numam-dpdk/drivers/net/enetc/enetc_rxtx.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright 2018-2020 NXP
 */

#include <stdbool.h>
#include <stdint.h>
#include <unistd.h>

#include "rte_ethdev.h"
#include "rte_malloc.h"
#include "rte_memzone.h"

#include "base/enetc_hw.h"
#include "enetc.h"
#include "enetc_logs.h"

#define ENETC_CACHE_LINE_RXBDS	(RTE_CACHE_LINE_SIZE / \
				 sizeof(union enetc_rx_bd))
#define ENETC_RXBD_BUNDLE 16 /* Number of buffers to allocate at once */

static int
enetc_clean_tx_ring(struct enetc_bdr *tx_ring)
{
	int tx_frm_cnt = 0;
	struct enetc_swbd *tx_swbd, *tx_swbd_base;
	int i, hwci, bd_count;
	struct rte_mbuf *m[ENETC_RXBD_BUNDLE];

	/* we don't need barriers here, we just want a relatively current value
	 * from HW.
	 */
	hwci = (int)(rte_read32_relaxed(tx_ring->tcisr) &
		     ENETC_TBCISR_IDX_MASK);

	tx_swbd_base = tx_ring->q_swbd;
	bd_count = tx_ring->bd_count;
	i = tx_ring->next_to_clean;
	tx_swbd = &tx_swbd_base[i];

	/* we're only reading the CI index once here, which means HW may update
	 * it while we're doing clean-up.  We could read the register in a loop
	 * but for now I assume it's OK to leave a few Tx frames for next call.
	 * The issue with reading the register in a loop is that we're stalling
	 * here trying to catch up with HW which keeps sending traffic as long
	 * as it has traffic to send, so in effect we could be waiting here for
	 * the Tx ring to be drained by HW, instead of us doing Rx in that
	 * meantime.
	 */
	while (i != hwci) {
		/* It seems calling rte_pktmbuf_free is wasting a lot of cycles,
		 * make a list and call _free when it's done.
		 */
		if (tx_frm_cnt == ENETC_RXBD_BUNDLE) {
			rte_pktmbuf_free_bulk(m, tx_frm_cnt);
			tx_frm_cnt = 0;
		}

		m[tx_frm_cnt] = tx_swbd->buffer_addr;
		tx_swbd->buffer_addr = NULL;

		i++;
		tx_swbd++;
		if (unlikely(i == bd_count)) {
			i = 0;
			tx_swbd = tx_swbd_base;
		}

		tx_frm_cnt++;
	}

	if (tx_frm_cnt)
		rte_pktmbuf_free_bulk(m, tx_frm_cnt);

	tx_ring->next_to_clean = i;

	return 0;
}

uint16_t
enetc_xmit_pkts(void *tx_queue,
		struct rte_mbuf **tx_pkts,
		uint16_t nb_pkts)
{
	struct enetc_swbd *tx_swbd;
	int i, start, bds_to_use;
	struct enetc_tx_bd *txbd;
	struct enetc_bdr *tx_ring = (struct enetc_bdr *)tx_queue;

	i = tx_ring->next_to_use;

	bds_to_use = enetc_bd_unused(tx_ring);
	if (bds_to_use < nb_pkts)
		nb_pkts = bds_to_use;

	start = 0;
	while (nb_pkts--) {
		tx_ring->q_swbd[i].buffer_addr = tx_pkts[start];
		txbd = ENETC_TXBD(*tx_ring, i);
		tx_swbd = &tx_ring->q_swbd[i];
		txbd->frm_len = tx_pkts[start]->pkt_len;
		txbd->buf_len = txbd->frm_len;
		txbd->flags = rte_cpu_to_le_16(ENETC_TXBD_FLAGS_F);
		txbd->addr = (uint64_t)(uintptr_t)
		rte_cpu_to_le_64((size_t)tx_swbd->buffer_addr->buf_iova +
				 tx_swbd->buffer_addr->data_off);
		i++;
		start++;
		if (unlikely(i == tx_ring->bd_count))
			i = 0;
	}

