[dpdk-dev] [PATCH v3 20/29] node: ipv4 lookup for arm64

[<jerinj@marvell.com>]

From: Nithin Dabilpuram <ndabilpuram@marvell.com>

Add arm64 specific IPv4 lookup process function
for ip4_lookup node. This node performs LPM lookup
on every packet received and forwards it to a next
node that is identified by lookup result.

Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
Signed-off-by: Kiran Kumar K <kirankumark@marvell.com>
Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
---
 lib/librte_node/ip4_lookup.c      |   6 +
 lib/librte_node/ip4_lookup_neon.h | 238 ++++++++++++++++++++++++++++++
 2 files changed, 244 insertions(+)
 create mode 100644 lib/librte_node/ip4_lookup_neon.h

diff --git a/lib/librte_node/ip4_lookup.c b/lib/librte_node/ip4_lookup.c
index a91d42423..e8732e31b 100644
--- a/lib/librte_node/ip4_lookup.c
+++ b/lib/librte_node/ip4_lookup.c
@@ -28,6 +28,10 @@ struct ip4_lookup_node_main {
 	struct rte_lpm *lpm_tbl[RTE_MAX_NUMA_NODES];
 };
 
+#if defined(RTE_MACHINE_CPUFLAG_NEON)
+#include "ip4_lookup_neon.h"
+#else
+
 static uint16_t
 ip4_lookup_node_process(struct rte_graph *graph, struct rte_node *node,
 			void **objs, uint16_t nb_objs)
@@ -101,6 +105,8 @@ ip4_lookup_node_process(struct rte_graph *graph, struct rte_node *node,
 	return nb_objs;
 }
 
