1 /** 2 * \file drm_context.c 3 * IOCTLs for generic contexts 4 * 5 * \author Rickard E. (Rik) Faith <faith@valinux.com> 6 * \author Gareth Hughes <gareth@valinux.com> 7 */ 8 9 /* 10 * Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com 11 * 12 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas. 13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 14 * All Rights Reserved. 15 * 16 * Permission is hereby granted, free of charge, to any person obtaining a 17 * copy of this software and associated documentation files (the "Software"), 18 * to deal in the Software without restriction, including without limitation 19 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 20 * and/or sell copies of the Software, and to permit persons to whom the 21 * Software is furnished to do so, subject to the following conditions: 22 * 23 * The above copyright notice and this permission notice (including the next 24 * paragraph) shall be included in all copies or substantial portions of the 25 * Software. 26 * 27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 33 * OTHER DEALINGS IN THE SOFTWARE. 34 */ 35 36 /* 37 * ChangeLog: 38 * 2001-11-16 Torsten Duwe <duwe@caldera.de> 39 * added context constructor/destructor hooks, 40 * needed by SiS driver's memory management. 41 */ 42 43 #include <drm/drmP.h> 44 45 /** 46 * Free a handle from the context bitmap. 47 * 48 * \param dev DRM device. 49 * \param ctx_handle context handle. 50 * 51 * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry 52 * in drm_device::ctx_idr, while holding the drm_device::struct_mutex 53 * lock. 54 */ 55 static void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle) 56 { 57 if (drm_core_check_feature(dev, DRIVER_MODESET)) 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 /** \name Context bitmap support */ 67 /*@{*/ 68 69 void drm_legacy_ctxbitmap_release(struct drm_device *dev, 70 struct drm_file *file_priv) 71 { 72 if (drm_core_check_feature(dev, DRIVER_MODESET)) 73 return; 74 75 mutex_lock(&dev->ctxlist_mutex); 76 if (!list_empty(&dev->ctxlist)) { 77 struct drm_ctx_list *pos, *n; 78 79 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) { 80 if (pos->tag == file_priv && 81 pos->handle != DRM_KERNEL_CONTEXT) { 82 if (dev->driver->context_dtor) 83 dev->driver->context_dtor(dev, 84 pos->handle); 85 86 drm_ctxbitmap_free(dev, pos->handle); 87 88 list_del(&pos->head); 89 kfree(pos); 90 --dev->ctx_count; 91 } 92 } 93 } 94 mutex_unlock(&dev->ctxlist_mutex); 95 } 96 97 /** 98 * Context bitmap allocation. 99 * 100 * \param dev DRM device. 101 * \return (non-negative) context handle on success or a negative number on failure. 102 * 103 * Allocate a new idr from drm_device::ctx_idr while holding the 104 * drm_device::struct_mutex lock. 105 */ 106 static int drm_ctxbitmap_next(struct drm_device * dev) 107 { 108 int ret; 109 110 mutex_lock(&dev->struct_mutex); 111 ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0, 112 GFP_KERNEL); 113 mutex_unlock(&dev->struct_mutex); 114 return ret; 115 } 116 117 /** 118 * Context bitmap initialization. 119 * 120 * \param dev DRM device. 121 * 122 * Initialise the drm_device::ctx_idr 123 */ 124 void drm_legacy_ctxbitmap_init(struct drm_device * dev) 125 { 126 if (drm_core_check_feature(dev, DRIVER_MODESET)) 127 return; 128 129 idr_init(&dev->ctx_idr); 130 } 131 132 /** 133 * Context bitmap cleanup. 134 * 135 * \param dev DRM device. 136 * 137 * Free all idr members using drm_ctx_sarea_free helper function 138 * while holding the drm_device::struct_mutex lock. 139 */ 140 void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev) 141 { 142 mutex_lock(&dev->struct_mutex); 143 idr_destroy(&dev->ctx_idr); 144 mutex_unlock(&dev->struct_mutex); 145 } 146 147 /*@}*/ 148 149 /******************************************************************/ 150 /** \name Per Context SAREA Support */ 151 /*@{*/ 152 153 /** 154 * Get per-context SAREA. 155 * 156 * \param inode device inode. 157 * \param file_priv DRM file private. 158 * \param cmd command. 159 * \param arg user argument pointing to a drm_ctx_priv_map structure. 160 * \return zero on success or a negative number on failure. 161 * 162 * Gets the map from drm_device::ctx_idr with the handle specified and 163 * returns its handle. 