> This patch add a new Toeplitz hash implementation using
> Galios Fields New Instructions (GFNI).
>
> Signed-off-by: Vladimir Medvedkin <vladimir.medved...@intel.com>
> ---
> doc/api/doxy-api-index.md | 1 +
> lib/hash/meson.build | 1 +
> lib/hash/rte_thash.c | 26 ++++++
> lib/hash/rte_thash.h | 22 +++++
> lib/hash/rte_thash_gfni.h | 229
> ++++++++++++++++++++++++++++++++++++++++++++++
> lib/hash/version.map | 2 +
> 6 files changed, 281 insertions(+)
> create mode 100644 lib/hash/rte_thash_gfni.h
>
> diff --git a/doc/api/doxy-api-index.md b/doc/api/doxy-api-index.md
> index 1992107..7549477 100644
> --- a/doc/api/doxy-api-index.md
> +++ b/doc/api/doxy-api-index.md
> @@ -139,6 +139,7 @@ The public API headers are grouped by topics:
> [hash] (@ref rte_hash.h),
> [jhash] (@ref rte_jhash.h),
> [thash] (@ref rte_thash.h),
> + [thash_gfni] (@ref rte_thash_gfni.h),
> [FBK hash] (@ref rte_fbk_hash.h),
> [CRC hash] (@ref rte_hash_crc.h)
>
> diff --git a/lib/hash/meson.build b/lib/hash/meson.build
> index 9bc5ef9..40444ac 100644
> --- a/lib/hash/meson.build
> +++ b/lib/hash/meson.build
> @@ -7,6 +7,7 @@ headers = files(
> 'rte_hash.h',
> 'rte_jhash.h',
> 'rte_thash.h',
> + 'rte_thash_gfni.h',
> )
> indirect_headers += files('rte_crc_arm64.h')
>
> diff --git a/lib/hash/rte_thash.c b/lib/hash/rte_thash.c
> index d5a95a6..07447f7 100644
> --- a/lib/hash/rte_thash.c
> +++ b/lib/hash/rte_thash.c
> @@ -11,6 +11,7 @@
> #include <rte_eal_memconfig.h>
> #include <rte_log.h>
> #include <rte_malloc.h>
> +#include <rte_thash_gfni.h>
>
> #define THASH_NAME_LEN 64
> #define TOEPLITZ_HASH_LEN 32
> @@ -88,6 +89,23 @@ struct rte_thash_ctx {
> uint8_t hash_key[0];
> };
>
> +uint8_t rte_thash_gfni_supported;
.. = 0;
?
> +
> +void
> +rte_thash_complete_matrix(uint64_t *matrixes, uint8_t *rss_key, int size)
> +{
> + int i, j;
> + uint8_t *m = (uint8_t *)matrixes;
> +
> + for (i = 0; i < size; i++) {
> + for (j = 0; j < 8; j++) {
> + m[i * 8 + j] = (rss_key[i] << j)|
> + (uint8_t)((uint16_t)(rss_key[i + 1]) >>
> + (8 - j));
> + }
> + }
> +}
> +
> static inline uint32_t
> get_bit_lfsr(struct thash_lfsr *lfsr)
> {
> @@ -759,3 +777,11 @@ rte_thash_adjust_tuple(struct rte_thash_ctx *ctx,
>
> return ret;
> }
> +
> +RTE_INIT(rte_thash_gfni_init)
> +{
> +#ifdef __GFNI__
> + if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_GFNI))
> + rte_thash_gfni_supported = 1;
> +#endif
> +}
> diff --git a/lib/hash/rte_thash.h b/lib/hash/rte_thash.h
> index 76109fc..e3f1fc6 100644
> --- a/lib/hash/rte_thash.h
> +++ b/lib/hash/rte_thash.h
> @@ -28,6 +28,7 @@ extern "C" {
> #include <rte_config.h>
> #include <rte_ip.h>
> #include <rte_common.h>
> +#include <rte_thash_gfni.h>
>
> #if defined(RTE_ARCH_X86) || defined(__ARM_NEON)
> #include <rte_vect.h>
> @@ -113,6 +114,8 @@ union rte_thash_tuple {
> };
> #endif
>
> +extern uint8_t rte_thash_gfni_supported;
> +
> /**
> * Prepare special converted key to use with rte_softrss_be()
> * @param orig
> @@ -223,6 +226,25 @@ rte_softrss_be(uint32_t *input_tuple, uint32_t input_len,
> return ret;
> }
>
> +/**
> + * Converts Toeplitz hash key (RSS key) into matrixes required
> + * for GFNI implementation
> + *
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * @param matrixes
> + * pointer to the memory where matrixes will be writen.
