xref: /dpdk/lib/hash/rte_fbk_hash.c (revision e9fd1ebf981f361844aea9ec94e17f4bda5e1479)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #include <stdint.h>
6 #include <stdio.h>
7 #include <string.h>
8 #include <errno.h>
9 #include <sys/queue.h>
10 
11 #include <rte_cpuflags.h>
12 #include <rte_eal_memconfig.h>
13 #include <rte_malloc.h>
14 #include <rte_common.h>
15 #include <rte_errno.h>
16 #include <rte_string_fns.h>
17 #include <rte_log.h>
18 #include <rte_tailq.h>
19 
20 #include "rte_fbk_hash.h"
21 
22 RTE_LOG_REGISTER_SUFFIX(fbk_hash_logtype, fbk, INFO);
23 #define RTE_LOGTYPE_HASH fbk_hash_logtype
24 #define HASH_LOG(level, ...) \
25 	RTE_LOG_LINE(level, HASH, "" __VA_ARGS__)
26 
27 TAILQ_HEAD(rte_fbk_hash_list, rte_tailq_entry);
28 
29 static struct rte_tailq_elem rte_fbk_hash_tailq = {
30 	.name = "RTE_FBK_HASH",
31 };
32 EAL_REGISTER_TAILQ(rte_fbk_hash_tailq)
33 
34 /**
35  * Performs a lookup for an existing hash table, and returns a pointer to
36  * the table if found.
37  *
38  * @param name
39  *   Name of the hash table to find
40  *
41  * @return
42  *   pointer to hash table structure or NULL on error.
43  */
44 struct rte_fbk_hash_table *
45 rte_fbk_hash_find_existing(const char *name)
46 {
47 	struct rte_fbk_hash_table *h = NULL;
48 	struct rte_tailq_entry *te;
49 	struct rte_fbk_hash_list *fbk_hash_list;
50 
51 	fbk_hash_list = RTE_TAILQ_CAST(rte_fbk_hash_tailq.head,
52 				       rte_fbk_hash_list);
53 
54 	rte_mcfg_tailq_read_lock();
55 	TAILQ_FOREACH(te, fbk_hash_list, next) {
56 		h = (struct rte_fbk_hash_table *) te->data;
57 		if (strncmp(name, h->name, RTE_FBK_HASH_NAMESIZE) == 0)
58 			break;
59 	}
60 	rte_mcfg_tailq_read_unlock();
61 	if (te == NULL) {
62 		rte_errno = ENOENT;
63 		return NULL;
64 	}
65 	return h;
66 }
67 
68 /**
69  * Create a new hash table for use with four byte keys.
70  *
71  * @param params
72  *   Parameters used in creation of hash table.
73  *
74  * @return
75  *   Pointer to hash table structure that is used in future hash table
76  *   operations, or NULL on error.
77  */
78 struct rte_fbk_hash_table *
79 rte_fbk_hash_create(const struct rte_fbk_hash_params *params)
80 {
81 	struct rte_fbk_hash_table *ht = NULL;
82 	struct rte_tailq_entry *te;
83 	char hash_name[RTE_FBK_HASH_NAMESIZE];
84 	const uint32_t mem_size =
85 			sizeof(*ht) + (sizeof(ht->t[0]) * params->entries);
86 	uint32_t i;
87 	struct rte_fbk_hash_list *fbk_hash_list;
88 	rte_fbk_hash_fn default_hash_func = (rte_fbk_hash_fn)rte_jhash_1word;
89 
90 	fbk_hash_list = RTE_TAILQ_CAST(rte_fbk_hash_tailq.head,
91 				       rte_fbk_hash_list);
92 
93 	/* Error checking of parameters. */
94 	if ((!rte_is_power_of_2(params->entries)) ||
95 			(!rte_is_power_of_2(params->entries_per_bucket)) ||
96 			(params->entries == 0) ||
97 			(params->entries_per_bucket == 0) ||
98 			(params->entries_per_bucket > params->entries) ||
99 			(params->entries > RTE_FBK_HASH_ENTRIES_MAX) ||
