xref: /openbmc/linux/drivers/gpu/drm/drm_drv.c (revision 95c96174)
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 "drmP.h"
53 #include "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}
61 
62 /** Ioctl table */
63 static 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_MASTER|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_MASTER|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_mode_attachmode_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
154 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_mode_detachmode_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
155 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_MASTER | 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_MASTER|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_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
160 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
161 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_MASTER|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_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
165 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
166 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED)
167 };
168 
169 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
170 
171 /**
172  * Take down the DRM device.
173  *
174  * \param dev DRM device structure.
175  *
176  * Frees every resource in \p dev.
177  *
178  * \sa drm_device
179  */
180 int drm_lastclose(struct drm_device * dev)
181 {
182 	struct drm_vma_entry *vma, *vma_temp;
183 	int i;
184 
185 	DRM_DEBUG("\n");
186 
187 	if (dev->driver->lastclose)
188 		dev->driver->lastclose(dev);
189 	DRM_DEBUG("driver lastclose completed\n");
190 
191 	if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
192 		drm_irq_uninstall(dev);
193 
194 	mutex_lock(&dev->struct_mutex);
195 
196 	/* Clear AGP information */
197 	if (drm_core_has_AGP(dev) && dev->agp &&
198 			!drm_core_check_feature(dev, DRIVER_MODESET)) {
199 		struct drm_agp_mem *entry, *tempe;
200 
201 		/* Remove AGP resources, but leave dev->agp
202 		   intact until drv_cleanup is called. */
203 		list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
204 			if (entry->bound)
205 				drm_unbind_agp(entry->memory);
206 			drm_free_agp(entry->memory, entry->pages);
207 			kfree(entry);
208 		}
209 		INIT_LIST_HEAD(&dev->agp->memory);
210 
211 		if (dev->agp->acquired)
212 			drm_agp_release(dev);
213 
214 		dev->agp->acquired = 0;
215 		dev->agp->enabled = 0;
216 	}
217 	if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
218 	    !drm_core_check_feature(dev, DRIVER_MODESET)) {
219 		drm_sg_cleanup(dev->sg);
220 		dev->sg = NULL;
221 	}
222 
223 	/* Clear vma list (only built for debugging) */
224 	list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
225 		list_del(&vma->head);
226 		kfree(vma);
227 	}
228 
229 	if (drm_core_check_feature(dev, DRIVER_DMA_QUEUE) && dev->queuelist) {
230 		for (i = 0; i < dev->queue_count; i++) {
231 			kfree(dev->queuelist[i]);
232 			dev->queuelist[i] = NULL;
233 		}
234 		kfree(dev->queuelist);
235 		dev->queuelist = NULL;
236 	}
237 	dev->queue_count = 0;
238 
239 	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
240 	    !drm_core_check_feature(dev, DRIVER_MODESET))
241 		drm_dma_takedown(dev);
242 
243 	dev->dev_mapping = NULL;
244 	mutex_unlock(&dev->struct_mutex);
245 
246 	DRM_DEBUG("lastclose completed\n");
247 	return 0;
248 }
249 
250 /** File operations structure */
251 static const struct file_operations drm_stub_fops = {
