sys/dev/drm2/ttm/ttm_object.c

   1 /**************************************************************************
   2  *
   3  * Copyright (c) 2009 VMware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27 /*
  28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  29  */
  30 /** @file ttm_ref_object.c
  31  *
  32  * Base- and reference object implementation for the various
  33  * ttm objects. Implements reference counting, minimal security checks
  34  * and release on file close.
  35  */
  36
  37
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD$");
  40
  41 /**
  42  * struct ttm_object_file
  43  *
  44  * @tdev: Pointer to the ttm_object_device.
  45  *
  46  * @lock: Lock that protects the ref_list list and the
  47  * ref_hash hash tables.
  48  *
  49  * @ref_list: List of ttm_ref_objects to be destroyed at
  50  * file release.
  51  *
  52  * @ref_hash: Hash tables of ref objects, one per ttm_ref_type,
  53  * for fast lookup of ref objects given a base object.
  54  */
  55
  56 #define pr_fmt(fmt) "[TTM] " fmt
  57
  58 #include <dev/drm2/drmP.h>
  59 #include <dev/drm2/drm.h>
  60 #include <sys/rwlock.h>
  61 #include <dev/drm2/ttm/ttm_object.h>
  62 #include <dev/drm2/ttm/ttm_module.h>
  63
  64 struct ttm_object_file {
  65         struct ttm_object_device *tdev;
  66         struct rwlock lock;
  67         struct list_head ref_list;
  68         struct drm_open_hash ref_hash[TTM_REF_NUM];
  69         u_int refcount;
  70 };
  71
  72 /**
  73  * struct ttm_object_device
  74  *
  75  * @object_lock: lock that protects the object_hash hash table.
  76  *
  77  * @object_hash: hash table for fast lookup of object global names.
  78  *
  79  * @object_count: Per device object count.
  80  *
  81  * This is the per-device data structure needed for ttm object management.
  82  */
  83
  84 struct ttm_object_device {
  85         struct rwlock object_lock;
  86         struct drm_open_hash object_hash;
  87         atomic_t object_count;
  88         struct ttm_mem_global *mem_glob;
  89 };
  90
  91 /**
  92  * struct ttm_ref_object
  93  *
  94  * @hash: Hash entry for the per-file object reference hash.
  95  *
  96  * @head: List entry for the per-file list of ref-objects.
  97  *
  98  * @kref: Ref count.
  99  *
 100  * @obj: Base object this ref object is referencing.
 101  *
 102  * @ref_type: Type of ref object.
 103  *
 104  * This is similar to an idr object, but it also has a hash table entry
 105  * that allows lookup with a pointer to the referenced object as a key. In
 106  * that way, one can easily detect whether a base object is referenced by
 107  * a particular ttm_object_file. It also carries a ref count to avoid creating
 108  * multiple ref objects if a ttm_object_file references the same base
 109  * object more than once.
