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