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 "drmP.h" 44 45 /******************************************************************/ 46 /** \name Context bitmap support */ 47 /*@{*/ 48 49 /** 50 * Free a handle from the context bitmap. 51 * 52 * \param dev DRM device. 53 * \param ctx_handle context handle. 54 * 55 * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry 56 * in drm_device::ctx_idr, while holding the drm_device::struct_mutex 57 * lock. 58 */ 59 void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle) 60 { 61 mutex_lock(&dev->struct_mutex); 62 idr_remove(&dev->ctx_idr, ctx_handle); 63 mutex_unlock(&dev->struct_mutex); 64 } 65 66 /** 67 * Context bitmap allocation. 68 * 69 * \param dev DRM device. 70 * \return (non-negative) context handle on success or a negative number on failure. 71 * 72 * Allocate a new idr from drm_device::ctx_idr while holding the 73 * drm_device::struct_mutex lock. 74 */ 75 static int drm_ctxbitmap_next(struct drm_device * dev) 76 { 77 int new_id; 78 int ret; 79 80 again: 81 if (idr_pre_get(&dev->ctx_idr, GFP_KERNEL) == 0) { 82 DRM_ERROR("Out of memory expanding drawable idr\n"); 83 return -ENOMEM; 84 } 85 mutex_lock(&dev->struct_mutex); 86 ret = idr_get_new_above(&dev->ctx_idr, NULL, 87 DRM_RESERVED_CONTEXTS, &new_id); 88 if (ret == -EAGAIN) { 89 mutex_unlock(&dev->struct_mutex); 90 goto again; 91 } 92 mutex_unlock(&dev->struct_mutex); 93 return new_id; 94 } 95 96 /** 97 * Context bitmap initialization. 98 * 99 * \param dev DRM device. 100 * 101 * Initialise the drm_device::ctx_idr 102 */ 103 int drm_ctxbitmap_init(struct drm_device * dev) 104 { 105 idr_init(&dev->ctx_idr); 106 return 0; 107 } 108 109 /** 110 * Context bitmap cleanup. 111 * 112 * \param dev DRM device. 113 * 114 * Free all idr members using drm_ctx_sarea_free helper function 115 * while holding the drm_device::struct_mutex lock. 116 */ 117 void drm_ctxbitmap_cleanup(struct drm_device * dev) 118 { 119 mutex_lock(&dev->struct_mutex); 120 idr_remove_all(&dev->ctx_idr); 121 mutex_unlock(&dev->struct_mutex); 122 } 123 124 /*@}*/ 125 126 /******************************************************************/ 127 /** \name Per Context SAREA Support */ 128 /*@{*/ 129 130 /** 131 * Get per-context SAREA. 132 * 133 * \param inode device inode. 134 * \param file_priv DRM file private. 135 * \param cmd command. 136 * \param arg user argument pointing to a drm_ctx_priv_map structure. 137 * \return zero on success or a negative number on failure. 138 * 139 * Gets the map from drm_device::ctx_idr with the handle specified and 140 * returns its handle. 141 */ 142 int drm_getsareactx(struct drm_device *dev, void *data, 143 struct drm_file *file_priv) 144 { 145 struct drm_ctx_priv_map *request = data; 146 struct drm_local_map *map; 147 struct drm_map_list *_entry; 148 149 mutex_lock(&dev->struct_mutex); 150 151 map = idr_find(&dev->ctx_idr, request->ctx_id); 152 if (!map) { 153 mutex_unlock(&dev->struct_mutex); 154 return -EINVAL; 155 } 156 157 request->handle = NULL; 158 list_for_each_entry(_entry, &dev->maplist, head) { 159 if (_entry->map == map) { 160 request->handle = 161 (void *)(unsigned long)_entry->user_token; 162 break; 163 } 164 } 165 166 mutex_unlock(&dev->struct_mutex); 167 168 if (request->handle == NULL) 169 return -EINVAL; 170 171 return 0; 172 } 173 174 /** 175 * Set per-context SAREA. 176 * 177 * \param inode device inode. 178 * \param file_priv DRM file private. 179 * \param cmd command. 180 * \param arg user argument pointing to a drm_ctx_priv_map structure. 