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 <linux/slab.h> 32 #include <linux/uaccess.h> 33 34 #include <drm/drm_drv.h> 35 #include <drm/drm_file.h> 36 #include <drm/drm_print.h> 37 38 #include "drm_legacy.h" 39 40 struct drm_ctx_list { 41 struct list_head head; 42 drm_context_t handle; 43 struct drm_file *tag; 44 }; 45 46 /******************************************************************/ 47 /** \name Context bitmap support */ 48 /*@{*/ 49 50 /* 51 * Free a handle from the context bitmap. 52 * 53 * \param dev DRM device. 54 * \param ctx_handle context handle. 55 * 56 * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry 57 * in drm_device::ctx_idr, while holding the drm_device::struct_mutex 58 * lock. 59 */ 60 void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle) 61 { 62 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 63 !drm_core_check_feature(dev, DRIVER_LEGACY)) 64 return; 65 66 mutex_lock(&dev->struct_mutex); 67 idr_remove(&dev->ctx_idr, ctx_handle); 68 mutex_unlock(&dev->struct_mutex); 69 } 70 71 /* 72 * Context bitmap allocation. 73 * 74 * \param dev DRM device. 75 * \return (non-negative) context handle on success or a negative number on failure. 76 * 77 * Allocate a new idr from drm_device::ctx_idr while holding the 78 * drm_device::struct_mutex lock. 79 */ 80 static int drm_legacy_ctxbitmap_next(struct drm_device * dev) 81 { 82 int ret; 83 84 mutex_lock(&dev->struct_mutex); 85 ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0, 86 GFP_KERNEL); 87 mutex_unlock(&dev->struct_mutex); 88 return ret; 89 } 90 91 /* 92 * Context bitmap initialization. 93 * 94 * \param dev DRM device. 95 * 96 * Initialise the drm_device::ctx_idr 97 */ 98 void drm_legacy_ctxbitmap_init(struct drm_device * dev) 99 { 100 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 101 !drm_core_check_feature(dev, DRIVER_LEGACY)) 102 return; 103 104 idr_init(&dev->ctx_idr); 105 } 106 107 /* 108 * Context bitmap cleanup. 109 * 110 * \param dev DRM device. 111 * 112 * Free all idr members using drm_ctx_sarea_free helper function 113 * while holding the drm_device::struct_mutex lock. 114 */ 115 void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev) 116 { 117 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 118 !drm_core_check_feature(dev, DRIVER_LEGACY)) 119 return; 120 121 mutex_lock(&dev->struct_mutex); 122 idr_destroy(&dev->ctx_idr); 123 mutex_unlock(&dev->struct_mutex); 124 } 125 126 /** 127 * drm_ctxbitmap_flush() - Flush all contexts owned by a file 128 * @dev: DRM device to operate on 129 * @file: Open file to flush contexts for 130 * 131 * This iterates over all contexts on @dev and drops them if they're owned by 132 * @file. Note that after this call returns, new contexts might be added if 133 * the file is still alive. 134 */ 135 void drm_legacy_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file) 136 { 137 struct drm_ctx_list *pos, *tmp; 138 139 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 140 !drm_core_check_feature(dev, DRIVER_LEGACY)) 141 return; 142 143 mutex_lock(&dev->ctxlist_mutex); 144 145 list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) { 146 if (pos->tag == file && 147 pos->handle != DRM_KERNEL_CONTEXT) { 148 if (dev->driver->context_dtor) 149 dev->driver->context_dtor(dev, pos->handle); 150 151 drm_legacy_ctxbitmap_free(dev, pos->handle); 152 list_del(&pos->head); 153 kfree(pos); 154 } 155 } 156 157 mutex_unlock(&dev->ctxlist_mutex); 158 } 159 160 /*@}*/ 161 162 /******************************************************************/ 163 /** \name Per Context SAREA Support */ 164 /*@{*/ 165 166 /* 167 * Get per-context SAREA. 168 * 169 * \param inode device inode. 170 * \param file_priv DRM file private. 171 * \param cmd command. 172 * \param arg user argument pointing to a drm_ctx_priv_map structure. 173 * \return zero on success or a negative number on failure. 174 * 175 * Gets the map from drm_device::ctx_idr with the handle specified and 176 * returns its handle. 177 */ 178 int drm_legacy_getsareactx(struct drm_device *dev, void *data, 179 struct drm_file *file_priv) 180 { 181 struct drm_ctx_priv_map *request = data; 182 struct drm_local_map *map; 183 struct drm_map_list *_entry; 184 185 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 186 !drm_core_check_feature(dev, DRIVER_LEGACY)) 187 return -EOPNOTSUPP; 188 189 mutex_lock(&dev->struct_mutex); 190 191 map = idr_find(&dev->ctx_idr, request->ctx_id); 192 if (!map) { 193 mutex_unlock(&dev->struct_mutex); 194 return -EINVAL; 195 } 196 197 request->handle = NULL; 198 list_for_each_entry(_entry, &dev->maplist, head) { 199 if (_entry->map == map) { 200 request->handle = 201 (void *)(unsigned long)_entry->user_token; 202 break; 203 } 204 } 205 206 mutex_unlock(&dev->struct_mutex); 207 208 if (request->handle == NULL) 209 return -EINVAL; 210 211 return 0; 212 } 213 214 /* 215 * Set per-context SAREA. 