xref: /dpdk/lib/hash/rte_cuckoo_hash.h (revision 9da077ad)
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 #if defined(RTE_ARCH_X86)
15 #include "rte_cmp_x86.h"
16 #endif
17 
18 #if defined(RTE_ARCH_ARM64)
19 #include "rte_cmp_arm64.h"
20 #endif
21 
22 /* Macro to enable/disable run-time checking of function parameters */
23 #if defined(RTE_LIBRTE_HASH_DEBUG)
24 #define RETURN_IF_TRUE(cond, retval) do { \
25 	if (cond) \
26 		return retval; \
27 } while (0)
28 #else
29 #define RETURN_IF_TRUE(cond, retval)
30 #endif
31 
32 #if defined(RTE_LIBRTE_HASH_DEBUG)
33 #define ERR_IF_TRUE(cond, fmt, args...) do { \
34 	if (cond) { \
35 		RTE_LOG(ERR, HASH, fmt, ##args); \
36 		return; \
37 	} \
38 } while (0)
39 #else
40 #define ERR_IF_TRUE(cond, fmt, args...)
41 #endif
42 
43 #include <rte_hash_crc.h>
44 #include <rte_jhash.h>
45 
46 #if defined(RTE_ARCH_X86) || defined(RTE_ARCH_ARM64)
47 /*
48  * All different options to select a key compare function,
49  * based on the key size and custom function.
50  */
51 enum cmp_jump_table_case {
52 	KEY_CUSTOM = 0,
53 	KEY_16_BYTES,
54 	KEY_32_BYTES,
55 	KEY_48_BYTES,
56 	KEY_64_BYTES,
57 	KEY_80_BYTES,
58 	KEY_96_BYTES,
59 	KEY_112_BYTES,
60 	KEY_128_BYTES,
61 	KEY_OTHER_BYTES,
62 	NUM_KEY_CMP_CASES,
63 };
64 
65 /*
66  * Table storing all different key compare functions
67  * (multi-process supported)
68  */
69 const rte_hash_cmp_eq_t cmp_jump_table[NUM_KEY_CMP_CASES] = {
70 	NULL,
71 	rte_hash_k16_cmp_eq,
72 	rte_hash_k32_cmp_eq,
73 	rte_hash_k48_cmp_eq,
74 	rte_hash_k64_cmp_eq,
75 	rte_hash_k80_cmp_eq,
76 	rte_hash_k96_cmp_eq,
77 	rte_hash_k112_cmp_eq,
78 	rte_hash_k128_cmp_eq,
79 	memcmp
80 };
81 #else
82 /*
83  * All different options to select a key compare function,
84  * based on the key size and custom function.
85  */
86 enum cmp_jump_table_case {
87 	KEY_CUSTOM = 0,
88 	KEY_OTHER_BYTES,
89 	NUM_KEY_CMP_CASES,
90 };
91 
92 /*
93  * Table storing all different key compare functions
94  * (multi-process supported)
95  */
96 const rte_hash_cmp_eq_t cmp_jump_table[NUM_KEY_CMP_CASES] = {
97 	NULL,
98 	memcmp
99 };
100 
101 #endif
102 
103 
104 /**
105  * Number of items per bucket.
106  * 8 is a tradeoff between performance and memory consumption.
107  * When it is equal to 8, multiple 'struct rte_hash_bucket' can be fit
108  * on a single cache line (64 or 128 bytes long) without any gaps
109  * in memory between them due to alignment.
