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),
  65         DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
  66         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
  67         DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
  68         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, DRM_UNLOCKED),
  69         DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
  70         DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
  71         DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED),
  72         DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
  73
  74         DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  75         DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  76         DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  77         DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_MASTER),
  78
  79         DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  80         DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_rmmap_ioctl, DRM_AUTH),
  81
  82         DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  83         DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_getsareactx, DRM_AUTH),
  84
  85         DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY),
  86         DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY),
  87
  88         DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_addctx, DRM_AUTH|DRM_ROOT_ONLY),
  89         DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  90         DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  91         DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_getctx, DRM_AUTH),
  92         DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  93         DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  94         DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_resctx, DRM_AUTH),
  95
  96         DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  97         DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
  98
  99         DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_lock, DRM_AUTH),
 100         DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_unlock, DRM_AUTH),
 101
 102         DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
 103
 104         DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 105         DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 106         DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_infobufs, DRM_AUTH),
 107         DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_mapbufs, DRM_AUTH),
 108         DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_freebufs, DRM_AUTH),
 109         /* 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, 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_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 /**
 175  * Take down the DRM device.
 176  *
 177  * \param dev DRM device structure.
 178  *
 179  * Frees every resource in \p dev.
 180  *
 181  * \sa drm_device
 182  */
 183 int drm_lastclose(struct drm_device * dev)
 184 {
 185         struct drm_vma_entry *vma, *vma_temp;
 186
 187         DRM_DEBUG("\n");
 188
 189         if (dev->driver->lastclose)
 190                 dev->driver->lastclose(dev);
 191         DRM_DEBUG("driver lastclose completed\n");
 192
 193         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 194                 drm_irq_uninstall(dev);
 195
 196         mutex_lock(&dev->struct_mutex);
 197
 198         drm_agp_clear(dev);
 199
 200         drm_legacy_sg_cleanup(dev);
 201
 202         /* Clear vma list (only built for debugging) */
 203         list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
 204                 list_del(&vma->head);
 205                 kfree(vma);
 206         }
 207
 208         drm_legacy_dma_takedown(dev);
 209
 210         dev->dev_mapping = NULL;
 211         mutex_unlock(&dev->struct_mutex);
 212
 213         DRM_DEBUG("lastclose completed\n");
 214         return 0;
 215 }
 216
 217 /** File operations structure */
 218 static const struct file_operations drm_stub_fops = {
 219         .owner = THIS_MODULE,
 220         .open = drm_stub_open,
 221         .llseek = noop_llseek,
 222 };
 223
 224 static int __init drm_core_init(void)
 225 {
 226         int ret = -ENOMEM;
 227
 228         drm_global_init();
 229         drm_connector_ida_init();
 230         idr_init(&drm_minors_idr);
 231
 232         if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
 233                 goto err_p1;
 234
 235         drm_class = drm_sysfs_create(THIS_MODULE, "drm");
 236         if (IS_ERR(drm_class)) {
 237                 printk(KERN_ERR "DRM: Error creating drm class.\n");
 238                 ret = PTR_ERR(drm_class);
 239                 goto err_p2;
 240         }
 241
 242         drm_proc_root = proc_mkdir("dri", NULL);
 243         if (!drm_proc_root) {
 244                 DRM_ERROR("Cannot create /proc/dri\n");
 245                 ret = -1;
 246                 goto err_p3;
 247         }
 248
 249         drm_debugfs_root = debugfs_create_dir("dri", NULL);
 250         if (!drm_debugfs_root) {
 251                 DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
 252                 ret = -1;
 253                 goto err_p3;
 254         }
 255
 256         DRM_INFO("Initialized %s %d.%d.%d %s\n",
 257                  CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
 258         return 0;
 259 err_p3:
 260         drm_sysfs_destroy();
 261 err_p2:
 262         unregister_chrdev(DRM_MAJOR, "drm");
 263
 264         idr_destroy(&drm_minors_idr);
 265 err_p1:
 266         return ret;
 267 }
 268
 269 static void __exit drm_core_exit(void)
 270 {
 271         remove_proc_entry("dri", NULL);
 272         debugfs_remove(drm_debugfs_root);
 273         drm_sysfs_destroy();
 274
 275         unregister_chrdev(DRM_MAJOR, "drm");
 276
 277         drm_connector_ida_destroy();
 278         idr_destroy(&drm_minors_idr);
 279 }
 280
 281 module_init(drm_core_init);
 282 module_exit(drm_core_exit);
 283
 284 /**
 285  * Copy and IOCTL return string to user space
 286  */
 287 static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
 288 {
 289         int len;
 290
 291         /* don't overflow userbuf */
 292         len = strlen(value);
 293         if (len > *buf_len)
 294                 len = *buf_len;
 295
 296         /* let userspace know exact length of driver value (which could be
 297          * larger than the userspace-supplied buffer) */
 298         *buf_len = strlen(value);
 299
 300         /* finally, try filling in the userbuf */
 301         if (len && buf)
 302                 if (copy_to_user(buf, value, len))
 303                         return -EFAULT;
 304         return 0;
 305 }
 306
 307 /**
 308  * Get version information
 309  *
 310  * \param inode device inode.
 311  * \param filp file pointer.
 312  * \param cmd command.
 313  * \param arg user argument, pointing to a drm_version structure.
 314  * \return zero on success or negative number on failure.
 315  *
 316  * Fills in the version information in \p arg.
