drivers/gpu/drm/drm_context.c

   1 /*
   2  * Legacy: Generic DRM Contexts
   3  *
   4  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
   5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   6  * All Rights Reserved.
   7  *
   8  * Author: Rickard E. (Rik) Faith <faith@valinux.com>
   9  * Author: Gareth Hughes <gareth@valinux.com>
  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  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  28  * OTHER DEALINGS IN THE SOFTWARE.
  29  */
  30
  31 #include <drm/drmP.h>
  32 #include "drm_legacy.h"
  33
  34 struct drm_ctx_list {
  35         struct list_head head;
  36         drm_context_t handle;
  37         struct drm_file *tag;
  38 };
  39
  40 /******************************************************************/
  41 /** \name Context bitmap support */
  42 /*@{*/
  43
  44 /**
  45  * Free a handle from the context bitmap.
  46  *
  47  * \param dev DRM device.
  48  * \param ctx_handle context handle.
  49  *
  50  * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
  51  * in drm_device::ctx_idr, while holding the drm_device::struct_mutex
  52  * lock.
  53  */
  54 void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
  55 {
  56         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
  57             !drm_core_check_feature(dev, DRIVER_LEGACY))
  58                 return;
  59
  60         mutex_lock(&dev->struct_mutex);
  61         idr_remove(&dev->ctx_idr, ctx_handle);
  62         mutex_unlock(&dev->struct_mutex);
  63 }
  64
  65 /**
  66  * Context bitmap allocation.
  67  *
  68  * \param dev DRM device.
  69  * \return (non-negative) context handle on success or a negative number on failure.
  70  *
  71  * Allocate a new idr from drm_device::ctx_idr while holding the
  72  * drm_device::struct_mutex lock.
  73  */
  74 static int drm_legacy_ctxbitmap_next(struct drm_device * dev)
  75 {
  76         int ret;
  77
  78         mutex_lock(&dev->struct_mutex);
  79         ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0,
  80                         GFP_KERNEL);
  81         mutex_unlock(&dev->struct_mutex);
  82         return ret;
  83 }
  84
  85 /**
  86  * Context bitmap initialization.
  87  *
  88  * \param dev DRM device.
  89  *
  90  * Initialise the drm_device::ctx_idr
  91  */
  92 void drm_legacy_ctxbitmap_init(struct drm_device * dev)
  93 {
  94         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
  95             !drm_core_check_feature(dev, DRIVER_LEGACY))
  96                 return;
  97
  98         idr_init(&dev->ctx_idr);
  99 }
 100
 101 /**
 102  * Context bitmap cleanup.
 103  *
 104  * \param dev DRM device.
 105  *
 106  * Free all idr members using drm_ctx_sarea_free helper function
 107  * while holding the drm_device::struct_mutex lock.
 108  */
 109 void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)
 110 {
 111         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 112             !drm_core_check_feature(dev, DRIVER_LEGACY))
 113                 return;
 114
 115         mutex_lock(&dev->struct_mutex);
 116         idr_destroy(&dev->ctx_idr);
 117         mutex_unlock(&dev->struct_mutex);
 118 }
 119
 120 /**
 121  * drm_ctxbitmap_flush() - Flush all contexts owned by a file
 122  * @dev: DRM device to operate on
 123  * @file: Open file to flush contexts for
 124  *
 125  * This iterates over all contexts on @dev and drops them if they're owned by
 126  * @file. Note that after this call returns, new contexts might be added if
 127  * the file is still alive.
 128  */
 129 void drm_legacy_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file)
 130 {
 131         struct drm_ctx_list *pos, *tmp;
 132
 133         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 134             !drm_core_check_feature(dev, DRIVER_LEGACY))
 135                 return;
 136
 137         mutex_lock(&dev->ctxlist_mutex);
 138
 139         list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) {
 140                 if (pos->tag == file &&
 141                     pos->handle != DRM_KERNEL_CONTEXT) {
 142                         if (dev->driver->context_dtor)
 143                                 dev->driver->context_dtor(dev, pos->handle);
 144
 145                         drm_legacy_ctxbitmap_free(dev, pos->handle);
 146                         list_del(&pos->head);
 147                         kfree(pos);
 148                 }
 149         }
 150
 151         mutex_unlock(&dev->ctxlist_mutex);
 152 }
 153
 154 /*@}*/
 155
 156 /******************************************************************/
 157 /** \name Per Context SAREA Support */
 158 /*@{*/
 159
 160 /**
 161  * Get per-context SAREA.