181 * \return zero on success or a negative number on failure. 182 * 183 * Searches the mapping specified in \p arg and update the entry in 184 * drm_device::ctx_idr with it. 185 */ 186 int drm_setsareactx(struct drm_device *dev, void *data, 187 struct drm_file *file_priv) 188 { 189 struct drm_ctx_priv_map *request = data; 190 struct drm_local_map *map = NULL; 191 struct drm_map_list *r_list = NULL; 192 193 mutex_lock(&dev->struct_mutex); 194 list_for_each_entry(r_list, &dev->maplist, head) { 195 if (r_list->map 196 && r_list->user_token == (unsigned long) request->handle) 197 goto found; 198 } 199 bad: 200 mutex_unlock(&dev->struct_mutex); 201 return -EINVAL; 202 203 found: 204 map = r_list->map; 205 if (!map) 206 goto bad; 207 208 if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id))) 209 goto bad; 210 211 mutex_unlock(&dev->struct_mutex); 212 213 return 0; 214 } 215 216 /*@}*/ 217 218 /******************************************************************/ 219 /** \name The actual DRM context handling routines */ 220 /*@{*/ 221 222 /** 223 * Switch context. 224 * 225 * \param dev DRM device. 226 * \param old old context handle. 227 * \param new new context handle. 228 * \return zero on success or a negative number on failure. 229 * 230 * Attempt to set drm_device::context_flag. 231 */ 232 static int drm_context_switch(struct drm_device * dev, int old, int new) 233 { 234 if (test_and_set_bit(0, &dev->context_flag)) { 235 DRM_ERROR("Reentering -- FIXME\n"); 236 return -EBUSY; 237 } 238 239 DRM_DEBUG("Context switch from %d to %d\n", old, new); 240 241 if (new == dev->last_context) { 242 clear_bit(0, &dev->context_flag); 243 return 0; 244 } 245 246 return 0; 247 } 248 249 /** 250 * Complete context switch. 251 * 252 * \param dev DRM device. 253 * \param new new context handle. 254 * \return zero on success or a negative number on failure. 255 * 256 * Updates drm_device::last_context and drm_device::last_switch. Verifies the 257 * hardware lock is held, clears the drm_device::context_flag and wakes up 258 * drm_device::context_wait. 259 */ 260 static int drm_context_switch_complete(struct drm_device *dev, 261 struct drm_file *file_priv, int new) 262 { 263 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */ 264 dev->last_switch = jiffies; 265 266 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) { 267 DRM_ERROR("Lock isn't held after context switch\n"); 268 } 269 270 /* If a context switch is ever initiated 271 when the kernel holds the lock, release 272 that lock here. */ 273 clear_bit(0, &dev->context_flag); 274 wake_up(&dev->context_wait); 275 276 return 0; 277 } 278 279 /** 280 * Reserve contexts. 281 * 282 * \param inode device inode. 283 * \param file_priv DRM file private. 284 * \param cmd command. 285 * \param arg user argument pointing to a drm_ctx_res structure. 286 * \return zero on success or a negative number on failure. 287 */ 288 int drm_resctx(struct drm_device *dev, void *data, 289 struct drm_file *file_priv) 290 { 291 struct drm_ctx_res *res = data; 292 struct drm_ctx ctx; 293 int i; 294 295 if (res->count >= DRM_RESERVED_CONTEXTS) { 296 memset(&ctx, 0, sizeof(ctx)); 297 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) { 298 ctx.handle = i; 299 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx))) 300 return -EFAULT; 301 } 302 } 303 res->count = DRM_RESERVED_CONTEXTS; 304 305 return 0; 306 } 307 308 /** 309 * Add context. 310 * 311 * \param inode device inode. 312 * \param file_priv DRM file private. 313 * \param cmd command. 314 * \param arg user argument pointing to a drm_ctx structure. 