164 */ 165 int drm_getsareactx(struct drm_device *dev, void *data, 166 struct drm_file *file_priv) 167 { 168 struct drm_ctx_priv_map *request = data; 169 struct drm_local_map *map; 170 struct drm_map_list *_entry; 171 172 if (drm_core_check_feature(dev, DRIVER_MODESET)) 173 return -EINVAL; 174 175 mutex_lock(&dev->struct_mutex); 176 177 map = idr_find(&dev->ctx_idr, request->ctx_id); 178 if (!map) { 179 mutex_unlock(&dev->struct_mutex); 180 return -EINVAL; 181 } 182 183 request->handle = NULL; 184 list_for_each_entry(_entry, &dev->maplist, head) { 185 if (_entry->map == map) { 186 request->handle = 187 (void *)(unsigned long)_entry->user_token; 188 break; 189 } 190 } 191 192 mutex_unlock(&dev->struct_mutex); 193 194 if (request->handle == NULL) 195 return -EINVAL; 196 197 return 0; 198 } 199 200 /** 201 * Set per-context SAREA. 202 * 203 * \param inode device inode. 204 * \param file_priv DRM file private. 205 * \param cmd command. 206 * \param arg user argument pointing to a drm_ctx_priv_map structure. 207 * \return zero on success or a negative number on failure. 208 * 209 * Searches the mapping specified in \p arg and update the entry in 210 * drm_device::ctx_idr with it. 211 */ 212 int drm_setsareactx(struct drm_device *dev, void *data, 213 struct drm_file *file_priv) 214 { 215 struct drm_ctx_priv_map *request = data; 216 struct drm_local_map *map = NULL; 217 struct drm_map_list *r_list = NULL; 218 219 if (drm_core_check_feature(dev, DRIVER_MODESET)) 220 return -EINVAL; 221 222 mutex_lock(&dev->struct_mutex); 223 list_for_each_entry(r_list, &dev->maplist, head) { 224 if (r_list->map 225 && r_list->user_token == (unsigned long) request->handle) 226 goto found; 227 } 228 bad: 229 mutex_unlock(&dev->struct_mutex); 230 return -EINVAL; 231 232 found: 233 map = r_list->map; 234 if (!map) 235 goto bad; 236 237 if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id))) 238 goto bad; 239 240 mutex_unlock(&dev->struct_mutex); 241 242 return 0; 243 } 244 245 /*@}*/ 246 247 /******************************************************************/ 248 /** \name The actual DRM context handling routines */ 249 /*@{*/ 250 251 /** 252 * Switch context. 253 * 254 * \param dev DRM device. 255 * \param old old context handle. 256 * \param new new context handle. 257 * \return zero on success or a negative number on failure. 258 * 259 * Attempt to set drm_device::context_flag. 260 */ 261 static int drm_context_switch(struct drm_device * dev, int old, int new) 262 { 263 if (test_and_set_bit(0, &dev->context_flag)) { 264 DRM_ERROR("Reentering -- FIXME\n"); 265 return -EBUSY; 266 } 267 268 DRM_DEBUG("Context switch from %d to %d\n", old, new); 269 270 if (new == dev->last_context) { 271 clear_bit(0, &dev->context_flag); 272 return 0; 273 } 274 275 return 0; 276 } 277 278 /** 279 * Complete context switch. 280 * 281 * \param dev DRM device. 282 * \param new new context handle. 283 * \return zero on success or a negative number on failure. 284 * 285 * Updates drm_device::last_context and drm_device::last_switch. Verifies the 286 * hardware lock is held, clears the drm_device::context_flag and wakes up 287 * drm_device::context_wait. 288 */ 289 static int drm_context_switch_complete(struct drm_device *dev, 290 struct drm_file *file_priv, int new) 291 { 292 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */ 293 294 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) { 295 DRM_ERROR("Lock isn't held after context switch\n"); 296 } 297 298 /* If a context switch is ever initiated 299 when the kernel holds the lock, release 300 that lock here. */ 301 clear_bit(0, &dev->context_flag); 302 303 return 0; 304 } 305 306 /** 307 * Reserve contexts. 308 * 309 * \param inode device inode. 310 * \param file_priv DRM file private. 311 * \param cmd command. 312 * \param arg user argument pointing to a drm_ctx_res structure. 313 * \return zero on success or a negative number on failure. 314 */ 315 int drm_resctx(struct drm_device *dev, void *data, 316 struct drm_file *file_priv) 317 { 318 struct drm_ctx_res *res = data; 319 struct drm_ctx ctx; 320 int i; 321 322 if (drm_core_check_feature(dev, DRIVER_MODESET)) 323 return -EINVAL; 324 325 if (res->count >= DRM_RESERVED_CONTEXTS) { 326 memset(&ctx, 0, sizeof(ctx)); 327 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) { 328 ctx.handle = i; 329 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx))) 330 return -EFAULT; 331 } 332 } 333 res->count = DRM_RESERVED_CONTEXTS; 334 335 return 0; 336 } 337 338 /** 339 * Add context. 