> -----Original Message-----
> From: Medvedkin, Vladimir <vladimir.medved...@intel.com>
> Sent: Tuesday, April 13, 2021 6:20 AM
> To: dev@dpdk.org
> Cc: Ananyev, Konstantin <konstantin.anan...@intel.com>; Chilikin, Andrey
> <andrey.chili...@intel.com>; Kinsella, Ray <ray.kinse...@intel.com>; Wang,
> Yipeng1 <yipeng1.w...@intel.com>; Gobriel, Sameh
> <sameh.gobr...@intel.com>; Richardson, Bruce
> <bruce.richard...@intel.com>
> Subject: [PATCH v4 1/3] hash: add predictable RSS API
>
> This patch adds predictable RSS API.
> It is based on the idea of searching partial Toeplitz hash collisions.
>
> Signed-off-by: Vladimir Medvedkin <vladimir.medved...@intel.com>
> ---
> lib/librte_hash/meson.build | 3 +-
> lib/librte_hash/rte_thash.c | 109 ++++++++++++++++++++++++
> lib/librte_hash/rte_thash.h | 198
> ++++++++++++++++++++++++++++++++++++++++++++
> lib/librte_hash/version.map | 8 ++
> 4 files changed, 317 insertions(+), 1 deletion(-) create mode 100644
> lib/librte_hash/rte_thash.c
>
> diff --git a/lib/librte_hash/meson.build b/lib/librte_hash/meson.build index
> 242859f..3546014 100644
> --- a/lib/librte_hash/meson.build
> +++ b/lib/librte_hash/meson.build
> @@ -8,6 +8,7 @@ headers = files('rte_fbk_hash.h',
> 'rte_thash.h')
> indirect_headers += files('rte_crc_arm64.h')
>
> -sources = files('rte_cuckoo_hash.c', 'rte_fbk_hash.c')
> +sources = files('rte_cuckoo_hash.c', 'rte_fbk_hash.c', 'rte_thash.c')
> +deps += ['net']
> deps += ['ring']
> deps += ['rcu']
> diff --git a/lib/librte_hash/rte_thash.c b/lib/librte_hash/rte_thash.c new
> file
> mode 100644 index 0000000..1325678
> --- /dev/null
> +++ b/lib/librte_hash/rte_thash.c
> @@ -0,0 +1,109 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2021 Intel Corporation
> + */
> +
> +#include <rte_thash.h>
> +#include <rte_tailq.h>
> +#include <rte_random.h>
> +#include <rte_memcpy.h>
> +#include <rte_errno.h>
> +#include <rte_eal.h>
> +#include <rte_eal_memconfig.h>
> +#include <rte_malloc.h>
> +
> +#define THASH_NAME_LEN 64
> +
> +struct thash_lfsr {
> + uint32_t ref_cnt;
> + uint32_t poly;
> + /**< polynomial associated with the lfsr */
> + uint32_t rev_poly;
> + /**< polynomial to generate the sequence in reverse direction */
> + uint32_t state;
> + /**< current state of the lfsr */
> + uint32_t rev_state;
> + /**< current state of the lfsr for reverse direction */
> + uint32_t deg; /**< polynomial degree*/
> + uint32_t bits_cnt; /**< number of bits generated by lfsr*/
> +};
> +
> +struct rte_thash_subtuple_helper {
> + char name[THASH_NAME_LEN]; /** < Name of subtuple
> configuration */
> + LIST_ENTRY(rte_thash_subtuple_helper) next;
> + struct thash_lfsr *lfsr;
> + uint32_t offset; /** < Offset of the m-sequence */
> + uint32_t len; /** < Length of the m-sequence */
> + uint32_t tuple_offset; /** < Offset in bits of the subtuple */
> + uint32_t tuple_len; /** < Length in bits of the subtuple
> */
