Home | History | Annotate | Line # | Download | only in drm
drm_ioc32.c revision 1.1
      1 /**
      2  * \file drm_ioc32.c
      3  *
      4  * 32-bit ioctl compatibility routines for the DRM.
      5  *
      6  * \author Paul Mackerras <paulus (at) samba.org>
      7  *
      8  * Copyright (C) Paul Mackerras 2005.
      9  * All Rights Reserved.
     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  * THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
     26  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     27  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
     28  * IN THE SOFTWARE.
     29  */
     30 #include <linux/compat.h>
     31 #include <linux/ratelimit.h>
     32 #include <linux/export.h>
     33 
     34 #include <drm/drmP.h>
     35 #include <drm/drm_core.h>
     36 
     37 #define DRM_IOCTL_VERSION32		DRM_IOWR(0x00, drm_version32_t)
     38 #define DRM_IOCTL_GET_UNIQUE32		DRM_IOWR(0x01, drm_unique32_t)
     39 #define DRM_IOCTL_GET_MAP32		DRM_IOWR(0x04, drm_map32_t)
     40 #define DRM_IOCTL_GET_CLIENT32		DRM_IOWR(0x05, drm_client32_t)
     41 #define DRM_IOCTL_GET_STATS32		DRM_IOR( 0x06, drm_stats32_t)
     42 
     43 #define DRM_IOCTL_SET_UNIQUE32		DRM_IOW( 0x10, drm_unique32_t)
     44 #define DRM_IOCTL_ADD_MAP32		DRM_IOWR(0x15, drm_map32_t)
     45 #define DRM_IOCTL_ADD_BUFS32		DRM_IOWR(0x16, drm_buf_desc32_t)
     46 #define DRM_IOCTL_MARK_BUFS32		DRM_IOW( 0x17, drm_buf_desc32_t)
     47 #define DRM_IOCTL_INFO_BUFS32		DRM_IOWR(0x18, drm_buf_info32_t)
     48 #define DRM_IOCTL_MAP_BUFS32		DRM_IOWR(0x19, drm_buf_map32_t)
     49 #define DRM_IOCTL_FREE_BUFS32		DRM_IOW( 0x1a, drm_buf_free32_t)
     50 
     51 #define DRM_IOCTL_RM_MAP32		DRM_IOW( 0x1b, drm_map32_t)
     52 
     53 #define DRM_IOCTL_SET_SAREA_CTX32	DRM_IOW( 0x1c, drm_ctx_priv_map32_t)
     54 #define DRM_IOCTL_GET_SAREA_CTX32	DRM_IOWR(0x1d, drm_ctx_priv_map32_t)
     55 
     56 #define DRM_IOCTL_RES_CTX32		DRM_IOWR(0x26, drm_ctx_res32_t)
     57 #define DRM_IOCTL_DMA32			DRM_IOWR(0x29, drm_dma32_t)
     58 
     59 #define DRM_IOCTL_AGP_ENABLE32		DRM_IOW( 0x32, drm_agp_mode32_t)
     60 #define DRM_IOCTL_AGP_INFO32		DRM_IOR( 0x33, drm_agp_info32_t)
     61 #define DRM_IOCTL_AGP_ALLOC32		DRM_IOWR(0x34, drm_agp_buffer32_t)
     62 #define DRM_IOCTL_AGP_FREE32		DRM_IOW( 0x35, drm_agp_buffer32_t)
     63 #define DRM_IOCTL_AGP_BIND32		DRM_IOW( 0x36, drm_agp_binding32_t)
     64 #define DRM_IOCTL_AGP_UNBIND32		DRM_IOW( 0x37, drm_agp_binding32_t)
     65 
     66 #define DRM_IOCTL_SG_ALLOC32		DRM_IOW( 0x38, drm_scatter_gather32_t)
     67 #define DRM_IOCTL_SG_FREE32		DRM_IOW( 0x39, drm_scatter_gather32_t)
     68 
     69 #define DRM_IOCTL_UPDATE_DRAW32		DRM_IOW( 0x3f, drm_update_draw32_t)
     70 
     71 #define DRM_IOCTL_WAIT_VBLANK32		DRM_IOWR(0x3a, drm_wait_vblank32_t)
     72 
     73 typedef struct drm_version_32 {
     74 	int version_major;	  /**< Major version */
     75 	int version_minor;	  /**< Minor version */
     76 	int version_patchlevel;	   /**< Patch level */
     77 	u32 name_len;		  /**< Length of name buffer */
     78 	u32 name;		  /**< Name of driver */
     79 	u32 date_len;		  /**< Length of date buffer */
     80 	u32 date;		  /**< User-space buffer to hold date */
     81 	u32 desc_len;		  /**< Length of desc buffer */
     82 	u32 desc;		  /**< User-space buffer to hold desc */
     83 } drm_version32_t;
     84 
     85 static int compat_drm_version(struct file *file, unsigned int cmd,
     86 			      unsigned long arg)
     87 {
     88 	drm_version32_t v32;
     89 	struct drm_version __user *version;
     90 	int err;
     91 
     92 	if (copy_from_user(&v32, (void __user *)arg, sizeof(v32)))
     93 		return -EFAULT;
     94 
     95 	version = compat_alloc_user_space(sizeof(*version));
     96 	if (!access_ok(VERIFY_WRITE, version, sizeof(*version)))
     97 		return -EFAULT;
     98 	if (__put_user(v32.name_len, &version->name_len)
     99 	    || __put_user((void __user *)(unsigned long)v32.name,
    100 			  &version->name)
    101 	    || __put_user(v32.date_len, &version->date_len)
    102 	    || __put_user((void __user *)(unsigned long)v32.date,
    103 			  &version->date)
    104 	    || __put_user(v32.desc_len, &version->desc_len)
    105 	    || __put_user((void __user *)(unsigned long)v32.desc,
    106 			  &version->desc))
    107 		return -EFAULT;
    108 
    109 	err = drm_ioctl(file,
    110 			DRM_IOCTL_VERSION, (unsigned long)version);
    111 	if (err)
    112 		return err;
    113 
    114 	if (__get_user(v32.version_major, &version->version_major)
    115 	    || __get_user(v32.version_minor, &version->version_minor)
    116 	    || __get_user(v32.version_patchlevel, &version->version_patchlevel)
    117 	    || __get_user(v32.name_len, &version->name_len)
    118 	    || __get_user(v32.date_len, &version->date_len)
    119 	    || __get_user(v32.desc_len, &version->desc_len))
    120 		return -EFAULT;
    121 
    122 	if (copy_to_user((void __user *)arg, &v32, sizeof(v32)))
    123 		return -EFAULT;
