rte_efd.h

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/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2016-2017 Intel Corporation
 */

#ifndef _RTE_EFD_H_
#define _RTE_EFD_H_

#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

/*************************************************************************
 * User selectable constants
 *************************************************************************/

/*
 * If possible, best lookup performance will be achieved by ensuring that
 * the entire table fits in the L3 cache.
 *
 * Some formulas for calculating various sizes are listed below:
 *
 * # of chunks =
 *   2 ^ (ceiling(log2((requested # of rules) /
 *            (EFD_CHUNK_NUM_GROUPS * EFD_TARGET_GROUP_NUM_RULES))))
 *
 * Target # of rules = (# of chunks) * EFD_CHUNK_NUM_GROUPS *
 *            EFD_TARGET_GROUP_NUM_RULES
 *
 * Group Size (in bytes) = 4 (per value bit)
 *
 * Table size (in bytes) = RTE_EFD_VALUE_NUM_BITS * (# of chunks) *
 *            EFD_CHUNK_NUM_GROUPS * (group size)
 */

#ifndef RTE_EFD_VALUE_NUM_BITS
#define RTE_EFD_VALUE_NUM_BITS (8)
#endif

/*
 * EFD_TARGET_GROUP_NUM_RULES:
 *   Adjusts how many groups/chunks are allocated at table creation time
 *   to support the requested number of rules. Higher values pack entries
 *   more tightly in memory, resulting in a smaller memory footprint
 *   for the online table.
 *   This comes at the cost of lower insert/update performance.
 *
 * EFD_MAX_GROUP_NUM_RULES:
 *   This adjusts the amount of offline memory allocated to store key/value
 *   pairs for the table. The recommended numbers are upper-bounds for
 *   this parameter
 *   - any higher and it becomes very unlikely that a perfect hash function
 *   can be found for that group size. This value should be at
 *   least 40% larger than EFD_TARGET_GROUP_NUM_RULES
 *
 * Recommended values for various lookuptable and hashfunc sizes are:
 *
 *   HASH_FUNC_SIZE = 16, LOOKUPTBL_SIZE = 16:
 *     EFD_TARGET_GROUP_NUM_RULES = 22
 *     EFD_MAX_GROUP_NUM_RULES = 28
 */
#define EFD_TARGET_GROUP_NUM_RULES (22)
#define EFD_MAX_GROUP_NUM_RULES (28LU)

#define EFD_MIN_BALANCED_NUM_RULES      5

#ifndef RTE_EFD_BURST_MAX
#define RTE_EFD_BURST_MAX (32)
#endif

#define RTE_EFD_NAMESIZE                        32

#if (RTE_EFD_VALUE_NUM_BITS > 0 && RTE_EFD_VALUE_NUM_BITS <= 8)
typedef uint8_t efd_value_t;
#elif (RTE_EFD_VALUE_NUM_BITS > 8 && RTE_EFD_VALUE_NUM_BITS <= 16)
typedef uint16_t efd_value_t;
#elif (RTE_EFD_VALUE_NUM_BITS > 16 && RTE_EFD_VALUE_NUM_BITS <= 32)
typedef uint32_t efd_value_t;
#else
#error("RTE_EFD_VALUE_NUM_BITS must be in the range [1:32]")
#endif

#define EFD_LOOKUPTBL_SHIFT (32 - 4)
typedef uint16_t efd_lookuptbl_t;
typedef uint16_t efd_hashfunc_t;

struct rte_efd_table *
rte_efd_create(const char *name, uint32_t max_num_rules, uint32_t key_len,
        uint8_t online_cpu_socket_bitmask, uint8_t offline_cpu_socket);

void
rte_efd_free(struct rte_efd_table *table);

struct rte_efd_table*
rte_efd_find_existing(const char *name);

#define RTE_EFD_UPDATE_WARN_GROUP_FULL   (1)
#define RTE_EFD_UPDATE_NO_CHANGE         (2)
#define RTE_EFD_UPDATE_FAILED            (3)

int
rte_efd_update(struct rte_efd_table *table, unsigned int socket_id,
        const void *key, efd_value_t value);

int
rte_efd_delete(struct rte_efd_table *table, unsigned int socket_id,
        const void *key, efd_value_t *prev_value);

efd_value_t
rte_efd_lookup(const struct rte_efd_table *table, unsigned int socket_id,
                const void *key);

void
rte_efd_lookup_bulk(const struct rte_efd_table *table, unsigned int socket_id,
                int num_keys, const void **key_list,
                efd_value_t *value_list);

#ifdef __cplusplus
}
#endif

#endif /* _RTE_EFD_H_ */