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 40struct 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 */ 60void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle) 61{ 62 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 63 return; 64 65 mutex_lock(&dev->struct_mutex); 66 idr_remove(&dev->ctx_idr, ctx_handle); 67 mutex_unlock(&dev->struct_mutex); 68} 69 70/* 71 * Context bitmap allocation. 72 * 73 * \param dev DRM device. 74 * \return (non-negative) context handle on success or a negative number on failure. 75 * 76 * Allocate a new idr from drm_device::ctx_idr while holding the 77 * drm_device::struct_mutex lock. 78 */ 79static int drm_legacy_ctxbitmap_next(struct drm_device * dev) 80{ 81 int ret; 82 83 mutex_lock(&dev->struct_mutex); 84 ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0, 85 GFP_KERNEL); 86 mutex_unlock(&dev->struct_mutex); 87 return ret; 88} 89 90/* 91 * Context bitmap initialization. 92 * 93 * \param dev DRM device. 94 * 95 * Initialise the drm_device::ctx_idr 96 */ 97void drm_legacy_ctxbitmap_init(struct drm_device * dev) 98{ 99 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 100 return; 101 102 idr_init(&dev->ctx_idr); 103} 104 105/* 106 * Context bitmap cleanup. 107 * 108 * \param dev DRM device. 109 * 110 * Free all idr members using drm_ctx_sarea_free helper function 111 * while holding the drm_device::struct_mutex lock. 112 */ 113void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev) 114{ 115 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 116 return; 117 118 mutex_lock(&dev->struct_mutex); 119 idr_destroy(&dev->ctx_idr); 120 mutex_unlock(&dev->struct_mutex); 121} 122 123/** 124 * drm_legacy_ctxbitmap_flush() - Flush all contexts owned by a file 125 * @dev: DRM device to operate on 126 * @file: Open file to flush contexts for 127 * 128 * This iterates over all contexts on @dev and drops them if they're owned by 129 * @file. Note that after this call returns, new contexts might be added if 130 * the file is still alive. 131 */ 132void drm_legacy_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file) 133{ 134 struct drm_ctx_list *pos, *tmp; 135 136 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 137 return; 138 139 mutex_lock(&dev->ctxlist_mutex); 140 141 list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) { 142 if (pos->tag == file && 143 pos->handle != DRM_KERNEL_CONTEXT) { 144 if (dev->driver->context_dtor) 145 dev->driver->context_dtor(dev, pos->handle); 146 147 drm_legacy_ctxbitmap_free(dev, pos->handle); 148 list_del(&pos->head); 149 kfree(pos); 150 } 151 } 152 153 mutex_unlock(&dev->ctxlist_mutex); 154} 155 156/*@}*/ 157 158/******************************************************************/ 159/** \name Per Context SAREA Support */ 160/*@{*/ 161 162/* 163 * Get per-context SAREA. 164 * 165 * \param inode device inode. 166 * \param file_priv DRM file private. 167 * \param cmd command. 168 * \param arg user argument pointing to a drm_ctx_priv_map structure. 169 * \return zero on success or a negative number on failure. 170 * 171 * Gets the map from drm_device::ctx_idr with the handle specified and 172 * returns its handle. 173 */ 174int drm_legacy_getsareactx(struct drm_device *dev, void *data, 175 struct drm_file *file_priv) 176{ 177 struct drm_ctx_priv_map *request = data; 178 struct drm_local_map *map; 179 struct drm_map_list *_entry; 180 181 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 182 return -EOPNOTSUPP; 183 184 mutex_lock(&dev->struct_mutex); 185 186 map = idr_find(&dev->ctx_idr, request->ctx_id); 187 if (!map) { 188 mutex_unlock(&dev->struct_mutex); 189 return -EINVAL; 190 } 191 192 request->handle = NULL; 193 list_for_each_entry(_entry, &dev->maplist, head) { 194 if (_entry->map == map) { 195 request->handle = 196 (void *)(unsigned long)_entry->user_token; 197 break; 198 } 199 } 200 201 mutex_unlock(&dev->struct_mutex); 202 203 if (request->handle == NULL) 204 return -EINVAL; 205 206 return 0; 207} 208 209/* 210 * Set per-context SAREA. 211 * 212 * \param inode device inode. 213 * \param file_priv DRM file private. 214 * \param cmd command. 215 * \param arg user argument pointing to a drm_ctx_priv_map structure. 216 * \return zero on success or a negative number on failure. 