    124 	return 0;
    125 }
    126 
    127 typedef struct drm_unique32 {
    128 	u32 unique_len;	/**< Length of unique */
    129 	u32 unique;	/**< Unique name for driver instantiation */
    130 } drm_unique32_t;
    131 
    132 static int compat_drm_getunique(struct file *file, unsigned int cmd,
    133 				unsigned long arg)
    134 {
    135 	drm_unique32_t uq32;
    136 	struct drm_unique __user *u;
    137 	int err;
    138 
    139 	if (copy_from_user(&uq32, (void __user *)arg, sizeof(uq32)))
    140 		return -EFAULT;
    141 
    142 	u = compat_alloc_user_space(sizeof(*u));
    143 	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
    144 		return -EFAULT;
    145 	if (__put_user(uq32.unique_len, &u->unique_len)
    146 	    || __put_user((void __user *)(unsigned long)uq32.unique,
    147 			  &u->unique))
    148 		return -EFAULT;
    149 
    150 	err = drm_ioctl(file, DRM_IOCTL_GET_UNIQUE, (unsigned long)u);
    151 	if (err)
    152 		return err;
    153 
    154 	if (__get_user(uq32.unique_len, &u->unique_len))
    155 		return -EFAULT;
    156 	if (copy_to_user((void __user *)arg, &uq32, sizeof(uq32)))
    157 		return -EFAULT;
    158 	return 0;
    159 }
    160 
    161 static int compat_drm_setunique(struct file *file, unsigned int cmd,
    162 				unsigned long arg)
    163 {
    164 	drm_unique32_t uq32;
    165 	struct drm_unique __user *u;
    166 
    167 	if (copy_from_user(&uq32, (void __user *)arg, sizeof(uq32)))
    168 		return -EFAULT;
    169 
    170 	u = compat_alloc_user_space(sizeof(*u));
    171 	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
    172 		return -EFAULT;
    173 	if (__put_user(uq32.unique_len, &u->unique_len)
    174 	    || __put_user((void __user *)(unsigned long)uq32.unique,
    175 			  &u->unique))
    176 		return -EFAULT;
    177 
    178 	return drm_ioctl(file, DRM_IOCTL_SET_UNIQUE, (unsigned long)u);
    179 }
    180 
    181 typedef struct drm_map32 {
    182 	u32 offset;		/**< Requested physical address (0 for SAREA)*/
    183 	u32 size;		/**< Requested physical size (bytes) */
    184 	enum drm_map_type type;	/**< Type of memory to map */
    185 	enum drm_map_flags flags;	/**< Flags */
    186 	u32 handle;		/**< User-space: "Handle" to pass to mmap() */
    187 	int mtrr;		/**< MTRR slot used */
    188 } drm_map32_t;
    189 
    190 static int compat_drm_getmap(struct file *file, unsigned int cmd,
    191 			     unsigned long arg)
    192 {
    193 	drm_map32_t __user *argp = (void __user *)arg;
    194 	drm_map32_t m32;
    195 	struct drm_map __user *map;
    196 	int idx, err;
    197 	void *handle;
    198 
    199 	if (get_user(idx, &argp->offset))
    200 		return -EFAULT;
    201 
    202 	map = compat_alloc_user_space(sizeof(*map));
    203 	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
    204 		return -EFAULT;
    205 	if (__put_user(idx, &map->offset))
    206 		return -EFAULT;
    207 
    208 	err = drm_ioctl(file, DRM_IOCTL_GET_MAP, (unsigned long)map);
    209 	if (err)
    210 		return err;
    211 
    212 	if (__get_user(m32.offset, &map->offset)
    213 	    || __get_user(m32.size, &map->size)
    214 	    || __get_user(m32.type, &map->type)
    215 	    || __get_user(m32.flags, &map->flags)
    216 	    || __get_user(handle, &map->handle)
    217 	    || __get_user(m32.mtrr, &map->mtrr))
    218 		return -EFAULT;
    219 
    220 	m32.handle = (unsigned long)handle;
    221 	if (copy_to_user(argp, &m32, sizeof(m32)))
    222 		return -EFAULT;
    223 	return 0;
    224 
    225 }
    226 
    227 static int compat_drm_addmap(struct file *file, unsigned int cmd,
    228 			     unsigned long arg)
    229 {
    230 	drm_map32_t __user *argp = (void __user *)arg;
    231 	drm_map32_t m32;
    232 	struct drm_map __user *map;
    233 	int err;
    234 	void *handle;
    235 
    236 	if (copy_from_user(&m32, argp, sizeof(m32)))
    237 		return -EFAULT;
    238 
    239 	map = compat_alloc_user_space(sizeof(*map));
    240 	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
    241 		return -EFAULT;
    242 	if (__put_user(m32.offset, &map->offset)
    243 	    || __put_user(m32.size, &map->size)
    244 	    || __put_user(m32.type, &map->type)
    245 	    || __put_user(m32.flags, &map->flags))
    246 		return -EFAULT;
    247 
    248 	err = drm_ioctl(file, DRM_IOCTL_ADD_MAP, (unsigned long)map);
    249 	if (err)
    250 		return err;
    251 
    252 	if (__get_user(m32.offset, &map->offset)
    253 	    || __get_user(m32.mtrr, &map->mtrr)
    254 	    || __get_user(handle, &map->handle))
    255 		return -EFAULT;
    256 
    257 	m32.handle = (unsigned long)handle;
    258 	if (m32.handle != (unsigned long)handle)
    259 		printk_ratelimited(KERN_ERR "compat_drm_addmap truncated handle"
    260 				   " %p for type %d offset %x\n",
    261 				   handle, m32.type, m32.offset);
    262 
    263 	if (copy_to_user(argp, &m32, sizeof(m32)))
    264 		return -EFAULT;
    265 
    266 	return 0;
    267 }
    268 
    269 static int compat_drm_rmmap(struct file *file, unsigned int cmd,
