1 /**************************************************************************
3 * Copyright (c) 2009 VMware, Inc., Palo Alto, CA., USA
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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
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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.
26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30 /** @file ttm_ref_object.c
32 * Base- and reference object implementation for the various
33 * ttm objects. Implements reference counting, minimal security checks
34 * and release on file close.
38 * struct ttm_object_file
40 * @tdev: Pointer to the ttm_object_device.
42 * @lock: Lock that protects the ref_list list and the
43 * ref_hash hash tables.
45 * @ref_list: List of ttm_ref_objects to be destroyed at
48 * @ref_hash: Hash tables of ref objects, one per ttm_ref_type,
49 * for fast lookup of ref objects given a base object.
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>
60 struct ttm_object_file {
61 struct ttm_object_device *tdev;
63 struct list_head ref_list;
64 struct drm_open_hash ref_hash[TTM_REF_NUM];
69 * struct ttm_object_device
71 * @object_lock: lock that protects the object_hash hash table.
73 * @object_hash: hash table for fast lookup of object global names.
75 * @object_count: Per device object count.
77 * This is the per-device data structure needed for ttm object management.
80 struct ttm_object_device {
82 struct drm_open_hash object_hash;
83 atomic_t object_count;
84 struct ttm_mem_global *mem_glob;
88 * struct ttm_ref_object
90 * @hash: Hash entry for the per-file object reference hash.
92 * @head: List entry for the per-file list of ref-objects.
96 * @obj: Base object this ref object is referencing.
98 * @ref_type: Type of ref object.
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.
108 struct ttm_ref_object {
109 struct drm_hash_item hash;
110 struct list_head head;
112 enum ttm_ref_type ref_type;
113 struct ttm_base_object *obj;
114 struct ttm_object_file *tfile;
117 static inline struct ttm_object_file *
118 ttm_object_file_ref(struct ttm_object_file *tfile)
120 kref_get(&tfile->refcount);
124 static void ttm_object_file_destroy(struct kref *kref)
126 struct ttm_object_file *tfile =
127 container_of(kref, struct ttm_object_file, refcount);
133 static inline void ttm_object_file_unref(struct ttm_object_file **p_tfile)
135 struct ttm_object_file *tfile = *p_tfile;
138 kref_put(&tfile->refcount, ttm_object_file_destroy);
142 int ttm_base_object_init(struct ttm_object_file *tfile,
143 struct ttm_base_object *base,
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))
150 struct ttm_object_device *tdev = tfile->tdev;
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,
162 (unsigned long)base, 31, 0, 0);
163 write_unlock(&tdev->object_lock);
164 if (unlikely(ret != 0))
167 ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL);
168 if (unlikely(ret != 0))
171 ttm_base_object_unref(&base);
175 (void)drm_ht_remove_item(&tdev->object_hash, &base->hash);
179 EXPORT_SYMBOL(ttm_base_object_init);
181 static void ttm_release_base(struct kref *kref)
183 struct ttm_base_object *base =
184 container_of(kref, struct ttm_base_object, refcount);
185 struct ttm_object_device *tdev = base->tfile->tdev;
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);
193 write_lock(&tdev->object_lock);
196 void ttm_base_object_unref(struct ttm_base_object **p_base)
198 struct ttm_base_object *base = *p_base;
199 struct ttm_object_device *tdev = base->tfile->tdev;
204 * Need to take the lock here to avoid racing with
205 * users trying to look up the object.