216 * 217 * \param inode device inode. 218 * \param file_priv DRM file private. 219 * \param cmd command. 220 * \param arg user argument pointing to a drm_ctx_priv_map structure. 221 * \return zero on success or a negative number on failure. 222 * 223 * Searches the mapping specified in \p arg and update the entry in 224 * drm_device::ctx_idr with it. 225 */ 226 int drm_legacy_setsareactx(struct drm_device *dev, void *data, 227 struct drm_file *file_priv) 228 { 229 struct drm_ctx_priv_map *request = data; 230 struct drm_local_map *map = NULL; 231 struct drm_map_list *r_list = NULL; 232 233 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 234 !drm_core_check_feature(dev, DRIVER_LEGACY)) 235 return -EOPNOTSUPP; 236 237 mutex_lock(&dev->struct_mutex); 238 list_for_each_entry(r_list, &dev->maplist, head) { 239 if (r_list->map 240 && r_list->user_token == (unsigned long) request->handle) 241 goto found; 242 } 243 bad: 244 mutex_unlock(&dev->struct_mutex); 245 return -EINVAL; 246 247 found: 248 map = r_list->map; 249 if (!map) 250 goto bad; 251 252 if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id))) 253 goto bad; 254 255 mutex_unlock(&dev->struct_mutex); 256 257 return 0; 258 } 259 260 /*@}*/ 261 262 /******************************************************************/ 263 /** \name The actual DRM context handling routines */ 264 /*@{*/ 265 266 /* 267 * Switch context. 268 * 269 * \param dev DRM device. 270 * \param old old context handle. 271 * \param new new context handle. 272 * \return zero on success or a negative number on failure. 273 * 274 * Attempt to set drm_device::context_flag. 275 */ 276 static int drm_context_switch(struct drm_device * dev, int old, int new) 277 { 278 if (test_and_set_bit(0, &dev->context_flag)) { 279 DRM_ERROR("Reentering -- FIXME\n"); 280 return -EBUSY; 281 } 282 283 DRM_DEBUG("Context switch from %d to %d\n", old, new); 284 285 if (new == dev->last_context) { 286 clear_bit(0, &dev->context_flag); 287 return 0; 288 } 289 290 return 0; 291 } 292 293 /* 294 * Complete context switch. 295 * 296 * \param dev DRM device. 297 * \param new new context handle. 298 * \return zero on success or a negative number on failure. 299 * 300 * Updates drm_device::last_context and drm_device::last_switch. Verifies the 301 * hardware lock is held, clears the drm_device::context_flag and wakes up 302 * drm_device::context_wait. 303 */ 304 static int drm_context_switch_complete(struct drm_device *dev, 305 struct drm_file *file_priv, int new) 306 { 307 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */ 308 309 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) { 310 DRM_ERROR("Lock isn't held after context switch\n"); 311 } 312 313 /* If a context switch is ever initiated 314 when the kernel holds the lock, release 315 that lock here. */ 316 clear_bit(0, &dev->context_flag); 317 318 return 0; 319 } 320 321 /* 322 * Reserve contexts. 323 * 324 * \param inode device inode. 325 * \param file_priv DRM file private. 326 * \param cmd command. 327 * \param arg user argument pointing to a drm_ctx_res structure. 328 * \return zero on success or a negative number on failure. 329 */ 330 int drm_legacy_resctx(struct drm_device *dev, void *data, 331 struct drm_file *file_priv) 332 { 333 struct drm_ctx_res *res = data; 334 struct drm_ctx ctx; 335 int i; 336 337 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 338 !drm_core_check_feature(dev, DRIVER_LEGACY)) 339 return -EOPNOTSUPP; 340 341 if (res->count >= DRM_RESERVED_CONTEXTS) { 342 memset(&ctx, 0, sizeof(ctx)); 343 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) { 344 ctx.handle = i; 345 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx))) 346 return -EFAULT; 347 } 348 } 349 res->count = DRM_RESERVED_CONTEXTS; 350 351 return 0; 352 } 353 354 /* 355 * Add context. 356 * 357 * \param inode device inode. 358 * \param file_priv DRM file private. 359 * \param cmd command. 360 * \param arg user argument pointing to a drm_ctx structure. 361 * \return zero on success or a negative number on failure. 