 162  *
 163  * \param inode device inode.
 164  * \param file_priv DRM file private.
 165  * \param cmd command.
 166  * \param arg user argument pointing to a drm_ctx_priv_map structure.
 167  * \return zero on success or a negative number on failure.
 168  *
 169  * Gets the map from drm_device::ctx_idr with the handle specified and
 170  * returns its handle.
 171  */
 172 int drm_legacy_getsareactx(struct drm_device *dev, void *data,
 173                            struct drm_file *file_priv)
 174 {
 175         struct drm_ctx_priv_map *request = data;
 176         struct drm_local_map *map;
 177         struct drm_map_list *_entry;
 178
 179         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 180             !drm_core_check_feature(dev, DRIVER_LEGACY))
 181                 return -EINVAL;
 182
 183         mutex_lock(&dev->struct_mutex);
 184
 185         map = idr_find(&dev->ctx_idr, request->ctx_id);
 186         if (!map) {
 187                 mutex_unlock(&dev->struct_mutex);
 188                 return -EINVAL;
 189         }
 190
 191         request->handle = NULL;
 192         list_for_each_entry(_entry, &dev->maplist, head) {
 193                 if (_entry->map == map) {
 194                         request->handle =
 195                             (void *)(unsigned long)_entry->user_token;
 196                         break;
 197                 }
 198         }
 199
 200         mutex_unlock(&dev->struct_mutex);
 201
 202         if (request->handle == NULL)
 203                 return -EINVAL;
 204
 205         return 0;
 206 }
 207
 208 /**
 209  * Set per-context SAREA.
 210  *
 211  * \param inode device inode.
 212  * \param file_priv DRM file private.
 213  * \param cmd command.
 214  * \param arg user argument pointing to a drm_ctx_priv_map structure.
 215  * \return zero on success or a negative number on failure.
 216  *
 217  * Searches the mapping specified in \p arg and update the entry in
 218  * drm_device::ctx_idr with it.
 219  */
 220 int drm_legacy_setsareactx(struct drm_device *dev, void *data,
 221                            struct drm_file *file_priv)
 222 {
 223         struct drm_ctx_priv_map *request = data;
 224         struct drm_local_map *map = NULL;
 225         struct drm_map_list *r_list = NULL;
 226
 227         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 228             !drm_core_check_feature(dev, DRIVER_LEGACY))
 229                 return -EINVAL;
 230
 231         mutex_lock(&dev->struct_mutex);
 232         list_for_each_entry(r_list, &dev->maplist, head) {
 233                 if (r_list->map
 234                     && r_list->user_token == (unsigned long) request->handle)
 235                         goto found;
 236         }
 237       bad:
 238         mutex_unlock(&dev->struct_mutex);
 239         return -EINVAL;
 240
 241       found:
 242         map = r_list->map;
 243         if (!map)
 244                 goto bad;
 245
 246         if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
 247                 goto bad;
 248
 249         mutex_unlock(&dev->struct_mutex);
 250
 251         return 0;
 252 }
 253
 254 /*@}*/
 255
 256 /******************************************************************/
 257 /** \name The actual DRM context handling routines */
 258 /*@{*/
 259
 260 /**
 261  * Switch context.
 262  *
 263  * \param dev DRM device.
 264  * \param old old context handle.
 265  * \param new new context handle.
 266  * \return zero on success or a negative number on failure.
 267  *
 268  * Attempt to set drm_device::context_flag.