	/* we're only cleaning up the Tx ring here, on the assumption that
	 * software is slower than hardware and hardware completed sending
	 * older frames out by now.
	 * We're also cleaning up the ring before kicking off Tx for the new
	 * batch to minimize chances of contention on the Tx ring
	 */
	enetc_clean_tx_ring(tx_ring);

	tx_ring->next_to_use = i;
	enetc_wr_reg(tx_ring->tcir, i);
	return start;
}

int
enetc_refill_rx_ring(struct enetc_bdr *rx_ring, const int buff_cnt)
{
	struct enetc_swbd *rx_swbd;
	union enetc_rx_bd *rxbd;
	int i, j, k = ENETC_RXBD_BUNDLE;
	struct rte_mbuf *m[ENETC_RXBD_BUNDLE];
	struct rte_mempool *mb_pool;

	i = rx_ring->next_to_use;
	mb_pool = rx_ring->mb_pool;
	rx_swbd = &rx_ring->q_swbd[i];
	rxbd = ENETC_RXBD(*rx_ring, i);
	for (j = 0; j < buff_cnt; j++) {
		/* bulk alloc for the next up to 8 BDs */
		if (k == ENETC_RXBD_BUNDLE) {
			k = 0;
			int m_cnt = RTE_MIN(buff_cnt - j, ENETC_RXBD_BUNDLE);

			if (rte_pktmbuf_alloc_bulk(mb_pool, m, m_cnt))
				return -1;
		}

		rx_swbd->buffer_addr = m[k];
		rxbd->w.addr = (uint64_t)(uintptr_t)
			       rx_swbd->buffer_addr->buf_iova +
			       rx_swbd->buffer_addr->data_off;
		/* clear 'R" as well */
		rxbd->r.lstatus = 0;
		rx_swbd++;
		rxbd++;
		i++;
		k++;
		if (unlikely(i == rx_ring->bd_count)) {
			i = 0;
			rxbd = ENETC_RXBD(*rx_ring, 0);
			rx_swbd = &rx_ring->q_swbd[i];
		}
	}

	if (likely(j)) {
		rx_ring->next_to_alloc = i;
		rx_ring->next_to_use = i;
		enetc_wr_reg(rx_ring->rcir, i);
	}

	return j;
}

static inline void enetc_slow_parsing(struct rte_mbuf *m,
				     uint64_t parse_results)
{
	m->ol_flags &= ~(PKT_RX_IP_CKSUM_GOOD | PKT_RX_L4_CKSUM_GOOD);

	switch (parse_results) {
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV4:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4;
		m->ol_flags |= PKT_RX_IP_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV6:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6;
		m->ol_flags |= PKT_RX_IP_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV4_TCP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4 |
				 RTE_PTYPE_L4_TCP;
		m->ol_flags |= PKT_RX_IP_CKSUM_GOOD |
			       PKT_RX_L4_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV6_TCP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6 |
				 RTE_PTYPE_L4_TCP;
		m->ol_flags |= PKT_RX_IP_CKSUM_GOOD |
			       PKT_RX_L4_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV4_UDP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4 |
				 RTE_PTYPE_L4_UDP;
		m->ol_flags |= PKT_RX_IP_CKSUM_GOOD |
			       PKT_RX_L4_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV6_UDP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6 |
				 RTE_PTYPE_L4_UDP;
		m->ol_flags |= PKT_RX_IP_CKSUM_GOOD |
			       PKT_RX_L4_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV4_SCTP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4 |
				 RTE_PTYPE_L4_SCTP;
		m->ol_flags |= PKT_RX_IP_CKSUM_GOOD |
			       PKT_RX_L4_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV6_SCTP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6 |
				 RTE_PTYPE_L4_SCTP;
		m->ol_flags |= PKT_RX_IP_CKSUM_GOOD |
			       PKT_RX_L4_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV4_ICMP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4 |
				 RTE_PTYPE_L4_ICMP;
		m->ol_flags |= PKT_RX_IP_CKSUM_GOOD |
			       PKT_RX_L4_CKSUM_BAD;
		return;
	case ENETC_PARSE_ERROR | ENETC_PKT_TYPE_IPV6_ICMP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6 |
				 RTE_PTYPE_L4_ICMP;
		m->ol_flags |= PKT_RX_IP_CKSUM_GOOD |
			       PKT_RX_L4_CKSUM_BAD;
		return;
	/* More switch cases can be added */
	default:
		m->packet_type = RTE_PTYPE_UNKNOWN;
		m->ol_flags |= PKT_RX_IP_CKSUM_UNKNOWN |
			       PKT_RX_L4_CKSUM_UNKNOWN;
	}
}


static inline void __attribute__((hot))
enetc_dev_rx_parse(struct rte_mbuf *m, uint16_t parse_results)
{
	ENETC_PMD_DP_DEBUG("parse summary = 0x%x   ", parse_results);
	m->ol_flags |= PKT_RX_IP_CKSUM_GOOD | PKT_RX_L4_CKSUM_GOOD;

