ceph/src/dpdk/lib/librte_table/rte_table_hash.h

   1 /*-
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  33
  34 #ifndef __INCLUDE_RTE_TABLE_HASH_H__
  35 #define __INCLUDE_RTE_TABLE_HASH_H__
  36
  37 #ifdef __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 /**
  42  * @file
  43  * RTE Table Hash
  44  *
  45  * These tables use the exact match criterion to uniquely associate data to
  46  * lookup keys.
  47  *
  48  * Use-cases: Flow classification table, Address Resolution Protocol (ARP) table
  49  *
  50  * Hash table types:
  51  * 1. Entry add strategy on bucket full:
  52  *     a. Least Recently Used (LRU): One of the existing keys in the bucket is
  53  *        deleted and the new key is added in its place. The number of keys in
  54  *        each bucket never grows bigger than 4. The logic to pick the key to
  55  *        be dropped from the bucket is LRU. The hash table lookup operation
  56  *        maintains the order in which the keys in the same bucket are hit, so
  57  *        every time a key is hit, it becomes the new Most Recently Used (MRU)
  58  *        key, i.e. the most unlikely candidate for drop. When a key is added
  59  *        to the bucket, it also becomes the new MRU key. When a key needs to
  60  *        be picked and dropped, the most likely candidate for drop, i.e. the
  61  *        current LRU key, is always picked. The LRU logic requires maintaining
  62  *        specific data structures per each bucket.
  63  *     b. Extendible bucket (ext): The bucket is extended with space for 4 more
  64  *        keys. This is done by allocating additional memory at table init time,
  65  *        which is used to create a pool of free keys (the size of this pool is
  66  *        configurable and always a multiple of 4). On key add operation, the
  67  *        allocation of a group of 4 keys only happens successfully within the
  68  *        limit of free keys, otherwise the key add operation fails. On key
  69  *        delete operation, a group of 4 keys is freed back to the pool of free
  70  *        keys when the key to be deleted is the only key that was used within
  71  *        its group of 4 keys at that time. On key lookup operation, if the
  72  *        current bucket is in extended state and a match is not found in the
  73  *        first group of 4 keys, the search continues beyond the first group of
  74  *        4 keys, potentially until all keys in this bucket are examined. The
  75  *        extendible bucket logic requires maintaining specific data structures
  76  *        per table and per each bucket.
  77  * 2. Key signature computation:
  78  *     a. Pre-computed key signature: The key lookup operation is split between
  79  *        two CPU cores. The first CPU core (typically the CPU core performing
  80  *        packet RX) extracts the key from the input packet, computes the key
  81  *        signature and saves both the key and the key signature in the packet
  82  *        buffer as packet meta-data. The second CPU core reads both the key and
  83  *        the key signature from the packet meta-data and performs the bucket
  84  *        search step of the key lookup operation.
  85  *     b. Key signature computed on lookup (do-sig): The same CPU core reads
  86  *        the key from the packet meta-data, uses it to compute the key
  87  *        signature and also performs the bucket search step of the key lookup
  88  *        operation.
  89  * 3. Key size:
  90  *     a. Configurable key size
  91  *     b. Single key size (8-byte, 16-byte or 32-byte key size)
  92  *
  93  ***/
  94 #include <stdint.h>
  95
  96 #include "rte_table.h"
  97
  98 /** Hash function */
  99 typedef uint64_t (*rte_table_hash_op_hash)(
 100         void *key,
 101         uint32_t key_size,
 102         uint64_t seed);
 103
 104 /**
 105  * Hash tables with configurable key size
 106  *
 107  */
 108 /** Extendible bucket hash table parameters */
 109 struct rte_table_hash_ext_params {
 110         /** Key size (number of bytes) */
 111         uint32_t key_size;
 112
 113         /** Maximum number of keys */
 114         uint32_t n_keys;
 115
 116         /** Number of hash table buckets. Each bucket stores up to 4 keys. */
 117         uint32_t n_buckets;
 118
 119         /** Number of hash table bucket extensions. Each bucket extension has
 120         space for 4 keys and each bucket can have 0, 1 or more extensions. */
 121         uint32_t n_buckets_ext;
 122
 123         /** Hash function */
 124         rte_table_hash_op_hash f_hash;
 125
 126         /** Seed value for the hash function */
 127         uint64_t seed;
 128
 129         /** Byte offset within packet meta-data where the 4-byte key signature
 130         is located. Valid for pre-computed key signature tables, ignored for
 131         do-sig tables. */
