aboutsummaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/ttm/ttm_object.c
blob: 75e9d6f86ba45429f75f61067805b8abbde7b626 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
/**************************************************************************
 *
 * Copyright (c) 2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/
/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */
/** @file ttm_ref_object.c
 *
 * Base- and reference object implementation for the various
 * ttm objects. Implements reference counting, minimal security checks
 * and release on file close.
 */

/**
 * struct ttm_object_file
 *
 * @tdev: Pointer to the ttm_object_device.
 *
 * @lock: Lock that protects the ref_list list and the
 * ref_hash hash tables.
 *
 * @ref_list: List of ttm_ref_objects to be destroyed at
 * file release.
 *
 * @ref_hash: Hash tables of ref objects, one per ttm_ref_type,
 * for fast lookup of ref objects given a base object.
 */

#include "ttm/ttm_object.h"
#include "ttm/ttm_module.h"
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <asm/atomic.h>

struct ttm_object_file {
	struct ttm_object_device *tdev;
	rwlock_t lock;
	struct list_head ref_list;
	struct drm_open_hash ref_hash[TTM_REF_NUM];
	struct kref refcount;
};

/**
 * struct ttm_object_device
 *
 * @object_lock: lock that protects the object_hash hash table.
 *
 * @object_hash: hash table for fast lookup of object global names.
 *
 * @object_count: Per device object count.
 *
 * This is the per-device data structure needed for ttm object management.
 */

struct ttm_object_device {
	rwlock_t object_lock;
	struct drm_open_hash object_hash;
	atomic_t object_count;
	struct ttm_mem_global *mem_glob;
};

/**
 * struct ttm_ref_object
 *
 * @hash: Hash entry for the per-file object reference hash.
 *
 * @head: List entry for the per-file list of ref-objects.
 *
 * @kref: Ref count.
 *
 * @obj: Base object this ref object is referencing.
 *
 * @ref_type: Type of ref object.
 *
 * This is similar to an idr object, but it also has a hash table entry
 * that allows lookup with a pointer to the referenced object as a key. In
 * that way, one can easily detect whether a base object is referenced by
 * a particular ttm_object_file. It also carries a ref count to avoid creating
 * multiple ref objects if a ttm_object_file references the same base
 * object more than once.
 */

struct ttm_ref_object {
	struct drm_hash_item hash;
	struct list_head head;
	struct kref kref;
	enum ttm_ref_type ref_type;
	struct ttm_base_object *obj;
	struct ttm_object_file *tfile;
};

static inline struct ttm_object_file *
ttm_object_file_ref(struct ttm_object_file *tfile)
{
	kref_get(&tfile->refcount);
	return tfile;
}

static void ttm_object_file_destroy(struct kref *kref)
{
	struct ttm_object_file *tfile =
		container_of(kref, struct ttm_object_file, refcount);

	kfree(tfile);
}


static inline void ttm_object_file_unref(struct ttm_object_file **p_tfile)
{
	struct ttm_object_file *tfile = *p_tfile;

	*p_tfile = NULL;
	kref_put(&tfile->refcount, ttm_object_file_destroy);
}


int ttm_base_object_init(struct ttm_object_file *tfile,
			 struct ttm_base_object *base,
			 bool shareable,
			 enum ttm_object_type object_type,
			 void (*refcount_release) (struct ttm_base_object **),
			 void (*ref_obj_release) (struct ttm_base_object *,
						  enum ttm_ref_type ref_type))
{
	struct ttm_object_device *tdev = tfile->tdev;
	int ret;

	base->shareable = shareable;
	base->tfile = ttm_object_file_ref(tfile);
	base->refcount_release = refcount_release;
	base->ref_obj_release = ref_obj_release;
	base->object_type = object_type;
	write_lock(&tdev->object_lock);
	kref_init(&base->refcount);
	ret = drm_ht_just_insert_please(&tdev->object_hash,
					&base->hash,
					(unsigned long)base, 31, 0, 0);
	write_unlock(&tdev->object_lock);
	if (unlikely(ret != 0))
		goto out_err0;

	ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL);
	if (unlikely(ret != 0))
		goto out_err1;

	ttm_base_object_unref(&base);

	return 0;
out_err1:
	(void)drm_ht_remove_item(&tdev->object_hash, &base->hash);
out_err0:
	return ret;
}
EXPORT_SYMBOL(ttm_base_object_init);

static void ttm_release_base(struct kref *kref)
{
	struct ttm_base_object *base =
	    container_of(kref, struct ttm_base_object, refcount);
	struct ttm_object_device *tdev = base->tfile->tdev;

	(void)drm_ht_remove_item(&tdev->object_hash, &base->hash);
	write_unlock(&tdev->object_lock);
	if (base->refcount_release) {
		ttm_object_file_unref(&base->tfile);
		base->refcount_release(&base);
	}
	write_lock(&tdev->object_lock);
}

void ttm_base_object_unref(struct ttm_base_object **p_base)
{
	struct ttm_base_object *base = *p_base;
	struct ttm_object_device *tdev = base->tfile->tdev;

	*p_base = NULL;

	/*
	 * Need to take the lock here to avoid racing with
	 * users trying to look up the object.
	 */

	write_lock(&tdev->object_lock);
	(void)kref_put(&base->refcount, &ttm_release_base);
	write_unlock(&tdev->object_lock);
}
EXPORT_SYMBOL(ttm_base_object_unref);

struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file *tfile,
					       uint32_t key)
{
	struct ttm_object_device *tdev = tfile->tdev;
	struct ttm_base_object *base;
	struct drm_hash_item *hash;
	int ret;

	read_lock(&tdev->object_lock);
	ret = drm_ht_find_item(&tdev->object_hash, key, &hash);

	if (likely(ret == 0)) {
		base = drm_hash_entry(hash, struct ttm_base_object, hash);
		kref_get(&base->refcount);
	}
	read_unlock(&tdev->object_lock);

	if (unlikely(ret != 0))
		return NULL;

	if (tfile != base->tfile && !base->shareable) {
		printk(KERN_ERR TTM_PFX
		       "Attempted access of non-shareable object.\n");
		ttm_base_object_unref(&base);
		return NULL;
	}

	return base;
}
EXPORT_SYMBOL(ttm_base_object_lookup);

int ttm_ref_object_add(struct ttm_object_file *tfile,
		       struct ttm_base_object *base,
		       enum ttm_ref_type ref_type, bool *existed)
{
	struct drm_open_hash *ht = &tfile->ref_hash[ref_type];
	struct ttm_ref_object *ref;
	struct drm_hash_item *hash;
	struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob;
	int ret = -EINVAL;

	if (existed != NULL)
		*existed = true;

	while (ret == -EINVAL) {
		read_lock(&tfile->lock);
		ret = drm_ht_find_item(ht, base->hash.key, &hash);

		if (ret == 0) {
			ref = drm_hash_entry(hash, struct ttm_ref_object, hash);
			kref_get(&ref->kref);
			read_unlock(&tfile->lock);
			break;
		}

		read_unlock(&tfile->lock);
		ret = ttm_mem_global_alloc(mem_glob, sizeof(*ref),
					   false, false);
		if (unlikely(ret != 0))
			return ret;
		ref = kmalloc(sizeof(*ref), GFP_KERNEL);
		if (unlikely(ref == NULL)) {
			ttm_mem_global_free(mem_glob, sizeof(*ref));
			return -ENOMEM;
		}

		ref->hash.key = base->hash.key;
		ref->obj = base;
		ref->tfile = tfile;
		ref->ref_type = ref_type;
		kref_init(&ref->kref);

		write_lock(&tfile->lock);
		ret = drm_ht_insert_item(ht, &ref->hash);

		if (likely(ret == 0)) {
			list_add_tail(&ref->head, &tfile->ref_list);
			kref_get(&base->refcount);
			write_unlock(&tfile->lock);
			if (existed != NULL)
				*existed = false;
			break;
		}

		write_unlock(&tfile->lock);
		BUG_ON(ret != -EINVAL);

		ttm_mem_global_free(mem_glob, sizeof(*ref));
		kfree(ref);
	}

	return ret;
}
EXPORT_SYMBOL(ttm_ref_object_add);

static void ttm_ref_object_release(struct kref *kref)
{
	struct ttm_ref_object *ref =
	    container_of(kref, struct ttm_ref_object, kref);
	struct ttm_base_object *base = ref->obj;
	struct ttm_object_file *tfile = ref->tfile;
	struct drm_open_hash *ht;
	struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob;

