xref: /dpdk/drivers/common/mlx5/mlx5_common_utils.c (revision eeded2044af5bbe88220120b14933536cbb3edb6)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright 2019 Mellanox Technologies, Ltd
3  */
4 
5 #include <rte_malloc.h>
6 #include <rte_hash_crc.h>
7 #include <rte_errno.h>
8 
9 #include <mlx5_malloc.h>
10 
11 #include "mlx5_common_utils.h"
12 #include "mlx5_common_log.h"
13 
14 /********************* Hash List **********************/
15 
16 static struct mlx5_hlist_entry *
17 mlx5_hlist_default_create_cb(struct mlx5_hlist *h, uint64_t key __rte_unused,
18 			     void *ctx __rte_unused)
19 {
20 	return mlx5_malloc(MLX5_MEM_ZERO, h->entry_sz, 0, SOCKET_ID_ANY);
21 }
22 
23 static void
24 mlx5_hlist_default_remove_cb(struct mlx5_hlist *h __rte_unused,
25 			     struct mlx5_hlist_entry *entry)
26 {
27 	mlx5_free(entry);
28 }
29 
30 struct mlx5_hlist *
31 mlx5_hlist_create(const char *name, uint32_t size, uint32_t entry_size,
32 		  uint32_t flags, mlx5_hlist_create_cb cb_create,
33 		  mlx5_hlist_match_cb cb_match, mlx5_hlist_remove_cb cb_remove)
34 {
35 	struct mlx5_hlist *h;
36 	uint32_t act_size;
37 	uint32_t alloc_size;
38 	uint32_t i;
39 
40 	if (!size || !cb_match || (!cb_create ^ !cb_remove))
41 		return NULL;
42 	/* Align to the next power of 2, 32bits integer is enough now. */
43 	if (!rte_is_power_of_2(size)) {
44 		act_size = rte_align32pow2(size);
45 		DRV_LOG(DEBUG, "Size 0x%" PRIX32 " is not power of 2, "
46 			"will be aligned to 0x%" PRIX32 ".", size, act_size);
47 	} else {
48 		act_size = size;
49 	}
50 	alloc_size = sizeof(struct mlx5_hlist) +
51 		     sizeof(struct mlx5_hlist_bucket) * act_size;
52 	/* Using zmalloc, then no need to initialize the heads. */
53 	h = mlx5_malloc(MLX5_MEM_ZERO, alloc_size, RTE_CACHE_LINE_SIZE,
54 			SOCKET_ID_ANY);
55 	if (!h) {
56 		DRV_LOG(ERR, "No memory for hash list %s creation",
57 			name ? name : "None");
58 		return NULL;
59 	}
60 	if (name)
61 		snprintf(h->name, MLX5_HLIST_NAMESIZE, "%s", name);
62 	h->table_sz = act_size;
63 	h->mask = act_size - 1;
64 	h->entry_sz = entry_size;
65 	h->direct_key = !!(flags & MLX5_HLIST_DIRECT_KEY);
66 	h->write_most = !!(flags & MLX5_HLIST_WRITE_MOST);
67 	h->cb_create = cb_create ? cb_create : mlx5_hlist_default_create_cb;
68 	h->cb_match = cb_match;
69 	h->cb_remove = cb_remove ? cb_remove : mlx5_hlist_default_remove_cb;
70 	for (i = 0; i < act_size; i++)
71 		rte_rwlock_init(&h->buckets[i].lock);
72 	DRV_LOG(DEBUG, "Hash list with %s size 0x%" PRIX32 " is created.",
73 		h->name, act_size);
74 	return h;
75 }
76 
77 static struct mlx5_hlist_entry *
78 __hlist_lookup(struct mlx5_hlist *h, uint64_t key, uint32_t idx,
79 	       void *ctx, bool reuse)
80 {
81 	struct mlx5_hlist_head *first;
82 	struct mlx5_hlist_entry *node;
83 
84 	MLX5_ASSERT(h);
85 	first = &h->buckets[idx].head;
86 	LIST_FOREACH(node, first, next) {
87 		if (!h->cb_match(h, node, key, ctx)) {
88 			if (reuse) {
89 				__atomic_add_fetch(&node->ref_cnt, 1,
90 						   __ATOMIC_RELAXED);
91 				DRV_LOG(DEBUG, "Hash list %s entry %p "
92 					"reuse: %u.",
93 					h->name, (void *)node, node->ref_cnt);
94 			}
95 			break;
96 		}
97 	}
98 	return node;
99 }
100 
101 static struct mlx5_hlist_entry *
102 hlist_lookup(struct mlx5_hlist *h, uint64_t key, uint32_t idx,
103 	     void *ctx, bool reuse)
104 {
105 	struct mlx5_hlist_entry *node;
106 
107 	MLX5_ASSERT(h);
108 	rte_rwlock_read_lock(&h->buckets[idx].lock);
109 	node = __hlist_lookup(h, key, idx, ctx, reuse);
