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88071539 TH |
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 | * struct ttm_object_file | |
39 | * | |
40 | * @tdev: Pointer to the ttm_object_device. | |
41 | * | |
42 | * @lock: Lock that protects the ref_list list and the | |
43 | * ref_hash hash tables. | |
44 | * | |
45 | * @ref_list: List of ttm_ref_objects to be destroyed at | |
46 | * file release. | |
47 | * | |
48 | * @ref_hash: Hash tables of ref objects, one per ttm_ref_type, | |
49 | * for fast lookup of ref objects given a base object. | |
50 | */ | |
51 | ||
25d0479a JP |
52 | #define pr_fmt(fmt) "[TTM] " fmt |
53 | ||
760285e7 DH |
54 | #include <drm/ttm/ttm_object.h> |
55 | #include <drm/ttm/ttm_module.h> | |
88071539 TH |
56 | #include <linux/list.h> |
57 | #include <linux/spinlock.h> | |
58 | #include <linux/slab.h> | |
59 | #include <linux/module.h> | |
60063497 | 60 | #include <linux/atomic.h> |
88071539 TH |
61 | |
62 | struct ttm_object_file { | |
63 | struct ttm_object_device *tdev; | |
64 | rwlock_t lock; | |
65 | struct list_head ref_list; | |
66 | struct drm_open_hash ref_hash[TTM_REF_NUM]; | |
67 | struct kref refcount; | |
68 | }; | |
69 | ||
70 | /** | |
71 | * struct ttm_object_device | |
72 | * | |
73 | * @object_lock: lock that protects the object_hash hash table. | |
74 | * | |
75 | * @object_hash: hash table for fast lookup of object global names. | |
76 | * | |
77 | * @object_count: Per device object count. | |
78 | * | |
79 | * This is the per-device data structure needed for ttm object management. | |
80 | */ | |
81 | ||
82 | struct ttm_object_device { | |
83 | rwlock_t object_lock; | |
84 | struct drm_open_hash object_hash; | |
85 | atomic_t object_count; | |
86 | struct ttm_mem_global *mem_glob; | |
87 | }; | |
88 | ||
89 | /** | |
90 | * struct ttm_ref_object | |
91 | * | |
92 | * @hash: Hash entry for the per-file object reference hash. | |
93 | * | |
94 | * @head: List entry for the per-file list of ref-objects. | |
95 | * | |
96 | * @kref: Ref count. | |
97 | * | |
98 | * @obj: Base object this ref object is referencing. | |
99 | * | |
100 | * @ref_type: Type of ref object. | |
101 | * | |
102 | * This is similar to an idr object, but it also has a hash table entry | |
103 | * that allows lookup with a pointer to the referenced object as a key. In | |
104 | * that way, one can easily detect whether a base object is referenced by | |
105 | * a particular ttm_object_file. It also carries a ref count to avoid creating | |
106 | * multiple ref objects if a ttm_object_file references the same base | |
107 | * object more than once. | |
108 | */ | |
109 | ||
110 | struct ttm_ref_object { | |
111 | struct drm_hash_item hash; | |
112 | struct list_head head; | |
113 | struct kref kref; | |
88071539 | 114 | enum ttm_ref_type ref_type; |
dd5fde60 | 115 | struct ttm_base_object *obj; |
88071539 TH |
116 | struct ttm_object_file *tfile; |
117 | }; | |
118 | ||
119 | static inline struct ttm_object_file * | |
120 | ttm_object_file_ref(struct ttm_object_file *tfile) | |
121 | { | |
122 | kref_get(&tfile->refcount); | |
123 | return tfile; | |
124 | } | |
125 | ||
126 | static void ttm_object_file_destroy(struct kref *kref) | |
127 | { | |
128 | struct ttm_object_file *tfile = | |
129 | container_of(kref, struct ttm_object_file, refcount); | |
130 | ||
131 | kfree(tfile); | |
132 | } | |
133 | ||
134 | ||
135 | static inline void ttm_object_file_unref(struct ttm_object_file **p_tfile) | |