 269  */
 270 static int drm_context_switch(struct drm_device * dev, int old, int new)
 271 {
 272         if (test_and_set_bit(0, &dev->context_flag)) {
 273                 DRM_ERROR("Reentering -- FIXME\n");
 274                 return -EBUSY;
 275         }
 276
 277         DRM_DEBUG("Context switch from %d to %d\n", old, new);
 278
 279         if (new == dev->last_context) {
 280                 clear_bit(0, &dev->context_flag);
 281                 return 0;
 282         }
 283
 284         return 0;
 285 }
 286
 287 /**
 288  * Complete context switch.
 289  *
 290  * \param dev DRM device.
 291  * \param new new context handle.
 292  * \return zero on success or a negative number on failure.
 293  *
 294  * Updates drm_device::last_context and drm_device::last_switch. Verifies the
 295  * hardware lock is held, clears the drm_device::context_flag and wakes up
 296  * drm_device::context_wait.
 297  */
 298 static int drm_context_switch_complete(struct drm_device *dev,
 299                                        struct drm_file *file_priv, int new)
 300 {
 301         dev->last_context = new;        /* PRE/POST: This is the _only_ writer. */
 302
 303         if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
 304                 DRM_ERROR("Lock isn't held after context switch\n");
 305         }
 306
 307         /* If a context switch is ever initiated
 308            when the kernel holds the lock, release
 309            that lock here. */
 310         clear_bit(0, &dev->context_flag);
 311
 312         return 0;
 313 }
 314
 315 /**
 316  * Reserve contexts.
 317  *
 318  * \param inode device inode.
 319  * \param file_priv DRM file private.
 320  * \param cmd command.
 321  * \param arg user argument pointing to a drm_ctx_res structure.
 322  * \return zero on success or a negative number on failure.
 323  */
 324 int drm_legacy_resctx(struct drm_device *dev, void *data,
 325                       struct drm_file *file_priv)
 326 {
 327         struct drm_ctx_res *res = data;
 328         struct drm_ctx ctx;
 329         int i;
 330
 331         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 332             !drm_core_check_feature(dev, DRIVER_LEGACY))
 333                 return -EINVAL;
 334
 335         if (res->count >= DRM_RESERVED_CONTEXTS) {
 336                 memset(&ctx, 0, sizeof(ctx));
 337                 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
 338                         ctx.handle = i;
 339                         if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
 340                                 return -EFAULT;
 341                 }
 342         }
 343         res->count = DRM_RESERVED_CONTEXTS;
 344
 345         return 0;
 346 }
 347
 348 /**
 349  * Add context.
 350  *
 351  * \param inode device inode.
 352  * \param file_priv DRM file private.
 353  * \param cmd command.
 354  * \param arg user argument pointing to a drm_ctx structure.
 355  * \return zero on success or a negative number on failure.
 356  *
 357  * Get a new handle for the context and copy to userspace.
 358  */
 359 int drm_legacy_addctx(struct drm_device *dev, void *data,
 360                       struct drm_file *file_priv)
 361 {
 362         struct drm_ctx_list *ctx_entry;
 363         struct drm_ctx *ctx = data;
 364
 365         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 366             !drm_core_check_feature(dev, DRIVER_LEGACY))
 367                 return -EINVAL;
 368
 369         ctx->handle = drm_legacy_ctxbitmap_next(dev);
 370         if (ctx->handle == DRM_KERNEL_CONTEXT) {
 371                 /* Skip kernel's context and get a new one. */
 372                 ctx->handle = drm_legacy_ctxbitmap_next(dev);
 373         }
 374         DRM_DEBUG("%d\n", ctx->handle);
 375         if (ctx->handle == -1) {
 376                 DRM_DEBUG("Not enough free contexts.\n");
 377                 /* Should this return -EBUSY instead? */
 378                 return -ENOMEM;
 379         }
 380
 381         ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
 382         if (!ctx_entry) {
 383                 DRM_DEBUG("out of memory\n");
 384                 return -ENOMEM;
 385         }
 386
 387         INIT_LIST_HEAD(&ctx_entry->head);
 388         ctx_entry->handle = ctx->handle;
 389         ctx_entry->tag = file_priv;
 390
 391         mutex_lock(&dev->ctxlist_mutex);
 392         list_add(&ctx_entry->head, &dev->ctxlist);
 393         mutex_unlock(&dev->ctxlist_mutex);
 394
 395         return 0;
 396 }
 397
 398 /**
 399  * Get context.