 317  */
 318 static int drm_version(struct drm_device *dev, void *data,
 319                        struct drm_file *file_priv)
 320 {
 321         struct drm_version *version = data;
 322         int err;
 323
 324         version->version_major = dev->driver->major;
 325         version->version_minor = dev->driver->minor;
 326         version->version_patchlevel = dev->driver->patchlevel;
 327         err = drm_copy_field(version->name, &version->name_len,
 328                         dev->driver->name);
 329         if (!err)
 330                 err = drm_copy_field(version->date, &version->date_len,
 331                                 dev->driver->date);
 332         if (!err)
 333                 err = drm_copy_field(version->desc, &version->desc_len,
 334                                 dev->driver->desc);
 335
 336         return err;
 337 }
 338
 339 /**
 340  * Called whenever a process performs an ioctl on /dev/drm.
 341  *
 342  * \param inode device inode.
 343  * \param file_priv DRM file private.
 344  * \param cmd command.
 345  * \param arg user argument.
 346  * \return zero on success or negative number on failure.
 347  *
 348  * Looks up the ioctl function in the ::ioctls table, checking for root
 349  * previleges if so required, and dispatches to the respective function.
 350  */
 351 long drm_ioctl(struct file *filp,
 352               unsigned int cmd, unsigned long arg)
 353 {
 354         struct drm_file *file_priv = filp->private_data;
 355         struct drm_device *dev;
 356         const struct drm_ioctl_desc *ioctl = NULL;
 357         drm_ioctl_t *func;
 358         unsigned int nr = DRM_IOCTL_NR(cmd);
 359         int retcode = -EINVAL;
 360         char stack_kdata[128];
 361         char *kdata = NULL;
 362         unsigned int usize, asize;
 363
 364         dev = file_priv->minor->dev;
 365
 366         if (drm_device_is_unplugged(dev))
 367                 return -ENODEV;
 368
 369         atomic_inc(&dev->ioctl_count);
 370         atomic_inc(&dev->counts[_DRM_STAT_IOCTLS]);
 371         ++file_priv->ioctl_count;
 372
 373         if ((nr >= DRM_CORE_IOCTL_COUNT) &&
 374             ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
 375                 goto err_i1;
 376         if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
 377             (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls)) {
 378                 u32 drv_size;
 379                 ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
 380                 drv_size = _IOC_SIZE(ioctl->cmd_drv);
 381                 usize = asize = _IOC_SIZE(cmd);
 382                 if (drv_size > asize)
 383                         asize = drv_size;
 384                 cmd = ioctl->cmd_drv;
 385         }
 386         else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
 387                 ioctl = &drm_ioctls[nr];
 388                 cmd = ioctl->cmd;
 389                 usize = asize = _IOC_SIZE(cmd);
 390         } else
 391                 goto err_i1;
 392
 393         DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
 394                   task_pid_nr(current),
 395                   (long)old_encode_dev(file_priv->minor->device),
 396                   file_priv->authenticated, ioctl->name);
 397
 398         /* Do not trust userspace, use our own definition */
 399         func = ioctl->func;
 400         /* is there a local override? */
 401         if ((nr == DRM_IOCTL_NR(DRM_IOCTL_DMA)) && dev->driver->dma_ioctl)
 402                 func = dev->driver->dma_ioctl;
 403
 404         if (!func) {
 405                 DRM_DEBUG("no function\n");
 406                 retcode = -EINVAL;
 407         } else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
 408                    ((ioctl->flags & DRM_AUTH) && !file_priv->authenticated) ||
 409                    ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) ||
 410                    (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL))) {
 411                 retcode = -EACCES;
 412         } else {
 413                 if (cmd & (IOC_IN | IOC_OUT)) {
 414                         if (asize <= sizeof(stack_kdata)) {
 415                                 kdata = stack_kdata;
 416                         } else {
 417                                 kdata = kmalloc(asize, GFP_KERNEL);
 418                                 if (!kdata) {
 419                                         retcode = -ENOMEM;
 420                                         goto err_i1;
 421                                 }
 422                         }
 423                         if (asize > usize)
 424                                 memset(kdata + usize, 0, asize - usize);
 425                 }
 426
 427                 if (cmd & IOC_IN) {
 428                         if (copy_from_user(kdata, (void __user *)arg,
 429                                            usize) != 0) {
 430                                 retcode = -EFAULT;
 431                                 goto err_i1;
 432                         }
 433                 } else
 434                         memset(kdata, 0, usize);
 435
 436                 if (ioctl->flags & DRM_UNLOCKED)
 437                         retcode = func(dev, kdata, file_priv);
 438                 else {
 439                         mutex_lock(&drm_global_mutex);
 440                         retcode = func(dev, kdata, file_priv);
 441                         mutex_unlock(&drm_global_mutex);
 442                 }
 443
 444                 if (cmd & IOC_OUT) {
 445                         if (copy_to_user((void __user *)arg, kdata,
 446                                          usize) != 0)
 447                                 retcode = -EFAULT;
 448                 }
 449         }
 450
 451       err_i1:
 452         if (!ioctl)
 453                 DRM_DEBUG("invalid iotcl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
 454                           task_pid_nr(current),
 455                           (long)old_encode_dev(file_priv->minor->device),
 456                           file_priv->authenticated, cmd, nr);
 457
 458         if (kdata != stack_kdata)
 459                 kfree(kdata);
 460         atomic_dec(&dev->ioctl_count);
 461         if (retcode)
 462                 DRM_DEBUG("ret = %d\n", retcode);
 463         return retcode;
 464 }
 465 EXPORT_SYMBOL(drm_ioctl);