    270 			    unsigned long arg)
    271 {
    272 	drm_map32_t __user *argp = (void __user *)arg;
    273 	struct drm_map __user *map;
    274 	u32 handle;
    275 
    276 	if (get_user(handle, &argp->handle))
    277 		return -EFAULT;
    278 
    279 	map = compat_alloc_user_space(sizeof(*map));
    280 	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
    281 		return -EFAULT;
    282 	if (__put_user((void *)(unsigned long)handle, &map->handle))
    283 		return -EFAULT;
    284 
    285 	return drm_ioctl(file, DRM_IOCTL_RM_MAP, (unsigned long)map);
    286 }
    287 
    288 typedef struct drm_client32 {
    289 	int idx;	/**< Which client desired? */
    290 	int auth;	/**< Is client authenticated? */
    291 	u32 pid;	/**< Process ID */
    292 	u32 uid;	/**< User ID */
    293 	u32 magic;	/**< Magic */
    294 	u32 iocs;	/**< Ioctl count */
    295 } drm_client32_t;
    296 
    297 static int compat_drm_getclient(struct file *file, unsigned int cmd,
    298 				unsigned long arg)
    299 {
    300 	drm_client32_t c32;
    301 	drm_client32_t __user *argp = (void __user *)arg;
    302 	struct drm_client __user *client;
    303 	int idx, err;
    304 
    305 	if (get_user(idx, &argp->idx))
    306 		return -EFAULT;
    307 
    308 	client = compat_alloc_user_space(sizeof(*client));
    309 	if (!access_ok(VERIFY_WRITE, client, sizeof(*client)))
    310 		return -EFAULT;
    311 	if (__put_user(idx, &client->idx))
    312 		return -EFAULT;
    313 
    314 	err = drm_ioctl(file, DRM_IOCTL_GET_CLIENT, (unsigned long)client);
    315 	if (err)
    316 		return err;
    317 
    318 	if (__get_user(c32.idx, &client->idx)
    319 	    || __get_user(c32.auth, &client->auth)
    320 	    || __get_user(c32.pid, &client->pid)
    321 	    || __get_user(c32.uid, &client->uid)
    322 	    || __get_user(c32.magic, &client->magic)
    323 	    || __get_user(c32.iocs, &client->iocs))
    324 		return -EFAULT;
    325 
    326 	if (copy_to_user(argp, &c32, sizeof(c32)))
    327 		return -EFAULT;
    328 	return 0;
    329 }
    330 
    331 typedef struct drm_stats32 {
    332 	u32 count;
    333 	struct {
    334 		u32 value;
    335 		enum drm_stat_type type;
    336 	} data[15];
    337 } drm_stats32_t;
    338 
    339 static int compat_drm_getstats(struct file *file, unsigned int cmd,
    340 			       unsigned long arg)
    341 {
    342 	drm_stats32_t s32;
    343 	drm_stats32_t __user *argp = (void __user *)arg;
    344 	struct drm_stats __user *stats;
    345 	int i, err;
    346 
    347 	stats = compat_alloc_user_space(sizeof(*stats));
    348 	if (!access_ok(VERIFY_WRITE, stats, sizeof(*stats)))
    349 		return -EFAULT;
    350 
    351 	err = drm_ioctl(file, DRM_IOCTL_GET_STATS, (unsigned long)stats);
    352 	if (err)
    353 		return err;
    354 
    355 	if (__get_user(s32.count, &stats->count))
    356 		return -EFAULT;
    357 	for (i = 0; i < 15; ++i)
    358 		if (__get_user(s32.data[i].value, &stats->data[i].value)
    359 		    || __get_user(s32.data[i].type, &stats->data[i].type))
    360 			return -EFAULT;
    361 
    362 	if (copy_to_user(argp, &s32, sizeof(s32)))
    363 		return -EFAULT;
    364 	return 0;
    365 }
    366 
    367 typedef struct drm_buf_desc32 {
    368 	int count;		 /**< Number of buffers of this size */
    369 	int size;		 /**< Size in bytes */
    370 	int low_mark;		 /**< Low water mark */
    371 	int high_mark;		 /**< High water mark */
    372 	int flags;
    373 	u32 agp_start;		 /**< Start address in the AGP aperture */
    374 } drm_buf_desc32_t;
    375 
    376 static int compat_drm_addbufs(struct file *file, unsigned int cmd,
    377 			      unsigned long arg)
    378 {
    379 	drm_buf_desc32_t __user *argp = (void __user *)arg;
    380 	struct drm_buf_desc __user *buf;
    381 	int err;
    382 	unsigned long agp_start;
    383 
    384 	buf = compat_alloc_user_space(sizeof(*buf));
    385 	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf))
    386 	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp)))
    387 		return -EFAULT;
    388 
    389 	if (__copy_in_user(buf, argp, offsetof(drm_buf_desc32_t, agp_start))
    390 	    || __get_user(agp_start, &argp->agp_start)
    391 	    || __put_user(agp_start, &buf->agp_start))
    392 		return -EFAULT;
    393 
    394 	err = drm_ioctl(file, DRM_IOCTL_ADD_BUFS, (unsigned long)buf);
    395 	if (err)
    396 		return err;
    397 
    398 	if (__copy_in_user(argp, buf, offsetof(drm_buf_desc32_t, agp_start))
    399 	    || __get_user(agp_start, &buf->agp_start)
    400 	    || __put_user(agp_start, &argp->agp_start))
    401 		return -EFAULT;
    402 
    403 	return 0;
    404 }
    405 
    406 static int compat_drm_markbufs(struct file *file, unsigned int cmd,
    407 			       unsigned long arg)
    408 {
    409 	drm_buf_desc32_t b32;
    410 	drm_buf_desc32_t __user *argp = (void __user *)arg;
    411 	struct drm_buf_desc __user *buf;
    412 
    413 	if (copy_from_user(&b32, argp, sizeof(b32)))
    414 		return -EFAULT;
