etnaviv_bo_cache.c revision 7cdc0497 
1/*
2 * Copyright (C) 2016 Etnaviv Project
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 *
23 * Authors:
24 *    Christian Gmeiner <christian.gmeiner@gmail.com>
25 */
26
27#include "etnaviv_priv.h"
28#include "etnaviv_drmif.h"
29
30drm_private void bo_del(struct etna_bo *bo);
31drm_private extern pthread_mutex_t table_lock;
32
33static void add_bucket(struct etna_bo_cache *cache, int size)
34{
35	unsigned i = cache->num_buckets;
36
37	assert(i < ARRAY_SIZE(cache->cache_bucket));
38
39	list_inithead(&cache->cache_bucket[i].list);
40	cache->cache_bucket[i].size = size;
41	cache->num_buckets++;
42}
43
44drm_private void etna_bo_cache_init(struct etna_bo_cache *cache)
45{
46	unsigned long size, cache_max_size = 64 * 1024 * 1024;
47
48	/* OK, so power of two buckets was too wasteful of memory.
49	 * Give 3 other sizes between each power of two, to hopefully
50	 * cover things accurately enough.  (The alternative is
51	 * probably to just go for exact matching of sizes, and assume
52	 * that for things like composited window resize the tiled
53	 * width/height alignment and rounding of sizes to pages will
54	 * get us useful cache hit rates anyway)
55	 */
56	add_bucket(cache, 4096);
57	add_bucket(cache, 4096 * 2);
58	add_bucket(cache, 4096 * 3);
59
60	/* Initialize the linked lists for BO reuse cache. */
61	for (size = 4 * 4096; size <= cache_max_size; size *= 2) {
62		add_bucket(cache, size);
63		add_bucket(cache, size + size * 1 / 4);
64		add_bucket(cache, size + size * 2 / 4);
65		add_bucket(cache, size + size * 3 / 4);
66	}
67}
68
69/* Frees older cached buffers.  Called under table_lock */
70drm_private void etna_bo_cache_cleanup(struct etna_bo_cache *cache, time_t time)
71{
72	unsigned i;
73
74	if (cache->time == time)
75		return;
76
77	for (i = 0; i < cache->num_buckets; i++) {
78		struct etna_bo_bucket *bucket = &cache->cache_bucket[i];
79		struct etna_bo *bo;
80
81		while (!LIST_IS_EMPTY(&bucket->list)) {
82			bo = LIST_ENTRY(struct etna_bo, bucket->list.next, list);
83
84			/* keep things in cache for at least 1 second: */
85			if (time && ((time - bo->free_time) <= 1))
86				break;
87
88			list_del(&bo->list);
89			bo_del(bo);
90		}
91	}
92
93	cache->time = time;
94}
95
96static struct etna_bo_bucket *get_bucket(struct etna_bo_cache *cache, uint32_t size)
97{
98	unsigned i;
99
100	/* hmm, this is what intel does, but I suppose we could calculate our
101	 * way to the correct bucket size rather than looping..
102	 */
103	for (i = 0; i < cache->num_buckets; i++) {
104		struct etna_bo_bucket *bucket = &cache->cache_bucket[i];
105		if (bucket->size >= size) {
106			return bucket;
107		}
108	}
109
110	return NULL;
111}
112
113static int is_idle(struct etna_bo *bo)
114{
115	return etna_bo_cpu_prep(bo,
116			DRM_ETNA_PREP_READ |
117			DRM_ETNA_PREP_WRITE |
118			DRM_ETNA_PREP_NOSYNC) == 0;
119}
120
121static struct etna_bo *find_in_bucket(struct etna_bo_bucket *bucket, uint32_t flags)
122{
123	struct etna_bo *bo = NULL, *tmp;
124
125	pthread_mutex_lock(&table_lock);
126
127	if (LIST_IS_EMPTY(&bucket->list))
128		goto out_unlock;
129
130	LIST_FOR_EACH_ENTRY_SAFE(bo, tmp, &bucket->list, list) {
131		/* skip BOs with different flags */
132		if (bo->flags != flags)
133			continue;
134
135		/* check if the first BO with matching flags is idle */
136		if (is_idle(bo)) {
137			list_delinit(&bo->list);
138			goto out_unlock;
139		}
140
141		/* If the oldest BO is still busy, don't try younger ones */
142		break;
143	}
144
145	/* There was no matching buffer found */
146	bo = NULL;
147
148out_unlock:
149	pthread_mutex_unlock(&table_lock);
150
151	return bo;
152}
153
154/* allocate a new (un-tiled) buffer object
155 *
156 * NOTE: size is potentially rounded up to bucket size
157 */
158drm_private struct etna_bo *etna_bo_cache_alloc(struct etna_bo_cache *cache, uint32_t *size,
159    uint32_t flags)
160{
161	struct etna_bo *bo;
162	struct etna_bo_bucket *bucket;
163
164	*size = ALIGN(*size, 4096);
165	bucket = get_bucket(cache, *size);
166
167	/* see if we can be green and recycle: */
168	if (bucket) {
169		*size = bucket->size;
170		bo = find_in_bucket(bucket, flags);
171		if (bo) {
172			atomic_set(&bo->refcnt, 1);
173			etna_device_ref(bo->dev);
174			return bo;
175		}
176	}
177
178	return NULL;
179}
180
181drm_private int etna_bo_cache_free(struct etna_bo_cache *cache, struct etna_bo *bo)
182{
183	struct etna_bo_bucket *bucket = get_bucket(cache, bo->size);
184
185	/* see if we can be green and recycle: */
186	if (bucket) {
187		struct timespec time;
188
189		clock_gettime(CLOCK_MONOTONIC, &time);
190
191		bo->free_time = time.tv_sec;
192		list_addtail(&bo->list, &bucket->list);
193		etna_bo_cache_cleanup(cache, time.tv_sec);
194
195		/* bo's in the bucket cache don't have a ref and
196		 * don't hold a ref to the dev:
197		 */
198		etna_device_del_locked(bo->dev);
199
200		return 0;
201	}
202
203	return -1;
204}
205