136 | { | |
137 | struct ttm_object_file *tfile = *p_tfile; | |
138 | ||
139 | *p_tfile = NULL; | |
140 | kref_put(&tfile->refcount, ttm_object_file_destroy); | |
141 | } | |
142 | ||
143 | ||
144 | int ttm_base_object_init(struct ttm_object_file *tfile, | |
145 | struct ttm_base_object *base, | |
146 | bool shareable, | |
147 | enum ttm_object_type object_type, | |
148 | void (*refcount_release) (struct ttm_base_object **), | |
149 | void (*ref_obj_release) (struct ttm_base_object *, | |
150 | enum ttm_ref_type ref_type)) | |
151 | { | |
152 | struct ttm_object_device *tdev = tfile->tdev; | |
153 | int ret; | |
154 | ||
155 | base->shareable = shareable; | |
156 | base->tfile = ttm_object_file_ref(tfile); | |
157 | base->refcount_release = refcount_release; | |
158 | base->ref_obj_release = ref_obj_release; | |
159 | base->object_type = object_type; | |
160 | write_lock(&tdev->object_lock); | |
161 | kref_init(&base->refcount); | |
162 | ret = drm_ht_just_insert_please(&tdev->object_hash, | |
163 | &base->hash, | |
164 | (unsigned long)base, 31, 0, 0); | |
165 | write_unlock(&tdev->object_lock); | |
166 | if (unlikely(ret != 0)) | |
167 | goto out_err0; | |
168 | ||
169 | ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL); | |
170 | if (unlikely(ret != 0)) | |
171 | goto out_err1; | |
172 | ||
173 | ttm_base_object_unref(&base); | |
174 | ||
175 | return 0; | |
176 | out_err1: | |
177 | (void)drm_ht_remove_item(&tdev->object_hash, &base->hash); | |
178 | out_err0: | |
179 | return ret; | |
180 | } | |
181 | EXPORT_SYMBOL(ttm_base_object_init); | |
182 | ||
183 | static void ttm_release_base(struct kref *kref) | |
184 | { | |
185 | struct ttm_base_object *base = | |
186 | container_of(kref, struct ttm_base_object, refcount); | |
187 | struct ttm_object_device *tdev = base->tfile->tdev; | |
188 | ||
189 | (void)drm_ht_remove_item(&tdev->object_hash, &base->hash); | |
190 | write_unlock(&tdev->object_lock); | |
191 | if (base->refcount_release) { | |
192 | ttm_object_file_unref(&base->tfile); | |
193 | base->refcount_release(&base); | |
194 | } | |
195 | write_lock(&tdev->object_lock); | |
196 | } | |
197 | ||
198 | void ttm_base_object_unref(struct ttm_base_object **p_base) | |
199 | { | |
200 | struct ttm_base_object *base = *p_base; | |
201 | struct ttm_object_device *tdev = base->tfile->tdev; | |
202 | ||
203 | *p_base = NULL; | |
204 | ||
205 | /* | |
206 | * Need to take the lock here to avoid racing with | |
207 | * users trying to look up the object. | |
208 | */ | |
209 | ||
210 | write_lock(&tdev->object_lock); | |
cdb650a4 | 211 | kref_put(&base->refcount, ttm_release_base); |
88071539 TH |
212 | write_unlock(&tdev->object_lock); |
213 | } | |
214 | EXPORT_SYMBOL(ttm_base_object_unref); | |
215 | ||
216 | struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file *tfile, | |
217 | uint32_t key) | |
218 | { | |
219 | struct ttm_object_device *tdev = tfile->tdev; | |
220 | struct ttm_base_object *base; | |
221 | struct drm_hash_item *hash; | |
222 | int ret; | |
223 | ||
224 | read_lock(&tdev->object_lock); | |
225 | ret = drm_ht_find_item(&tdev->object_hash, key, &hash); | |
226 | ||
227 | if (likely(ret == 0)) { | |
228 | base = drm_hash_entry(hash, struct ttm_base_object, hash); | |
229 | kref_get(&base->refcount); | |
230 | } | |
231 | read_unlock(&tdev->object_lock); | |
232 | ||
233 | if (unlikely(ret != 0)) | |
234 | return NULL; | |
235 | ||
236 | if (tfile != base->tfile && !base->shareable) { | |