    415 
    416 	buf = compat_alloc_user_space(sizeof(*buf));
    417 	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf)))
    418 		return -EFAULT;
    419 
    420 	if (__put_user(b32.size, &buf->size)
    421 	    || __put_user(b32.low_mark, &buf->low_mark)
    422 	    || __put_user(b32.high_mark, &buf->high_mark))
    423 		return -EFAULT;
    424 
    425 	return drm_ioctl(file, DRM_IOCTL_MARK_BUFS, (unsigned long)buf);
    426 }
    427 
    428 typedef struct drm_buf_info32 {
    429 	int count;		/**< Entries in list */
    430 	u32 list;
    431 } drm_buf_info32_t;
    432 
    433 static int compat_drm_infobufs(struct file *file, unsigned int cmd,
    434 			       unsigned long arg)
    435 {
    436 	drm_buf_info32_t req32;
    437 	drm_buf_info32_t __user *argp = (void __user *)arg;
    438 	drm_buf_desc32_t __user *to;
    439 	struct drm_buf_info __user *request;
    440 	struct drm_buf_desc __user *list;
    441 	size_t nbytes;
    442 	int i, err;
    443 	int count, actual;
    444 
    445 	if (copy_from_user(&req32, argp, sizeof(req32)))
    446 		return -EFAULT;
    447 
    448 	count = req32.count;
    449 	to = (drm_buf_desc32_t __user *) (unsigned long)req32.list;
    450 	if (count < 0)
    451 		count = 0;
    452 	if (count > 0
    453 	    && !access_ok(VERIFY_WRITE, to, count * sizeof(drm_buf_desc32_t)))
    454 		return -EFAULT;
    455 
    456 	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_desc);
    457 	request = compat_alloc_user_space(nbytes);
    458 	if (!access_ok(VERIFY_WRITE, request, nbytes))
    459 		return -EFAULT;
    460 	list = (struct drm_buf_desc *) (request + 1);
    461 
    462 	if (__put_user(count, &request->count)
    463 	    || __put_user(list, &request->list))
    464 		return -EFAULT;
    465 
    466 	err = drm_ioctl(file, DRM_IOCTL_INFO_BUFS, (unsigned long)request);
    467 	if (err)
    468 		return err;
    469 
    470 	if (__get_user(actual, &request->count))
    471 		return -EFAULT;
    472 	if (count >= actual)
    473 		for (i = 0; i < actual; ++i)
    474 			if (__copy_in_user(&to[i], &list[i],
    475 					   offsetof(struct drm_buf_desc, flags)))
    476 				return -EFAULT;
    477 
    478 	if (__put_user(actual, &argp->count))
    479 		return -EFAULT;
    480 
    481 	return 0;
    482 }
    483 
    484 typedef struct drm_buf_pub32 {
    485 	int idx;		/**< Index into the master buffer list */
    486 	int total;		/**< Buffer size */
    487 	int used;		/**< Amount of buffer in use (for DMA) */
    488 	u32 address;		/**< Address of buffer */
    489 } drm_buf_pub32_t;
    490 
    491 typedef struct drm_buf_map32 {
    492 	int count;		/**< Length of the buffer list */
    493 	u32 virtual;		/**< Mmap'd area in user-virtual */
    494 	u32 list;		/**< Buffer information */
    495 } drm_buf_map32_t;
    496 
    497 static int compat_drm_mapbufs(struct file *file, unsigned int cmd,
    498 			      unsigned long arg)
    499 {
    500 	drm_buf_map32_t __user *argp = (void __user *)arg;
    501 	drm_buf_map32_t req32;
    502 	drm_buf_pub32_t __user *list32;
    503 	struct drm_buf_map __user *request;
    504 	struct drm_buf_pub __user *list;
    505 	int i, err;
    506 	int count, actual;
    507 	size_t nbytes;
    508 	void __user *addr;
    509 
    510 	if (copy_from_user(&req32, argp, sizeof(req32)))
    511 		return -EFAULT;
    512 	count = req32.count;
    513 	list32 = (void __user *)(unsigned long)req32.list;
    514 
    515 	if (count < 0)
    516 		return -EINVAL;
    517 	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_pub);
    518 	request = compat_alloc_user_space(nbytes);
    519 	if (!access_ok(VERIFY_WRITE, request, nbytes))
    520 		return -EFAULT;
    521 	list = (struct drm_buf_pub *) (request + 1);
    522 
    523 	if (__put_user(count, &request->count)
    524 	    || __put_user(list, &request->list))
    525 		return -EFAULT;
    526 
    527 	err = drm_ioctl(file, DRM_IOCTL_MAP_BUFS, (unsigned long)request);
    528 	if (err)
    529 		return err;
    530 
    531 	if (__get_user(actual, &request->count))
    532 		return -EFAULT;
    533 	if (count >= actual)
    534 		for (i = 0; i < actual; ++i)
    535 			if (__copy_in_user(&list32[i], &list[i],
    536 					   offsetof(struct drm_buf_pub, address))
    537 			    || __get_user(addr, &list[i].address)
    538 			    || __put_user((unsigned long)addr,
    539 					  &list32[i].address))
    540 				return -EFAULT;
    541 
    542 	if (__put_user(actual, &argp->count)
    543 	    || __get_user(addr, &request->virtual)
    544 	    || __put_user((unsigned long)addr, &argp->virtual))
    545 		return -EFAULT;
    546 
    547 	return 0;
    548 }
    549 
    550 typedef struct drm_buf_free32 {
    551 	int count;
    552 	u32 list;
    553 } drm_buf_free32_t;
    554 
    555 static int compat_drm_freebufs(struct file *file, unsigned int cmd,
    556 			       unsigned long arg)
    557 {
    558 	drm_buf_free32_t req32;
    559 	struct drm_buf_free __user *request;
