From: sunyuechi@iscas.ac.cn
To: dev@dpdk.org
Cc: Zijian <zijian.oerv@isrc.iscas.ac.cn>,
"Stanisław Kardach" <stanislaw.kardach@gmail.com>,
"Nithin Dabilpuram" <ndabilpuram@marvell.com>,
"Pavan Nikhilesh" <pbhagavatula@marvell.com>
Subject: Re: [PATCH] node: lookup with RISC-V vector extension
Date: Fri, 5 Dec 2025 18:56:37 +0800 (GMT+08:00) [thread overview]
Message-ID: <3904297.3ad64.19aee281d5c.Coremail.sunyuechi@iscas.ac.cn> (raw)
In-Reply-To: <20251116155001.2809998-1-sunyuechi@iscas.ac.cn>
ping
> -----原始邮件-----
> 发件人: "Sun Yuechi" <sunyuechi@iscas.ac.cn>
> 发送时间: 2025-11-16 23:50:01 (星期日)
> 收件人: dev@dpdk.org
> 抄送: "Sun Yuechi" <sunyuechi@iscas.ac.cn>, Zijian <zijian.oerv@isrc.iscas.ac.cn>, "Stanisław Kardach" <stanislaw.kardach@gmail.com>, "Nithin Dabilpuram" <ndabilpuram@marvell.com>, "Pavan Nikhilesh" <pbhagavatula@marvell.com>
> 主题: [PATCH] node: lookup with RISC-V vector extension
>
> Implement ip4_lookup_node_process_vec function for RISC-V architecture
> using RISC-V Vector Extension instruction set
>
> Signed-off-by: Sun Yuechi <sunyuechi@iscas.ac.cn>
> Signed-off-by: Zijian <zijian.oerv@isrc.iscas.ac.cn>
> ---
> lib/eal/riscv/include/rte_vect.h | 2 +-
> lib/node/ip4_lookup.c | 5 +-
> lib/node/ip4_lookup_rvv.h | 167 +++++++++++++++++++++++++++++++
> 3 files changed, 172 insertions(+), 2 deletions(-)
> create mode 100644 lib/node/ip4_lookup_rvv.h
>
> diff --git a/lib/eal/riscv/include/rte_vect.h b/lib/eal/riscv/include/rte_vect.h
> index a4357e266a..4d16082449 100644
> --- a/lib/eal/riscv/include/rte_vect.h
> +++ b/lib/eal/riscv/include/rte_vect.h
> @@ -19,7 +19,7 @@
> extern "C" {
> #endif
>
> -#define RTE_VECT_DEFAULT_SIMD_BITWIDTH RTE_VECT_SIMD_DISABLED
> +#define RTE_VECT_DEFAULT_SIMD_BITWIDTH RTE_VECT_SIMD_128
>
> typedef int32_t xmm_t __attribute__((vector_size(16)));
>
> diff --git a/lib/node/ip4_lookup.c b/lib/node/ip4_lookup.c
> index 9673a0d78d..d3aed089f4 100644
> --- a/lib/node/ip4_lookup.c
> +++ b/lib/node/ip4_lookup.c
> @@ -44,6 +44,8 @@ static struct ip4_lookup_node_main ip4_lookup_nm;
> #include "ip4_lookup_neon.h"
> #elif defined(RTE_ARCH_X86)
> #include "ip4_lookup_sse.h"
> +#elif defined(RTE_ARCH_RISCV) && defined(RTE_RISCV_FEATURE_V)
> +#include "ip4_lookup_rvv.h"
> #endif
>
> static uint16_t
> @@ -211,7 +213,8 @@ ip4_lookup_node_init(const struct rte_graph *graph, struct rte_node *node)
> IP4_LOOKUP_NODE_LPM(node->ctx) = ip4_lookup_nm.lpm_tbl[graph->socket];
> IP4_LOOKUP_NODE_PRIV1_OFF(node->ctx) = dyn;
>
> -#if defined(__ARM_NEON) || defined(RTE_ARCH_X86)
> +#if defined(__ARM_NEON) || defined(RTE_ARCH_X86) || \
> + (defined(RTE_ARCH_RISCV) && defined(RTE_RISCV_FEATURE_V))
> if (rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_128)
> node->process = ip4_lookup_node_process_vec;
> #endif
> diff --git a/lib/node/ip4_lookup_rvv.h b/lib/node/ip4_lookup_rvv.h
> new file mode 100644
> index 0000000000..a74e4fa204
> --- /dev/null
> +++ b/lib/node/ip4_lookup_rvv.h
> @@ -0,0 +1,167 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright (c) 2025 Institute of Software Chinese Academy of Sciences (ISCAS).