25d0479a | 237 | pr_err("Attempted access of non-shareable object\n"); |
88071539 TH |
238 | ttm_base_object_unref(&base); |
239 | return NULL; | |
240 | } | |
241 | ||
242 | return base; | |
243 | } | |
244 | EXPORT_SYMBOL(ttm_base_object_lookup); | |
245 | ||
246 | int ttm_ref_object_add(struct ttm_object_file *tfile, | |
247 | struct ttm_base_object *base, | |
248 | enum ttm_ref_type ref_type, bool *existed) | |
249 | { | |
250 | struct drm_open_hash *ht = &tfile->ref_hash[ref_type]; | |
251 | struct ttm_ref_object *ref; | |
252 | struct drm_hash_item *hash; | |
253 | struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob; | |
254 | int ret = -EINVAL; | |
255 | ||
256 | if (existed != NULL) | |
257 | *existed = true; | |
258 | ||
259 | while (ret == -EINVAL) { | |
260 | read_lock(&tfile->lock); | |
261 | ret = drm_ht_find_item(ht, base->hash.key, &hash); | |
262 | ||
263 | if (ret == 0) { | |
264 | ref = drm_hash_entry(hash, struct ttm_ref_object, hash); | |
265 | kref_get(&ref->kref); | |
266 | read_unlock(&tfile->lock); | |
267 | break; | |
268 | } | |
269 | ||
270 | read_unlock(&tfile->lock); | |
271 | ret = ttm_mem_global_alloc(mem_glob, sizeof(*ref), | |
272 | false, false); | |
273 | if (unlikely(ret != 0)) | |
274 | return ret; | |
275 | ref = kmalloc(sizeof(*ref), GFP_KERNEL); | |
276 | if (unlikely(ref == NULL)) { | |
277 | ttm_mem_global_free(mem_glob, sizeof(*ref)); | |
278 | return -ENOMEM; | |
279 | } | |
280 | ||
281 | ref->hash.key = base->hash.key; | |
282 | ref->obj = base; | |
283 | ref->tfile = tfile; | |
284 | ref->ref_type = ref_type; | |
285 | kref_init(&ref->kref); | |
286 | ||
287 | write_lock(&tfile->lock); | |
288 | ret = drm_ht_insert_item(ht, &ref->hash); | |
289 | ||
290 | if (likely(ret == 0)) { | |
291 | list_add_tail(&ref->head, &tfile->ref_list); | |
292 | kref_get(&base->refcount); | |
293 | write_unlock(&tfile->lock); | |
294 | if (existed != NULL) | |
295 | *existed = false; | |
296 | break; | |
297 | } | |
298 | ||
299 | write_unlock(&tfile->lock); | |
300 | BUG_ON(ret != -EINVAL); | |
301 | ||
302 | ttm_mem_global_free(mem_glob, sizeof(*ref)); | |
303 | kfree(ref); | |
304 | } | |
305 | ||
306 | return ret; | |
307 | } | |
308 | EXPORT_SYMBOL(ttm_ref_object_add); | |
309 | ||
310 | static void ttm_ref_object_release(struct kref *kref) | |
311 | { | |
312 | struct ttm_ref_object *ref = | |
313 | container_of(kref, struct ttm_ref_object, kref); | |
314 | struct ttm_base_object *base = ref->obj; | |
315 | struct ttm_object_file *tfile = ref->tfile; | |
316 | struct drm_open_hash *ht; | |
317 | struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob; | |
318 | ||
319 | ht = &tfile->ref_hash[ref->ref_type]; | |
320 | (void)drm_ht_remove_item(ht, &ref->hash); | |
321 | list_del(&ref->head); | |
322 | write_unlock(&tfile->lock); | |
323 | ||
324 | if (ref->ref_type != TTM_REF_USAGE && base->ref_obj_release) | |
325 | base->ref_obj_release(base, ref->ref_type); | |
326 | ||
327 | ttm_base_object_unref(&ref->obj); | |
328 | ttm_mem_global_free(mem_glob, sizeof(*ref)); | |
329 | kfree(ref); | |
330 | write_lock(&tfile->lock); | |
331 | } | |
332 | ||
333 | int ttm_ref_object_base_unref(struct ttm_object_file *tfile, | |
334 | unsigned long key, enum ttm_ref_type ref_type) | |
335 | { | |
336 | struct drm_open_hash *ht = &tfile->ref_hash[ref_type]; | |
337 | struct ttm_ref_object *ref; | |
338 | struct drm_hash_item *hash; | |
339 | int ret; | |
340 | ||