208 write_lock(&tdev->object_lock);
209 (void)kref_put(&base->refcount, &ttm_release_base);
210 write_unlock(&tdev->object_lock);
212 EXPORT_SYMBOL(ttm_base_object_unref);
214 struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file *tfile,
217 struct ttm_object_device *tdev = tfile->tdev;
218 struct ttm_base_object *base;
219 struct drm_hash_item *hash;
222 read_lock(&tdev->object_lock);
223 ret = drm_ht_find_item(&tdev->object_hash, key, &hash);
225 if (likely(ret == 0)) {
226 base = drm_hash_entry(hash, struct ttm_base_object, hash);
227 kref_get(&base->refcount);
229 read_unlock(&tdev->object_lock);
231 if (unlikely(ret != 0))
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);
243 EXPORT_SYMBOL(ttm_base_object_lookup);
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)
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;
258 while (ret == -EINVAL) {
259 read_lock(&tfile->lock);
260 ret = drm_ht_find_item(ht, base->hash.key, &hash);
263 ref = drm_hash_entry(hash, struct ttm_ref_object, hash);
264 kref_get(&ref->kref);
265 read_unlock(&tfile->lock);
269 read_unlock(&tfile->lock);
270 ret = ttm_mem_global_alloc(mem_glob, sizeof(*ref),
272 if (unlikely(ret != 0))
274 ref = kmalloc(sizeof(*ref), GFP_KERNEL);
275 if (unlikely(ref == NULL)) {
276 ttm_mem_global_free(mem_glob, sizeof(*ref));
280 ref->hash.key = base->hash.key;
283 ref->ref_type = ref_type;
284 kref_init(&ref->kref);
286 write_lock(&tfile->lock);
287 ret = drm_ht_insert_item(ht, &ref->hash);
289 if (likely(ret == 0)) {
290 list_add_tail(&ref->head, &tfile->ref_list);
291 kref_get(&base->refcount);
292 write_unlock(&tfile->lock);
298 write_unlock(&tfile->lock);
299 BUG_ON(ret != -EINVAL);
301 ttm_mem_global_free(mem_glob, sizeof(*ref));
307 EXPORT_SYMBOL(ttm_ref_object_add);
309 static void ttm_ref_object_release(struct kref *kref)
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;
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);
323 if (ref->ref_type != TTM_REF_USAGE && base->ref_obj_release)
324 base->ref_obj_release(base, ref->ref_type);
326 ttm_base_object_unref(&ref->obj);
327 ttm_mem_global_free(mem_glob, sizeof(*ref));
329 write_lock(&tfile->lock);
332 int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
333 unsigned long key, enum ttm_ref_type ref_type)
335 struct drm_open_hash *ht = &tfile->ref_hash[ref_type];
336 struct ttm_ref_object *ref;
337 struct drm_hash_item *hash;
340 write_lock(&tfile->lock);
341 ret = drm_ht_find_item(ht, key, &hash);
342 if (unlikely(ret != 0)) {
343 write_unlock(&tfile->lock);
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);
351 EXPORT_SYMBOL(ttm_ref_object_base_unref);
353 void ttm_object_file_release(struct ttm_object_file **p_tfile)
355 struct ttm_ref_object *ref;
356 struct list_head *list;
358 struct ttm_object_file *tfile = *p_tfile;
361 write_lock(&tfile->lock);
364 * Since we release the lock within the loop, we have to
365 * restart it from the beginning each time.
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);
374 for (i = 0; i < TTM_REF_NUM; ++i)
375 drm_ht_remove(&tfile->ref_hash[i]);
377 write_unlock(&tfile->lock);
378 ttm_object_file_unref(&tfile);
380 EXPORT_SYMBOL(ttm_object_file_release);
382 struct ttm_object_file *ttm_object_file_init(struct ttm_object_device *tdev,
383 unsigned int hash_order)
385 struct ttm_object_file *tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
390 if (unlikely(tfile == NULL))
393 rwlock_init(&tfile->lock);
395 kref_init(&tfile->refcount);
396 INIT_LIST_HEAD(&tfile->ref_list);
398 for (i = 0; i < TTM_REF_NUM; ++i) {
399 ret = drm_ht_create(&tfile->ref_hash[i], hash_order);
408 for (i = 0; i < j; ++i)
409 drm_ht_remove(&tfile->ref_hash[i]);
415 EXPORT_SYMBOL(ttm_object_file_init);
417 struct ttm_object_device *ttm_object_device_init(struct ttm_mem_global
419 unsigned int hash_order)
421 struct ttm_object_device *tdev = kmalloc(sizeof(*tdev), GFP_KERNEL);
424 if (unlikely(tdev == NULL))
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);
432 if (likely(ret == 0))
438 EXPORT_SYMBOL(ttm_object_device_init);
440 void ttm_object_device_release(struct ttm_object_device **p_tdev)
442 struct ttm_object_device *tdev = *p_tdev;
446 write_lock(&tdev->object_lock);
447 drm_ht_remove(&tdev->object_hash);
448 write_unlock(&tdev->object_lock);
452 EXPORT_SYMBOL(ttm_object_device_release);