> + */
> +
> +#ifndef __INCLUDE_IP4_LOOKUP_RVV_H__
> +#define __INCLUDE_IP4_LOOKUP_RVV_H__
> +
> +#define RTE_LPM_LOOKUP_SUCCESS 0x01000000
> +#define RTE_LPM_VALID_EXT_ENTRY_BITMASK 0x03000000
> +
> +static __rte_always_inline vuint32m8_t
> +bswap32_vec(vuint32m8_t v, size_t vl)
> +{
> + vuint32m8_t low16 = __riscv_vor_vv_u32m8(
> + __riscv_vsll_vx_u32m8(__riscv_vand_vx_u32m8(v, 0xFF, vl), 24, vl),
> + __riscv_vsll_vx_u32m8(__riscv_vand_vx_u32m8(v, 0xFF00, vl), 8, vl),
> + vl);
> +
> + vuint32m8_t high16 = __riscv_vor_vv_u32m8(
> + __riscv_vsrl_vx_u32m8(__riscv_vand_vx_u32m8(v, 0xFF0000, vl), 8, vl),
> + __riscv_vsrl_vx_u32m8(v, 24, vl),
> + vl);
> +
> + return __riscv_vor_vv_u32m8(low16, high16, vl);
> +}
> +
> +static __rte_always_inline void
> +rte_lpm_lookup_vec(const struct rte_lpm *lpm, const uint32_t *ips,
> + uint32_t *hop, size_t vl, uint32_t defv)
> +{
> + /* Load IP addresses (network byte order) */
> + vuint32m8_t v_ip = bswap32_vec(__riscv_vle32_v_u32m8(ips, vl), vl);
> +
> + vuint32m8_t v_tbl24_byte_offset = __riscv_vsll_vx_u32m8(
> + __riscv_vsrl_vx_u32m8(v_ip, 8, vl), 2, vl);
> +
> + vuint32m8_t vtbl_entry = __riscv_vluxei32_v_u32m8(
> + (const uint32_t *)lpm->tbl24, v_tbl24_byte_offset, vl);
> +
> + vbool4_t mask = __riscv_vmseq_vx_u32m8_b4(
> + __riscv_vand_vx_u32m8(vtbl_entry, RTE_LPM_VALID_EXT_ENTRY_BITMASK, vl),
> + RTE_LPM_VALID_EXT_ENTRY_BITMASK, vl);
> +
> + vuint32m8_t vtbl8_index = __riscv_vsll_vx_u32m8(
> + __riscv_vadd_vv_u32m8(
> + __riscv_vsll_vx_u32m8(
> + __riscv_vand_vx_u32m8(vtbl_entry, 0x00FFFFFF, vl), 8, vl),
> + __riscv_vand_vx_u32m8(v_ip, 0x000000FF, vl), vl),
> + 2, vl);
> +
> + vtbl_entry = __riscv_vluxei32_v_u32m8_mu(
> + mask, vtbl_entry, (const uint32_t *)(lpm->tbl8), vtbl8_index, vl);
> +
> + vuint32m8_t vnext_hop = __riscv_vand_vx_u32m8(vtbl_entry, 0x00FFFFFF, vl);
> + mask = __riscv_vmseq_vx_u32m8_b4(
> + __riscv_vand_vx_u32m8(vtbl_entry, RTE_LPM_LOOKUP_SUCCESS, vl), 0, vl);
> +
> + vnext_hop = __riscv_vmerge_vxm_u32m8(vnext_hop, defv, mask, vl);
> +
> + __riscv_vse32_v_u32m8(hop, vnext_hop, vl);
> +}
> +
> +/* Can be increased further for VLEN > 256 */
> +#define RVV_MAX_BURST 64U
> +
> +static uint16_t
> +ip4_lookup_node_process_vec(struct rte_graph *graph, struct rte_node *node,
> + void **objs, uint16_t nb_objs)
> +{
> + struct rte_mbuf **pkts;
> + struct rte_lpm *lpm = IP4_LOOKUP_NODE_LPM(node->ctx);
> + const int dyn = IP4_LOOKUP_NODE_PRIV1_OFF(node->ctx);
> + rte_edge_t next_index;
> + void **to_next, **from;
> + uint16_t last_spec = 0;
> + uint16_t n_left_from;
> + uint16_t held = 0;
> + uint32_t drop_nh;
> +
> + /* Temporary arrays for batch processing */
> + uint32_t ips[RVV_MAX_BURST];
> + uint32_t res[RVV_MAX_BURST];
> + rte_edge_t next_hops[RVV_MAX_BURST];
> +
> + /* Speculative next */