    560 	drm_buf_free32_t __user *argp = (void __user *)arg;
    561 
    562 	if (copy_from_user(&req32, argp, sizeof(req32)))
    563 		return -EFAULT;
    564 
    565 	request = compat_alloc_user_space(sizeof(*request));
    566 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
    567 		return -EFAULT;
    568 	if (__put_user(req32.count, &request->count)
    569 	    || __put_user((int __user *)(unsigned long)req32.list,
    570 			  &request->list))
    571 		return -EFAULT;
    572 
    573 	return drm_ioctl(file, DRM_IOCTL_FREE_BUFS, (unsigned long)request);
    574 }
    575 
    576 typedef struct drm_ctx_priv_map32 {
    577 	unsigned int ctx_id;	 /**< Context requesting private mapping */
    578 	u32 handle;		/**< Handle of map */
    579 } drm_ctx_priv_map32_t;
    580 
    581 static int compat_drm_setsareactx(struct file *file, unsigned int cmd,
    582 				  unsigned long arg)
    583 {
    584 	drm_ctx_priv_map32_t req32;
    585 	struct drm_ctx_priv_map __user *request;
    586 	drm_ctx_priv_map32_t __user *argp = (void __user *)arg;
    587 
    588 	if (copy_from_user(&req32, argp, sizeof(req32)))
    589 		return -EFAULT;
    590 
    591 	request = compat_alloc_user_space(sizeof(*request));
    592 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
    593 		return -EFAULT;
    594 	if (__put_user(req32.ctx_id, &request->ctx_id)
    595 	    || __put_user((void *)(unsigned long)req32.handle,
    596 			  &request->handle))
    597 		return -EFAULT;
    598 
    599 	return drm_ioctl(file, DRM_IOCTL_SET_SAREA_CTX, (unsigned long)request);
    600 }
    601 
    602 static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
    603 				  unsigned long arg)
    604 {
    605 	struct drm_ctx_priv_map __user *request;
    606 	drm_ctx_priv_map32_t __user *argp = (void __user *)arg;
    607 	int err;
    608 	unsigned int ctx_id;
    609 	void *handle;
    610 
    611 	if (!access_ok(VERIFY_WRITE, argp, sizeof(*argp))
    612 	    || __get_user(ctx_id, &argp->ctx_id))
    613 		return -EFAULT;
    614 
    615 	request = compat_alloc_user_space(sizeof(*request));
    616 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
    617 		return -EFAULT;
    618 	if (__put_user(ctx_id, &request->ctx_id))
    619 		return -EFAULT;
    620 
    621 	err = drm_ioctl(file, DRM_IOCTL_GET_SAREA_CTX, (unsigned long)request);
    622 	if (err)
    623 		return err;
    624 
    625 	if (__get_user(handle, &request->handle)
    626 	    || __put_user((unsigned long)handle, &argp->handle))
    627 		return -EFAULT;
    628 
    629 	return 0;
    630 }
    631 
    632 typedef struct drm_ctx_res32 {
    633 	int count;
    634 	u32 contexts;
    635 } drm_ctx_res32_t;
    636 
    637 static int compat_drm_resctx(struct file *file, unsigned int cmd,
    638 			     unsigned long arg)
    639 {
    640 	drm_ctx_res32_t __user *argp = (void __user *)arg;
    641 	drm_ctx_res32_t res32;
    642 	struct drm_ctx_res __user *res;
    643 	int err;
    644 
    645 	if (copy_from_user(&res32, argp, sizeof(res32)))
    646 		return -EFAULT;
    647 
    648 	res = compat_alloc_user_space(sizeof(*res));
    649 	if (!access_ok(VERIFY_WRITE, res, sizeof(*res)))
    650 		return -EFAULT;
    651 	if (__put_user(res32.count, &res->count)
    652 	    || __put_user((struct drm_ctx __user *) (unsigned long)res32.contexts,
    653 			  &res->contexts))
    654 		return -EFAULT;
    655 
    656 	err = drm_ioctl(file, DRM_IOCTL_RES_CTX, (unsigned long)res);
    657 	if (err)
    658 		return err;
    659 
    660 	if (__get_user(res32.count, &res->count)
    661 	    || __put_user(res32.count, &argp->count))
    662 		return -EFAULT;
    663 
    664 	return 0;
    665 }
    666 
    667 typedef struct drm_dma32 {
    668 	int context;		  /**< Context handle */
    669 	int send_count;		  /**< Number of buffers to send */
    670 	u32 send_indices;	  /**< List of handles to buffers */
    671 	u32 send_sizes;		  /**< Lengths of data to send */
    672 	enum drm_dma_flags flags;		  /**< Flags */
    673 	int request_count;	  /**< Number of buffers requested */
    674 	int request_size;	  /**< Desired size for buffers */
    675 	u32 request_indices;	  /**< Buffer information */
    676 	u32 request_sizes;
    677 	int granted_count;	  /**< Number of buffers granted */
    678 } drm_dma32_t;
    679 
    680 static int compat_drm_dma(struct file *file, unsigned int cmd,
    681 			  unsigned long arg)
    682 {
    683 	drm_dma32_t d32;
    684 	drm_dma32_t __user *argp = (void __user *)arg;
    685 	struct drm_dma __user *d;
    686 	int err;
    687 
    688 	if (copy_from_user(&d32, argp, sizeof(d32)))
    689 		return -EFAULT;
    690 
    691 	d = compat_alloc_user_space(sizeof(*d));
    692 	if (!access_ok(VERIFY_WRITE, d, sizeof(*d)))
    693 		return -EFAULT;
    694 
    695 	if (__put_user(d32.context, &d->context)
    696 	    || __put_user(d32.send_count, &d->send_count)
    697 	    || __put_user((int __user *)(unsigned long)d32.send_indices,
    698 			  &d->send_indices)
