xref: /dpdk/lib/hash/rte_cuckoo_hash.h (revision 141b7947852143055f4edeb4ef953f88c2cc03c6)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2016 Intel Corporation
3  * Copyright(c) 2018 Arm Limited
4  */
5 
6 /* rte_cuckoo_hash.h
7  * This file hold Cuckoo Hash private data structures to allows include from
8  * platform specific files like rte_cuckoo_hash_x86.h
9  */
10 
11 #ifndef _RTE_CUCKOO_HASH_H_
12 #define _RTE_CUCKOO_HASH_H_
13 
14 #include <stdalign.h>
15 
16 #if defined(RTE_ARCH_X86)
17 #include "rte_cmp_x86.h"
18 #endif
19 
20 #if defined(RTE_ARCH_ARM64)
21 #include "rte_cmp_arm64.h"
22 #endif
23 
24 /* Macro to enable/disable run-time checking of function parameters */
25 #if defined(RTE_LIBRTE_HASH_DEBUG)
26 #define RETURN_IF_TRUE(cond, retval) do { \
27 	if (cond) \
28 		return retval; \
29 } while (0)
30 #else
31 #define RETURN_IF_TRUE(cond, retval)
32 #endif
33 
34 #include <rte_hash_crc.h>
35 #include <rte_jhash.h>
36 
37 #if defined(RTE_ARCH_X86) || defined(RTE_ARCH_ARM64)
38 /*
39  * All different options to select a key compare function,
40  * based on the key size and custom function.
41  */
42 enum cmp_jump_table_case {
43 	KEY_CUSTOM = 0,
44 	KEY_16_BYTES,
45 	KEY_32_BYTES,
46 	KEY_48_BYTES,
47 	KEY_64_BYTES,
48 	KEY_80_BYTES,
49 	KEY_96_BYTES,
50 	KEY_112_BYTES,
51 	KEY_128_BYTES,
52 	KEY_OTHER_BYTES,
53 	NUM_KEY_CMP_CASES,
54 };
55 
56 /*
57  * Table storing all different key compare functions
58  * (multi-process supported)
59  */
60 const rte_hash_cmp_eq_t cmp_jump_table[NUM_KEY_CMP_CASES] = {
61 	NULL,
62 	rte_hash_k16_cmp_eq,
63 	rte_hash_k32_cmp_eq,
64 	rte_hash_k48_cmp_eq,
65 	rte_hash_k64_cmp_eq,
66 	rte_hash_k80_cmp_eq,
67 	rte_hash_k96_cmp_eq,
68 	rte_hash_k112_cmp_eq,
69 	rte_hash_k128_cmp_eq,
70 	memcmp
71 };
72 #else
73 /*
74  * All different options to select a key compare function,
75  * based on the key size and custom function.
76  */
77 enum cmp_jump_table_case {
78 	KEY_CUSTOM = 0,
79 	KEY_OTHER_BYTES,
80 	NUM_KEY_CMP_CASES,
81 };
82 
83 /*
84  * Table storing all different key compare functions
85  * (multi-process supported)
86  */
87 const rte_hash_cmp_eq_t cmp_jump_table[NUM_KEY_CMP_CASES] = {
88 	NULL,
89 	memcmp
90 };
91 
92 #endif
93 
94 
95 /**
96  * Number of items per bucket.
97  * 8 is a tradeoff between performance and memory consumption.
98  * When it is equal to 8, multiple 'struct rte_hash_bucket' can be fit
99  * on a single cache line (64 or 128 bytes long) without any gaps
100  * in memory between them due to alignment.
