xref: /dpdk/drivers/net/mlx5/mlx5_rxtx_vec.c (revision 5fc2e5c27d69bcebb352d17603a1d3ca2628f17b)

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright 2017 6WIND S.A.
 * Copyright 2017 Mellanox Technologies, Ltd
 */

#include <stdint.h>
#include <string.h>
#include <stdlib.h>

#include <rte_mbuf.h>
#include <rte_mempool.h>
#include <rte_prefetch.h>
#include <rte_vect.h>

#include <mlx5_glue.h>
#include <mlx5_prm.h>

#include "mlx5_defs.h"
#include "mlx5.h"
#include "mlx5_utils.h"
#include "mlx5_rxtx.h"
#include "mlx5_rxtx_vec.h"
#include "mlx5_autoconf.h"

#if defined RTE_ARCH_X86_64
#include "mlx5_rxtx_vec_sse.h"
#elif defined RTE_ARCH_ARM64
#include "mlx5_rxtx_vec_neon.h"
#elif defined RTE_ARCH_PPC_64
#include "mlx5_rxtx_vec_altivec.h"
#else
#error "This should not be compiled if SIMD instructions are not supported."
#endif

/**
 * Skip error packets.
 *
 * @param rxq
 *   Pointer to RX queue structure.
 * @param[out] pkts
 *   Array to store received packets.
 * @param pkts_n
 *   Maximum number of packets in array.
 *
 * @return
 *   Number of packets successfully received (<= pkts_n).
 */
static uint16_t
rxq_handle_pending_error(struct mlx5_rxq_data *rxq, struct rte_mbuf **pkts,
			 uint16_t pkts_n)
{
	uint16_t n = 0;
	unsigned int i;
#ifdef MLX5_PMD_SOFT_COUNTERS
	uint32_t err_bytes = 0;
#endif

	for (i = 0; i < pkts_n; ++i) {
		struct rte_mbuf *pkt = pkts[i];

		if (pkt->packet_type == RTE_PTYPE_ALL_MASK || rxq->err_state) {
#ifdef MLX5_PMD_SOFT_COUNTERS
			err_bytes += PKT_LEN(pkt);
#endif
			rte_pktmbuf_free_seg(pkt);
		} else {
			pkts[n++] = pkt;
		}
	}
	rxq->stats.idropped += (pkts_n - n);
#ifdef MLX5_PMD_SOFT_COUNTERS
	/* Correct counters of errored completions. */
	rxq->stats.ipackets -= (pkts_n - n);
	rxq->stats.ibytes -= err_bytes;
#endif
	mlx5_rx_err_handle(rxq, 1);
	return n;
}

/**
 * Replenish buffers for RX in bulk.
 *
 * @param rxq
 *   Pointer to RX queue structure.
 */
static inline void
mlx5_rx_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq)
{
	const uint16_t q_n = 1 << rxq->elts_n;
	const uint16_t q_mask = q_n - 1;
	uint16_t n = q_n - (rxq->rq_ci - rxq->rq_pi);
	uint16_t elts_idx = rxq->rq_ci & q_mask;
	struct rte_mbuf **elts = &(*rxq->elts)[elts_idx];
	volatile struct mlx5_wqe_data_seg *wq =
		&((volatile struct mlx5_wqe_data_seg *)rxq->wqes)[elts_idx];
	unsigned int i;

	if (n >= rxq->rq_repl_thresh) {
		MLX5_ASSERT(n >= MLX5_VPMD_RXQ_RPLNSH_THRESH(q_n));
		MLX5_ASSERT(MLX5_VPMD_RXQ_RPLNSH_THRESH(q_n) >
			    MLX5_VPMD_DESCS_PER_LOOP);
		/* Not to cross queue end. */
		n = RTE_MIN(n - MLX5_VPMD_DESCS_PER_LOOP, q_n - elts_idx);
		if (rte_mempool_get_bulk(rxq->mp, (void *)elts, n) < 0) {
			rxq->stats.rx_nombuf += n;
			return;
		}
		for (i = 0; i < n; ++i) {
			void *buf_addr;