362 * 363 * Get a new handle for the context and copy to userspace. 364 */ 365 int drm_legacy_addctx(struct drm_device *dev, void *data, 366 struct drm_file *file_priv) 367 { 368 struct drm_ctx_list *ctx_entry; 369 struct drm_ctx *ctx = data; 370 int tmp_handle; 371 372 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 373 !drm_core_check_feature(dev, DRIVER_LEGACY)) 374 return -EOPNOTSUPP; 375 376 tmp_handle = drm_legacy_ctxbitmap_next(dev); 377 if (tmp_handle == DRM_KERNEL_CONTEXT) { 378 /* Skip kernel's context and get a new one. */ 379 tmp_handle = drm_legacy_ctxbitmap_next(dev); 380 } 381 DRM_DEBUG("%d\n", tmp_handle); 382 if (tmp_handle < 0) { 383 DRM_DEBUG("Not enough free contexts.\n"); 384 /* Should this return -EBUSY instead? */ 385 return tmp_handle; 386 } 387 388 ctx->handle = tmp_handle; 389 390 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL); 391 if (!ctx_entry) { 392 DRM_DEBUG("out of memory\n"); 393 return -ENOMEM; 394 } 395 396 INIT_LIST_HEAD(&ctx_entry->head); 397 ctx_entry->handle = ctx->handle; 398 ctx_entry->tag = file_priv; 399 400 mutex_lock(&dev->ctxlist_mutex); 401 list_add(&ctx_entry->head, &dev->ctxlist); 402 mutex_unlock(&dev->ctxlist_mutex); 403 404 return 0; 405 } 406 407 /* 408 * Get context. 409 * 410 * \param inode device inode. 411 * \param file_priv DRM file private. 412 * \param cmd command. 413 * \param arg user argument pointing to a drm_ctx structure. 414 * \return zero on success or a negative number on failure. 415 */ 416 int drm_legacy_getctx(struct drm_device *dev, void *data, 417 struct drm_file *file_priv) 418 { 419 struct drm_ctx *ctx = data; 420 421 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 422 !drm_core_check_feature(dev, DRIVER_LEGACY)) 423 return -EOPNOTSUPP; 424 425 /* This is 0, because we don't handle any context flags */ 426 ctx->flags = 0; 427 428 return 0; 429 } 430 431 /* 432 * Switch context. 433 * 434 * \param inode device inode. 435 * \param file_priv DRM file private. 436 * \param cmd command. 437 * \param arg user argument pointing to a drm_ctx structure. 438 * \return zero on success or a negative number on failure. 439 * 440 * Calls context_switch(). 441 */ 442 int drm_legacy_switchctx(struct drm_device *dev, void *data, 443 struct drm_file *file_priv) 444 { 445 struct drm_ctx *ctx = data; 446 447 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 448 !drm_core_check_feature(dev, DRIVER_LEGACY)) 449 return -EOPNOTSUPP; 450 451 DRM_DEBUG("%d\n", ctx->handle); 452 return drm_context_switch(dev, dev->last_context, ctx->handle); 453 } 454 455 /* 456 * New context. 457 * 458 * \param inode device inode. 459 * \param file_priv DRM file private. 460 * \param cmd command. 461 * \param arg user argument pointing to a drm_ctx structure. 462 * \return zero on success or a negative number on failure. 463 * 464 * Calls context_switch_complete(). 465 */ 466 int drm_legacy_newctx(struct drm_device *dev, void *data, 467 struct drm_file *file_priv) 468 { 469 struct drm_ctx *ctx = data; 470 471 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 472 !drm_core_check_feature(dev, DRIVER_LEGACY)) 473 return -EOPNOTSUPP; 474 475 DRM_DEBUG("%d\n", ctx->handle); 476 drm_context_switch_complete(dev, file_priv, ctx->handle); 477 478 return 0; 479 } 480 481 /* 482 * Remove context. 483 * 484 * \param inode device inode. 485 * \param file_priv DRM file private. 486 * \param cmd command. 487 * \param arg user argument pointing to a drm_ctx structure. 488 * \return zero on success or a negative number on failure. 489 * 490 * If not the special kernel context, calls ctxbitmap_free() to free the specified context. 491 */ 492 int drm_legacy_rmctx(struct drm_device *dev, void *data, 493 struct drm_file *file_priv) 494 { 495 struct drm_ctx *ctx = data; 496 497 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) && 498 !drm_core_check_feature(dev, DRIVER_LEGACY)) 499 return -EOPNOTSUPP; 500 501 DRM_DEBUG("%d\n", ctx->handle); 502 if (ctx->handle != DRM_KERNEL_CONTEXT) { 503 if (dev->driver->context_dtor) 504 dev->driver->context_dtor(dev, ctx->handle); 505 drm_legacy_ctxbitmap_free(dev, ctx->handle); 506 } 507 508 mutex_lock(&dev->ctxlist_mutex); 509 if (!list_empty(&dev->ctxlist)) { 510 struct drm_ctx_list *pos, *n; 511 512 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) { 513 if (pos->handle == ctx->handle) { 514 list_del(&pos->head); 515 kfree(pos); 516 } 517 } 518 } 519 mutex_unlock(&dev->ctxlist_mutex); 520 521 return 0; 522 } 523 524 /*@}*/ 525