+#endif
+
 static int
 ip4_lookup_node_init(const struct rte_graph *graph, struct rte_node *node)
 {
diff --git a/lib/librte_node/ip4_lookup_neon.h b/lib/librte_node/ip4_lookup_neon.h
new file mode 100644
index 000000000..0aafe4db2
--- /dev/null
+++ b/lib/librte_node/ip4_lookup_neon.h
@@ -0,0 +1,238 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2020 Marvell International Ltd.
+ */
+
+#ifndef __INCLUDE_IP4_LOOKUP_NEON_H__
+#define __INCLUDE_IP4_LOOKUP_NEON_H__
+
+/* ARM64 NEON */
+static uint16_t
+ip4_lookup_node_process(struct rte_graph *graph, struct rte_node *node,
+			void **objs, uint16_t nb_objs)
+{
+	struct rte_mbuf *mbuf0, *mbuf1, *mbuf2, *mbuf3, **pkts;
+	struct rte_ipv4_hdr *ipv4_hdr;
+	void **to_next, **from;
+	uint16_t last_spec = 0;
+	rte_edge_t next_index;
+	uint16_t n_left_from;
+	struct rte_lpm *lpm;
+	uint16_t held = 0;
+	uint32_t drop_nh;
+	rte_xmm_t result;
+	rte_xmm_t priv01;
+	rte_xmm_t priv23;
+	int32x4_t dip;
+	int rc, i;
+
+	/* Speculative next */
+	next_index = RTE_NODE_IP4_LOOKUP_NEXT_REWRITE;
+	/* Drop node */
+	drop_nh = ((uint32_t)RTE_NODE_IP4_LOOKUP_NEXT_PKT_DROP) << 16;
+
+	/* Get socket specific LPM from ctx */
+	lpm = *((struct rte_lpm **)node->ctx);
+
+	pkts = (struct rte_mbuf **)objs;
+	from = objs;
+	n_left_from = nb_objs;
+
+#define OBJS_PER_CLINE (RTE_CACHE_LINE_SIZE / sizeof(void *))
+	for (i = OBJS_PER_CLINE; i < RTE_GRAPH_BURST_SIZE; i += OBJS_PER_CLINE)
+		rte_prefetch0(&objs[i]);
+
+	for (i = 0; i < 4 && i < n_left_from; i++)
+		rte_prefetch0(rte_pktmbuf_mtod_offset(pkts[i], void *,
+						sizeof(struct rte_ether_hdr)));
+
+	/* Get stream for the speculated next node */
+	to_next = rte_node_next_stream_get(graph, node, next_index, nb_objs);
+	while (n_left_from >= 4) {
+#if RTE_GRAPH_BURST_SIZE > 64
+		/* Prefetch next-next mbufs */
+		if (likely(n_left_from > 11)) {
+			rte_prefetch0(pkts[8]);
+			rte_prefetch0(pkts[9]);
+			rte_prefetch0(pkts[10]);
+			rte_prefetch0(pkts[11]);
+		}
+#endif
+		/* Prefetch next mbuf data */
+		if (likely(n_left_from > 7)) {
+			rte_prefetch0(rte_pktmbuf_mtod_offset(pkts[4], void *,
+						sizeof(struct rte_ether_hdr)));
+			rte_prefetch0(rte_pktmbuf_mtod_offset(pkts[5], void *,
+						sizeof(struct rte_ether_hdr)));
+			rte_prefetch0(rte_pktmbuf_mtod_offset(pkts[6], void *,
+						sizeof(struct rte_ether_hdr)));
+			rte_prefetch0(rte_pktmbuf_mtod_offset(pkts[7], void *,
+						sizeof(struct rte_ether_hdr)));
+		}
+
+		mbuf0 = pkts[0];
+		mbuf1 = pkts[1];
+		mbuf2 = pkts[2];
+		mbuf3 = pkts[3];
+
+		pkts += 4;
+		n_left_from -= 4;
+
+		/* Extract DIP of mbuf0 */
+		ipv4_hdr = rte_pktmbuf_mtod_offset(mbuf0, struct rte_ipv4_hdr *,
+						sizeof(struct rte_ether_hdr));
+		dip = vsetq_lane_s32(ipv4_hdr->dst_addr, dip, 0);
+		/* Extract cksum, ttl as ipv4 hdr is in cache */
+		priv01.u16[1] = ipv4_hdr->time_to_live;
+		priv01.u32[1] = ipv4_hdr->hdr_checksum;
+
+		/* Extract DIP of mbuf1 */
+		ipv4_hdr = rte_pktmbuf_mtod_offset(mbuf1, struct rte_ipv4_hdr *,
+						sizeof(struct rte_ether_hdr));
+		dip = vsetq_lane_s32(ipv4_hdr->dst_addr, dip, 1);
+		/* Extract cksum, ttl as ipv4 hdr is in cache */
+		priv01.u16[5] = ipv4_hdr->time_to_live;
+		priv01.u32[3] = ipv4_hdr->hdr_checksum;
+
+		/* Extract DIP of mbuf2 */
+		ipv4_hdr = rte_pktmbuf_mtod_offset(mbuf2, struct rte_ipv4_hdr *,
+						sizeof(struct rte_ether_hdr));
+		dip = vsetq_lane_s32(ipv4_hdr->dst_addr, dip, 2);
+		/* Extract cksum, ttl as ipv4 hdr is in cache */
