drivers/gpu/drm/drm_drv.c

   1 /**
   2  * \file drm_drv.c
   3  * Generic driver template
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  * \author Gareth Hughes <gareth@valinux.com>
   7  *
   8  * To use this template, you must at least define the following (samples
   9  * given for the MGA driver):
  10  *
  11  * \code
  12  * #define DRIVER_AUTHOR        "VA Linux Systems, Inc."
  13  *
  14  * #define DRIVER_NAME          "mga"
  15  * #define DRIVER_DESC          "Matrox G200/G400"
  16  * #define DRIVER_DATE          "20001127"
  17  *
  18  * #define drm_x                mga_##x
  19  * \endcode
  20  */
  21
  22 /*
  23  * Created: Thu Nov 23 03:10:50 2000 by gareth@valinux.com
  24  *
  25  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
  26  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  27  * All Rights Reserved.
  28  *
  29  * Permission is hereby granted, free of charge, to any person obtaining a
  30  * copy of this software and associated documentation files (the "Software"),
  31  * to deal in the Software without restriction, including without limitation
  32  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  33  * and/or sell copies of the Software, and to permit persons to whom the
  34  * Software is furnished to do so, subject to the following conditions:
  35  *
  36  * The above copyright notice and this permission notice (including the next
  37  * paragraph) shall be included in all copies or substantial portions of the
  38  * Software.
  39  *
  40  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  41  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  42  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  43  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  44  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  45  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  46  * OTHER DEALINGS IN THE SOFTWARE.
  47  */
  48
  49 #include <linux/debugfs.h>
  50 #include <linux/slab.h>
  51 #include <linux/export.h>
  52 #include <drm/drmP.h>
  53 #include <drm/drm_core.h>
  54
  55
  56 static int drm_version(struct drm_device *dev, void *data,
  57                        struct drm_file *file_priv);
  58
  59 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \
  60         [DRM_IOCTL_NR(ioctl)] = {.cmd = ioctl, .func = _func, .flags = _flags, .cmd_drv = 0, .name = #ioctl}
  61
  62 /** Ioctl table */
  63 static const struct drm_ioctl_desc drm_ioctls[] = {
  64         DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_UNLOCKED|DRM_RENDER_ALLOW),
  65         DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
  66         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
  67         DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
  68         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, DRM_UNLOCKED),
  69         DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
  70         DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
  71         DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
  72         DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
  73         DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
  74
  75         DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  76         DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  77         DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  78         DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_MASTER),
  79
  80         DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  81         DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_rmmap_ioctl, DRM_AUTH),
  82
  83         DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  84         DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_getsareactx, DRM_AUTH),
  85
  86         DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY),
  87         DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY),
  88
  89         DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_addctx, DRM_AUTH|DRM_ROOT_ONLY),
  90         DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  91         DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  92         DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_getctx, DRM_AUTH),
  93         DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  94         DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  95         DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_resctx, DRM_AUTH),
  96
  97         DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  98         DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  99
 100         DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_lock, DRM_AUTH),
 101         DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_unlock, DRM_AUTH),
 102
 103         DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
 104
 105         DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 106         DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 107         DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_infobufs, DRM_AUTH),
 108         DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_mapbufs, DRM_AUTH),
 109         DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_freebufs, DRM_AUTH),
 110         DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_dma_ioctl, DRM_AUTH),
 111
 112         DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 113
 114 #if __OS_HAS_AGP
 115         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 116         DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 117         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 118         DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
 119         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 120         DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 121         DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 122         DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 123 #endif
 124
 125         DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 126         DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 127
 128         DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
 129
 130         DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
 131
 132         DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 133
 134         DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 135         DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
 136         DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
 137
 138         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 139
 140         DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
 141         DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
 142
 143         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 144         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 145         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 146         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 147         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 148         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 149         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