 110  */
 111
 112 struct ttm_ref_object {
 113         struct drm_hash_item hash;
 114         struct list_head head;
 115         u_int kref;
 116         enum ttm_ref_type ref_type;
 117         struct ttm_base_object *obj;
 118         struct ttm_object_file *tfile;
 119 };
 120
 121 MALLOC_DEFINE(M_TTM_OBJ_FILE, "ttm_obj_file", "TTM File Objects");
 122
 123 static inline struct ttm_object_file *
 124 ttm_object_file_ref(struct ttm_object_file *tfile)
 125 {
 126         refcount_acquire(&tfile->refcount);
 127         return tfile;
 128 }
 129
 130 static void ttm_object_file_destroy(struct ttm_object_file *tfile)
 131 {
 132
 133         free(tfile, M_TTM_OBJ_FILE);
 134 }
 135
 136
 137 static inline void ttm_object_file_unref(struct ttm_object_file **p_tfile)
 138 {
 139         struct ttm_object_file *tfile = *p_tfile;
 140
 141         *p_tfile = NULL;
 142         if (refcount_release(&tfile->refcount))
 143                 ttm_object_file_destroy(tfile);
 144 }
 145
 146
 147 int ttm_base_object_init(struct ttm_object_file *tfile,
 148                          struct ttm_base_object *base,
 149                          bool shareable,
 150                          enum ttm_object_type object_type,
 151                          void (*rcount_release) (struct ttm_base_object **),
 152                          void (*ref_obj_release) (struct ttm_base_object *,
 153                                                   enum ttm_ref_type ref_type))
 154 {
 155         struct ttm_object_device *tdev = tfile->tdev;
 156         int ret;
 157
 158         base->shareable = shareable;
 159         base->tfile = ttm_object_file_ref(tfile);
 160         base->refcount_release = rcount_release;
 161         base->ref_obj_release = ref_obj_release;
 162         base->object_type = object_type;
 163         refcount_init(&base->refcount, 1);
 164         rw_init(&tdev->object_lock, "ttmbao");
 165         rw_wlock(&tdev->object_lock);
 166         ret = drm_ht_just_insert_please(&tdev->object_hash,
 167                                             &base->hash,
 168                                             (unsigned long)base, 31, 0, 0);
 169         rw_wunlock(&tdev->object_lock);
 170         if (unlikely(ret != 0))
 171                 goto out_err0;
 172
 173         ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL);
 174         if (unlikely(ret != 0))
 175                 goto out_err1;
 176
 177         ttm_base_object_unref(&base);
 178
 179         return 0;
 180 out_err1:
 181         rw_wlock(&tdev->object_lock);
 182         (void)drm_ht_remove_item(&tdev->object_hash, &base->hash);
 183         rw_wunlock(&tdev->object_lock);
 184 out_err0:
 185         return ret;
 186 }
 187
 188 static void ttm_release_base(struct ttm_base_object *base)
 189 {
 190         struct ttm_object_device *tdev = base->tfile->tdev;
 191
 192         (void)drm_ht_remove_item(&tdev->object_hash, &base->hash);
 193         rw_wunlock(&tdev->object_lock);
 194         /*
 195          * Note: We don't use synchronize_rcu() here because it's far
 196          * too slow. It's up to the user to free the object using
 197          * call_rcu() or ttm_base_object_kfree().
 198          */
 199
 200         if (base->refcount_release) {
 201                 ttm_object_file_unref(&base->tfile);
 202                 base->refcount_release(&base);
 203         }
 204         rw_wlock(&tdev->object_lock);
 205 }
 206
 207 void ttm_base_object_unref(struct ttm_base_object **p_base)
 208 {
 209         struct ttm_base_object *base = *p_base;
 210         struct ttm_object_device *tdev = base->tfile->tdev;
 211
 212         *p_base = NULL;
 213
 214         /*
 215          * Need to take the lock here to avoid racing with
 216          * users trying to look up the object.