252 	.owner = THIS_MODULE,
253 	.open = drm_stub_open,
254 	.llseek = noop_llseek,
255 };
256 
257 static int __init drm_core_init(void)
258 {
259 	int ret = -ENOMEM;
260 
261 	drm_global_init();
262 	idr_init(&drm_minors_idr);
263 
264 	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
265 		goto err_p1;
266 
267 	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
268 	if (IS_ERR(drm_class)) {
269 		printk(KERN_ERR "DRM: Error creating drm class.\n");
270 		ret = PTR_ERR(drm_class);
271 		goto err_p2;
272 	}
273 
274 	drm_proc_root = proc_mkdir("dri", NULL);
275 	if (!drm_proc_root) {
276 		DRM_ERROR("Cannot create /proc/dri\n");
277 		ret = -1;
278 		goto err_p3;
279 	}
280 
281 	drm_debugfs_root = debugfs_create_dir("dri", NULL);
282 	if (!drm_debugfs_root) {
283 		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
284 		ret = -1;
285 		goto err_p3;
286 	}
287 
288 	DRM_INFO("Initialized %s %d.%d.%d %s\n",
289 		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
290 	return 0;
291 err_p3:
292 	drm_sysfs_destroy();
293 err_p2:
294 	unregister_chrdev(DRM_MAJOR, "drm");
295 
296 	idr_destroy(&drm_minors_idr);
297 err_p1:
298 	return ret;
299 }
300 
301 static void __exit drm_core_exit(void)
302 {
303 	remove_proc_entry("dri", NULL);
304 	debugfs_remove(drm_debugfs_root);
305 	drm_sysfs_destroy();
306 
307 	unregister_chrdev(DRM_MAJOR, "drm");
308 
309 	idr_remove_all(&drm_minors_idr);
310 	idr_destroy(&drm_minors_idr);
311 }
312 
313 module_init(drm_core_init);
314 module_exit(drm_core_exit);
315 
316 /**
317  * Copy and IOCTL return string to user space
318  */
319 static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
320 {
321 	int len;
322 
323 	/* don't overflow userbuf */
324 	len = strlen(value);
325 	if (len > *buf_len)
326 		len = *buf_len;
327 
328 	/* let userspace know exact length of driver value (which could be
329 	 * larger than the userspace-supplied buffer) */
330 	*buf_len = strlen(value);
331 
332 	/* finally, try filling in the userbuf */
333 	if (len && buf)
334 		if (copy_to_user(buf, value, len))
335 			return -EFAULT;
336 	return 0;
337 }
338 
339 /**
340  * Get version information
341  *
342  * \param inode device inode.
343  * \param filp file pointer.
344  * \param cmd command.
345  * \param arg user argument, pointing to a drm_version structure.
346  * \return zero on success or negative number on failure.
347  *
348  * Fills in the version information in \p arg.
349  */
350 static int drm_version(struct drm_device *dev, void *data,
351 		       struct drm_file *file_priv)
352 {
353 	struct drm_version *version = data;
354 	int err;
355 
356 	version->version_major = dev->driver->major;
357 	version->version_minor = dev->driver->minor;
358 	version->version_patchlevel = dev->driver->patchlevel;
359 	err = drm_copy_field(version->name, &version->name_len,
360 			dev->driver->name);
361 	if (!err)
362 		err = drm_copy_field(version->date, &version->date_len,
363 				dev->driver->date);
364 	if (!err)
365 		err = drm_copy_field(version->desc, &version->desc_len,
366 				dev->driver->desc);
367 
368 	return err;
369 }
370 
371 /**
372  * Called whenever a process performs an ioctl on /dev/drm.
373  *
374  * \param inode device inode.
375  * \param file_priv DRM file private.
376  * \param cmd command.
377  * \param arg user argument.
378  * \return zero on success or negative number on failure.
379  *
380  * Looks up the ioctl function in the ::ioctls table, checking for root
381  * previleges if so required, and dispatches to the respective function.
