identifying the caller.
593  *
594  * Checks whether the caller is allowed to run an ioctl with the
595  * indicated permissions. If so, returns zero. Otherwise returns an
596  * error code suitable for ioctl return.
597  */
598 static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
599 {
600 	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
601 	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
602 		return -EACCES;
603 
604 	/* AUTH is only for authenticated or render client */
605 	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
606 		     !file_priv->authenticated))
607 		return -EACCES;
608 
609 	/* MASTER is only for master or control clients */
610 	if (unlikely((flags & DRM_MASTER) && !file_priv->is_master &&
611 		     !drm_is_control_client(file_priv)))
612 		return -EACCES;
613 
614 	/* Control clients must be explicitly allowed */
615 	if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
616 		     drm_is_control_client(file_priv)))
617 		return -EACCES;
618 
619 	/* Render clients must be explicitly allowed */
620 	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
621 		     drm_is_render_client(file_priv)))
622 		return -EACCES;
623 
624 	return 0;
625 }
626 
627 /**
628  * Called whenever a process performs an ioctl on /dev/drm.
629  *
630  * \param inode device inode.
631  * \param file_priv DRM file private.
632  * \param cmd command.
633  * \param arg user argument.
634  * \return zero on success or negative number on failure.
635  *
636  * Looks up the ioctl function in the ::ioctls table, checking for root
637  * previleges if so required, and dispatches to the respective function.
638  */
639 long drm_ioctl(struct file *filp,
640 	      unsigned int cmd, unsigned long arg)
641 {
642 	struct drm_file *file_priv = filp->private_data;
643 	struct drm_device *dev;
644 	const struct drm_ioctl_desc *ioctl = NULL;
645 	drm_ioctl_t *func;
646 	unsigned int nr = DRM_IOCTL_NR(cmd);
647 	int retcode = -EINVAL;
648 	char stack_kdata[128];
649 	char *kdata = NULL;
650 	unsigned int usize, asize;
651 
652 	dev = file_priv->minor->dev;
653 
654 	if (drm_device_is_unplugged(dev))
655 		return -ENODEV;
656 
657 	if ((nr >= DRM_CORE_IOCTL_COUNT) &&
658 	    ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
659 		goto err_i1;
660 	if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
661 	    (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls)) {
662 		u32 drv_size;
663 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
664 		drv_size = _IOC_SIZE(ioctl->cmd_drv);
665 		usize = asize = _IOC_SIZE(cmd);
666 		if (drv_size > asize)
667 			asize = drv_size;
668 		cmd = ioctl->cmd_drv;
669 	}
670 	else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
671 		u32 drv_size;
672 
673 		ioctl = &drm_ioctls[nr];
674 
675 		drv_size = _IOC_SIZE(ioctl->cmd);
676 		usize = asize = _IOC_SIZE(cmd);
677 		if (drv_size > asize)
678 			asize = drv_size;
679 
680 		cmd = ioctl->cmd;
681 	} else
682 		goto err_i1;
683 
684 	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
685 		  task_pid_nr(current),
686 		  (long)old_encode_dev(file_priv->minor->kdev->devt),
687 		  file_priv->authenticated, ioctl->name);
688 
689 	/* Do not trust userspace, use our own definition */
690 	func = ioctl->func;
691 
692 	if (unlikely(!func)) {
693 		DRM_DEBUG("no function\n");
694 		retcode = -EINVAL;
695 		goto err_i1;
696 	}
697 
698 	retcode = drm_ioctl_permit(ioctl->flags, file_priv);
699 	if (unlikely(retcode))
700 		goto err_i1;
701 
702 	if (cmd & (IOC_IN | IOC_OUT)) {
703 		if (asize <= sizeof(stack_kdata)) {
704 			kdata = stack_kdata;
705 		} else {
706 			kdata = kmalloc(asize, GFP_KERNEL);
707 			if (!kdata) {
708 				retcode = -ENOMEM;
709 				goto err_i1;
710 			}
711 		}
712 		if (asize > usize)
713 			memset(kdata + usize, 0, asize - usize);
714 	}
715 
716 	if (cmd & IOC_IN) {
717 		if (copy_from_user(kdata, (void __user *)arg,
718 				   usize) != 0) {
719 			retcode = -EFAULT;
720 			goto err_i1;
721 		}
722 	} else if (cmd & IOC_OUT) {
723 		memset(kdata, 0, usize);
724 	}
725 
726 	if (ioctl->flags & DRM_UNLOCKED)
727 		retcode = func(dev, kdata, file_priv);
728 	else {
729 		mutex_lock(&drm_global_mutex);
730 		retcode = func(dev, kdata, file_priv);
731 		mutex_unlock(&drm_global_mutex);
732 	}
733 
734 	if (cmd & IOC_OUT) {
735 		if (copy_to_user((void __user *)arg, kdata,
736 				 usize) != 0)
737 			retcode = -EFAULT;
738 	}
739 
740       err_i1:
741 	if (!ioctl)
742 		DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
743 			  task_pid_nr(current),
744 			  (long)old_encode_dev(file_priv->minor->kdev->devt),
745 			  file_priv->authenticated, cmd, nr);
746 
747 	if (kdata != stack_kdata)
748 		kfree(kdata);
749 	if (retcode)
750 		DRM_DEBUG("ret = %d\n", retcode);
751 	return retcode;
752 }
753 EXPORT_SYMBOL(drm_ioctl);
754 
755 /**
756  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
757  *
758  * @nr: Ioctl number.
759  * @flags: Where to return the ioctl permission flags
760  */
761 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
762 {
763 	if ((nr >= DRM_COMMAND_END && nr < DRM_CORE_IOCTL_COUNT) ||
764 	    (nr < DRM_COMMAND_BASE)) {
765 		*flags = drm_ioctls[nr].flags;
766 		return true;
767 	}
768 
769 	return false;
770 }
771 EXPORT_SYMBOL(drm_ioctl_flags);
772