rte_lpm_neon.h

/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2015 Cavium Networks. All rights reserved.
 *   All rights reserved.
 *
 *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
 *   All rights reserved.
 *
 *   Derived rte_lpm_lookupx4 implementation from lib/librte_lpm/rte_lpm_sse.h
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Cavium Networks nor the names of its
 *       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
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _RTE_LPM_NEON_H_
#define _RTE_LPM_NEON_H_

#include <rte_branch_prediction.h>
#include <rte_byteorder.h>
#include <rte_common.h>
#include <rte_vect.h>
#include <rte_lpm.h>

#ifdef __cplusplus
extern "C" {
#endif

static inline void
rte_lpm_lookupx4(const struct rte_lpm *lpm, xmm_t ip, uint32_t hop[4],
    uint32_t defv)
{
    uint32x4_t i24;
    rte_xmm_t i8;
    uint32_t tbl[4];
    uint64_t idx, pt, pt2;
    const uint32_t *ptbl;

    const uint32_t mask = UINT8_MAX;
    const int32x4_t mask8 = vdupq_n_s32(mask);

    /*
     * RTE_LPM_VALID_EXT_ENTRY_BITMASK for 2 LPM entries
     * as one 64-bit value (0x0300000003000000).
     */
    const uint64_t mask_xv =
        ((uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK |
        (uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK << 32);

    /*
     * RTE_LPM_LOOKUP_SUCCESS for 2 LPM entries
     * as one 64-bit value (0x0100000001000000).
     */
    const uint64_t mask_v =
        ((uint64_t)RTE_LPM_LOOKUP_SUCCESS |
        (uint64_t)RTE_LPM_LOOKUP_SUCCESS << 32);

    /* get 4 indexes for tbl24[]. */
    i24 = vshrq_n_u32((uint32x4_t)ip, CHAR_BIT);

    /* extract values from tbl24[] */
    idx = vgetq_lane_u64((uint64x2_t)i24, 0);

    ptbl = (const uint32_t *)&lpm->tbl24[(uint32_t)idx];
    tbl[0] = *ptbl;
    ptbl = (const uint32_t *)&lpm->tbl24[idx >> 32];
    tbl[1] = *ptbl;

    idx = vgetq_lane_u64((uint64x2_t)i24, 1);

    ptbl = (const uint32_t *)&lpm->tbl24[(uint32_t)idx];
    tbl[2] = *ptbl;
    ptbl = (const uint32_t *)&lpm->tbl24[idx >> 32];
    tbl[3] = *ptbl;

    /* get 4 indexes for tbl8[]. */
    i8.x = vandq_s32(ip, mask8);

    pt = (uint64_t)tbl[0] |
        (uint64_t)tbl[1] << 32;
    pt2 = (uint64_t)tbl[2] |
        (uint64_t)tbl[3] << 32;

    /* search successfully finished for all 4 IP addresses. */
    if (likely((pt & mask_xv) == mask_v) &&
            likely((pt2 & mask_xv) == mask_v)) {
        *(uint64_t *)hop = pt & RTE_LPM_MASKX4_RES;
        *(uint64_t *)(hop + 2) = pt2 & RTE_LPM_MASKX4_RES;
        return;
    }

    if (unlikely((pt & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
            RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
        i8.u32[0] = i8.u32[0] +
            (uint8_t)tbl[0] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
        ptbl = (const uint32_t *)&lpm->tbl8[i8.u32[0]];
        tbl[0] = *ptbl;
    }
    if (unlikely((pt >> 32 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
            RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
        i8.u32[1] = i8.u32[1] +
            (uint8_t)tbl[1] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
        ptbl = (const uint32_t *)&lpm->tbl8[i8.u32[1]];
        tbl[1] = *ptbl;
    }
    if (unlikely((pt2 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
            RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
        i8.u32[2] = i8.u32[2] +
            (uint8_t)tbl[2] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
        ptbl = (const uint32_t *)&lpm->tbl8[i8.u32[2]];
        tbl[2] = *ptbl;
    }
    if (unlikely((pt2 >> 32 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
            RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
        i8.u32[3] = i8.u32[3] +
            (uint8_t)tbl[3] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
        ptbl = (const uint32_t *)&lpm->tbl8[i8.u32[3]];
        tbl[3] = *ptbl;
    }

    hop[0] = (tbl[0] & RTE_LPM_LOOKUP_SUCCESS) ? tbl[0] & 0x00FFFFFF : defv;
    hop[1] = (tbl[1] & RTE_LPM_LOOKUP_SUCCESS) ? tbl[1] & 0x00FFFFFF : defv;
    hop[2] = (tbl[2] & RTE_LPM_LOOKUP_SUCCESS) ? tbl[2] & 0x00FFFFFF : defv;
    hop[3] = (tbl[3] & RTE_LPM_LOOKUP_SUCCESS) ? tbl[3] & 0x00FFFFFF : defv;
}

#ifdef __cplusplus
}
#endif

#endif /* _RTE_LPM_NEON_H_ */