340 * 341 * \param inode device inode. 342 * \param file_priv DRM file private. 343 * \param cmd command. 344 * \param arg user argument pointing to a drm_ctx structure. 345 * \return zero on success or a negative number on failure. 346 * 347 * Get a new handle for the context and copy to userspace. 348 */ 349 int drm_addctx(struct drm_device *dev, void *data, 350 struct drm_file *file_priv) 351 { 352 struct drm_ctx_list *ctx_entry; 353 struct drm_ctx *ctx = data; 354 355 if (drm_core_check_feature(dev, DRIVER_MODESET)) 356 return -EINVAL; 357 358 ctx->handle = drm_ctxbitmap_next(dev); 359 if (ctx->handle == DRM_KERNEL_CONTEXT) { 360 /* Skip kernel's context and get a new one. */ 361 ctx->handle = drm_ctxbitmap_next(dev); 362 } 363 DRM_DEBUG("%d\n", ctx->handle); 364 if (ctx->handle == -1) { 365 DRM_DEBUG("Not enough free contexts.\n"); 366 /* Should this return -EBUSY instead? */ 367 return -ENOMEM; 368 } 369 370 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL); 371 if (!ctx_entry) { 372 DRM_DEBUG("out of memory\n"); 373 return -ENOMEM; 374 } 375 376 INIT_LIST_HEAD(&ctx_entry->head); 377 ctx_entry->handle = ctx->handle; 378 ctx_entry->tag = file_priv; 379 380 mutex_lock(&dev->ctxlist_mutex); 381 list_add(&ctx_entry->head, &dev->ctxlist); 382 ++dev->ctx_count; 383 mutex_unlock(&dev->ctxlist_mutex); 384 385 return 0; 386 } 387 388 /** 389 * Get context. 390 * 391 * \param inode device inode. 392 * \param file_priv DRM file private. 393 * \param cmd command. 394 * \param arg user argument pointing to a drm_ctx structure. 395 * \return zero on success or a negative number on failure. 396 */ 397 int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv) 398 { 399 struct drm_ctx *ctx = data; 400 401 if (drm_core_check_feature(dev, DRIVER_MODESET)) 402 return -EINVAL; 403 404 /* This is 0, because we don't handle any context flags */ 405 ctx->flags = 0; 406 407 return 0; 408 } 409 410 /** 411 * Switch context. 412 * 413 * \param inode device inode. 414 * \param file_priv DRM file private. 415 * \param cmd command. 416 * \param arg user argument pointing to a drm_ctx structure. 417 * \return zero on success or a negative number on failure. 418 * 419 * Calls context_switch(). 420 */ 421 int drm_switchctx(struct drm_device *dev, void *data, 422 struct drm_file *file_priv) 423 { 424 struct drm_ctx *ctx = data; 425 426 if (drm_core_check_feature(dev, DRIVER_MODESET)) 427 return -EINVAL; 428 429 DRM_DEBUG("%d\n", ctx->handle); 430 return drm_context_switch(dev, dev->last_context, ctx->handle); 431 } 432 433 /** 434 * New context. 435 * 436 * \param inode device inode. 437 * \param file_priv DRM file private. 438 * \param cmd command. 439 * \param arg user argument pointing to a drm_ctx structure. 440 * \return zero on success or a negative number on failure. 441 * 442 * Calls context_switch_complete(). 443 */ 444 int drm_newctx(struct drm_device *dev, void *data, 445 struct drm_file *file_priv) 446 { 447 struct drm_ctx *ctx = data; 448 449 if (drm_core_check_feature(dev, DRIVER_MODESET)) 450 return -EINVAL; 451 452 DRM_DEBUG("%d\n", ctx->handle); 453 drm_context_switch_complete(dev, file_priv, ctx->handle); 454 455 return 0; 456 } 457 458 /** 459 * Remove context. 460 * 461 * \param inode device inode. 462 * \param file_priv DRM file private. 463 * \param cmd command. 464 * \param arg user argument pointing to a drm_ctx structure. 465 * \return zero on success or a negative number on failure. 466 * 467 * If not the special kernel context, calls ctxbitmap_free() to free the specified context. 468 */ 469 int drm_rmctx(struct drm_device *dev, void *data, 470 struct drm_file *file_priv) 471 { 472 struct drm_ctx *ctx = data; 473 474 if (drm_core_check_feature(dev, DRIVER_MODESET)) 475 return -EINVAL; 476 477 DRM_DEBUG("%d\n", ctx->handle); 478 if (ctx->handle != DRM_KERNEL_CONTEXT) { 479 if (dev->driver->context_dtor) 480 dev->driver->context_dtor(dev, ctx->handle); 481 drm_ctxbitmap_free(dev, ctx->handle); 482 } 483 484 mutex_lock(&dev->ctxlist_mutex); 485 if (!list_empty(&dev->ctxlist)) { 486 struct drm_ctx_list *pos, *n; 487 488 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) { 489 if (pos->handle == ctx->handle) { 490 list_del(&pos->head); 491 kfree(pos); 492 --dev->ctx_count; 493 } 494 } 495 } 496 mutex_unlock(&dev->ctxlist_mutex); 497 498 return 0; 499 } 500 501 /*@}*/ 502