			/*
			 * In order to support the mbufs with external attached
			 * data buffer we should use the buf_addr pointer
			 * instead of rte_mbuf_buf_addr(). It touches the mbuf
			 * itself and may impact the performance.
			 */
			buf_addr = elts[i]->buf_addr;
			wq[i].addr = rte_cpu_to_be_64((uintptr_t)buf_addr +
						      RTE_PKTMBUF_HEADROOM);
			/* If there's a single MR, no need to replace LKey. */
			if (unlikely(mlx5_mr_btree_len(&rxq->mr_ctrl.cache_bh)
				     > 1))
				wq[i].lkey = mlx5_rx_mb2mr(rxq, elts[i]);
		}
		rxq->rq_ci += n;
		/* Prevent overflowing into consumed mbufs. */
		elts_idx = rxq->rq_ci & q_mask;
		for (i = 0; i < MLX5_VPMD_DESCS_PER_LOOP; ++i)
			(*rxq->elts)[elts_idx + i] = &rxq->fake_mbuf;
		rte_io_wmb();
		*rxq->rq_db = rte_cpu_to_be_32(rxq->rq_ci);
	}
}

/**
 * Replenish buffers for MPRQ RX in bulk.
 *
 * @param rxq
 *   Pointer to RX queue structure.
 */
static inline void
mlx5_rx_mprq_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq)
{
	const uint16_t wqe_n = 1 << rxq->elts_n;
	const uint32_t strd_n = 1 << rxq->strd_num_n;
	const uint32_t elts_n = wqe_n * strd_n;
	const uint32_t wqe_mask = elts_n - 1;
	uint32_t n = elts_n - (rxq->elts_ci - rxq->rq_pi);
	uint32_t elts_idx = rxq->elts_ci & wqe_mask;
	struct rte_mbuf **elts = &(*rxq->elts)[elts_idx];
	unsigned int i;

	if (n >= rxq->rq_repl_thresh &&
	    rxq->elts_ci - rxq->rq_pi <= rxq->rq_repl_thresh) {
		MLX5_ASSERT(n >= MLX5_VPMD_RXQ_RPLNSH_THRESH(elts_n));
		MLX5_ASSERT(MLX5_VPMD_RXQ_RPLNSH_THRESH(elts_n) >
			     MLX5_VPMD_DESCS_PER_LOOP);
		/* Not to cross queue end. */
		n = RTE_MIN(n - MLX5_VPMD_DESCS_PER_LOOP, elts_n - elts_idx);
		/* Limit replenish number to threshold value. */
		n = RTE_MIN(n, rxq->rq_repl_thresh);
		if (rte_mempool_get_bulk(rxq->mp, (void *)elts, n) < 0) {
			rxq->stats.rx_nombuf += n;
			return;
		}
		rxq->elts_ci += n;
		/* Prevent overflowing into consumed mbufs. */
		elts_idx = rxq->elts_ci & wqe_mask;
		for (i = 0; i < MLX5_VPMD_DESCS_PER_LOOP; ++i)
			(*rxq->elts)[elts_idx + i] = &rxq->fake_mbuf;
	}
}

/**
 * Copy or attach MPRQ buffers to RX SW ring.
 *
 * @param rxq
 *   Pointer to RX queue structure.
 * @param pkts
 *   Pointer to array of packets to be stored.
 * @param pkts_n
 *   Number of packets to be stored.
 *
 * @return
 *   Number of packets successfully copied/attached (<= pkts_n).
 */
static inline uint16_t
rxq_copy_mprq_mbuf_v(struct mlx5_rxq_data *rxq,
		     struct rte_mbuf **pkts, uint16_t pkts_n)
{
	const uint16_t wqe_n = 1 << rxq->elts_n;
	const uint16_t wqe_mask = wqe_n - 1;
	const uint16_t strd_sz = 1 << rxq->strd_sz_n;
	const uint32_t strd_n = 1 << rxq->strd_num_n;
	const uint32_t elts_n = wqe_n * strd_n;
	const uint32_t elts_mask = elts_n - 1;
	uint32_t elts_idx = rxq->rq_pi & elts_mask;
	struct rte_mbuf **elts = &(*rxq->elts)[elts_idx];
	uint32_t rq_ci = rxq->rq_ci;
	struct mlx5_mprq_buf *buf = (*rxq->mprq_bufs)[rq_ci & wqe_mask];
	uint16_t copied = 0;
	uint16_t i = 0;