    699 	    || __put_user((int __user *)(unsigned long)d32.send_sizes,
    700 			  &d->send_sizes)
    701 	    || __put_user(d32.flags, &d->flags)
    702 	    || __put_user(d32.request_count, &d->request_count)
    703 	    || __put_user((int __user *)(unsigned long)d32.request_indices,
    704 			  &d->request_indices)
    705 	    || __put_user((int __user *)(unsigned long)d32.request_sizes,
    706 			  &d->request_sizes))
    707 		return -EFAULT;
    708 
    709 	err = drm_ioctl(file, DRM_IOCTL_DMA, (unsigned long)d);
    710 	if (err)
    711 		return err;
    712 
    713 	if (__get_user(d32.request_size, &d->request_size)
    714 	    || __get_user(d32.granted_count, &d->granted_count)
    715 	    || __put_user(d32.request_size, &argp->request_size)
    716 	    || __put_user(d32.granted_count, &argp->granted_count))
    717 		return -EFAULT;
    718 
    719 	return 0;
    720 }
    721 
    722 #if __OS_HAS_AGP
    723 typedef struct drm_agp_mode32 {
    724 	u32 mode;	/**< AGP mode */
    725 } drm_agp_mode32_t;
    726 
    727 static int compat_drm_agp_enable(struct file *file, unsigned int cmd,
    728 				 unsigned long arg)
    729 {
    730 	drm_agp_mode32_t __user *argp = (void __user *)arg;
    731 	drm_agp_mode32_t m32;
    732 	struct drm_agp_mode __user *mode;
    733 
    734 	if (get_user(m32.mode, &argp->mode))
    735 		return -EFAULT;
    736 
    737 	mode = compat_alloc_user_space(sizeof(*mode));
    738 	if (put_user(m32.mode, &mode->mode))
    739 		return -EFAULT;
    740 
    741 	return drm_ioctl(file, DRM_IOCTL_AGP_ENABLE, (unsigned long)mode);
    742 }
    743 
    744 typedef struct drm_agp_info32 {
    745 	int agp_version_major;
    746 	int agp_version_minor;
    747 	u32 mode;
    748 	u32 aperture_base;	/* physical address */
    749 	u32 aperture_size;	/* bytes */
    750 	u32 memory_allowed;	/* bytes */
    751 	u32 memory_used;
    752 
    753 	/* PCI information */
    754 	unsigned short id_vendor;
    755 	unsigned short id_device;
    756 } drm_agp_info32_t;
    757 
    758 static int compat_drm_agp_info(struct file *file, unsigned int cmd,
    759 			       unsigned long arg)
    760 {
    761 	drm_agp_info32_t __user *argp = (void __user *)arg;
    762 	drm_agp_info32_t i32;
    763 	struct drm_agp_info __user *info;
    764 	int err;
    765 
    766 	info = compat_alloc_user_space(sizeof(*info));
    767 	if (!access_ok(VERIFY_WRITE, info, sizeof(*info)))
    768 		return -EFAULT;
    769 
    770 	err = drm_ioctl(file, DRM_IOCTL_AGP_INFO, (unsigned long)info);
    771 	if (err)
    772 		return err;
    773 
    774 	if (__get_user(i32.agp_version_major, &info->agp_version_major)
    775 	    || __get_user(i32.agp_version_minor, &info->agp_version_minor)
    776 	    || __get_user(i32.mode, &info->mode)
    777 	    || __get_user(i32.aperture_base, &info->aperture_base)
    778 	    || __get_user(i32.aperture_size, &info->aperture_size)
    779 	    || __get_user(i32.memory_allowed, &info->memory_allowed)
    780 	    || __get_user(i32.memory_used, &info->memory_used)
    781 	    || __get_user(i32.id_vendor, &info->id_vendor)
    782 	    || __get_user(i32.id_device, &info->id_device))
    783 		return -EFAULT;
    784 
    785 	if (copy_to_user(argp, &i32, sizeof(i32)))
    786 		return -EFAULT;
    787 
    788 	return 0;
    789 }
    790 
    791 typedef struct drm_agp_buffer32 {
    792 	u32 size;	/**< In bytes -- will round to page boundary */
    793 	u32 handle;	/**< Used for binding / unbinding */
    794 	u32 type;	/**< Type of memory to allocate */
    795 	u32 physical;	/**< Physical used by i810 */
    796 } drm_agp_buffer32_t;
    797 
    798 static int compat_drm_agp_alloc(struct file *file, unsigned int cmd,
    799 				unsigned long arg)
    800 {
    801 	drm_agp_buffer32_t __user *argp = (void __user *)arg;
    802 	drm_agp_buffer32_t req32;
    803 	struct drm_agp_buffer __user *request;
    804 	int err;
    805 
    806 	if (copy_from_user(&req32, argp, sizeof(req32)))
    807 		return -EFAULT;
    808 
    809 	request = compat_alloc_user_space(sizeof(*request));
    810 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
    811 	    || __put_user(req32.size, &request->size)
    812 	    || __put_user(req32.type, &request->type))
    813 		return -EFAULT;
    814 
    815 	err = drm_ioctl(file, DRM_IOCTL_AGP_ALLOC, (unsigned long)request);
    816 	if (err)
    817 		return err;
    818 
    819 	if (__get_user(req32.handle, &request->handle)
    820 	    || __get_user(req32.physical, &request->physical)
    821 	    || copy_to_user(argp, &req32, sizeof(req32))) {
    822 		drm_ioctl(file, DRM_IOCTL_AGP_FREE, (unsigned long)request);
    823 		return -EFAULT;
    824 	}
    825 
    826 	return 0;
    827 }
    828 
    829 static int compat_drm_agp_free(struct file *file, unsigned int cmd,
    830 			       unsigned long arg)
    831 {
    832 	drm_agp_buffer32_t __user *argp = (void __user *)arg;
    833 	struct drm_agp_buffer __user *request;
    834 	u32 handle;
    835 