 150         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
 151         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 152         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 153         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 154         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 155         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 156         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 157         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 158         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 159         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 160         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 161         DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 162         DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 163         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 164         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 165         DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 166         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 167         DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 168         DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 169         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 170 };
 171
 172 #define DRM_CORE_IOCTL_COUNT    ARRAY_SIZE( drm_ioctls )
 173
 174 /** File operations structure */
 175 static const struct file_operations drm_stub_fops = {
 176         .owner = THIS_MODULE,
 177         .open = drm_stub_open,
 178         .llseek = noop_llseek,
 179 };
 180
 181 static int __init drm_core_init(void)
 182 {
 183         int ret = -ENOMEM;
 184
 185         drm_global_init();
 186         drm_connector_ida_init();
 187         idr_init(&drm_minors_idr);
 188
 189         if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
 190                 goto err_p1;
 191
 192         drm_class = drm_sysfs_create(THIS_MODULE, "drm");
 193         if (IS_ERR(drm_class)) {
 194                 printk(KERN_ERR "DRM: Error creating drm class.\n");
 195                 ret = PTR_ERR(drm_class);
 196                 goto err_p2;
 197         }
 198
 199         drm_debugfs_root = debugfs_create_dir("dri", NULL);
 200         if (!drm_debugfs_root) {
 201                 DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
 202                 ret = -1;
 203                 goto err_p3;
 204         }
 205
 206         DRM_INFO("Initialized %s %d.%d.%d %s\n",
 207                  CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
 208         return 0;
 209 err_p3:
 210         drm_sysfs_destroy();
 211 err_p2:
 212         unregister_chrdev(DRM_MAJOR, "drm");
 213
 214         idr_destroy(&drm_minors_idr);
 215 err_p1:
 216         return ret;
 217 }
 218
 219 static void __exit drm_core_exit(void)
 220 {
 221         debugfs_remove(drm_debugfs_root);
 222         drm_sysfs_destroy();
 223
 224         unregister_chrdev(DRM_MAJOR, "drm");
 225
 226         drm_connector_ida_destroy();
 227         idr_destroy(&drm_minors_idr);
 228 }
 229
 230 module_init(drm_core_init);
 231 module_exit(drm_core_exit);
 232
 233 /**
 234  * Copy and IOCTL return string to user space
 235  */
 236 static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
 237 {
 238         int len;
 239
 240         /* don't overflow userbuf */
 241         len = strlen(value);
 242         if (len > *buf_len)
 243                 len = *buf_len;
 244
 245         /* let userspace know exact length of driver value (which could be
 246          * larger than the userspace-supplied buffer) */
 247         *buf_len = strlen(value);
 248
 249         /* finally, try filling in the userbuf */
 250         if (len && buf)
 251                 if (copy_to_user(buf, value, len))
 252                         return -EFAULT;
 253         return 0;
 254 }
 255
 256 /**
 257  * Get version information
 258  *
 259  * \param inode device inode.
 260  * \param filp file pointer.
 261  * \param cmd command.
 262  * \param arg user argument, pointing to a drm_version structure.
 263  * \return zero on success or negative number on failure.
 264  *
 265  * Fills in the version information in \p arg.
 266  */
 267 static int drm_version(struct drm_device *dev, void *data,
 268                        struct drm_file *file_priv)
 269 {
 270         struct drm_version *version = data;
 271         int err;
 272
 273         version->version_major = dev->driver->major;
 274         version->version_minor = dev->driver->minor;
 275         version->version_patchlevel = dev->driver->patchlevel;
 276         err = drm_copy_field(version->name, &version->name_len,
 277                         dev->driver->name);
 278         if (!err)
 279                 err = drm_copy_field(version->date, &version->date_len,
 280                                 dev->driver->date);
 281         if (!err)
 282                 err = drm_copy_field(version->desc, &version->desc_len,
 283                                 dev->driver->desc);
 284
 285         return err;
 286 }
 287
 288 /**
 289  * drm_ioctl_permit - Check ioctl permissions against caller
 290  *
 291  * @flags: ioctl permission flags.
 292  * @file_priv: Pointer to struct drm_file identifying the caller.
 293  *
 294  * Checks whether the caller is allowed to run an ioctl with the
 295  * indicated permissions. If so, returns zero. Otherwise returns an
 296  * error code suitable for ioctl return.
 297  */
 298 static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
 299 {
 300         /* ROOT_ONLY is only for CAP_SYS_ADMIN */
 301         if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
 302                 return -EACCES;
 303
 304         /* AUTH is only for authenticated or render client */
 305         if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
 306                      !file_priv->authenticated))
 307                 return -EACCES;
 308
 309         /* MASTER is only for master or control clients */
 310         if (unlikely((flags & DRM_MASTER) && !file_priv->is_master &&
 311                      !drm_is_control_client(file_priv)))
 312                 return -EACCES;
 313
 314         /* Control clients must be explicitly allowed */
 315         if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
 316                      drm_is_control_client(file_priv)))
 317                 return -EACCES;
 318
 319         /* Render clients must be explicitly allowed */
 320         if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
 321                      drm_is_render_client(file_priv)))
 322                 return -EACCES;
 323
 324         return 0;
 325 }
 326
 327 /**
 328  * Called whenever a process performs an ioctl on /dev/drm.
 329  *
 330  * \param inode device inode.
 331  * \param file_priv DRM file private.
 332  * \param cmd command.
 333  * \param arg user argument.
 334  * \return zero on success or negative number on failure.