	for (i = 0; i < pkts_n; ++i) {
		uint16_t strd_cnt;
		enum mlx5_rqx_code rxq_code;

		if (rxq->consumed_strd == strd_n) {
			/* Replace WQE if the buffer is still in use. */
			mprq_buf_replace(rxq, rq_ci & wqe_mask);
			/* Advance to the next WQE. */
			rxq->consumed_strd = 0;
			rq_ci++;
			buf = (*rxq->mprq_bufs)[rq_ci & wqe_mask];
		}

		if (!elts[i]->pkt_len) {
			rxq->consumed_strd = strd_n;
			rte_pktmbuf_free_seg(elts[i]);
#ifdef MLX5_PMD_SOFT_COUNTERS
			rxq->stats.ipackets -= 1;
#endif
			continue;
		}
		strd_cnt = (elts[i]->pkt_len / strd_sz) +
			   ((elts[i]->pkt_len % strd_sz) ? 1 : 0);
		rxq_code = mprq_buf_to_pkt(rxq, elts[i], elts[i]->pkt_len,
					   buf, rxq->consumed_strd, strd_cnt);
		rxq->consumed_strd += strd_cnt;
		if (unlikely(rxq_code != MLX5_RXQ_CODE_EXIT)) {
			rte_pktmbuf_free_seg(elts[i]);
#ifdef MLX5_PMD_SOFT_COUNTERS
			rxq->stats.ipackets -= 1;
			rxq->stats.ibytes -= elts[i]->pkt_len;
#endif
			if (rxq_code == MLX5_RXQ_CODE_NOMBUF) {
				++rxq->stats.rx_nombuf;
				break;
			}
			if (rxq_code == MLX5_RXQ_CODE_DROPPED) {
				++rxq->stats.idropped;
				continue;
			}
		}
		pkts[copied++] = elts[i];
	}
	rxq->rq_pi += i;
	rxq->cq_ci += i;
	rte_io_wmb();
	*rxq->cq_db = rte_cpu_to_be_32(rxq->cq_ci);
	if (rq_ci != rxq->rq_ci) {
		rxq->rq_ci = rq_ci;
		rte_io_wmb();
		*rxq->rq_db = rte_cpu_to_be_32(rxq->rq_ci);
	}
	return copied;
}

/**
 * Receive burst of packets. An errored completion also consumes a mbuf, but the
 * packet_type is set to be RTE_PTYPE_ALL_MASK. Marked mbufs should be freed
 * before returning to application.
 *
 * @param rxq
 *   Pointer to RX queue structure.
 * @param[out] pkts
 *   Array to store received packets.
 * @param pkts_n
 *   Maximum number of packets in array.
 * @param[out] err
 *   Pointer to a flag. Set non-zero value if pkts array has at least one error
 *   packet to handle.
 * @param[out] no_cq
 *   Pointer to a boolean. Set true if no new CQE seen.
 *
 * @return
 *   Number of packets received including errors (<= pkts_n).
 */
static inline uint16_t
rxq_burst_v(struct mlx5_rxq_data *rxq, struct rte_mbuf **pkts,
	    uint16_t pkts_n, uint64_t *err, bool *no_cq)
{
	const uint16_t q_n = 1 << rxq->cqe_n;
	const uint16_t q_mask = q_n - 1;
	const uint16_t e_n = 1 << rxq->elts_n;
	const uint16_t e_mask = e_n - 1;
	volatile struct mlx5_cqe *cq;
	struct rte_mbuf **elts;
	uint64_t comp_idx = MLX5_VPMD_DESCS_PER_LOOP;
	uint16_t nocmp_n = 0;
	uint16_t rcvd_pkt = 0;
	unsigned int cq_idx = rxq->cq_ci & q_mask;
	unsigned int elts_idx;