	ht = &tfile->ref_hash[ref->ref_type];
	(void)drm_ht_remove_item(ht, &ref->hash);
	list_del(&ref->head);
	write_unlock(&tfile->lock);

	if (ref->ref_type != TTM_REF_USAGE && base->ref_obj_release)
		base->ref_obj_release(base, ref->ref_type);

	ttm_base_object_unref(&ref->obj);
	ttm_mem_global_free(mem_glob, sizeof(*ref));
	kfree(ref);
	write_lock(&tfile->lock);
}

int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
			      unsigned long key, enum ttm_ref_type ref_type)
{
	struct drm_open_hash *ht = &tfile->ref_hash[ref_type];
	struct ttm_ref_object *ref;
	struct drm_hash_item *hash;
	int ret;

	write_lock(&tfile->lock);
	ret = drm_ht_find_item(ht, key, &hash);
	if (unlikely(ret != 0)) {
		write_unlock(&tfile->lock);
		return -EINVAL;
	}
	ref = drm_hash_entry(hash, struct ttm_ref_object, hash);
	kref_put(&ref->kref, ttm_ref_object_release);
	write_unlock(&tfile->lock);
	return 0;
}
EXPORT_SYMBOL(ttm_ref_object_base_unref);

void ttm_object_file_release(struct ttm_object_file **p_tfile)
{
	struct ttm_ref_object *ref;
	struct list_head *list;
	unsigned int i;
	struct ttm_object_file *tfile = *p_tfile;

	*p_tfile = NULL;
	write_lock(&tfile->lock);

	/*
	 * Since we release the lock within the loop, we have to
	 * restart it from the beginning each time.
	 */

	while (!list_empty(&tfile->ref_list)) {
		list = tfile->ref_list.next;
		ref = list_entry(list, struct ttm_ref_object, head);
		ttm_ref_object_release(&ref->kref);
	}

	for (i = 0; i < TTM_REF_NUM; ++i)
		drm_ht_remove(&tfile->ref_hash[i]);

	write_unlock(&tfile->lock);
	ttm_object_file_unref(&tfile);
}
EXPORT_SYMBOL(ttm_object_file_release);

struct ttm_object_file *ttm_object_file_init(struct ttm_object_device *tdev,
					     unsigned int hash_order)
{
	struct ttm_object_file *tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
	unsigned int i;
	unsigned int j = 0;
	int ret;

	if (unlikely(tfile == NULL))
		return NULL;

	rwlock_init(&tfile->lock);
	tfile->tdev = tdev;
	kref_init(&tfile->refcount);
	INIT_LIST_HEAD(&tfile->ref_list);

	for (i = 0; i < TTM_REF_NUM; ++i) {
		ret = drm_ht_create(&tfile->ref_hash[i], hash_order);
		if (ret) {
			j = i;
			goto out_err;
		}
	}

	return tfile;
out_err:
	for (i = 0; i < j; ++i)
		drm_ht_remove(&tfile->ref_hash[i]);

	kfree(tfile);

	return NULL;
}
EXPORT_SYMBOL(ttm_object_file_init);

struct ttm_object_device *ttm_object_device_init(struct ttm_mem_global
						 *mem_glob,
						 unsigned int hash_order)
{
	struct ttm_object_device *tdev = kmalloc(sizeof(*tdev), GFP_KERNEL);
	int ret;

	if (unlikely(tdev == NULL))
		return NULL;

	tdev->mem_glob = mem_glob;
	rwlock_init(&tdev->object_lock);
	atomic_set(&tdev->object_count, 0);
	ret = drm_ht_create(&tdev->object_hash, hash_order);

	if (likely(ret == 0))
		return tdev;

	kfree(tdev);
	return NULL;
}
EXPORT_SYMBOL(ttm_object_device_init);

void ttm_object_device_release(struct ttm_object_device **p_tdev)
{
	struct ttm_object_device *tdev = *p_tdev;

	*p_tdev = NULL;

	write_lock(&tdev->object_lock);
	drm_ht_remove(&tdev->object_hash);
	write_unlock(&tdev->object_lock);

	kfree(tdev);
}
EXPORT_SYMBOL(ttm_object_device_release);