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 "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, 0),
  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, 0),
  69         DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
  70         DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
  71         DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, 0),
  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, 0),
 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_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 139         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 140         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 141         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 142         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 143         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 144         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 145         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_MASTER|DRM_UNLOCKED),
 146         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
 147         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 148         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 149         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_mode_attachmode_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 150         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_mode_detachmode_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 151         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_MASTER | DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 152         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 153         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 154         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 155         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 156         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 157         DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 158         DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 159         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 160         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 161         DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 162         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED)
 163 };
 164
 165 #define DRM_CORE_IOCTL_COUNT    ARRAY_SIZE( drm_ioctls )
 166
 167 /**
 168  * Take down the DRM device.
 169  *
 170  * \param dev DRM device structure.
 171  *
 172  * Frees every resource in \p dev.
 173  *
 174  * \sa drm_device
 175  */
 176 int drm_lastclose(struct drm_device * dev)
 177 {
 178         struct drm_vma_entry *vma, *vma_temp;
 179         int i;
 180
 181         DRM_DEBUG("\n");
 182
 183         if (dev->driver->lastclose)
 184                 dev->driver->lastclose(dev);
 185         DRM_DEBUG("driver lastclose completed\n");
 186
 187         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 188                 drm_irq_uninstall(dev);
 189
 190         mutex_lock(&dev->struct_mutex);
 191
 192         /* Clear AGP information */
 193         if (drm_core_has_AGP(dev) && dev->agp &&
 194                         !drm_core_check_feature(dev, DRIVER_MODESET)) {
 195                 struct drm_agp_mem *entry, *tempe;
 196
 197                 /* Remove AGP resources, but leave dev->agp
 198                    intact until drv_cleanup is called. */
 199                 list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
 200                         if (entry->bound)
 201                                 drm_unbind_agp(entry->memory);
 202                         drm_free_agp(entry->memory, entry->pages);
 203                         kfree(entry);
 204                 }
 205                 INIT_LIST_HEAD(&dev->agp->memory);
 206
 207                 if (dev->agp->acquired)
 208                         drm_agp_release(dev);
 209
 210                 dev->agp->acquired = 0;
 211                 dev->agp->enabled = 0;
 212         }
 213         if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
 214             !drm_core_check_feature(dev, DRIVER_MODESET)) {
 215                 drm_sg_cleanup(dev->sg);
 216                 dev->sg = NULL;
 217         }
 218
 219         /* Clear vma list (only built for debugging) */
 220         list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
 221                 list_del(&vma->head);
 222                 kfree(vma);
 223         }
 224
 225         if (drm_core_check_feature(dev, DRIVER_DMA_QUEUE) && dev->queuelist) {
 226                 for (i = 0; i < dev->queue_count; i++) {
 227                         kfree(dev->queuelist[i]);
 228                         dev->queuelist[i] = NULL;
 229                 }
 230                 kfree(dev->queuelist);