> + * Note: the size of this memory must be equal to size * 8
> + * @param rss_key
> + * pointer to the Toeplitz hash key
> + * @param size
> + * Size of the rss_key in bytes.
> + */
> +__rte_experimental
> +void
> +rte_thash_complete_matrix(uint64_t *matrixes, uint8_t *rss_key, int size);
> +
> /** @internal Logarithm of minimum size of the RSS ReTa */
> #define RTE_THASH_RETA_SZ_MIN 2U
> /** @internal Logarithm of maximum size of the RSS ReTa */
> diff --git a/lib/hash/rte_thash_gfni.h b/lib/hash/rte_thash_gfni.h
> new file mode 100644
> index 0000000..8f89d7d
> --- /dev/null
> +++ b/lib/hash/rte_thash_gfni.h
> @@ -0,0 +1,229 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2021 Intel Corporation
> + */
> +
> +#ifndef _RTE_THASH_GFNI_H_
> +#define _RTE_THASH_GFNI_H_
> +
> +/**
> + * @file
> + *
> + * Optimized Toeplitz hash functions implementation
> + * using Galois Fields New Instructions.
> + */
> +
> +#include <rte_vect.h>
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +#ifdef __GFNI__
> +
> +#define RTE_THASH_FIRST_ITER_MSK 0x0f0f0f0f0f0e0c08
> +#define RTE_THASH_PERM_MSK 0x0f0f0f0f0f0f0f0f
> +#define RTE_THASH_FIRST_ITER_MSK_2 0xf0f0f0f0f0e0c080
> +#define RTE_THASH_PERM_MSK_2 0xf0f0f0f0f0f0f0f0
> +#define RTE_THASH_REWIND_MSK 0x0000000000113377
> +
> +__rte_internal
> +static inline void
> +__rte_thash_xor_reduce(__m512i xor_acc, uint32_t *val_1, uint32_t *val_2)
> +{
> + __m256i tmp_256_1, tmp_256_2;
> + __m128i tmp128_1, tmp128_2;
> + uint64_t tmp_1, tmp_2;
> +
> + tmp_256_1 = _mm512_castsi512_si256(xor_acc);
> + tmp_256_2 = _mm512_extracti32x8_epi32(xor_acc, 1);
> + tmp_256_1 = _mm256_xor_si256(tmp_256_1, tmp_256_2);
> +
> + tmp128_1 = _mm256_castsi256_si128(tmp_256_1);
> + tmp128_2 = _mm256_extracti32x4_epi32(tmp_256_1, 1);
> + tmp128_1 = _mm_xor_si128(tmp128_1, tmp128_2);
> +
> + tmp_1 = _mm_extract_epi64(tmp128_1, 0);
> + tmp_2 = _mm_extract_epi64(tmp128_1, 1);
> + tmp_1 ^= tmp_2;
> +
> + *val_1 = (uint32_t)tmp_1;
> + *val_2 = (uint32_t)(tmp_1 >> 32);
> +}
> +
> +__rte_internal
> +static inline __m512i
> +__rte_thash_gfni(uint64_t *mtrx, uint8_t *tuple, uint8_t *secondary_tuple,
> + int len)
Here and in other fast-path functions:
const uint64_t *mtrx
> +{
> + __m512i permute_idx = _mm512_set_epi8(7, 6, 5, 4, 7, 6, 5, 4,
> + 6, 5, 4, 3, 6, 5, 4, 3,
> + 5, 4, 3, 2, 5, 4, 3, 2,
> + 4, 3, 2, 1, 4, 3, 2, 1,
> + 3, 2, 1, 0, 3, 2, 1, 0,
> + 2, 1, 0, -1, 2, 1, 0, -1,
> + 1, 0, -1, -2, 1, 0, -1, -2,
> + 0, -1, -2, -3, 0, -1, -2, -3);
> +