	MLX5_ASSERT(rxq->sges_n == 0);
	MLX5_ASSERT(rxq->cqe_n == rxq->elts_n);
	cq = &(*rxq->cqes)[cq_idx];
	rte_prefetch0(cq);
	rte_prefetch0(cq + 1);
	rte_prefetch0(cq + 2);
	rte_prefetch0(cq + 3);
	pkts_n = RTE_MIN(pkts_n, MLX5_VPMD_RX_MAX_BURST);
	mlx5_rx_replenish_bulk_mbuf(rxq);
	/* See if there're unreturned mbufs from compressed CQE. */
	rcvd_pkt = rxq->decompressed;
	if (rcvd_pkt > 0) {
		rcvd_pkt = RTE_MIN(rcvd_pkt, pkts_n);
		rxq_copy_mbuf_v(&(*rxq->elts)[rxq->rq_pi & e_mask],
				pkts, rcvd_pkt);
		rxq->rq_pi += rcvd_pkt;
		rxq->decompressed -= rcvd_pkt;
		pkts += rcvd_pkt;
	}
	elts_idx = rxq->rq_pi & e_mask;
	elts = &(*rxq->elts)[elts_idx];
	/* Not to overflow pkts array. */
	pkts_n = RTE_ALIGN_FLOOR(pkts_n - rcvd_pkt, MLX5_VPMD_DESCS_PER_LOOP);
	/* Not to cross queue end. */
	pkts_n = RTE_MIN(pkts_n, q_n - elts_idx);
	pkts_n = RTE_MIN(pkts_n, q_n - cq_idx);
	if (!pkts_n) {
		*no_cq = !rcvd_pkt;
		return rcvd_pkt;
	}
	/* At this point, there shouldn't be any remaining packets. */
	MLX5_ASSERT(rxq->decompressed == 0);
	/* Process all the CQEs */
	nocmp_n = rxq_cq_process_v(rxq, cq, elts, pkts, pkts_n, err, &comp_idx);
	/* If no new CQE seen, return without updating cq_db. */
	if (unlikely(!nocmp_n && comp_idx == MLX5_VPMD_DESCS_PER_LOOP)) {
		*no_cq = true;
		return rcvd_pkt;
	}
	/* Update the consumer indexes for non-compressed CQEs. */
	MLX5_ASSERT(nocmp_n <= pkts_n);
	rxq->cq_ci += nocmp_n;
	rxq->rq_pi += nocmp_n;
	rcvd_pkt += nocmp_n;
	/* Decompress the last CQE if compressed. */
	if (comp_idx < MLX5_VPMD_DESCS_PER_LOOP) {
		MLX5_ASSERT(comp_idx == (nocmp_n % MLX5_VPMD_DESCS_PER_LOOP));
		rxq->decompressed = rxq_cq_decompress_v(rxq, &cq[nocmp_n],
							&elts[nocmp_n]);
		rxq->cq_ci += rxq->decompressed;
		/* Return more packets if needed. */
		if (nocmp_n < pkts_n) {
			uint16_t n = rxq->decompressed;

			n = RTE_MIN(n, pkts_n - nocmp_n);
			rxq_copy_mbuf_v(&(*rxq->elts)[rxq->rq_pi & e_mask],
					&pkts[nocmp_n], n);
			rxq->rq_pi += n;
			rcvd_pkt += n;
			rxq->decompressed -= n;
		}
	}
	rte_io_wmb();
	*rxq->cq_db = rte_cpu_to_be_32(rxq->cq_ci);
	*no_cq = !rcvd_pkt;
	return rcvd_pkt;
}

/**
 * DPDK callback for vectorized RX.
 *
 * @param dpdk_rxq
 *   Generic pointer to RX queue structure.
 * @param[out] pkts
 *   Array to store received packets.
 * @param pkts_n
 *   Maximum number of packets in array.
 *
 * @return
 *   Number of packets successfully received (<= pkts_n).
 */
uint16_t
mlx5_rx_burst_vec(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
{
	struct mlx5_rxq_data *rxq = dpdk_rxq;
	uint16_t nb_rx = 0;
	uint16_t tn = 0;
	uint64_t err = 0;
	bool no_cq = false;

	do {
		nb_rx = rxq_burst_v(rxq, pkts + tn, pkts_n - tn,
				    &err, &no_cq);
		if (unlikely(err | rxq->err_state))
			nb_rx = rxq_handle_pending_error(rxq, pkts + tn, nb_rx);
		tn += nb_rx;
		if (unlikely(no_cq))
			break;
	} while (tn != pkts_n);
	return tn;
}