	switch (parse_results) {
	case ENETC_PKT_TYPE_ETHER:
		m->packet_type = RTE_PTYPE_L2_ETHER;
		return;
	case ENETC_PKT_TYPE_IPV4:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4;
		return;
	case ENETC_PKT_TYPE_IPV6:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6;
		return;
	case ENETC_PKT_TYPE_IPV4_TCP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4 |
				 RTE_PTYPE_L4_TCP;
		return;
	case ENETC_PKT_TYPE_IPV6_TCP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6 |
				 RTE_PTYPE_L4_TCP;
		return;
	case ENETC_PKT_TYPE_IPV4_UDP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4 |
				 RTE_PTYPE_L4_UDP;
		return;
	case ENETC_PKT_TYPE_IPV6_UDP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6 |
				 RTE_PTYPE_L4_UDP;
		return;
	case ENETC_PKT_TYPE_IPV4_SCTP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4 |
				 RTE_PTYPE_L4_SCTP;
		return;
	case ENETC_PKT_TYPE_IPV6_SCTP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6 |
				 RTE_PTYPE_L4_SCTP;
		return;
	case ENETC_PKT_TYPE_IPV4_ICMP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV4 |
				 RTE_PTYPE_L4_ICMP;
		return;
	case ENETC_PKT_TYPE_IPV6_ICMP:
		m->packet_type = RTE_PTYPE_L2_ETHER |
				 RTE_PTYPE_L3_IPV6 |
				 RTE_PTYPE_L4_ICMP;
		return;
	/* More switch cases can be added */
	default:
		enetc_slow_parsing(m, parse_results);
	}

}

static int
enetc_clean_rx_ring(struct enetc_bdr *rx_ring,
		    struct rte_mbuf **rx_pkts,
		    int work_limit)
{
	int rx_frm_cnt = 0;
	int cleaned_cnt, i, bd_count;
	struct enetc_swbd *rx_swbd;
	union enetc_rx_bd *rxbd;

	/* next descriptor to process */
	i = rx_ring->next_to_clean;
	/* next descriptor to process */
	rxbd = ENETC_RXBD(*rx_ring, i);
	rte_prefetch0(rxbd);
	bd_count = rx_ring->bd_count;
	/* LS1028A does not have platform cache so any software access following
	 * a hardware write will go directly to DDR.  Latency of such a read is
	 * in excess of 100 core cycles, so try to prefetch more in advance to
	 * mitigate this.
	 * How much is worth prefetching really depends on traffic conditions.
	 * With congested Rx this could go up to 4 cache lines or so.  But if
	 * software keeps up with hardware and follows behind Rx PI by a cache
	 * line or less then it's harmful in terms of performance to cache more.
	 * We would only prefetch BDs that have yet to be written by ENETC,
	 * which will have to be evicted again anyway.
	 */
	rte_prefetch0(ENETC_RXBD(*rx_ring,
				 (i + ENETC_CACHE_LINE_RXBDS) % bd_count));
	rte_prefetch0(ENETC_RXBD(*rx_ring,
				 (i + ENETC_CACHE_LINE_RXBDS * 2) % bd_count));

	cleaned_cnt = enetc_bd_unused(rx_ring);
	rx_swbd = &rx_ring->q_swbd[i];
	while (likely(rx_frm_cnt < work_limit)) {
		uint32_t bd_status;

		bd_status = rte_le_to_cpu_32(rxbd->r.lstatus);
		if (!bd_status)
			break;

		rx_swbd->buffer_addr->pkt_len = rxbd->r.buf_len -
						rx_ring->crc_len;
		rx_swbd->buffer_addr->data_len = rxbd->r.buf_len -
						 rx_ring->crc_len;
		rx_swbd->buffer_addr->hash.rss = rxbd->r.rss_hash;
		rx_swbd->buffer_addr->ol_flags = 0;
		enetc_dev_rx_parse(rx_swbd->buffer_addr,
				   rxbd->r.parse_summary);
		rx_pkts[rx_frm_cnt] = rx_swbd->buffer_addr;
		cleaned_cnt++;
		rx_swbd++;
		i++;
		if (unlikely(i == rx_ring->bd_count)) {
			i = 0;
			rx_swbd = &rx_ring->q_swbd[i];
		}
		rxbd = ENETC_RXBD(*rx_ring, i);
		rte_prefetch0(ENETC_RXBD(*rx_ring,
					 (i + ENETC_CACHE_LINE_RXBDS) %
					  bd_count));
		rte_prefetch0(ENETC_RXBD(*rx_ring,
					 (i + ENETC_CACHE_LINE_RXBDS * 2) %
					 bd_count));

		rx_frm_cnt++;
	}

	rx_ring->next_to_clean = i;
	enetc_refill_rx_ring(rx_ring, cleaned_cnt);

	return rx_frm_cnt;
}

uint16_t
enetc_recv_pkts(void *rxq, struct rte_mbuf **rx_pkts,
		uint16_t nb_pkts)
{
	struct enetc_bdr *rx_ring = (struct enetc_bdr *)rxq;

	return enetc_clean_rx_ring(rx_ring, rx_pkts, nb_pkts);
}