> + const __m512i rewind_idx = _mm512_set_epi8(0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 59, 0, 0, 0, 59,
> + 0, 0, 59, 58, 0, 0, 59, 58,
> + 0, 59, 58, 57, 0, 59, 58, 57);
> + const __mmask64 rewind_mask = RTE_THASH_REWIND_MSK;
> + const __m512i shift_8 = _mm512_set1_epi8(8);
> + __m512i xor_acc = _mm512_setzero_si512();
> + __m512i perm_bytes = _mm512_setzero_si512();
> + __m512i vals, matrixes, tuple_bytes, tuple_bytes_2;
> + __mmask64 load_mask, permute_mask, permute_mask_2;
> + int chunk_len = 0, i = 0;
> + uint8_t mtrx_msk;
> + const int prepend = 3;
> +
> + for (; len > 0; len -= 64, tuple += 64) {
What will happen if len < 64?
> + if (i == 8)
> + perm_bytes = _mm512_maskz_permutexvar_epi8(rewind_mask,
> + rewind_idx, perm_bytes);
> +
> + permute_mask = RTE_THASH_FIRST_ITER_MSK;
> + load_mask = (len >= 64) ? UINT64_MAX : ((1ULL << len) - 1);
> + tuple_bytes = _mm512_maskz_loadu_epi8(load_mask, tuple);
> + if (secondary_tuple) {
> + permute_mask_2 = RTE_THASH_FIRST_ITER_MSK_2;
> + tuple_bytes_2 = _mm512_maskz_loadu_epi8(load_mask,
> + secondary_tuple);
> + }
> +
> + chunk_len = __builtin_popcountll(load_mask);
> + for (i = 0; i < ((chunk_len + prepend) / 8); i++, mtrx += 8) {
> + perm_bytes = _mm512_mask_permutexvar_epi8(perm_bytes,
> + permute_mask, permute_idx, tuple_bytes);
> +
> + if (secondary_tuple)
> + perm_bytes =
> + _mm512_mask_permutexvar_epi8(perm_bytes,
> + permute_mask_2, permute_idx,
> + tuple_bytes_2);
> +
> + matrixes = _mm512_maskz_loadu_epi64(UINT8_MAX, mtrx);
> + vals = _mm512_gf2p8affine_epi64_epi8(perm_bytes,
> + matrixes, 0);
> +
> + xor_acc = _mm512_xor_si512(xor_acc, vals);
> + permute_idx = _mm512_add_epi8(permute_idx, shift_8);
> + permute_mask = RTE_THASH_PERM_MSK;
> + if (secondary_tuple)
> + permute_mask_2 = RTE_THASH_PERM_MSK_2;
> + }
> + }
> +
> + int rest_len = (chunk_len + prepend) % 8;
> + if (rest_len != 0) {
> + mtrx_msk = (1 << (rest_len % 8)) - 1;
> + matrixes = _mm512_maskz_loadu_epi64(mtrx_msk, mtrx);
> + if (i == 8) {
> + perm_bytes = _mm512_maskz_permutexvar_epi8(rewind_mask,
> + rewind_idx, perm_bytes);
> + } else {
> + perm_bytes = _mm512_mask_permutexvar_epi8(perm_bytes,
> + permute_mask, permute_idx, tuple_bytes);
> +
> + if (secondary_tuple)
> + perm_bytes =
> + _mm512_mask_permutexvar_epi8(
> + perm_bytes, permute_mask_2,
> + permute_idx, tuple_bytes_2);
> + }
> +
> + vals = _mm512_gf2p8affine_epi64_epi8(perm_bytes, matrixes, 0);
> + xor_acc = _mm512_xor_si512(xor_acc, vals);
> + }
> +
> + return xor_acc;
> +}
> +
> +/**
> + * Calculate Toeplitz hash.