 231                 dev->queuelist = NULL;
 232         }
 233         dev->queue_count = 0;
 234
 235         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 236             !drm_core_check_feature(dev, DRIVER_MODESET))
 237                 drm_dma_takedown(dev);
 238
 239         dev->dev_mapping = NULL;
 240         mutex_unlock(&dev->struct_mutex);
 241
 242         DRM_DEBUG("lastclose completed\n");
 243         return 0;
 244 }
 245
 246 /** File operations structure */
 247 static const struct file_operations drm_stub_fops = {
 248         .owner = THIS_MODULE,
 249         .open = drm_stub_open,
 250         .llseek = noop_llseek,
 251 };
 252
 253 static int __init drm_core_init(void)
 254 {
 255         int ret = -ENOMEM;
 256
 257         drm_global_init();
 258         idr_init(&drm_minors_idr);
 259
 260         if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
 261                 goto err_p1;
 262
 263         drm_class = drm_sysfs_create(THIS_MODULE, "drm");
 264         if (IS_ERR(drm_class)) {
 265                 printk(KERN_ERR "DRM: Error creating drm class.\n");
 266                 ret = PTR_ERR(drm_class);
 267                 goto err_p2;
 268         }
 269
 270         drm_proc_root = proc_mkdir("dri", NULL);
 271         if (!drm_proc_root) {
 272                 DRM_ERROR("Cannot create /proc/dri\n");
 273                 ret = -1;
 274                 goto err_p3;
 275         }
 276
 277         drm_debugfs_root = debugfs_create_dir("dri", NULL);
 278         if (!drm_debugfs_root) {
 279                 DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
 280                 ret = -1;
 281                 goto err_p3;
 282         }
 283
 284         DRM_INFO("Initialized %s %d.%d.%d %s\n",
 285                  CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
 286         return 0;
 287 err_p3:
 288         drm_sysfs_destroy();
 289 err_p2:
 290         unregister_chrdev(DRM_MAJOR, "drm");
 291
 292         idr_destroy(&drm_minors_idr);
 293 err_p1:
 294         return ret;
 295 }
 296
 297 static void __exit drm_core_exit(void)
 298 {
 299         remove_proc_entry("dri", NULL);
 300         debugfs_remove(drm_debugfs_root);
 301         drm_sysfs_destroy();
 302
 303         unregister_chrdev(DRM_MAJOR, "drm");
 304
 305         idr_remove_all(&drm_minors_idr);
 306         idr_destroy(&drm_minors_idr);
 307 }
 308
 309 module_init(drm_core_init);
 310 module_exit(drm_core_exit);
 311
 312 /**
 313  * Copy and IOCTL return string to user space
 314  */
 315 static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
 316 {
 317         int len;
 318
 319         /* don't overflow userbuf */
 320         len = strlen(value);
 321         if (len > *buf_len)
 322                 len = *buf_len;
 323
 324         /* let userspace know exact length of driver value (which could be
 325          * larger than the userspace-supplied buffer) */
 326         *buf_len = strlen(value);
 327
 328         /* finally, try filling in the userbuf */
 329         if (len && buf)
 330                 if (copy_to_user(buf, value, len))
 331                         return -EFAULT;
 332         return 0;
 333 }
 334
 335 /**
 336  * Get version information
 337  *
 338  * \param inode device inode.
 339  * \param filp file pointer.
 340  * \param cmd command.
 341  * \param arg user argument, pointing to a drm_version structure.
 342  * \return zero on success or negative number on failure.
 343  *
 344  * Fills in the version information in \p arg.
 345  */
 346 static int drm_version(struct drm_device *dev, void *data,
 347                        struct drm_file *file_priv)
 348 {
 349         struct drm_version *version = data;
 350         int err;
 351
 352         version->version_major = dev->driver->major;
 353         version->version_minor = dev->driver->minor;
 354         version->version_patchlevel = dev->driver->patchlevel;
 355         err = drm_copy_field(version->name, &version->name_len,
 356                         dev->driver->name);
 357         if (!err)
 358                 err = drm_copy_field(version->date, &version->date_len,
 359                                 dev->driver->date);
 360         if (!err)
 361                 err = drm_copy_field(version->desc, &version->desc_len,
 362                                 dev->driver->desc);
 363
 364         return err;
 365 }
 366
 367 /**
 368  * Called whenever a process performs an ioctl on /dev/drm.
 369  *
 370  * \param inode device inode.
 371  * \param file_priv DRM file private.
 372  * \param cmd command.
 373  * \param arg user argument.
 374  * \return zero on success or negative number on failure.
 375  *
 376  * Looks up the ioctl function in the ::ioctls table, checking for root
 377  * previleges if so required, and dispatches to the respective function.
