/*-
* BSD LICENSE
*
* Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
* All rights reserved.
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* modification, are permitted provided that the following conditions
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*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
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* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
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* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef __INCLUDE_RTE_TABLE_HASH_H__
#define __INCLUDE_RTE_TABLE_HASH_H__
#ifdef __cplusplus
extern "C" {
#endif
/**
* @file
* RTE Table Hash
*
* These tables use the exact match criterion to uniquely associate data to
* lookup keys.
*
* Use-cases: Flow classification table, Address Resolution Protocol (ARP) table
*
* Hash table types:
* 1. Entry add strategy on bucket full:
* a. Least Recently Used (LRU): One of the existing keys in the bucket is
* deleted and the new key is added in its place. The number of keys in
* each bucket never grows bigger than 4. The logic to pick the key to
* be dropped from the bucket is LRU. The hash table lookup operation
* maintains the order in which the keys in the same bucket are hit, so
* every time a key is hit, it becomes the new Most Recently Used (MRU)
* key, i.e. the most unlikely candidate for drop. When a key is added
* to the bucket, it also becomes the new MRU key. When a key needs to
* be picked and dropped, the most likely candidate for drop, i.e. the
* current LRU key, is always picked. The LRU logic requires maintaining
* specific data structures per each bucket.
* b. Extendible bucket (ext): The bucket is extended with space for 4 more
* keys. This is done by allocating additional memory at table init time,
* which is used to create a pool of free keys (the size of this pool is
* configurable and always a multiple of 4). On key add operation, the
* allocation of a group of 4 keys only happens successfully within the
* limit of free keys, otherwise the key add operation fails. On key
* delete operation, a group of 4 keys is freed back to the pool of free
* keys when the key to be deleted is the only key that was used within
* its group of 4 keys at that time. On key lookup operation, if the
* current bucket is in extended state and a match is not found in the
* first group of 4 keys, the search continues beyond the first group of
* 4 keys, potentially until all keys in this bucket are examined. The
* extendible bucket logic requires maintaining specific data structures
* per table and per each bucket.
* 2. Key signature computation:
* a. Pre-computed key signature: The key lookup operation is split between
* two CPU cores. The first CPU core (typically the CPU core performing
* packet RX) extracts the key from the input packet, computes the key
* signature and saves both the key and the key signature in the packet
* buffer as packet meta-data. The second CPU core reads both the key and
* the key signature from the packet meta-data and performs the bucket
* search step of the key lookup operation.
* b. Key signature computed on lookup (do-sig): The same CPU core reads
* the key from the packet meta-data, uses it to compute the key
* signature and also performs the bucket search step of the key lookup
* operation.
* 3. Key size:
* a. Configurable key size
* b. Single key size (8-byte, 16-byte or 32-byte key size)
*
***/
#include
#include "rte_table.h"
/** Hash function */
typedef uint64_t (*rte_table_hash_op_hash)(
void *key,
uint32_t key_size,
uint64_t seed);
/**
* Hash tables with configurable key size
*
*/
/** Extendible bucket hash table parameters */
struct rte_table_hash_ext_params {
/** Key size (number of bytes) */
uint32_t key_size;
/** Maximum number of keys */
uint32_t n_keys;
/** Number of hash table buckets. Each bucket stores up to 4 keys. */
uint32_t n_buckets;
/** Number of hash table bucket extensions. Each bucket extension has
space for 4 keys and each bucket can have 0, 1 or more extensions. */
uint32_t n_buckets_ext;
/** Hash function */
rte_table_hash_op_hash f_hash;
/** Seed value for the hash function */
uint64_t seed;
/** Byte offset within packet meta-data where the 4-byte key signature
is located. Valid for pre-computed key signature tables, ignored for
do-sig tables. */
uint32_t signature_offset;
/** Byte offset within packet meta-data where the key is located */
uint32_t key_offset;
};
/** Extendible bucket hash table operations for pre-computed key signature */
extern struct rte_table_ops rte_table_hash_ext_ops;
/** Extendible bucket hash table operations for key signature computed on
lookup ("do-sig") */
extern struct rte_table_ops rte_table_hash_ext_dosig_ops;
/** LRU hash table parameters */
struct rte_table_hash_lru_params {
/** Key size (number of bytes) */
uint32_t key_size;
/** Maximum number of keys */
uint32_t n_keys;
/** Number of hash table buckets. Each bucket stores up to 4 keys. */
uint32_t n_buckets;
/** Hash function */
rte_table_hash_op_hash f_hash;
/** Seed value for the hash function */
uint64_t seed;
/** Byte offset within packet meta-data where the 4-byte key signature
is located. Valid for pre-computed key signature tables, ignored for
do-sig tables. */
uint32_t signature_offset;
/** Byte offset within packet meta-data where the key is located */
uint32_t key_offset;
};
/** LRU hash table operations for pre-computed key signature */
extern struct rte_table_ops rte_table_hash_lru_ops;