 400  *
 401  * \param inode device inode.
 402  * \param file_priv DRM file private.
 403  * \param cmd command.
 404  * \param arg user argument pointing to a drm_ctx structure.
 405  * \return zero on success or a negative number on failure.
 406  */
 407 int drm_legacy_getctx(struct drm_device *dev, void *data,
 408                       struct drm_file *file_priv)
 409 {
 410         struct drm_ctx *ctx = data;
 411
 412         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 413             !drm_core_check_feature(dev, DRIVER_LEGACY))
 414                 return -EINVAL;
 415
 416         /* This is 0, because we don't handle any context flags */
 417         ctx->flags = 0;
 418
 419         return 0;
 420 }
 421
 422 /**
 423  * Switch context.
 424  *
 425  * \param inode device inode.
 426  * \param file_priv DRM file private.
 427  * \param cmd command.
 428  * \param arg user argument pointing to a drm_ctx structure.
 429  * \return zero on success or a negative number on failure.
 430  *
 431  * Calls context_switch().
 432  */
 433 int drm_legacy_switchctx(struct drm_device *dev, void *data,
 434                          struct drm_file *file_priv)
 435 {
 436         struct drm_ctx *ctx = data;
 437
 438         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 439             !drm_core_check_feature(dev, DRIVER_LEGACY))
 440                 return -EINVAL;
 441
 442         DRM_DEBUG("%d\n", ctx->handle);
 443         return drm_context_switch(dev, dev->last_context, ctx->handle);
 444 }
 445
 446 /**
 447  * New context.
 448  *
 449  * \param inode device inode.
 450  * \param file_priv DRM file private.
 451  * \param cmd command.
 452  * \param arg user argument pointing to a drm_ctx structure.
 453  * \return zero on success or a negative number on failure.
 454  *
 455  * Calls context_switch_complete().
 456  */
 457 int drm_legacy_newctx(struct drm_device *dev, void *data,
 458                       struct drm_file *file_priv)
 459 {
 460         struct drm_ctx *ctx = data;
 461
 462         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 463             !drm_core_check_feature(dev, DRIVER_LEGACY))
 464                 return -EINVAL;
 465
 466         DRM_DEBUG("%d\n", ctx->handle);
 467         drm_context_switch_complete(dev, file_priv, ctx->handle);
 468
 469         return 0;
 470 }
 471
 472 /**
 473  * Remove context.
 474  *
 475  * \param inode device inode.
 476  * \param file_priv DRM file private.
 477  * \param cmd command.
 478  * \param arg user argument pointing to a drm_ctx structure.
 479  * \return zero on success or a negative number on failure.
 480  *
 481  * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
 482  */
 483 int drm_legacy_rmctx(struct drm_device *dev, void *data,
 484                      struct drm_file *file_priv)
 485 {
 486         struct drm_ctx *ctx = data;
 487
 488         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 489             !drm_core_check_feature(dev, DRIVER_LEGACY))
 490                 return -EINVAL;
 491
 492         DRM_DEBUG("%d\n", ctx->handle);
 493         if (ctx->handle != DRM_KERNEL_CONTEXT) {
 494                 if (dev->driver->context_dtor)
 495                         dev->driver->context_dtor(dev, ctx->handle);
 496                 drm_legacy_ctxbitmap_free(dev, ctx->handle);
 497         }
 498
 499         mutex_lock(&dev->ctxlist_mutex);
 500         if (!list_empty(&dev->ctxlist)) {
 501                 struct drm_ctx_list *pos, *n;
 502
 503                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 504                         if (pos->handle == ctx->handle) {
 505                                 list_del(&pos->head);
 506                                 kfree(pos);
 507                         }
 508                 }
 509         }
 510         mutex_unlock(&dev->ctxlist_mutex);
 511
 512         return 0;
 513 }
 514
 515 /*@}*/