 132         uint32_t signature_offset;
 133
 134         /** Byte offset within packet meta-data where the key is located */
 135         uint32_t key_offset;
 136 };
 137
 138 /** Extendible bucket hash table operations for pre-computed key signature */
 139 extern struct rte_table_ops rte_table_hash_ext_ops;
 140
 141 /** Extendible bucket hash table operations for key signature computed on
 142         lookup ("do-sig") */
 143 extern struct rte_table_ops rte_table_hash_ext_dosig_ops;
 144
 145 /** LRU hash table parameters */
 146 struct rte_table_hash_lru_params {
 147         /** Key size (number of bytes) */
 148         uint32_t key_size;
 149
 150         /** Maximum number of keys */
 151         uint32_t n_keys;
 152
 153         /** Number of hash table buckets. Each bucket stores up to 4 keys. */
 154         uint32_t n_buckets;
 155
 156         /** Hash function */
 157         rte_table_hash_op_hash f_hash;
 158
 159         /** Seed value for the hash function */
 160         uint64_t seed;
 161
 162         /** Byte offset within packet meta-data where the 4-byte key signature
 163         is located. Valid for pre-computed key signature tables, ignored for
 164         do-sig tables. */
 165         uint32_t signature_offset;
 166
 167         /** Byte offset within packet meta-data where the key is located */
 168         uint32_t key_offset;
 169 };
 170
 171 /** LRU hash table operations for pre-computed key signature */
 172 extern struct rte_table_ops rte_table_hash_lru_ops;
 173
 174 /** LRU hash table operations for key signature computed on lookup ("do-sig") */
 175 extern struct rte_table_ops rte_table_hash_lru_dosig_ops;
 176
 177 /**
 178  * 8-byte key hash tables
 179  *
 180  */
 181 /** LRU hash table parameters */
 182 struct rte_table_hash_key8_lru_params {
 183         /** Maximum number of entries (and keys) in the table */
 184         uint32_t n_entries;
 185
 186         /** Hash function */
 187         rte_table_hash_op_hash f_hash;
 188
 189         /** Seed for the hash function */
 190         uint64_t seed;
 191
 192         /** Byte offset within packet meta-data where the 4-byte key signature
 193         is located. Valid for pre-computed key signature tables, ignored for
 194         do-sig tables. */
 195         uint32_t signature_offset;
 196
 197         /** Byte offset within packet meta-data where the key is located */
 198         uint32_t key_offset;
 199
 200         /** Bit-mask to be AND-ed to the key on lookup */
 201         uint8_t *key_mask;
 202 };
 203
 204 /** LRU hash table operations for pre-computed key signature */
 205 extern struct rte_table_ops rte_table_hash_key8_lru_ops;
 206
 207 /** LRU hash table operations for key signature computed on lookup ("do-sig") */
 208 extern struct rte_table_ops rte_table_hash_key8_lru_dosig_ops;
 209
 210 /** Extendible bucket hash table parameters */
 211 struct rte_table_hash_key8_ext_params {
 212         /** Maximum number of entries (and keys) in the table */
 213         uint32_t n_entries;
 214
 215         /** Number of entries (and keys) for hash table bucket extensions. Each
 216                 bucket is extended in increments of 4 keys. */
 217         uint32_t n_entries_ext;
 218
 219         /** Hash function */
 220         rte_table_hash_op_hash f_hash;
 221
 222         /** Seed for the hash function */
 223         uint64_t seed;
 224
 225         /** Byte offset within packet meta-data where the 4-byte key signature
 226         is located. Valid for pre-computed key signature tables, ignored for
 227         do-sig tables. */
 228         uint32_t signature_offset;
 229
 230         /** Byte offset within packet meta-data where the key is located */
 231         uint32_t key_offset;
 232
 233         /** Bit-mask to be AND-ed to the key on lookup */
 234         uint8_t *key_mask;
 235 };
 236
 237 /** Extendible bucket hash table operations for pre-computed key signature */
 238 extern struct rte_table_ops rte_table_hash_key8_ext_ops;
 239
 240 /** Extendible bucket hash table operations for key signature computed on
 241     lookup ("do-sig") */
 242 extern struct rte_table_ops rte_table_hash_key8_ext_dosig_ops;
 243
 244 /**
 245  * 16-byte key hash tables
 246  *
 247  */
 248 /** LRU hash table parameters */
 249 struct rte_table_hash_key16_lru_params {
 250         /** Maximum number of entries (and keys) in the table */
 251         uint32_t n_entries;
 252
 253         /** Hash function */
 254         rte_table_hash_op_hash f_hash;
 255
 256         /** Seed for the hash function */
 257         uint64_t seed;
 258
 259         /** Byte offset within packet meta-data where the 4-byte key signature
 260         is located. Valid for pre-computed key signature tables, ignored for
 261         do-sig tables. */
 262         uint32_t signature_offset;
 263