382  */
383 long drm_ioctl(struct file *filp,
384 	      unsigned int cmd, unsigned long arg)
385 {
386 	struct drm_file *file_priv = filp->private_data;
387 	struct drm_device *dev;
388 	struct drm_ioctl_desc *ioctl;
389 	drm_ioctl_t *func;
390 	unsigned int nr = DRM_IOCTL_NR(cmd);
391 	int retcode = -EINVAL;
392 	char stack_kdata[128];
393 	char *kdata = NULL;
394 	unsigned int usize, asize;
395 
396 	dev = file_priv->minor->dev;
397 
398 	if (drm_device_is_unplugged(dev))
399 		return -ENODEV;
400 
401 	atomic_inc(&dev->ioctl_count);
402 	atomic_inc(&dev->counts[_DRM_STAT_IOCTLS]);
403 	++file_priv->ioctl_count;
404 
405 	DRM_DEBUG("pid=%d, cmd=0x%02x, nr=0x%02x, dev 0x%lx, auth=%d\n",
406 		  task_pid_nr(current), cmd, nr,
407 		  (long)old_encode_dev(file_priv->minor->device),
408 		  file_priv->authenticated);
409 
410 	if ((nr >= DRM_CORE_IOCTL_COUNT) &&
411 	    ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
412 		goto err_i1;
413 	if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
414 	    (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls)) {
415 		u32 drv_size;
416 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
417 		drv_size = _IOC_SIZE(ioctl->cmd_drv);
418 		usize = asize = _IOC_SIZE(cmd);
419 		if (drv_size > asize)
420 			asize = drv_size;
421 	}
422 	else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
423 		ioctl = &drm_ioctls[nr];
424 		cmd = ioctl->cmd;
425 		usize = asize = _IOC_SIZE(cmd);
426 	} else
427 		goto err_i1;
428 
429 	/* Do not trust userspace, use our own definition */
430 	func = ioctl->func;
431 	/* is there a local override? */
432 	if ((nr == DRM_IOCTL_NR(DRM_IOCTL_DMA)) && dev->driver->dma_ioctl)
433 		func = dev->driver->dma_ioctl;
434 
435 	if (!func) {
436 		DRM_DEBUG("no function\n");
437 		retcode = -EINVAL;
438 	} else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
439 		   ((ioctl->flags & DRM_AUTH) && !file_priv->authenticated) ||
440 		   ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) ||
441 		   (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL))) {
442 		retcode = -EACCES;
443 	} else {
444 		if (cmd & (IOC_IN | IOC_OUT)) {
445 			if (asize <= sizeof(stack_kdata)) {
446 				kdata = stack_kdata;
447 			} else {
448 				kdata = kmalloc(asize, GFP_KERNEL);
449 				if (!kdata) {
450 					retcode = -ENOMEM;
451 					goto err_i1;
452 				}
453 			}
454 			if (asize > usize)
455 				memset(kdata + usize, 0, asize - usize);
456 		}
457 
458 		if (cmd & IOC_IN) {
459 			if (copy_from_user(kdata, (void __user *)arg,
460 					   usize) != 0) {
461 				retcode = -EFAULT;
462 				goto err_i1;
463 			}
464 		} else
465 			memset(kdata, 0, usize);
466 
467 		if (ioctl->flags & DRM_UNLOCKED)
468 			retcode = func(dev, kdata, file_priv);
469 		else {
470 			mutex_lock(&drm_global_mutex);
471 			retcode = func(dev, kdata, file_priv);
472 			mutex_unlock(&drm_global_mutex);
473 		}
474 
475 		if (cmd & IOC_OUT) {
476 			if (copy_to_user((void __user *)arg, kdata,
477 					 usize) != 0)
478 				retcode = -EFAULT;
479 		}
480 	}
481 
482       err_i1:
483 	if (kdata != stack_kdata)
484 		kfree(kdata);
485 	atomic_dec(&dev->ioctl_count);
486 	if (retcode)
487 		DRM_DEBUG("ret = %x\n", retcode);
488 	return retcode;
489 }
490 
491 EXPORT_SYMBOL(drm_ioctl);
492 
493 struct drm_local_map *drm_getsarea(struct drm_device *dev)
494 {
495 	struct drm_map_list *entry;
496 
497 	list_for_each_entry(entry, &dev->maplist, head) {
498 		if (entry->map && entry->map->type == _DRM_SHM &&
499 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
500 			return entry->map;
501 		}
502 	}
503 	return NULL;
504 }
505 EXPORT_SYMBOL(drm_getsarea);
506