 378  */
 379 long drm_ioctl(struct file *filp,
 380               unsigned int cmd, unsigned long arg)
 381 {
 382         struct drm_file *file_priv = filp->private_data;
 383         struct drm_device *dev;
 384         struct drm_ioctl_desc *ioctl;
 385         drm_ioctl_t *func;
 386         unsigned int nr = DRM_IOCTL_NR(cmd);
 387         int retcode = -EINVAL;
 388         char stack_kdata[128];
 389         char *kdata = NULL;
 390         unsigned int usize, asize;
 391
 392         dev = file_priv->minor->dev;
 393         atomic_inc(&dev->ioctl_count);
 394         atomic_inc(&dev->counts[_DRM_STAT_IOCTLS]);
 395         ++file_priv->ioctl_count;
 396
 397         DRM_DEBUG("pid=%d, cmd=0x%02x, nr=0x%02x, dev 0x%lx, auth=%d\n",
 398                   task_pid_nr(current), cmd, nr,
 399                   (long)old_encode_dev(file_priv->minor->device),
 400                   file_priv->authenticated);
 401
 402         if ((nr >= DRM_CORE_IOCTL_COUNT) &&
 403             ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
 404                 goto err_i1;
 405         if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END) &&
 406             (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls)) {
 407                 u32 drv_size;
 408                 ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
 409                 drv_size = _IOC_SIZE(ioctl->cmd_drv);
 410                 usize = asize = _IOC_SIZE(cmd);
 411                 if (drv_size > asize)
 412                         asize = drv_size;
 413         }
 414         else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
 415                 ioctl = &drm_ioctls[nr];
 416                 cmd = ioctl->cmd;
 417                 usize = asize = _IOC_SIZE(cmd);
 418         } else
 419                 goto err_i1;
 420
 421         /* Do not trust userspace, use our own definition */
 422         func = ioctl->func;
 423         /* is there a local override? */
 424         if ((nr == DRM_IOCTL_NR(DRM_IOCTL_DMA)) && dev->driver->dma_ioctl)
 425                 func = dev->driver->dma_ioctl;
 426
 427         if (!func) {
 428                 DRM_DEBUG("no function\n");
 429                 retcode = -EINVAL;
 430         } else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
 431                    ((ioctl->flags & DRM_AUTH) && !file_priv->authenticated) ||
 432                    ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) ||
 433                    (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL))) {
 434                 retcode = -EACCES;
 435         } else {
 436                 if (cmd & (IOC_IN | IOC_OUT)) {
 437                         if (asize <= sizeof(stack_kdata)) {
 438                                 kdata = stack_kdata;
 439                         } else {
 440                                 kdata = kmalloc(asize, GFP_KERNEL);
 441                                 if (!kdata) {
 442                                         retcode = -ENOMEM;
 443                                         goto err_i1;
 444                                 }
 445                         }
 446                         if (asize > usize)
 447                                 memset(kdata + usize, 0, asize - usize);
 448                 }
 449
 450                 if (cmd & IOC_IN) {
 451                         if (copy_from_user(kdata, (void __user *)arg,
 452                                            usize) != 0) {
 453                                 retcode = -EFAULT;
 454                                 goto err_i1;
 455                         }
 456                 } else
 457                         memset(kdata, 0, usize);
 458
 459                 if (ioctl->flags & DRM_UNLOCKED)
 460                         retcode = func(dev, kdata, file_priv);
 461                 else {
 462                         mutex_lock(&drm_global_mutex);
 463                         retcode = func(dev, kdata, file_priv);
 464                         mutex_unlock(&drm_global_mutex);
 465                 }
 466
 467                 if (cmd & IOC_OUT) {
 468                         if (copy_to_user((void __user *)arg, kdata,
 469                                          usize) != 0)
 470                                 retcode = -EFAULT;
 471                 }
 472         }
 473
 474       err_i1:
 475         if (kdata != stack_kdata)
 476                 kfree(kdata);
 477         atomic_dec(&dev->ioctl_count);
 478         if (retcode)
 479                 DRM_DEBUG("ret = %x\n", retcode);
 480         return retcode;
 481 }
 482
 483 EXPORT_SYMBOL(drm_ioctl);
 484
 485 struct drm_local_map *drm_getsarea(struct drm_device *dev)
 486 {
 487         struct drm_map_list *entry;
 488
 489         list_for_each_entry(entry, &dev->maplist, head) {
 490                 if (entry->map && entry->map->type == _DRM_SHM &&
 491                     (entry->map->flags & _DRM_CONTAINS_LOCK)) {
 492                         return entry->map;
 493                 }
 494         }
 495         return NULL;
 496 }
 497 EXPORT_SYMBOL(drm_getsarea);