rte_thash_x86_gfni.h

Go to the documentation of this file.

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2021 Intel Corporation
 */

#ifndef _RTE_THASH_X86_GFNI_H_
#define _RTE_THASH_X86_GFNI_H_

#include <rte_bitops.h>
#include <rte_compat.h>
#include <rte_vect.h>

#ifdef __cplusplus
extern "C" {
#endif

#if defined(__GFNI__) && defined(__AVX512F__)
#define RTE_THASH_GFNI_DEFINED

#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;

    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);

#ifdef RTE_ARCH_X86_64
    uint64_t tmp_1, tmp_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);
#else
    uint32_t tmp_1, tmp_2;
    tmp_1 = _mm_extract_epi32(tmp128_1, 0);
    tmp_2 = _mm_extract_epi32(tmp128_1, 1);
    tmp_1 ^= _mm_extract_epi32(tmp128_1, 2);
    tmp_2 ^= _mm_extract_epi32(tmp128_1, 3);

    *val_1 = tmp_1;
    *val_2 = tmp_2;
#endif
}

__rte_internal
static inline __m512i
__rte_thash_gfni(const uint64_t *mtrx, const uint8_t *tuple,
    const uint8_t *secondary_tuple, int len)
{
    __m512i permute_idx = _mm512_set_epi32(0x07060504, 0x07060504,
        0x06050403, 0x06050403,
        0x05040302, 0x05040302,
        0x04030201, 0x04030201,
        0x03020100, 0x03020100,
        0x020100FF, 0x020100FF,
        0x0100FFFE, 0x0100FFFE,
        0x00FFFEFD, 0x00FFFEFD);
    const __m512i rewind_idx = _mm512_set_epi32(0x00000000, 0x00000000,
        0x00000000, 0x00000000,
        0x00000000, 0x00000000,
        0x00000000, 0x00000000,
        0x00000000, 0x00000000,
        0x0000003B, 0x0000003B,
        0x00003B3A, 0x00003B3A,
        0x003B3A39, 0x003B3A39);
    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_2;
    __m512i tuple_bytes = _mm512_setzero_si512();
    __mmask64 load_mask, permute_mask_2;
    __mmask64 permute_mask = 0;
    int chunk_len = 0, i = 0;
    uint8_t mtrx_msk;
    const int prepend = 3;

    for (; len > 0; len -= 64, tuple += 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 = rte_popcount64(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;
}

static inline uint32_t
rte_thash_gfni(const uint64_t *m, const 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;
}

static inline void
rte_thash_gfni_bulk(const uint64_t *mtrx, int len, uint8_t *tuple[],
    uint32_t val[], uint32_t num)
{
    uint32_t i;
    uint32_t val_zero;
    __m512i xor_acc;

    for (i = 0; i != (num & ~1); i += 2) {
        xor_acc = __rte_thash_gfni(mtrx, tuple[i], tuple[i + 1], len);
        __rte_thash_xor_reduce(xor_acc, val + i, val + i + 1);
    }

    if (num & 1) {
        xor_acc = __rte_thash_gfni(mtrx, tuple[i], NULL, len);
        __rte_thash_xor_reduce(xor_acc, val + i, &val_zero);
    }
}

#endif /* __GFNI__ && __AVX512F__ */

#ifdef __cplusplus
}
#endif

#endif /* _RTE_THASH_X86_GFNI_H_ */