/**
 * Receive burst of packets. An errored completion also consumes a mbuf, but the
 * packet_type is set to be RTE_PTYPE_ALL_MASK. Marked mbufs should be freed
 * before returning to application.
 *
 * @param rxq
 *   Pointer to RX queue structure.
 * @param[out] pkts
 *   Array to store received packets.
 * @param pkts_n
 *   Maximum number of packets in array.
 * @param[out] err
 *   Pointer to a flag. Set non-zero value if pkts array has at least one error
 *   packet to handle.
 * @param[out] no_cq
 *   Pointer to a boolean. Set true if no new CQE seen.
 *
 * @return
 *   Number of packets received including errors (<= pkts_n).
 */
static inline uint16_t
rxq_burst_mprq_v(struct mlx5_rxq_data *rxq, struct rte_mbuf **pkts,
		 uint16_t pkts_n, uint64_t *err, bool *no_cq)
{
	const uint16_t q_n = 1 << rxq->cqe_n;
	const uint16_t q_mask = q_n - 1;
	const uint16_t wqe_n = 1 << rxq->elts_n;
	const uint32_t strd_n = 1 << rxq->strd_num_n;
	const uint32_t elts_n = wqe_n * strd_n;
	const uint32_t elts_mask = elts_n - 1;
	volatile struct mlx5_cqe *cq;
	struct rte_mbuf **elts;
	uint64_t comp_idx = MLX5_VPMD_DESCS_PER_LOOP;
	uint16_t nocmp_n = 0;
	uint16_t rcvd_pkt = 0;
	uint16_t cp_pkt = 0;
	unsigned int cq_idx = rxq->cq_ci & q_mask;
	unsigned int elts_idx;

	MLX5_ASSERT(rxq->sges_n == 0);
	cq = &(*rxq->cqes)[cq_idx];
	rte_prefetch0(cq);
	rte_prefetch0(cq + 1);
	rte_prefetch0(cq + 2);
	rte_prefetch0(cq + 3);
	pkts_n = RTE_MIN(pkts_n, MLX5_VPMD_RX_MAX_BURST);
	mlx5_rx_mprq_replenish_bulk_mbuf(rxq);
	/* See if there're unreturned mbufs from compressed CQE. */
	rcvd_pkt = rxq->decompressed;
	if (rcvd_pkt > 0) {
		rcvd_pkt = RTE_MIN(rcvd_pkt, pkts_n);
		cp_pkt = rxq_copy_mprq_mbuf_v(rxq, pkts, rcvd_pkt);
		rxq->decompressed -= rcvd_pkt;
		pkts += cp_pkt;
	}
	elts_idx = rxq->rq_pi & elts_mask;
	elts = &(*rxq->elts)[elts_idx];
	/* Not to overflow pkts array. */
	pkts_n = RTE_ALIGN_FLOOR(pkts_n - cp_pkt, MLX5_VPMD_DESCS_PER_LOOP);
	/* Not to cross queue end. */
	pkts_n = RTE_MIN(pkts_n, elts_n - elts_idx);
	pkts_n = RTE_MIN(pkts_n, q_n - cq_idx);
	/* Not to move past the allocated mbufs. */
	pkts_n = RTE_MIN(pkts_n, rxq->elts_ci - rxq->rq_pi);
	if (!pkts_n) {
		*no_cq = !cp_pkt;
		return cp_pkt;
	}
	/* At this point, there shouldn't be any remaining packets. */
	MLX5_ASSERT(rxq->decompressed == 0);
	/* Process all the CQEs */
	nocmp_n = rxq_cq_process_v(rxq, cq, elts, pkts, pkts_n, err, &comp_idx);
	/* If no new CQE seen, return without updating cq_db. */
	if (unlikely(!nocmp_n && comp_idx == MLX5_VPMD_DESCS_PER_LOOP)) {
		*no_cq = true;
		return cp_pkt;
	}
	/* Update the consumer indexes for non-compressed CQEs. */
	MLX5_ASSERT(nocmp_n <= pkts_n);
	cp_pkt = rxq_copy_mprq_mbuf_v(rxq, pkts, nocmp_n);
	rcvd_pkt += cp_pkt;
	/* Decompress the last CQE if compressed. */
	if (comp_idx < MLX5_VPMD_DESCS_PER_LOOP) {
		MLX5_ASSERT(comp_idx == (nocmp_n % MLX5_VPMD_DESCS_PER_LOOP));
		rxq->decompressed = rxq_cq_decompress_v(rxq, &cq[nocmp_n],
							&elts[nocmp_n]);
		/* Return more packets if needed. */
		if (nocmp_n < pkts_n) {
			uint16_t n = rxq->decompressed;

