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 }
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