100 			(params->entries_per_bucket > RTE_FBK_HASH_ENTRIES_PER_BUCKET_MAX)){
101 		rte_errno = EINVAL;
102 		return NULL;
103 	}
104 
105 	snprintf(hash_name, sizeof(hash_name), "FBK_%s", params->name);
106 
107 	rte_mcfg_tailq_write_lock();
108 
109 	/* guarantee there's no existing */
110 	TAILQ_FOREACH(te, fbk_hash_list, next) {
111 		ht = (struct rte_fbk_hash_table *) te->data;
112 		if (strncmp(params->name, ht->name, RTE_FBK_HASH_NAMESIZE) == 0)
113 			break;
114 	}
115 	ht = NULL;
116 	if (te != NULL) {
117 		rte_errno = EEXIST;
118 		goto exit;
119 	}
120 
121 	te = rte_zmalloc("FBK_HASH_TAILQ_ENTRY", sizeof(*te), 0);
122 	if (te == NULL) {
123 		HASH_LOG(ERR, "Failed to allocate tailq entry");
124 		goto exit;
125 	}
126 
127 	/* Allocate memory for table. */
128 	ht = rte_zmalloc_socket(hash_name, mem_size,
129 			0, params->socket_id);
130 	if (ht == NULL) {
131 		HASH_LOG(ERR, "Failed to allocate fbk hash table");
132 		rte_free(te);
133 		goto exit;
134 	}
135 
136 	/* Default hash function */
137 #if defined(RTE_ARCH_X86)
138 	default_hash_func = (rte_fbk_hash_fn)rte_hash_crc_4byte;
139 #elif defined(RTE_ARCH_ARM64)
140 	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_CRC32))
141 		default_hash_func = (rte_fbk_hash_fn)rte_hash_crc_4byte;
142 #endif
143 
144 	/* Set up hash table context. */
145 	strlcpy(ht->name, params->name, sizeof(ht->name));
146 	ht->entries = params->entries;
147 	ht->entries_per_bucket = params->entries_per_bucket;
148 	ht->used_entries = 0;
149 	ht->bucket_mask = (params->entries / params->entries_per_bucket) - 1;
150 	for (ht->bucket_shift = 0, i = 1;
151 	    (params->entries_per_bucket & i) == 0;
152 	    ht->bucket_shift++, i <<= 1)
153 		; /* empty loop body */
154 
155 	if (params->hash_func != NULL) {
156 		ht->hash_func = params->hash_func;
157 		ht->init_val = params->init_val;
158 	}
159 	else {
160 		ht->hash_func = default_hash_func;
161 		ht->init_val = RTE_FBK_HASH_INIT_VAL_DEFAULT;
162 	}
163 
164 	te->data = (void *) ht;
165 
166 	TAILQ_INSERT_TAIL(fbk_hash_list, te, next);
167 
168 exit:
169 	rte_mcfg_tailq_write_unlock();
170 
171 	return ht;
172 }
173 
174 /**
175  * Free all memory used by a hash table.
176  *
177  * @param ht
178  *   Hash table to deallocate.
179  */
180 void
181 rte_fbk_hash_free(struct rte_fbk_hash_table *ht)
182 {
183 	struct rte_tailq_entry *te;
184 	struct rte_fbk_hash_list *fbk_hash_list;
185 
186 	if (ht == NULL)
187 		return;
188 
189 	fbk_hash_list = RTE_TAILQ_CAST(rte_fbk_hash_tailq.head,
190 				       rte_fbk_hash_list);
191 
192 	rte_mcfg_tailq_write_lock();
193 
194 	/* find out tailq entry */
195 	TAILQ_FOREACH(te, fbk_hash_list, next) {
196 		if (te->data == (void *) ht)
197 			break;
198 	}
199 
200 	if (te == NULL) {
201 		rte_mcfg_tailq_write_unlock();
202 		return;
203 	}
204 
205 	TAILQ_REMOVE(fbk_hash_list, te, next);
206 
207 	rte_mcfg_tailq_write_unlock();
208 
209 	rte_free(ht);
210 	rte_free(te);
211 }
212