+		priv23.u16[1] = ipv4_hdr->time_to_live;
+		priv23.u32[1] = ipv4_hdr->hdr_checksum;
+
+		/* Extract DIP of mbuf3 */
+		ipv4_hdr = rte_pktmbuf_mtod_offset(mbuf3, struct rte_ipv4_hdr *,
+						sizeof(struct rte_ether_hdr));
+		dip = vsetq_lane_s32(ipv4_hdr->dst_addr, dip, 3);
+
+		dip = vreinterpretq_s32_u8(
+			vrev32q_u8(vreinterpretq_u8_s32(dip)));
+		/* Extract cksum, ttl as ipv4 hdr is in cache */
+		priv23.u16[5] = ipv4_hdr->time_to_live;
+		priv23.u32[3] = ipv4_hdr->hdr_checksum;
+
+		/* Perform LPM lookup to get NH and next node */
+		rte_lpm_lookupx4(lpm, dip, result.u32, drop_nh);
+		priv01.u16[0] = result.u16[0];
+		priv01.u16[4] = result.u16[2];
+		priv23.u16[0] = result.u16[4];
+		priv23.u16[4] = result.u16[6];
+
+		rte_node_mbuf_priv1(mbuf0)->u = priv01.u64[0];
+		rte_node_mbuf_priv1(mbuf1)->u = priv01.u64[1];
+		rte_node_mbuf_priv1(mbuf2)->u = priv23.u64[0];
+		rte_node_mbuf_priv1(mbuf3)->u = priv23.u64[1];
+
+		/* Enqueue four to next node */
+		rte_edge_t fix_spec = ((next_index == result.u16[1]) &&
+				       (result.u16[1] == result.u16[3]) &&
+				       (result.u16[3] == result.u16[5]) &&
+				       (result.u16[5] == result.u16[7]));
+
+		if (unlikely(fix_spec == 0)) {
+			/* Copy things successfully speculated till now */
+			rte_memcpy(to_next, from, last_spec * sizeof(from[0]));
+			from += last_spec;
+			to_next += last_spec;
+			held += last_spec;
+			last_spec = 0;
+
+			/* Next0 */
+			if (next_index == result.u16[1]) {
+				to_next[0] = from[0];
+				to_next++;
+				held++;
+			} else {
+				rte_node_enqueue_x1(graph, node, result.u16[1],
+						    from[0]);
+			}
+
+			/* Next1 */
+			if (next_index == result.u16[3]) {
+				to_next[0] = from[1];
+				to_next++;
+				held++;
+			} else {
+				rte_node_enqueue_x1(graph, node, result.u16[3],
+						    from[1]);
+			}
+
+			/* Next2 */
+			if (next_index == result.u16[5]) {
+				to_next[0] = from[2];
+				to_next++;
+				held++;
+			} else {
+				rte_node_enqueue_x1(graph, node, result.u16[5],
+						    from[2]);
+			}
+
+			/* Next3 */
+			if (next_index == result.u16[7]) {
+				to_next[0] = from[3];
+				to_next++;
+				held++;
+			} else {
+				rte_node_enqueue_x1(graph, node, result.u16[7],
+						    from[3]);
+			}
+
+			from += 4;
+		} else {
+			last_spec += 4;
+		}
+	}
+
+	while (n_left_from > 0) {
+		uint32_t next_hop;
+		uint16_t next0;
+
+		mbuf0 = pkts[0];
+
+		pkts += 1;
+		n_left_from -= 1;
+
+		/* Extract DIP of mbuf0 */
+		ipv4_hdr = rte_pktmbuf_mtod_offset(mbuf0, struct rte_ipv4_hdr *,
+						sizeof(struct rte_ether_hdr));
+		/* Extract cksum, ttl as ipv4 hdr is in cache */
+		rte_node_mbuf_priv1(mbuf0)->cksum = ipv4_hdr->hdr_checksum;
+		rte_node_mbuf_priv1(mbuf0)->ttl = ipv4_hdr->time_to_live;
+
+		rc = rte_lpm_lookup(lpm, rte_be_to_cpu_32(ipv4_hdr->dst_addr),
+				    &next_hop);
+		next_hop = (rc == 0) ? next_hop : drop_nh;
+
+		rte_node_mbuf_priv1(mbuf0)->nh = (uint16_t)next_hop;
+		next_hop = next_hop >> 16;
+		next0 = (uint16_t)next_hop;
+
+		if (unlikely(next_index ^ next0)) {
+			/* Copy things successfully speculated till now */
+			rte_memcpy(to_next, from, last_spec * sizeof(from[0]));
+			from += last_spec;
+			to_next += last_spec;
+			held += last_spec;
+			last_spec = 0;
+
+			rte_node_enqueue_x1(graph, node, next0, from[0]);
+			from += 1;
+		} else {
+			last_spec += 1;
+		}
+	}
+
+	/* !!! Home run !!! */
+	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 /* __INCLUDE_IP4_LOOKUP_NEON_H__ */
-- 
2.25.1