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 */ 59void 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 */ 75static int drm_ctxbitmap_next(struct drm_device * dev) 76{ 77 int new_id; 78 int ret; 79 80again: 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 */ 103int 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 */ 117void 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 */ 142int 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 mutex_unlock(&dev->struct_mutex); 158 159 request->handle = NULL; 160 list_for_each_entry(_entry, &dev->maplist, head) { 161 if (_entry->map == map) { 162 request->handle = 163 (void *)(unsigned long)_entry->user_token; 164 break; 165 } 166 } 167 if (request->handle == NULL) 168 return -EINVAL; 169 170 return 0; 171} 172 173/** 174 * Set per-context SAREA. 175 * 176 * \param inode device inode. 177 * \param file_priv DRM file private. 178 * \param cmd command. 179 * \param arg user argument pointing to a drm_ctx_priv_map structure. 180 * \return zero on success or a negative number on failure. 181 * 182 * Searches the mapping specified in \p arg and update the entry in 183 * drm_device::ctx_idr with it. 184 */ 185int drm_setsareactx(struct drm_device *dev, void *data, 186 struct drm_file *file_priv) 187{ 188 struct drm_ctx_priv_map *request = data; 189 struct drm_local_map *map = NULL; 190 struct drm_map_list *r_list = NULL; 191 192 mutex_lock(&dev->struct_mutex); 193 list_for_each_entry(r_list, &dev->maplist, head) { 194 if (r_list->map 195 && r_list->user_token == (unsigned long) request->handle) 196 goto found; 197 } 198 bad: 199 mutex_unlock(&dev->struct_mutex); 200 return -EINVAL; 201 202 found: 203 map = r_list->map; 204 if (!map) 205 goto bad; 206 207 if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id))) 208 goto bad; 209 210 mutex_unlock(&dev->struct_mutex); 211 212 return 0; 213} 214 215/*@}*/ 216 217/******************************************************************/ 218/** \name The actual DRM context handling routines */ 219/*@{*/ 220 221/** 222 * Switch context. 223 * 224 * \param dev DRM device. 225 * \param old old context handle. 226 * \param new new context handle. 227 * \return zero on success or a negative number on failure. 228 * 229 * Attempt to set drm_device::context_flag. 230 */ 231static int drm_context_switch(struct drm_device * dev, int old, int new) 232{ 233 if (test_and_set_bit(0, &dev->context_flag)) { 234 DRM_ERROR("Reentering -- FIXME\n"); 235 return -EBUSY; 236 } 237 238 DRM_DEBUG("Context switch from %d to %d\n", old, new); 239 240 if (new == dev->last_context) { 241 clear_bit(0, &dev->context_flag); 242 return 0; 243 } 244 245 return 0; 246} 247 248/** 249 * Complete context switch. 250 * 251 * \param dev DRM device. 252 * \param new new context handle. 253 * \return zero on success or a negative number on failure. 254 * 255 * Updates drm_device::last_context and drm_device::last_switch. Verifies the 256 * hardware lock is held, clears the drm_device::context_flag and wakes up 257 * drm_device::context_wait. 258 */ 259static int drm_context_switch_complete(struct drm_device *dev, 260 struct drm_file *file_priv, int new) 261{ 262 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */ 263 dev->last_switch = jiffies; 264 265 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) { 266 DRM_ERROR("Lock isn't held after context switch\n"); 267 } 268 269 /* If a context switch is ever initiated 270 when the kernel holds the lock, release 271 that lock here. */ 272 clear_bit(0, &dev->context_flag); 273 wake_up(&dev->context_wait); 274 275 return 0; 276} 277 278/** 279 * Reserve contexts. 280 * 281 * \param inode device inode. 282 * \param file_priv DRM file private. 283 * \param cmd command. 284 * \param arg user argument pointing to a drm_ctx_res structure. 285 * \return zero on success or a negative number on failure. 286 */ 287int drm_resctx(struct drm_device *dev, void *data, 288 struct drm_file *file_priv) 289{ 290 struct drm_ctx_res *res = data; 291 struct drm_ctx ctx; 292 int i; 293 294 if (res->count >= DRM_RESERVED_CONTEXTS) { 295 memset(&ctx, 0, sizeof(ctx)); 296 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) { 297 ctx.handle = i; 298 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx))) 299 return -EFAULT; 300 } 301 } 302 res->count = DRM_RESERVED_CONTEXTS; 303 304 return 0; 305} 306 307/** 308 * Add context. 309 * 310 * \param inode device inode. 311 * \param file_priv DRM file private. 312 * \param cmd command. 313 * \param arg user argument pointing to a drm_ctx structure. 314 * \return zero on success or a negative number on failure. 315 * 316 * Get a new handle for the context and copy to userspace. 317 */ 318int drm_addctx(struct drm_device *dev, void *data, 319 struct drm_file *file_priv) 320{ 321 struct drm_ctx_list *ctx_entry; 322 struct drm_ctx *ctx = data; 323 324 ctx->handle = drm_ctxbitmap_next(dev); 325 if (ctx->handle == DRM_KERNEL_CONTEXT) { 326 /* Skip kernel's context and get a new one. */ 327 ctx->handle = drm_ctxbitmap_next(dev); 328 } 329 DRM_DEBUG("%d\n", ctx->handle); 330 if (ctx->handle == -1) { 331 DRM_DEBUG("Not enough free contexts.\n"); 332 /* Should this return -EBUSY instead? */ 333 return -ENOMEM; 334 } 335 336 if (ctx->handle != DRM_KERNEL_CONTEXT) { 337 if (dev->driver->context_ctor) 338 if (!dev->driver->context_ctor(dev, ctx->handle)) { 339 DRM_DEBUG("Running out of ctxs or memory.\n"); 340 return -ENOMEM; 341 } 342 } 343 344 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL); 345 if (!ctx_entry) { 346 DRM_DEBUG("out of memory\n"); 347 return -ENOMEM; 348 } 349 350 INIT_LIST_HEAD(&ctx_entry->head); 351 ctx_entry->handle = ctx->handle; 352 ctx_entry->tag = file_priv; 353 354 mutex_lock(&dev->ctxlist_mutex); 355 list_add(&ctx_entry->head, &dev->ctxlist); 356 ++dev->ctx_count; 357 mutex_unlock(&dev->ctxlist_mutex); 358 359 return 0; 360} 361 362int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv) 363{ 364 /* This does nothing */ 365 return 0; 366} 367 368/** 369 * Get context. 370 * 371 * \param inode device inode. 372 * \param file_priv DRM file private. 373 * \param cmd command. 374 * \param arg user argument pointing to a drm_ctx structure. 375 * \return zero on success or a negative number on failure. 376 */ 377int drm_getctx(struct drm_device *dev, void *data, 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_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_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_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_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 --dev->ctx_count; 461 } 462 } 463 } 464 mutex_unlock(&dev->ctxlist_mutex); 465 466 return 0; 467} 468 469/*@}*/ 470