341 | write_lock(&tfile->lock); | |
342 | ret = drm_ht_find_item(ht, key, &hash); | |
343 | if (unlikely(ret != 0)) { | |
344 | write_unlock(&tfile->lock); | |
345 | return -EINVAL; | |
346 | } | |
347 | ref = drm_hash_entry(hash, struct ttm_ref_object, hash); | |
348 | kref_put(&ref->kref, ttm_ref_object_release); | |
349 | write_unlock(&tfile->lock); | |
350 | return 0; | |
351 | } | |
352 | EXPORT_SYMBOL(ttm_ref_object_base_unref); | |
353 | ||
354 | void ttm_object_file_release(struct ttm_object_file **p_tfile) | |
355 | { | |
356 | struct ttm_ref_object *ref; | |
357 | struct list_head *list; | |
358 | unsigned int i; | |
359 | struct ttm_object_file *tfile = *p_tfile; | |
360 | ||
361 | *p_tfile = NULL; | |
362 | write_lock(&tfile->lock); | |
363 | ||
364 | /* | |
365 | * Since we release the lock within the loop, we have to | |
366 | * restart it from the beginning each time. | |
367 | */ | |
368 | ||
369 | while (!list_empty(&tfile->ref_list)) { | |
370 | list = tfile->ref_list.next; | |
371 | ref = list_entry(list, struct ttm_ref_object, head); | |
372 | ttm_ref_object_release(&ref->kref); | |
373 | } | |
374 | ||
375 | for (i = 0; i < TTM_REF_NUM; ++i) | |
376 | drm_ht_remove(&tfile->ref_hash[i]); | |
377 | ||
378 | write_unlock(&tfile->lock); | |
379 | ttm_object_file_unref(&tfile); | |
380 | } | |
381 | EXPORT_SYMBOL(ttm_object_file_release); | |
382 | ||
383 | struct ttm_object_file *ttm_object_file_init(struct ttm_object_device *tdev, | |
384 | unsigned int hash_order) | |
385 | { | |
386 | struct ttm_object_file *tfile = kmalloc(sizeof(*tfile), GFP_KERNEL); | |
387 | unsigned int i; | |
388 | unsigned int j = 0; | |
389 | int ret; | |
390 | ||
391 | if (unlikely(tfile == NULL)) | |
392 | return NULL; | |
393 | ||
394 | rwlock_init(&tfile->lock); | |
395 | tfile->tdev = tdev; | |
396 | kref_init(&tfile->refcount); | |
397 | INIT_LIST_HEAD(&tfile->ref_list); | |
398 | ||
399 | for (i = 0; i < TTM_REF_NUM; ++i) { | |
400 | ret = drm_ht_create(&tfile->ref_hash[i], hash_order); | |
401 | if (ret) { | |
402 | j = i; | |
403 | goto out_err; | |
404 | } | |
405 | } | |
406 | ||
407 | return tfile; | |
408 | out_err: | |
409 | for (i = 0; i < j; ++i) | |
410 | drm_ht_remove(&tfile->ref_hash[i]); | |
411 | ||
412 | kfree(tfile); | |
413 | ||
414 | return NULL; | |
415 | } | |
416 | EXPORT_SYMBOL(ttm_object_file_init); | |
417 | ||
418 | struct ttm_object_device *ttm_object_device_init(struct ttm_mem_global | |
419 | *mem_glob, | |
420 | unsigned int hash_order) | |
421 | { | |
422 | struct ttm_object_device *tdev = kmalloc(sizeof(*tdev), GFP_KERNEL); | |
423 | int ret; | |
424 | ||
425 | if (unlikely(tdev == NULL)) | |
426 | return NULL; | |
427 | ||
428 | tdev->mem_glob = mem_glob; | |
429 | rwlock_init(&tdev->object_lock); | |
430 | atomic_set(&tdev->object_count, 0); | |
431 | ret = drm_ht_create(&tdev->object_hash, hash_order); | |
432 | ||
433 | if (likely(ret == 0)) | |
434 | return tdev; | |
435 | ||
436 | kfree(tdev); | |
437 | return NULL; | |
438 | } | |
439 | EXPORT_SYMBOL(ttm_object_device_init); | |
440 | ||
441 | void ttm_object_device_release(struct ttm_object_device **p_tdev) | |
442 | { | |
443 | struct ttm_object_device *tdev = *p_tdev; | |
444 | ||
445 | *p_tdev = NULL; | |
446 | ||
447 | write_lock(&tdev->object_lock); | |
448 | drm_ht_remove(&tdev->object_hash); | |
449 | write_unlock(&tdev->object_lock); | |
450 | ||
451 | kfree(tdev); | |
452 | } | |
453 | EXPORT_SYMBOL(ttm_object_device_release); |