/** LRU hash table operations for key signature computed on lookup ("do-sig") */
extern struct rte_table_ops rte_table_hash_lru_dosig_ops;
/**
* 8-byte key hash tables
*
*/
/** LRU hash table parameters */
struct rte_table_hash_key8_lru_params {
/** Maximum number of entries (and keys) in the table */
uint32_t n_entries;
/** Hash function */
rte_table_hash_op_hash f_hash;
/** Seed for the hash function */
uint64_t seed;
/** Byte offset within packet meta-data where the 4-byte key signature
is located. Valid for pre-computed key signature tables, ignored for
do-sig tables. */
uint32_t signature_offset;
/** Byte offset within packet meta-data where the key is located */
uint32_t key_offset;
/** Bit-mask to be AND-ed to the key on lookup */
uint8_t *key_mask;
};
/** LRU hash table operations for pre-computed key signature */
extern struct rte_table_ops rte_table_hash_key8_lru_ops;
/** LRU hash table operations for key signature computed on lookup ("do-sig") */
extern struct rte_table_ops rte_table_hash_key8_lru_dosig_ops;
/** Extendible bucket hash table parameters */
struct rte_table_hash_key8_ext_params {
/** Maximum number of entries (and keys) in the table */
uint32_t n_entries;
/** Number of entries (and keys) for hash table bucket extensions. Each
bucket is extended in increments of 4 keys. */
uint32_t n_entries_ext;
/** Hash function */
rte_table_hash_op_hash f_hash;
/** Seed for the hash function */
uint64_t seed;
/** Byte offset within packet meta-data where the 4-byte key signature
is located. Valid for pre-computed key signature tables, ignored for
do-sig tables. */
uint32_t signature_offset;
/** Byte offset within packet meta-data where the key is located */
uint32_t key_offset;
/** Bit-mask to be AND-ed to the key on lookup */
uint8_t *key_mask;
};
/** Extendible bucket hash table operations for pre-computed key signature */
extern struct rte_table_ops rte_table_hash_key8_ext_ops;
/** Extendible bucket hash table operations for key signature computed on
lookup ("do-sig") */
extern struct rte_table_ops rte_table_hash_key8_ext_dosig_ops;
/**
* 16-byte key hash tables
*
*/
/** LRU hash table parameters */
struct rte_table_hash_key16_lru_params {
/** Maximum number of entries (and keys) in the table */
uint32_t n_entries;
/** Hash function */
rte_table_hash_op_hash f_hash;
/** Seed for the hash function */
uint64_t seed;
/** Byte offset within packet meta-data where the 4-byte key signature
is located. Valid for pre-computed key signature tables, ignored for
do-sig tables. */
uint32_t signature_offset;
/** Byte offset within packet meta-data where the key is located */
uint32_t key_offset;
/** Bit-mask to be AND-ed to the key on lookup */
uint8_t *key_mask;
};
/** LRU hash table operations for pre-computed key signature */
extern struct rte_table_ops rte_table_hash_key16_lru_ops;
/** LRU hash table operations for key signature computed on lookup
("do-sig") */
extern struct rte_table_ops rte_table_hash_key16_lru_dosig_ops;
/** Extendible bucket hash table parameters */
struct rte_table_hash_key16_ext_params {
/** Maximum number of entries (and keys) in the table */
uint32_t n_entries;
/** Number of entries (and keys) for hash table bucket extensions. Each
bucket is extended in increments of 4 keys. */
uint32_t n_entries_ext;
/** Hash function */
rte_table_hash_op_hash f_hash;
/** Seed for the hash function */
uint64_t seed;
/** Byte offset within packet meta-data where the 4-byte key signature
is located. Valid for pre-computed key signature tables, ignored for
do-sig tables. */
uint32_t signature_offset;
/** Byte offset within packet meta-data where the key is located */
uint32_t key_offset;
/** Bit-mask to be AND-ed to the key on lookup */
uint8_t *key_mask;
};
/** Extendible bucket operations for pre-computed key signature */
extern struct rte_table_ops rte_table_hash_key16_ext_ops;
/** Extendible bucket hash table operations for key signature computed on
lookup ("do-sig") */
extern struct rte_table_ops rte_table_hash_key16_ext_dosig_ops;
/**
* 32-byte key hash tables
*
*/
/** LRU hash table parameters */
struct rte_table_hash_key32_lru_params {
/** Maximum number of entries (and keys) in the table */
uint32_t n_entries;
/** Hash function */
rte_table_hash_op_hash f_hash;
/** Seed for the hash function */
uint64_t seed;
/** Byte offset within packet meta-data where the 4-byte key signature
is located. Valid for pre-computed key signature tables, ignored for
do-sig tables. */
uint32_t signature_offset;
/** Byte offset within packet meta-data where the key is located */
uint32_t key_offset;
};
/** LRU hash table operations for pre-computed key signature */
extern struct rte_table_ops rte_table_hash_key32_lru_ops;
/** Extendible bucket hash table parameters */
struct rte_table_hash_key32_ext_params {
/** Maximum number of entries (and keys) in the table */
uint32_t n_entries;
/** Number of entries (and keys) for hash table bucket extensions. Each
bucket is extended in increments of 4 keys. */
uint32_t n_entries_ext;
/** Hash function */
rte_table_hash_op_hash f_hash;
/** Seed for the hash function */
uint64_t seed;
/** Byte offset within packet meta-data where the 4-byte key signature
is located. Valid for pre-computed key signature tables, ignored for
do-sig tables. */
uint32_t signature_offset;
/** Byte offset within packet meta-data where the key is located */
uint32_t key_offset;
};
/** Extendible bucket hash table operations */
extern struct rte_table_ops rte_table_hash_key32_ext_ops;
#ifdef __cplusplus
}
#endif
#endif