 217          */
 218
 219         rw_wlock(&tdev->object_lock);
 220         if (refcount_release(&base->refcount))
 221                 ttm_release_base(base);
 222         rw_wunlock(&tdev->object_lock);
 223 }
 224
 225 struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file *tfile,
 226                                                uint32_t key)
 227 {
 228         struct ttm_object_device *tdev = tfile->tdev;
 229         struct ttm_base_object *base;
 230         struct drm_hash_item *hash;
 231         int ret;
 232
 233         rw_rlock(&tdev->object_lock);
 234         ret = drm_ht_find_item(&tdev->object_hash, key, &hash);
 235
 236         if (ret == 0) {
 237                 base = drm_hash_entry(hash, struct ttm_base_object, hash);
 238                 refcount_acquire(&base->refcount);
 239         }
 240         rw_runlock(&tdev->object_lock);
 241
 242         if (unlikely(ret != 0))
 243                 return NULL;
 244
 245         if (tfile != base->tfile && !base->shareable) {
 246                 printf("[TTM] Attempted access of non-shareable object %p\n",
 247                     base);
 248                 ttm_base_object_unref(&base);
 249                 return NULL;
 250         }
 251
 252         return base;
 253 }
 254
 255 MALLOC_DEFINE(M_TTM_OBJ_REF, "ttm_obj_ref", "TTM Ref Objects");
 256
 257 int ttm_ref_object_add(struct ttm_object_file *tfile,
 258                        struct ttm_base_object *base,
 259                        enum ttm_ref_type ref_type, bool *existed)
 260 {
 261         struct drm_open_hash *ht = &tfile->ref_hash[ref_type];
 262         struct ttm_ref_object *ref;
 263         struct drm_hash_item *hash;
 264         struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob;
 265         int ret = -EINVAL;
 266
 267         if (existed != NULL)
 268                 *existed = true;
 269
 270         while (ret == -EINVAL) {
 271                 rw_rlock(&tfile->lock);
 272                 ret = drm_ht_find_item(ht, base->hash.key, &hash);
 273
 274                 if (ret == 0) {
 275                         ref = drm_hash_entry(hash, struct ttm_ref_object, hash);
 276                         refcount_acquire(&ref->kref);
 277                         rw_runlock(&tfile->lock);
 278                         break;
 279                 }
 280
 281                 rw_runlock(&tfile->lock);
 282                 ret = ttm_mem_global_alloc(mem_glob, sizeof(*ref),
 283                                            false, false);
 284                 if (unlikely(ret != 0))
 285                         return ret;
 286                 ref = malloc(sizeof(*ref), M_TTM_OBJ_REF, M_WAITOK);
 287                 if (unlikely(ref == NULL)) {
 288                         ttm_mem_global_free(mem_glob, sizeof(*ref));
 289                         return -ENOMEM;
 290                 }
 291
 292                 ref->hash.key = base->hash.key;
 293                 ref->obj = base;
 294                 ref->tfile = tfile;
 295                 ref->ref_type = ref_type;
 296                 refcount_init(&ref->kref, 1);
 297
 298                 rw_wlock(&tfile->lock);
 299                 ret = drm_ht_insert_item(ht, &ref->hash);
 300
 301                 if (ret == 0) {
 302                         list_add_tail(&ref->head, &tfile->ref_list);
 303                         refcount_acquire(&base->refcount);
 304                         rw_wunlock(&tfile->lock);
 305                         if (existed != NULL)
 306                                 *existed = false;
 307                         break;
 308                 }
 309
 310                 rw_wunlock(&tfile->lock);
 311                 MPASS(ret == -EINVAL);
 312
 313                 ttm_mem_global_free(mem_glob, sizeof(*ref));
 314                 free(ref, M_TTM_OBJ_REF);
 315         }
 316
 317         return ret;
 318 }
 319
 320 static void ttm_ref_object_release(struct ttm_ref_object *ref)
 321 {
 322         struct ttm_base_object *base = ref->obj;
 323         struct ttm_object_file *tfile = ref->tfile;
 324         struct drm_open_hash *ht;
 325         struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob;
 326
 327         ht = &tfile->ref_hash[ref->ref_type];
 328         (void)drm_ht_remove_item(ht, &ref->hash);
 329         list_del(&ref->head);
 330         rw_wunlock(&tfile->lock);
 331
 332         if (ref->ref_type != TTM_REF_USAGE && base->ref_obj_release)
 333                 base->ref_obj_release(base, ref->ref_type);
 334
 335         ttm_base_object_unref(&ref->obj);
 336         ttm_mem_global_free(mem_glob, sizeof(*ref));
 337         free(ref, M_TTM_OBJ_REF);
 338         rw_wlock(&tfile->lock);
 339 }
 340
 341 int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
 342                               unsigned long key, enum ttm_ref_type ref_type)
 343 {
 344         struct drm_open_hash *ht = &tfile->ref_hash[ref_type];
 345         struct ttm_ref_object *ref;
 346         struct drm_hash_item *hash;
 347         int ret;
 348
 349         rw_wlock(&tfile->lock);
 350         ret = drm_ht_find_item(ht, key, &hash);
 351         if (unlikely(ret != 0)) {
 352                 rw_wunlock(&tfile->lock);
 353                 return -EINVAL;
 354         }
 355         ref = drm_hash_entry(hash, struct ttm_ref_object, hash);
 356         if (refcount_release(&ref->kref))
 357                 ttm_ref_object_release(ref);
 358         rw_wunlock(&tfile->lock);
 359         return 0;
 360 }
 361
 362 void ttm_object_file_release(struct ttm_object_file **p_tfile)
 363 {
 364         struct ttm_ref_object *ref;
 365         struct list_head *list;
 366         unsigned int i;
 367         struct ttm_object_file *tfile = *p_tfile;
 368
 369         *p_tfile = NULL;
 370         rw_wlock(&tfile->lock);
 371
 372         /*
 373          * Since we release the lock within the loop, we have to
 374          * restart it from the beginning each time.