 335  *
 336  * Looks up the ioctl function in the ::ioctls table, checking for root
 337  * previleges if so required, and dispatches to the respective function.
 338  */
 339 long drm_ioctl(struct file *filp,
 340               unsigned int cmd, unsigned long arg)
 341 {
 342         struct drm_file *file_priv = filp->private_data;
 343         struct drm_device *dev;
 344         const struct drm_ioctl_desc *ioctl = NULL;
 345         drm_ioctl_t *func;
 346         unsigned int nr = DRM_IOCTL_NR(cmd);
 347         int retcode = -EINVAL;
 348         char stack_kdata[128];
 349         char *kdata = NULL;
 350         unsigned int usize, asize;
 351
 352         dev = file_priv->minor->dev;
 353
 354         if (drm_device_is_unplugged(dev))
 355                 return -ENODEV;
 356
 357         if ((nr >= DRM_CORE_IOCTL_COUNT) &&
 358             ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
 359                 goto err_i1;
 360         if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
 361             (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls)) {
 362                 u32 drv_size;
 363                 ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
 364                 drv_size = _IOC_SIZE(ioctl->cmd_drv);
 365                 usize = asize = _IOC_SIZE(cmd);
 366                 if (drv_size > asize)
 367                         asize = drv_size;
 368                 cmd = ioctl->cmd_drv;
 369         }
 370         else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
 371                 u32 drv_size;
 372
 373                 ioctl = &drm_ioctls[nr];
 374
 375                 drv_size = _IOC_SIZE(ioctl->cmd);
 376                 usize = asize = _IOC_SIZE(cmd);
 377                 if (drv_size > asize)
 378                         asize = drv_size;
 379
 380                 cmd = ioctl->cmd;
 381         } else
 382                 goto err_i1;
 383
 384         DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
 385                   task_pid_nr(current),
 386                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 387                   file_priv->authenticated, ioctl->name);
 388
 389         /* Do not trust userspace, use our own definition */
 390         func = ioctl->func;
 391
 392         if (unlikely(!func)) {
 393                 DRM_DEBUG("no function\n");
 394                 retcode = -EINVAL;
 395                 goto err_i1;
 396         }
 397
 398         retcode = drm_ioctl_permit(ioctl->flags, file_priv);
 399         if (unlikely(retcode))
 400                 goto err_i1;
 401
 402         if (cmd & (IOC_IN | IOC_OUT)) {
 403                 if (asize <= sizeof(stack_kdata)) {
 404                         kdata = stack_kdata;
 405                 } else {
 406                         kdata = kmalloc(asize, GFP_KERNEL);
 407                         if (!kdata) {
 408                                 retcode = -ENOMEM;
 409                                 goto err_i1;
 410                         }
 411                 }
 412                 if (asize > usize)
 413                         memset(kdata + usize, 0, asize - usize);
 414         }
 415
 416         if (cmd & IOC_IN) {
 417                 if (copy_from_user(kdata, (void __user *)arg,
 418                                    usize) != 0) {
 419                         retcode = -EFAULT;
 420                         goto err_i1;
 421                 }
 422         } else
 423                 memset(kdata, 0, usize);
 424
 425         if (ioctl->flags & DRM_UNLOCKED)
 426                 retcode = func(dev, kdata, file_priv);
 427         else {
 428                 mutex_lock(&drm_global_mutex);
 429                 retcode = func(dev, kdata, file_priv);
 430                 mutex_unlock(&drm_global_mutex);
 431         }
 432
 433         if (cmd & IOC_OUT) {
 434                 if (copy_to_user((void __user *)arg, kdata,
 435                                  usize) != 0)
 436                         retcode = -EFAULT;
 437         }
 438
 439       err_i1:
 440         if (!ioctl)
 441                 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
 442                           task_pid_nr(current),
 443                           (long)old_encode_dev(file_priv->minor->kdev->devt),
 444                           file_priv->authenticated, cmd, nr);
 445
 446         if (kdata != stack_kdata)
 447                 kfree(kdata);
 448         if (retcode)
 449                 DRM_DEBUG("ret = %d\n", retcode);
 450         return retcode;
 451 }
 452 EXPORT_SYMBOL(drm_ioctl);
 453
 454 /**
 455  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
 456  *
 457  * @nr: Ioctl number.
 458  * @flags: Where to return the ioctl permission flags
 459  */
 460 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
 461 {
 462         if ((nr >= DRM_COMMAND_END && nr < DRM_CORE_IOCTL_COUNT) ||
 463             (nr < DRM_COMMAND_BASE)) {
 464                 *flags = drm_ioctls[nr].flags;
 465                 return true;
 466         }
 467
 468         return false;
 469 }
 470 EXPORT_SYMBOL(drm_ioctl_flags);