 264         /** Byte offset within packet meta-data where the key is located */
 265         uint32_t key_offset;
 266
 267         /** Bit-mask to be AND-ed to the key on lookup */
 268         uint8_t *key_mask;
 269 };
 270
 271 /** LRU hash table operations for pre-computed key signature */
 272 extern struct rte_table_ops rte_table_hash_key16_lru_ops;
 273
 274 /** LRU hash table operations for key signature computed on lookup
 275     ("do-sig") */
 276 extern struct rte_table_ops rte_table_hash_key16_lru_dosig_ops;
 277
 278 /** Extendible bucket hash table parameters */
 279 struct rte_table_hash_key16_ext_params {
 280         /** Maximum number of entries (and keys) in the table */
 281         uint32_t n_entries;
 282
 283         /** Number of entries (and keys) for hash table bucket extensions. Each
 284         bucket is extended in increments of 4 keys. */
 285         uint32_t n_entries_ext;
 286
 287         /** Hash function */
 288         rte_table_hash_op_hash f_hash;
 289
 290         /** Seed for the hash function */
 291         uint64_t seed;
 292
 293         /** Byte offset within packet meta-data where the 4-byte key signature
 294         is located. Valid for pre-computed key signature tables, ignored for
 295         do-sig tables. */
 296         uint32_t signature_offset;
 297
 298         /** Byte offset within packet meta-data where the key is located */
 299         uint32_t key_offset;
 300
 301         /** Bit-mask to be AND-ed to the key on lookup */
 302         uint8_t *key_mask;
 303 };
 304
 305 /** Extendible bucket operations for pre-computed key signature */
 306 extern struct rte_table_ops rte_table_hash_key16_ext_ops;
 307
 308 /** Extendible bucket hash table operations for key signature computed on
 309     lookup ("do-sig") */
 310 extern struct rte_table_ops rte_table_hash_key16_ext_dosig_ops;
 311
 312 /**
 313  * 32-byte key hash tables
 314  *
 315  */
 316 /** LRU hash table parameters */
 317 struct rte_table_hash_key32_lru_params {
 318         /** Maximum number of entries (and keys) in the table */
 319         uint32_t n_entries;
 320
 321         /** Hash function */
 322         rte_table_hash_op_hash f_hash;
 323
 324         /** Seed for the hash function */
 325         uint64_t seed;
 326
 327         /** Byte offset within packet meta-data where the 4-byte key signature
 328         is located. Valid for pre-computed key signature tables, ignored for
 329         do-sig tables. */
 330         uint32_t signature_offset;
 331
 332         /** Byte offset within packet meta-data where the key is located */
 333         uint32_t key_offset;
 334 };
 335
 336 /** LRU hash table operations for pre-computed key signature */
 337 extern struct rte_table_ops rte_table_hash_key32_lru_ops;
 338
 339 /** Extendible bucket hash table parameters */
 340 struct rte_table_hash_key32_ext_params {
 341         /** Maximum number of entries (and keys) in the table */
 342         uint32_t n_entries;
 343
 344         /** Number of entries (and keys) for hash table bucket extensions. Each
 345                 bucket is extended in increments of 4 keys. */
 346         uint32_t n_entries_ext;
 347
 348         /** Hash function */
 349         rte_table_hash_op_hash f_hash;
 350
 351         /** Seed for the hash function */
 352         uint64_t seed;
 353
 354         /** Byte offset within packet meta-data where the 4-byte key signature
 355         is located. Valid for pre-computed key signature tables, ignored for
 356         do-sig tables. */
 357         uint32_t signature_offset;
 358
 359         /** Byte offset within packet meta-data where the key is located */
 360         uint32_t key_offset;
 361 };
 362
 363 /** Extendible bucket hash table operations */
 364 extern struct rte_table_ops rte_table_hash_key32_ext_ops;
 365
 366 /** Cuckoo hash table parameters */
 367 struct rte_table_hash_cuckoo_params {
 368     /** Key size (number of bytes */
 369                 uint32_t key_size;
 370
 371         /** Maximum number of hash table entries */
 372         uint32_t n_keys;
 373
 374         /** Hash function used to calculate hash */
 375         rte_table_hash_op_hash f_hash;
 376
 377         /** Seed value or Init value used by f_hash */
 378         uint32_t seed;
 379
 380         /** Byte offset within packet meta-data where the 4-byte key signature
 381         is located. Valid for pre-computed key signature tables, ignored for
 382         do-sig tables. */
 383         uint32_t signature_offset;
 384
 385         /** Byte offset within packet meta-data where the key is located */
 386         uint32_t key_offset;
 387
 388         /** Hash table name */
 389         const char *name;
 390 };
 391
 392 /** Cuckoo hash table operations */
 393 extern struct rte_table_ops rte_table_hash_cuckoo_dosig_ops;
 394
 395 #ifdef __cplusplus
 396 }
 397 #endif
 398
 399 #endif