315 * \return zero on success or a negative number on failure. 316 * 317 * Get a new handle for the context and copy to userspace. 318 */ 319 int drm_addctx(struct drm_device *dev, void *data, 320 struct drm_file *file_priv) 321 { 322 struct drm_ctx_list *ctx_entry; 323 struct drm_ctx *ctx = data; 324 325 ctx->handle = drm_ctxbitmap_next(dev); 326 if (ctx->handle == DRM_KERNEL_CONTEXT) { 327 /* Skip kernel's context and get a new one. */ 328 ctx->handle = drm_ctxbitmap_next(dev); 329 } 330 DRM_DEBUG("%d\n", ctx->handle); 331 if (ctx->handle == -1) { 332 DRM_DEBUG("Not enough free contexts.\n"); 333 /* Should this return -EBUSY instead? */ 334 return -ENOMEM; 335 } 336 337 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL); 338 if (!ctx_entry) { 339 DRM_DEBUG("out of memory\n"); 340 return -ENOMEM; 341 } 342 343 INIT_LIST_HEAD(&ctx_entry->head); 344 ctx_entry->handle = ctx->handle; 345 ctx_entry->tag = file_priv; 346 347 mutex_lock(&dev->ctxlist_mutex); 348 list_add(&ctx_entry->head, &dev->ctxlist); 349 ++dev->ctx_count; 350 mutex_unlock(&dev->ctxlist_mutex); 351 352 return 0; 353 } 354 355 int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv) 356 { 357 /* This does nothing */ 358 return 0; 359 } 360 361 /** 362 * Get context. 363 * 364 * \param inode device inode. 365 * \param file_priv DRM file private. 366 * \param cmd command. 367 * \param arg user argument pointing to a drm_ctx structure. 368 * \return zero on success or a negative number on failure. 369 */ 370 int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv) 371 { 372 struct drm_ctx *ctx = data; 373 374 /* This is 0, because we don't handle any context flags */ 375 ctx->flags = 0; 376 377 return 0; 378 } 379 380 /** 381 * Switch context. 382 * 383 * \param inode device inode. 384 * \param file_priv DRM file private. 385 * \param cmd command. 386 * \param arg user argument pointing to a drm_ctx structure. 387 * \return zero on success or a negative number on failure. 388 * 389 * Calls context_switch(). 390 */ 391 int drm_switchctx(struct drm_device *dev, void *data, 392 struct drm_file *file_priv) 393 { 394 struct drm_ctx *ctx = data; 395 396 DRM_DEBUG("%d\n", ctx->handle); 397 return drm_context_switch(dev, dev->last_context, ctx->handle); 398 } 399 400 /** 401 * New 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 * 409 * Calls context_switch_complete(). 410 */ 411 int drm_newctx(struct drm_device *dev, void *data, 412 struct drm_file *file_priv) 413 { 414 struct drm_ctx *ctx = data; 415 416 DRM_DEBUG("%d\n", ctx->handle); 417 drm_context_switch_complete(dev, file_priv, ctx->handle); 418 419 return 0; 420 } 421 422 /** 423 * Remove 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 * If not the special kernel context, calls ctxbitmap_free() to free the specified context. 432 */ 433 int drm_rmctx(struct drm_device *dev, void *data, 434 struct drm_file *file_priv) 435 { 436 struct drm_ctx *ctx = data; 437 438 DRM_DEBUG("%d\n", ctx->handle); 439 if (ctx->handle != DRM_KERNEL_CONTEXT) { 440 if (dev->driver->context_dtor) 441 dev->driver->context_dtor(dev, ctx->handle); 442 drm_ctxbitmap_free(dev, ctx->handle); 443 } 444 445 mutex_lock(&dev->ctxlist_mutex); 446 if (!list_empty(&dev->ctxlist)) { 447 struct drm_ctx_list *pos, *n; 448 449 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) { 450 if (pos->handle == ctx->handle) { 451 list_del(&pos->head); 452 kfree(pos); 453 --dev->ctx_count; 454 } 455 } 456 } 457 mutex_unlock(&dev->ctxlist_mutex); 458 459 return 0; 460 } 461 462 /*@}*/ 463