 375          */
 376
 377         while (!list_empty(&tfile->ref_list)) {
 378                 list = tfile->ref_list.next;
 379                 ref = list_entry(list, struct ttm_ref_object, head);
 380                 ttm_ref_object_release(ref);
 381         }
 382
 383         for (i = 0; i < TTM_REF_NUM; ++i)
 384                 drm_ht_remove(&tfile->ref_hash[i]);
 385
 386         rw_wunlock(&tfile->lock);
 387         ttm_object_file_unref(&tfile);
 388 }
 389
 390 struct ttm_object_file *ttm_object_file_init(struct ttm_object_device *tdev,
 391                                              unsigned int hash_order)
 392 {
 393         struct ttm_object_file *tfile;
 394         unsigned int i;
 395         unsigned int j = 0;
 396         int ret;
 397
 398         tfile = malloc(sizeof(*tfile), M_TTM_OBJ_FILE, M_WAITOK);
 399         rw_init(&tfile->lock, "ttmfo");
 400         tfile->tdev = tdev;
 401         refcount_init(&tfile->refcount, 1);
 402         INIT_LIST_HEAD(&tfile->ref_list);
 403
 404         for (i = 0; i < TTM_REF_NUM; ++i) {
 405                 ret = drm_ht_create(&tfile->ref_hash[i], hash_order);
 406                 if (ret) {
 407                         j = i;
 408                         goto out_err;
 409                 }
 410         }
 411
 412         return tfile;
 413 out_err:
 414         for (i = 0; i < j; ++i)
 415                 drm_ht_remove(&tfile->ref_hash[i]);
 416
 417         free(tfile, M_TTM_OBJ_FILE);
 418
 419         return NULL;
 420 }
 421
 422 MALLOC_DEFINE(M_TTM_OBJ_DEV, "ttm_obj_dev", "TTM Device Objects");
 423
 424 struct ttm_object_device *ttm_object_device_init(struct ttm_mem_global
 425                                                  *mem_glob,
 426                                                  unsigned int hash_order)
 427 {
 428         struct ttm_object_device *tdev;
 429         int ret;
 430
 431         tdev = malloc(sizeof(*tdev), M_TTM_OBJ_DEV, M_WAITOK);
 432         tdev->mem_glob = mem_glob;
 433         rw_init(&tdev->object_lock, "ttmdo");
 434         atomic_set(&tdev->object_count, 0);
 435         ret = drm_ht_create(&tdev->object_hash, hash_order);
 436
 437         if (ret == 0)
 438                 return tdev;
 439
 440         free(tdev, M_TTM_OBJ_DEV);
 441         return NULL;
 442 }
 443
 444 void ttm_object_device_release(struct ttm_object_device **p_tdev)
 445 {
 446         struct ttm_object_device *tdev = *p_tdev;
 447
 448         *p_tdev = NULL;
 449
 450         rw_wlock(&tdev->object_lock);
 451         drm_ht_remove(&tdev->object_hash);
 452         rw_wunlock(&tdev->object_lock);
 453
 454         free(tdev, M_TTM_OBJ_DEV);
 455 }