101  */
102 #define RTE_HASH_BUCKET_ENTRIES		8
103 
104 #if !RTE_IS_POWER_OF_2(RTE_HASH_BUCKET_ENTRIES)
105 #error RTE_HASH_BUCKET_ENTRIES must be a power of 2
106 #endif
107 
108 #define NULL_SIGNATURE			0
109 
110 #define EMPTY_SLOT			0
111 
112 #define KEY_ALIGNMENT			16
113 
114 #define LCORE_CACHE_SIZE		64
115 
116 #define RTE_HASH_BFS_QUEUE_MAX_LEN       1000
117 
118 #define RTE_XABORT_CUCKOO_PATH_INVALIDED 0x4
119 
120 #define RTE_HASH_TSX_MAX_RETRY  10
121 
122 struct __rte_cache_aligned lcore_cache {
123 	unsigned len; /**< Cache len */
124 	uint32_t objs[LCORE_CACHE_SIZE]; /**< Cache objects */
125 };
126 
127 /* Structure that stores key-value pair */
128 struct rte_hash_key {
129 	union {
130 		uintptr_t idata;
131 		RTE_ATOMIC(void *) pdata;
132 	};
133 	/* Variable key size */
134 	char key[0];
135 };
136 
137 /** Bucket structure */
138 struct __rte_cache_aligned rte_hash_bucket {
139 	uint16_t sig_current[RTE_HASH_BUCKET_ENTRIES];
140 
141 	RTE_ATOMIC(uint32_t) key_idx[RTE_HASH_BUCKET_ENTRIES];
142 
143 	uint8_t flag[RTE_HASH_BUCKET_ENTRIES];
144 
145 	void *next;
146 };
147 
148 /** A hash table structure. */
149 struct __rte_cache_aligned rte_hash {
150 	char name[RTE_HASH_NAMESIZE];   /**< Name of the hash. */
151 	uint32_t entries;               /**< Total table entries. */
152 	uint32_t num_buckets;           /**< Number of buckets in table. */
153 
154 	struct rte_ring *free_slots;
155 	/**< Ring that stores all indexes of the free slots in the key table */
156 
157 	struct lcore_cache *local_free_slots;
158 	/**< Local cache per lcore, storing some indexes of the free slots */
159 
160 	/* RCU config */
161 	struct rte_hash_rcu_config *hash_rcu_cfg;
162 	/**< HASH RCU QSBR configuration structure */
163 	struct rte_rcu_qsbr_dq *dq;	/**< RCU QSBR defer queue. */
164 
165 	/* Fields used in lookup */
166 
167 	alignas(RTE_CACHE_LINE_SIZE) uint32_t key_len;
168 	/**< Length of hash key. */
169 	uint8_t hw_trans_mem_support;
170 	/**< If hardware transactional memory is used. */
171 	uint8_t use_local_cache;
172 	/**< If multi-writer support is enabled, use local cache
173 	 * to allocate key-store slots.
174 	 */
175 	uint8_t readwrite_concur_support;
176 	/**< If read-write concurrency support is enabled */
177 	uint8_t ext_table_support;     /**< Enable extendable bucket table */
178 	uint8_t no_free_on_del;
179 	/**< If key index should be freed on calling rte_hash_del_xxx APIs.
180 	 * If this is set, rte_hash_free_key_with_position must be called to
181 	 * free the key index associated with the deleted entry.
182 	 * This flag is enabled by default.
183 	 */
184 	uint8_t readwrite_concur_lf_support;
185 	/**< If read-write concurrency lock free support is enabled */
186 	uint8_t writer_takes_lock;
187 	/**< Indicates if the writer threads need to take lock */
188 	rte_hash_function hash_func;    /**< Function used to calculate hash. */
189 	uint32_t hash_func_init_val;    /**< Init value used by hash_func. */
190 	rte_hash_cmp_eq_t rte_hash_custom_cmp_eq;
191 	/**< Custom function used to compare keys. */
192 	enum cmp_jump_table_case cmp_jump_table_idx;
193 	/**< Indicates which compare function to use. */
194 	unsigned int sig_cmp_fn;
195 	/**< Indicates which signature compare function to use. */
196 	uint32_t bucket_bitmask;
197 	/**< Bitmask for getting bucket index from hash signature. */
198 	uint32_t key_entry_size;         /**< Size of each key entry. */
199 
200 	void *key_store;                /**< Table storing all keys and data */
201 	struct rte_hash_bucket *buckets;
202 	/**< Table with buckets storing all the	hash values and key indexes
203 	 * to the key table.
204 	 */
205 	rte_rwlock_t *readwrite_lock; /**< Read-write lock thread-safety. */
206 	struct rte_hash_bucket *buckets_ext; /**< Extra buckets array */
207 	struct rte_ring *free_ext_bkts; /**< Ring of indexes of free buckets */
208 	/* Stores index of an empty ext bkt to be recycled on calling
209 	 * rte_hash_del_xxx APIs. When lock free read-write concurrency is
210 	 * enabled, an empty ext bkt cannot be put into free list immediately
211 	 * (as readers might be using it still). Hence freeing of the ext bkt
212 	 * is piggy-backed to freeing of the key index.
213 	 */
214 	uint32_t *ext_bkt_to_free;
215 	RTE_ATOMIC(uint32_t) *tbl_chng_cnt;
216 	/**< Indicates if the hash table changed from last read. */
217 };
218 
219 struct queue_node {
220 	struct rte_hash_bucket *bkt; /* Current bucket on the bfs search */
221 	uint32_t cur_bkt_idx;
222 
223 	struct queue_node *prev;     /* Parent(bucket) in search path */
224 	int prev_slot;               /* Parent(slot) in search path */
225 };
226 
227 /** @internal Default RCU defer queue entries to reclaim in one go. */
228 #define RTE_HASH_RCU_DQ_RECLAIM_MAX	16
229 
230 #endif
231