110  */
111 #define RTE_HASH_BUCKET_ENTRIES		8
112 
113 #if !RTE_IS_POWER_OF_2(RTE_HASH_BUCKET_ENTRIES)
114 #error RTE_HASH_BUCKET_ENTRIES must be a power of 2
115 #endif
116 
117 #define NULL_SIGNATURE			0
118 
119 #define EMPTY_SLOT			0
120 
121 #define KEY_ALIGNMENT			16
122 
123 #define LCORE_CACHE_SIZE		64
124 
125 #define RTE_HASH_BFS_QUEUE_MAX_LEN       1000
126 
127 #define RTE_XABORT_CUCKOO_PATH_INVALIDED 0x4
128 
129 #define RTE_HASH_TSX_MAX_RETRY  10
130 
131 struct lcore_cache {
132 	unsigned len; /**< Cache len */
133 	uint32_t objs[LCORE_CACHE_SIZE]; /**< Cache objects */
134 } __rte_cache_aligned;
135 
136 /* Structure that stores key-value pair */
137 struct rte_hash_key {
138 	union {
139 		uintptr_t idata;
140 		void *pdata;
141 	};
142 	/* Variable key size */
143 	char key[0];
144 };
145 
146 /* All different signature compare functions */
147 enum rte_hash_sig_compare_function {
148 	RTE_HASH_COMPARE_SCALAR = 0,
149 	RTE_HASH_COMPARE_SSE,
150 	RTE_HASH_COMPARE_NEON,
151 	RTE_HASH_COMPARE_NUM
152 };
153 
154 /** Bucket structure */
155 struct rte_hash_bucket {
156 	uint16_t sig_current[RTE_HASH_BUCKET_ENTRIES];
157 
158 	uint32_t key_idx[RTE_HASH_BUCKET_ENTRIES];
159 
160 	uint8_t flag[RTE_HASH_BUCKET_ENTRIES];
161 
162 	void *next;
163 } __rte_cache_aligned;
164 
165 /** A hash table structure. */
166 struct rte_hash {
167 	char name[RTE_HASH_NAMESIZE];   /**< Name of the hash. */
168 	uint32_t entries;               /**< Total table entries. */
169 	uint32_t num_buckets;           /**< Number of buckets in table. */
170 
171 	struct rte_ring *free_slots;
172 	/**< Ring that stores all indexes of the free slots in the key table */
173 
174 	struct lcore_cache *local_free_slots;
175 	/**< Local cache per lcore, storing some indexes of the free slots */
176 
177 	/* RCU config */
178 	struct rte_hash_rcu_config *hash_rcu_cfg;
179 	/**< HASH RCU QSBR configuration structure */
180 	struct rte_rcu_qsbr_dq *dq;	/**< RCU QSBR defer queue. */
181 
182 	/* Fields used in lookup */
183 
184 	uint32_t key_len __rte_cache_aligned;
185 	/**< Length of hash key. */
186 	uint8_t hw_trans_mem_support;
187 	/**< If hardware transactional memory is used. */
188 	uint8_t use_local_cache;
189 	/**< If multi-writer support is enabled, use local cache
190 	 * to allocate key-store slots.
191 	 */
192 	uint8_t readwrite_concur_support;
193 	/**< If read-write concurrency support is enabled */
194 	uint8_t ext_table_support;     /**< Enable extendable bucket table */
195 	uint8_t no_free_on_del;
196 	/**< If key index should be freed on calling rte_hash_del_xxx APIs.
197 	 * If this is set, rte_hash_free_key_with_position must be called to
198 	 * free the key index associated with the deleted entry.
199 	 * This flag is enabled by default.
200 	 */
201 	uint8_t readwrite_concur_lf_support;
202 	/**< If read-write concurrency lock free support is enabled */
203 	uint8_t writer_takes_lock;
204 	/**< Indicates if the writer threads need to take lock */
205 	rte_hash_function hash_func;    /**< Function used to calculate hash. */
206 	uint32_t hash_func_init_val;    /**< Init value used by hash_func. */
207 	rte_hash_cmp_eq_t rte_hash_custom_cmp_eq;
208 	/**< Custom function used to compare keys. */
209 	enum cmp_jump_table_case cmp_jump_table_idx;
210 	/**< Indicates which compare function to use. */
211 	enum rte_hash_sig_compare_function sig_cmp_fn;
212 	/**< Indicates which signature compare function to use. */
213 	uint32_t bucket_bitmask;
214 	/**< Bitmask for getting bucket index from hash signature. */
215 	uint32_t key_entry_size;         /**< Size of each key entry. */
216 
217 	void *key_store;                /**< Table storing all keys and data */
218 	struct rte_hash_bucket *buckets;
219 	/**< Table with buckets storing all the	hash values and key indexes
220 	 * to the key table.
221 	 */
222 	rte_rwlock_t *readwrite_lock; /**< Read-write lock thread-safety. */
223 	struct rte_hash_bucket *buckets_ext; /**< Extra buckets array */
224 	struct rte_ring *free_ext_bkts; /**< Ring of indexes of free buckets */
225 	/* Stores index of an empty ext bkt to be recycled on calling
226 	 * rte_hash_del_xxx APIs. When lock free read-write concurrency is
227 	 * enabled, an empty ext bkt cannot be put into free list immediately
228 	 * (as readers might be using it still). Hence freeing of the ext bkt
229 	 * is piggy-backed to freeing of the key index.
230 	 */
231 	uint32_t *ext_bkt_to_free;
232 	uint32_t *tbl_chng_cnt;
233 	/**< Indicates if the hash table changed from last read. */
234 } __rte_cache_aligned;
235 
236 struct queue_node {
237 	struct rte_hash_bucket *bkt; /* Current bucket on the bfs search */
238 	uint32_t cur_bkt_idx;
239 
240 	struct queue_node *prev;     /* Parent(bucket) in search path */
241 	int prev_slot;               /* Parent(slot) in search path */
242 };
243 
244 /** @internal Default RCU defer queue entries to reclaim in one go. */
245 #define RTE_HASH_RCU_DQ_RECLAIM_MAX	16
246 
247 #endif
248