    836 	request = compat_alloc_user_space(sizeof(*request));
    837 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
    838 	    || get_user(handle, &argp->handle)
    839 	    || __put_user(handle, &request->handle))
    840 		return -EFAULT;
    841 
    842 	return drm_ioctl(file, DRM_IOCTL_AGP_FREE, (unsigned long)request);
    843 }
    844 
    845 typedef struct drm_agp_binding32 {
    846 	u32 handle;	/**< From drm_agp_buffer */
    847 	u32 offset;	/**< In bytes -- will round to page boundary */
    848 } drm_agp_binding32_t;
    849 
    850 static int compat_drm_agp_bind(struct file *file, unsigned int cmd,
    851 			       unsigned long arg)
    852 {
    853 	drm_agp_binding32_t __user *argp = (void __user *)arg;
    854 	drm_agp_binding32_t req32;
    855 	struct drm_agp_binding __user *request;
    856 
    857 	if (copy_from_user(&req32, argp, sizeof(req32)))
    858 		return -EFAULT;
    859 
    860 	request = compat_alloc_user_space(sizeof(*request));
    861 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
    862 	    || __put_user(req32.handle, &request->handle)
    863 	    || __put_user(req32.offset, &request->offset))
    864 		return -EFAULT;
    865 
    866 	return drm_ioctl(file, DRM_IOCTL_AGP_BIND, (unsigned long)request);
    867 }
    868 
    869 static int compat_drm_agp_unbind(struct file *file, unsigned int cmd,
    870 				 unsigned long arg)
    871 {
    872 	drm_agp_binding32_t __user *argp = (void __user *)arg;
    873 	struct drm_agp_binding __user *request;
    874 	u32 handle;
    875 
    876 	request = compat_alloc_user_space(sizeof(*request));
    877 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
    878 	    || get_user(handle, &argp->handle)
    879 	    || __put_user(handle, &request->handle))
    880 		return -EFAULT;
    881 
    882 	return drm_ioctl(file, DRM_IOCTL_AGP_UNBIND, (unsigned long)request);
    883 }
    884 #endif				/* __OS_HAS_AGP */
    885 
    886 typedef struct drm_scatter_gather32 {
    887 	u32 size;	/**< In bytes -- will round to page boundary */
    888 	u32 handle;	/**< Used for mapping / unmapping */
    889 } drm_scatter_gather32_t;
    890 
    891 static int compat_drm_sg_alloc(struct file *file, unsigned int cmd,
    892 			       unsigned long arg)
    893 {
    894 	drm_scatter_gather32_t __user *argp = (void __user *)arg;
    895 	struct drm_scatter_gather __user *request;
    896 	int err;
    897 	unsigned long x;
    898 
    899 	request = compat_alloc_user_space(sizeof(*request));
    900 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
    901 	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
    902 	    || __get_user(x, &argp->size)
    903 	    || __put_user(x, &request->size))
    904 		return -EFAULT;
    905 
    906 	err = drm_ioctl(file, DRM_IOCTL_SG_ALLOC, (unsigned long)request);
    907 	if (err)
    908 		return err;
    909 
    910 	/* XXX not sure about the handle conversion here... */
    911 	if (__get_user(x, &request->handle)
    912 	    || __put_user(x >> PAGE_SHIFT, &argp->handle))
    913 		return -EFAULT;
    914 
    915 	return 0;
    916 }
    917 
    918 static int compat_drm_sg_free(struct file *file, unsigned int cmd,
    919 			      unsigned long arg)
    920 {
    921 	drm_scatter_gather32_t __user *argp = (void __user *)arg;
    922 	struct drm_scatter_gather __user *request;
    923 	unsigned long x;
    924 
    925 	request = compat_alloc_user_space(sizeof(*request));
    926 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
    927 	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
    928 	    || __get_user(x, &argp->handle)
    929 	    || __put_user(x << PAGE_SHIFT, &request->handle))
    930 		return -EFAULT;
    931 
    932 	return drm_ioctl(file, DRM_IOCTL_SG_FREE, (unsigned long)request);
    933 }
    934 
    935 #if defined(CONFIG_X86) || defined(CONFIG_IA64)
    936 typedef struct drm_update_draw32 {
    937 	drm_drawable_t handle;
    938 	unsigned int type;
    939 	unsigned int num;
    940 	/* 64-bit version has a 32-bit pad here */
    941 	u64 data;	/**< Pointer */
    942 } __attribute__((packed)) drm_update_draw32_t;
    943 
    944 static int compat_drm_update_draw(struct file *file, unsigned int cmd,
    945 				  unsigned long arg)
    946 {
    947 	drm_update_draw32_t update32;
    948 	struct drm_update_draw __user *request;
    949 	int err;
    950 
    951 	if (copy_from_user(&update32, (void __user *)arg, sizeof(update32)))
    952 		return -EFAULT;
    953 
    954 	request = compat_alloc_user_space(sizeof(*request));
    955 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)) ||
    956 	    __put_user(update32.handle, &request->handle) ||
    957 	    __put_user(update32.type, &request->type) ||
    958 	    __put_user(update32.num, &request->num) ||
    959 	    __put_user(update32.data, &request->data))
    960 		return -EFAULT;
    961 
    962 	err = drm_ioctl(file, DRM_IOCTL_UPDATE_DRAW, (unsigned long)request);
    963 	return err;
    964 }
    965 #endif
    966 