> + next_index = RTE_NODE_IP4_LOOKUP_NEXT_REWRITE;
> + /* Drop node */
> + drop_nh = ((uint32_t)RTE_NODE_IP4_LOOKUP_NEXT_PKT_DROP) << 16;
> +
> + pkts = (struct rte_mbuf **)objs;
> + from = objs;
> + n_left_from = nb_objs;
> +
> + /* Get stream for the speculated next node */
> + to_next = rte_node_next_stream_get(graph, node, next_index, nb_objs);
> +
> + while (n_left_from > 0) {
> + rte_edge_t fix_spec = 0;
> +
> + size_t vl = __riscv_vsetvl_e32m8(RTE_MIN(n_left_from, RVV_MAX_BURST));
> +
> + /* Extract IP addresses and metadata from current batch */
> + for (size_t i = 0; i < vl; i++) {
> + struct rte_ipv4_hdr *ipv4_hdr =
> + rte_pktmbuf_mtod_offset(pkts[i], struct rte_ipv4_hdr *,
> + sizeof(struct rte_ether_hdr));
> + ips[i] = ipv4_hdr->dst_addr;
> + node_mbuf_priv1(pkts[i], dyn)->cksum = ipv4_hdr->hdr_checksum;
> + node_mbuf_priv1(pkts[i], dyn)->ttl = ipv4_hdr->time_to_live;
> + }
> +
> + /* Perform LPM lookup */
> + rte_lpm_lookup_vec(lpm, ips, res, vl, drop_nh);
> +
> + for (size_t i = 0; i < vl; i++) {
> + /* Update statistics */
> + if ((res[i] >> 16) == (drop_nh >> 16))
> + NODE_INCREMENT_XSTAT_ID(node, 0, 1, 1);
> +
> + /* Extract next hop and next node */
> + node_mbuf_priv1(pkts[i], dyn)->nh = res[i] & 0xFFFF;
> + next_hops[i] = res[i] >> 16;
> +
> + /* Check speculation */
> + fix_spec |= (next_index ^ next_hops[i]);
> + }
> +
> + if (unlikely(fix_spec)) {
> + /* Copy successfully speculated packets before this batch */
> + rte_memcpy(to_next, from, last_spec * sizeof(from[0]));
> + from += last_spec;
> + to_next += last_spec;
> + held += last_spec;
> + last_spec = 0;
> +
> + /* Process each packet in current batch individually */
> + for (size_t i = 0; i < vl; i++) {
> + if (next_index == next_hops[i]) {
> + *to_next++ = from[i];
> + held++;
> + } else {
> + rte_node_enqueue_x1(graph, node, next_hops[i], from[i]);
> + }
> + }
> +
> + from += vl;
> + } else {
> + last_spec += vl;
> + }
> +
> + pkts += vl;
> + n_left_from -= vl;
> + }
> +
> + /* Handle successfully speculated packets */
> + if (likely(last_spec == nb_objs)) {
> + rte_node_next_stream_move(graph, node, next_index);
> + return nb_objs;
> + }
> +
> + held += last_spec;
> + rte_memcpy(to_next, from, last_spec * sizeof(from[0]));
> + rte_node_next_stream_put(graph, node, next_index, held);
> +
> + return nb_objs;
> +}
> +#endif
> --
> 2.51.2
</zijian.oerv@isrc.iscas.ac.cn></sunyuechi@iscas.ac.cn></pbhagavatula@marvell.com></ndabilpuram@marvell.com></stanislaw.kardach@gmail.com></zijian.oerv@isrc.iscas.ac.cn></sunyuechi@iscas.ac.cn></sunyuechi@iscas.ac.cn>
prev parent reply other threads:[~2025-12-05 10:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-16 15:50 Sun Yuechi
2025-11-17 1:43 ` sunyuechi
2025-12-05 10:56 ` sunyuechi [this message]
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