110 	rte_rwlock_read_unlock(&h->buckets[idx].lock);
111 	return node;
112 }
113 
114 struct mlx5_hlist_entry *
115 mlx5_hlist_lookup(struct mlx5_hlist *h, uint64_t key, void *ctx)
116 {
117 	uint32_t idx;
118 
119 	if (h->direct_key)
120 		idx = (uint32_t)(key & h->mask);
121 	else
122 		idx = rte_hash_crc_8byte(key, 0) & h->mask;
123 	return hlist_lookup(h, key, idx, ctx, false);
124 }
125 
126 struct mlx5_hlist_entry*
127 mlx5_hlist_register(struct mlx5_hlist *h, uint64_t key, void *ctx)
128 {
129 	uint32_t idx;
130 	struct mlx5_hlist_head *first;
131 	struct mlx5_hlist_bucket *b;
132 	struct mlx5_hlist_entry *entry;
133 	uint32_t prev_gen_cnt = 0;
134 
135 	if (h->direct_key)
136 		idx = (uint32_t)(key & h->mask);
137 	else
138 		idx = rte_hash_crc_8byte(key, 0) & h->mask;
139 	MLX5_ASSERT(h);
140 	b = &h->buckets[idx];
141 	/* Use write lock directly for write-most list. */
142 	if (!h->write_most) {
143 		prev_gen_cnt = __atomic_load_n(&b->gen_cnt, __ATOMIC_ACQUIRE);
144 		entry = hlist_lookup(h, key, idx, ctx, true);
145 		if (entry)
146 			return entry;
147 	}
148 	rte_rwlock_write_lock(&b->lock);
149 	/* Check if the list changed by other threads. */
150 	if (h->write_most ||
151 	    prev_gen_cnt != __atomic_load_n(&b->gen_cnt, __ATOMIC_ACQUIRE)) {
152 		entry = __hlist_lookup(h, key, idx, ctx, true);
153 		if (entry)
154 			goto done;
155 	}
156 	first = &b->head;
157 	entry = h->cb_create(h, key, ctx);
158 	if (!entry) {
159 		rte_errno = ENOMEM;
160 		DRV_LOG(DEBUG, "Can't allocate hash list %s entry.", h->name);
161 		goto done;
162 	}
163 	entry->idx = idx;
164 	entry->ref_cnt = 1;
165 	LIST_INSERT_HEAD(first, entry, next);
166 	__atomic_add_fetch(&b->gen_cnt, 1, __ATOMIC_ACQ_REL);
167 	DRV_LOG(DEBUG, "Hash list %s entry %p new: %u.",
168 		h->name, (void *)entry, entry->ref_cnt);
169 done:
170 	rte_rwlock_write_unlock(&b->lock);
171 	return entry;
172 }
173 
174 int
175 mlx5_hlist_unregister(struct mlx5_hlist *h, struct mlx5_hlist_entry *entry)
176 {
177 	uint32_t idx = entry->idx;
178 
179 	rte_rwlock_write_lock(&h->buckets[idx].lock);
180 	MLX5_ASSERT(entry && entry->ref_cnt && entry->next.le_prev);
181 	DRV_LOG(DEBUG, "Hash list %s entry %p deref: %u.",
182 		h->name, (void *)entry, entry->ref_cnt);
183 	if (--entry->ref_cnt) {
184 		rte_rwlock_write_unlock(&h->buckets[idx].lock);
185 		return 1;
186 	}
187 	LIST_REMOVE(entry, next);
188 	/* Set to NULL to get rid of removing action for more than once. */
189 	entry->next.le_prev = NULL;
190 	h->cb_remove(h, entry);
191 	rte_rwlock_write_unlock(&h->buckets[idx].lock);
192 	DRV_LOG(DEBUG, "Hash list %s entry %p removed.",
193 		h->name, (void *)entry);
194 	return 0;
195 }
196 
197 void
198 mlx5_hlist_destroy(struct mlx5_hlist *h)
199 {
200 	uint32_t idx;
201 	struct mlx5_hlist_entry *entry;
202 
203 	MLX5_ASSERT(h);
204 	for (idx = 0; idx < h->table_sz; ++idx) {
205 		/* No LIST_FOREACH_SAFE, using while instead. */
206 		while (!LIST_EMPTY(&h->buckets[idx].head)) {
207 			entry = LIST_FIRST(&h->buckets[idx].head);
208 			LIST_REMOVE(entry, next);
209 			/*
210 			 * The owner of whole element which contains data entry
211 			 * is the user, so it's the user's duty to do the clean
212 			 * up and the free work because someone may not put the
213 			 * hlist entry at the beginning(suggested to locate at
214 			 * the beginning). Or else the default free function
215 			 * will be used.
216 			 */
217 			h->cb_remove(h, entry);
218 		}
219 	}
220 	mlx5_free(h);
221 }
222