> + uint32_t lsb_msk; /** < (1 << reta_sz_log) - 1 */
> + __extension__ uint32_t compl_table[0] __rte_cache_aligned;
> + /** < Complementary table */
> +};
> +
> +struct rte_thash_ctx {
> + char name[THASH_NAME_LEN];
> + LIST_HEAD(, rte_thash_subtuple_helper) head;
> + uint32_t key_len; /** < Length of the NIC RSS hash key
> */
> + uint32_t reta_sz_log; /** < size of the RSS ReTa in bits */
> + uint32_t subtuples_nb; /** < number of subtuples */
> + uint32_t flags;
> + uint8_t hash_key[0];
> +};
> +
> +struct rte_thash_ctx *
> +rte_thash_init_ctx(const char *name __rte_unused,
> + uint32_t key_len __rte_unused, uint32_t reta_sz __rte_unused,
> + uint8_t *key __rte_unused, uint32_t flags __rte_unused) {
> + return NULL;
> +}
> +
> +struct rte_thash_ctx *
> +rte_thash_find_existing(const char *name __rte_unused) {
> + return NULL;
> +}
> +
> +void
> +rte_thash_free_ctx(struct rte_thash_ctx *ctx __rte_unused) { }
> +
> +int
> +rte_thash_add_helper(struct rte_thash_ctx *ctx __rte_unused,
> + const char *name __rte_unused, uint32_t len __rte_unused,
> + uint32_t offset __rte_unused)
> +{
> + return 0;
> +}
> +
> +struct rte_thash_subtuple_helper *
> +rte_thash_get_helper(struct rte_thash_ctx *ctx __rte_unused,
> + const char *name __rte_unused)
> +{
> + return NULL;
> +}
> +
> +uint32_t
> +rte_thash_get_complement(struct rte_thash_subtuple_helper *h
> __rte_unused,
> + uint32_t hash __rte_unused, uint32_t desired_hash __rte_unused) {
> + return 0;
> +}
> +
> +const uint8_t *
> +rte_thash_get_key(struct rte_thash_ctx *ctx __rte_unused) {
> + return NULL;
> +}
> +
> +int
> +rte_thash_adjust_tuple(struct rte_thash_ctx *ctx __rte_unused,
> + struct rte_thash_subtuple_helper *h __rte_unused,
> + uint8_t *tuple __rte_unused, unsigned int tuple_len __rte_unused,
> + uint32_t desired_value __rte_unused,
> + unsigned int attempts __rte_unused,
> + rte_thash_check_tuple_t fn __rte_unused, void *userdata
> __rte_unused)
> +{
> + return 0;
> +}
> diff --git a/lib/librte_hash/rte_thash.h b/lib/librte_hash/rte_thash.h index
> 061efa2..f3e05fc 100644
> --- a/lib/librte_hash/rte_thash.h
> +++ b/lib/librte_hash/rte_thash.h
> @@ -1,5 +1,6 @@
> /* SPDX-License-Identifier: BSD-3-Clause
> * Copyright(c) 2015-2019 Vladimir Medvedkin <medvedk...@gmail.com>
> + * Copyright(c) 2021 Intel Corporation
> */
>
> #ifndef _RTE_THASH_H
> @@ -222,6 +223,203 @@ rte_softrss_be(uint32_t *input_tuple, uint32_t
> input_len,
> return ret;
> }
>
> +/** @internal Minimum size of the RSS ReTa */
[Wang, Yipeng] Logarithm of minimum size.
> +#define RTE_THASH_RETA_SZ_MIN 2U
> +/** @internal Maximum size of the RSS ReTa */
> +#define RTE_THASH_RETA_SZ_MAX 16U
> +
> +/**
> + * LFSR will ignore if generated m-sequence has more than 2^n -1 bits
[Wang, Yipeng] Have you mentioned what is n here in the comment?
> +*/
<snip>
> };
> --
> 2.7.4
[Wang, Yipeng]
Acked-by: Yipeng Wang <yipeng1.w...@intel.com>