> + *
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * @param m
> + * Pointer to the matrices generated from the corresponding
> + * RSS hash key using rte_thash_complete_matrix().
> + * @param tuple
> + * Pointer to the data to be hashed. Data must be in network byte order.
> + * @param len
> + * Length of the data to be hashed.
> + * @return
> + * Calculated Toeplitz hash value.
> + */
> +__rte_experimental
> +static inline uint32_t
> +rte_thash_gfni(uint64_t *m, uint8_t *tuple, int len)
> +{
> + uint32_t val, val_zero;
> +
> + __m512i xor_acc = __rte_thash_gfni(m, tuple, NULL, len);
> + __rte_thash_xor_reduce(xor_acc, &val, &val_zero);
> +
> + return val;
> +}
> +
> +/**
> + * Calculate Toeplitz hash for two independent data buffers.
> + *
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * @param m
> + * Pointer to the matrices generated from the corresponding
> + * RSS hash key using rte_thash_complete_matrix().
> + * @param tuple_1
> + * Pointer to the data to be hashed. Data must be in network byte order.
> + * @param tuple_2
> + * Pointer to the data to be hashed. Data must be in network byte order.
> + * @param len
> + * Length of the largest data buffer to be hashed.
> + * @param val_1
> + * Pointer to uint32_t where to put calculated Toeplitz hash value for
> + * the first tuple.
> + * @param val_2
> + * Pointer to uint32_t where to put calculated Toeplitz hash value for
> + * the second tuple.
> + */
> +__rte_experimental
> +static inline void
> +rte_thash_gfni_x2(uint64_t *mtrx, uint8_t *tuple_1, uint8_t *tuple_2, int
> len,
> + uint32_t *val_1, uint32_t *val_2)
Why just two?
Why not uint8_t *tuple[]
?
> +{
> + __m512i xor_acc = __rte_thash_gfni(mtrx, tuple_1, tuple_2, len);
> + __rte_thash_xor_reduce(xor_acc, val_1, val_2);
> +}
> +
> +#else /* __GFNI__ */
> +
> +static inline uint32_t
> +rte_thash_gfni(uint64_t *mtrx __rte_unused, uint8_t *key __rte_unused,
> + int len __rte_unused)
> +{
> + return 0;
> +}
> +
> +static inline void
> +rte_thash_gfni_x2(uint64_t *mtrx __rte_unused, uint8_t *tuple_1 __rte_unused,
> + uint8_t *tuple_2 __rte_unused, int len __rte_unused,
> + uint32_t *val_1 __rte_unused, uint32_t *val_2 __rte_unused)
> +{
> +
That seems inconsistent with dummy rte_thash_gfni() above.
Should be:
*val_1 = 0; *val_2 = 0;
I think.
> +}
> +
> +#endif
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif /* _RTE_THASH_GFNI_H_ */
> diff --git a/lib/hash/version.map b/lib/hash/version.map
> index ce4309a..cecf922 100644
> --- a/lib/hash/version.map
> +++ b/lib/hash/version.map
> @@ -39,10 +39,12 @@ EXPERIMENTAL {
> rte_hash_rcu_qsbr_add;
> rte_thash_add_helper;
> rte_thash_adjust_tuple;
> + rte_thash_complete_matrix;
> rte_thash_find_existing;
> rte_thash_free_ctx;
> rte_thash_get_complement;
> rte_thash_get_helper;
> rte_thash_get_key;
> + rte_thash_gfni_supported;
> rte_thash_init_ctx;
> };
> --
> 2.7.4
