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