217 * 218 * Searches the mapping specified in \p arg and update the entry in 219 * drm_device::ctx_idr with it. 220 */ 221int drm_legacy_setsareactx(struct drm_device *dev, void *data, 222 struct drm_file *file_priv) 223{ 224 struct drm_ctx_priv_map *request = data; 225 struct drm_local_map *map = NULL; 226 struct drm_map_list *r_list = NULL; 227 228 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 229 return -EOPNOTSUPP; 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 */ 270static 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 */ 298static 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 */ 311 clear_bit(0, &dev->context_flag); 312 313 return 0; 314} 315 316/* 317 * Reserve contexts. 318 * 319 * \param inode device inode. 320 * \param file_priv DRM file private. 321 * \param cmd command. 322 * \param arg user argument pointing to a drm_ctx_res structure. 323 * \return zero on success or a negative number on failure. 324 */ 325int drm_legacy_resctx(struct drm_device *dev, void *data, 326 struct drm_file *file_priv) 327{ 328 struct drm_ctx_res *res = data; 329 struct drm_ctx ctx; 330 int i; 331 332 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 333 return -EOPNOTSUPP; 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 */ 359int 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 int tmp_handle; 365 366 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 367 return -EOPNOTSUPP; 368 369 tmp_handle = drm_legacy_ctxbitmap_next(dev); 370 if (tmp_handle == DRM_KERNEL_CONTEXT) { 371 /* Skip kernel's context and get a new one. */ 372 tmp_handle = drm_legacy_ctxbitmap_next(dev); 373 } 374 DRM_DEBUG("%d\n", tmp_handle); 375 if (tmp_handle < 0) { 376 DRM_DEBUG("Not enough free contexts.\n"); 377 /* Should this return -EBUSY instead? */ 378 return tmp_handle; 379 } 380 381 ctx->handle = tmp_handle; 382 383 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL); 384 if (!ctx_entry) { 385 DRM_DEBUG("out of memory\n"); 386 return -ENOMEM; 387 } 388 389 INIT_LIST_HEAD(&ctx_entry->head); 390 ctx_entry->handle = ctx->handle; 391 ctx_entry->tag = file_priv; 392 393 mutex_lock(&dev->ctxlist_mutex); 394 list_add(&ctx_entry->head, &dev->ctxlist); 395 mutex_unlock(&dev->ctxlist_mutex); 396 397 return 0; 398} 399 400/* 401 * Get context. 402 * 403 * \param inode device inode. 404 * \param file_priv DRM file private. 405 * \param cmd command. 406 * \param arg user argument pointing to a drm_ctx structure. 407 * \return zero on success or a negative number on failure. 408 */ 409int drm_legacy_getctx(struct drm_device *dev, void *data, 410 struct drm_file *file_priv) 411{ 412 struct drm_ctx *ctx = data; 413 414 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 415 return -EOPNOTSUPP; 416 417 /* This is 0, because we don't handle any context flags */ 418 ctx->flags = 0; 419 420 return 0; 421} 422 423/* 424 * Switch context. 425 * 426 * \param inode device inode. 427 * \param file_priv DRM file private. 428 * \param cmd command. 429 * \param arg user argument pointing to a drm_ctx structure. 430 * \return zero on success or a negative number on failure. 431 * 432 * Calls context_switch(). 433 */ 434int drm_legacy_switchctx(struct drm_device *dev, void *data, 435 struct drm_file *file_priv) 436{ 437 struct drm_ctx *ctx = data; 438 439 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 440 return -EOPNOTSUPP; 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 */ 457int 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_LEGACY)) 463 return -EOPNOTSUPP; 464 465 DRM_DEBUG("%d\n", ctx->handle); 466 drm_context_switch_complete(dev, file_priv, ctx->handle); 467 468 return 0; 469} 470 471/* 472 * Remove context. 473 * 474 * \param inode device inode. 475 * \param file_priv DRM file private. 476 * \param cmd command. 477 * \param arg user argument pointing to a drm_ctx structure. 478 * \return zero on success or a negative number on failure. 479 * 480 * If not the special kernel context, calls ctxbitmap_free() to free the specified context. 481 */ 482int drm_legacy_rmctx(struct drm_device *dev, void *data, 483 struct drm_file *file_priv) 484{ 485 struct drm_ctx *ctx = data; 486 487 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 488 return -EOPNOTSUPP; 489 490 DRM_DEBUG("%d\n", ctx->handle); 491 if (ctx->handle != DRM_KERNEL_CONTEXT) { 492 if (dev->driver->context_dtor) 493 dev->driver->context_dtor(dev, ctx->handle); 494 drm_legacy_ctxbitmap_free(dev, ctx->handle); 495 } 496 497 mutex_lock(&dev->ctxlist_mutex); 498 if (!list_empty(&dev->ctxlist)) { 499 struct drm_ctx_list *pos, *n; 500 501 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) { 502 if (pos->handle == ctx->handle) { 503 list_del(&pos->head); 504 kfree(pos); 505 } 506 } 507 } 508 mutex_unlock(&dev->ctxlist_mutex); 509 510 return 0; 511} 512 513/*@}*/ 514