    967 struct drm_wait_vblank_request32 {
    968 	enum drm_vblank_seq_type type;
    969 	unsigned int sequence;
    970 	u32 signal;
    971 };
    972 
    973 struct drm_wait_vblank_reply32 {
    974 	enum drm_vblank_seq_type type;
    975 	unsigned int sequence;
    976 	s32 tval_sec;
    977 	s32 tval_usec;
    978 };
    979 
    980 typedef union drm_wait_vblank32 {
    981 	struct drm_wait_vblank_request32 request;
    982 	struct drm_wait_vblank_reply32 reply;
    983 } drm_wait_vblank32_t;
    984 
    985 static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
    986 				  unsigned long arg)
    987 {
    988 	drm_wait_vblank32_t __user *argp = (void __user *)arg;
    989 	drm_wait_vblank32_t req32;
    990 	union drm_wait_vblank __user *request;
    991 	int err;
    992 
    993 	if (copy_from_user(&req32, argp, sizeof(req32)))
    994 		return -EFAULT;
    995 
    996 	request = compat_alloc_user_space(sizeof(*request));
    997 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
    998 	    || __put_user(req32.request.type, &request->request.type)
    999 	    || __put_user(req32.request.sequence, &request->request.sequence)
   1000 	    || __put_user(req32.request.signal, &request->request.signal))
   1001 		return -EFAULT;
   1002 
   1003 	err = drm_ioctl(file, DRM_IOCTL_WAIT_VBLANK, (unsigned long)request);
   1004 	if (err)
   1005 		return err;
   1006 
   1007 	if (__get_user(req32.reply.type, &request->reply.type)
   1008 	    || __get_user(req32.reply.sequence, &request->reply.sequence)
   1009 	    || __get_user(req32.reply.tval_sec, &request->reply.tval_sec)
   1010 	    || __get_user(req32.reply.tval_usec, &request->reply.tval_usec))
   1011 		return -EFAULT;
   1012 
   1013 	if (copy_to_user(argp, &req32, sizeof(req32)))
   1014 		return -EFAULT;
   1015 
   1016 	return 0;
   1017 }
   1018 
   1019 drm_ioctl_compat_t *drm_compat_ioctls[] = {
   1020 	[DRM_IOCTL_NR(DRM_IOCTL_VERSION32)] = compat_drm_version,
   1021 	[DRM_IOCTL_NR(DRM_IOCTL_GET_UNIQUE32)] = compat_drm_getunique,
   1022 	[DRM_IOCTL_NR(DRM_IOCTL_GET_MAP32)] = compat_drm_getmap,
   1023 	[DRM_IOCTL_NR(DRM_IOCTL_GET_CLIENT32)] = compat_drm_getclient,
   1024 	[DRM_IOCTL_NR(DRM_IOCTL_GET_STATS32)] = compat_drm_getstats,
   1025 	[DRM_IOCTL_NR(DRM_IOCTL_SET_UNIQUE32)] = compat_drm_setunique,
   1026 	[DRM_IOCTL_NR(DRM_IOCTL_ADD_MAP32)] = compat_drm_addmap,
   1027 	[DRM_IOCTL_NR(DRM_IOCTL_ADD_BUFS32)] = compat_drm_addbufs,
   1028 	[DRM_IOCTL_NR(DRM_IOCTL_MARK_BUFS32)] = compat_drm_markbufs,
   1029 	[DRM_IOCTL_NR(DRM_IOCTL_INFO_BUFS32)] = compat_drm_infobufs,
   1030 	[DRM_IOCTL_NR(DRM_IOCTL_MAP_BUFS32)] = compat_drm_mapbufs,
   1031 	[DRM_IOCTL_NR(DRM_IOCTL_FREE_BUFS32)] = compat_drm_freebufs,
   1032 	[DRM_IOCTL_NR(DRM_IOCTL_RM_MAP32)] = compat_drm_rmmap,
   1033 	[DRM_IOCTL_NR(DRM_IOCTL_SET_SAREA_CTX32)] = compat_drm_setsareactx,
   1034 	[DRM_IOCTL_NR(DRM_IOCTL_GET_SAREA_CTX32)] = compat_drm_getsareactx,
   1035 	[DRM_IOCTL_NR(DRM_IOCTL_RES_CTX32)] = compat_drm_resctx,
   1036 	[DRM_IOCTL_NR(DRM_IOCTL_DMA32)] = compat_drm_dma,
   1037 #if __OS_HAS_AGP
   1038 	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ENABLE32)] = compat_drm_agp_enable,
   1039 	[DRM_IOCTL_NR(DRM_IOCTL_AGP_INFO32)] = compat_drm_agp_info,
   1040 	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ALLOC32)] = compat_drm_agp_alloc,
   1041 	[DRM_IOCTL_NR(DRM_IOCTL_AGP_FREE32)] = compat_drm_agp_free,
   1042 	[DRM_IOCTL_NR(DRM_IOCTL_AGP_BIND32)] = compat_drm_agp_bind,
   1043 	[DRM_IOCTL_NR(DRM_IOCTL_AGP_UNBIND32)] = compat_drm_agp_unbind,
   1044 #endif
   1045 	[DRM_IOCTL_NR(DRM_IOCTL_SG_ALLOC32)] = compat_drm_sg_alloc,
   1046 	[DRM_IOCTL_NR(DRM_IOCTL_SG_FREE32)] = compat_drm_sg_free,
   1047 #if defined(CONFIG_X86) || defined(CONFIG_IA64)
   1048 	[DRM_IOCTL_NR(DRM_IOCTL_UPDATE_DRAW32)] = compat_drm_update_draw,
   1049 #endif
   1050 	[DRM_IOCTL_NR(DRM_IOCTL_WAIT_VBLANK32)] = compat_drm_wait_vblank,
   1051 };
   1052 
   1053 /**
   1054  * Called whenever a 32-bit process running under a 64-bit kernel
   1055  * performs an ioctl on /dev/drm.
   1056  *
   1057  * \param file_priv DRM file private.
   1058  * \param cmd command.
   1059  * \param arg user argument.
   1060  * \return zero on success or negative number on failure.
   1061  */
   1062 long drm_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
   1063 {
   1064 	unsigned int nr = DRM_IOCTL_NR(cmd);
   1065 	drm_ioctl_compat_t *fn;
   1066 	int ret;
   1067 
   1068 	/* Assume that ioctls without an explicit compat routine will just
   1069 	 * work.  This may not always be a good assumption, but it's better
   1070 	 * than always failing.
   1071 	 */
   1072 	if (nr >= ARRAY_SIZE(drm_compat_ioctls))
   1073 		return drm_ioctl(filp, cmd, arg);
   1074 
   1075 	fn = drm_compat_ioctls[nr];
   1076 
   1077 	if (fn != NULL)
   1078 		ret = (*fn) (filp, cmd, arg);
   1079 	else
   1080 		ret = drm_ioctl(filp, cmd, arg);
   1081 
   1082 	return ret;
   1083 }
   1084 
   1085 EXPORT_SYMBOL(drm_compat_ioctl);
   1086