			n = RTE_MIN(n, pkts_n - nocmp_n);
			cp_pkt = rxq_copy_mprq_mbuf_v(rxq, &pkts[cp_pkt], n);
			rcvd_pkt += cp_pkt;
			rxq->decompressed -= n;
		}
	}
	*no_cq = !rcvd_pkt;
	return rcvd_pkt;
}

/**
 * DPDK callback for vectorized MPRQ RX.
 *
 * @param dpdk_rxq
 *   Generic pointer to RX queue structure.
 * @param[out] pkts
 *   Array to store received packets.
 * @param pkts_n
 *   Maximum number of packets in array.
 *
 * @return
 *   Number of packets successfully received (<= pkts_n).
 */
uint16_t
mlx5_rx_burst_mprq_vec(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
{
	struct mlx5_rxq_data *rxq = dpdk_rxq;
	uint16_t nb_rx = 0;
	uint16_t tn = 0;
	uint64_t err = 0;
	bool no_cq = false;

	do {
		nb_rx = rxq_burst_mprq_v(rxq, pkts + tn, pkts_n - tn,
					 &err, &no_cq);
		if (unlikely(err | rxq->err_state))
			nb_rx = rxq_handle_pending_error(rxq, pkts + tn, nb_rx);
		tn += nb_rx;
		if (unlikely(no_cq))
			break;
	} while (tn != pkts_n);
	return tn;
}

/**
 * Check a RX queue can support vectorized RX.
 *
 * @param rxq
 *   Pointer to RX queue.
 *
 * @return
 *   1 if supported, negative errno value if not.
 */
int __rte_cold
mlx5_rxq_check_vec_support(struct mlx5_rxq_data *rxq)
{
	struct mlx5_rxq_ctrl *ctrl =
		container_of(rxq, struct mlx5_rxq_ctrl, rxq);

	if (!ctrl->priv->config.rx_vec_en || rxq->sges_n != 0)
		return -ENOTSUP;
	if (rxq->lro)
		return -ENOTSUP;
	return 1;
}

/**
 * Check a device can support vectorized RX.
 *
 * @param dev
 *   Pointer to Ethernet device.
 *
 * @return
 *   1 if supported, negative errno value if not.
 */
int __rte_cold
mlx5_check_vec_rx_support(struct rte_eth_dev *dev)
{
	struct mlx5_priv *priv = dev->data->dev_private;
	uint32_t i;

	if (rte_vect_get_max_simd_bitwidth() < RTE_VECT_SIMD_128)
		return -ENOTSUP;
	if (!priv->config.rx_vec_en)
		return -ENOTSUP;
	/* All the configured queues should support. */
	for (i = 0; i < priv->rxqs_n; ++i) {
		struct mlx5_rxq_data *rxq = (*priv->rxqs)[i];

		if (!rxq)
			continue;
		if (mlx5_rxq_check_vec_support(rxq) < 0)
			break;
	}
	if (i != priv->rxqs_n)
		return -ENOTSUP;
	return 1;
}