// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2015-2019 Netronome Systems, Inc. */

#include <linux/bpf_trace.h>
#include <linux/netdevice.h>
#include <linux/overflow.h>
#include <linux/sizes.h>
#include <linux/bitfield.h>
#include <net/xfrm.h>

#include "../nfp_app.h"
#include "../nfp_net.h"
#include "../nfp_net_dp.h"
#include "../crypto/crypto.h"
#include "../crypto/fw.h"
#include "nfdk.h"

static int nfp_nfdk_tx_ring_should_wake(struct nfp_net_tx_ring *tx_ring)
{
        return !nfp_net_tx_full(tx_ring, NFDK_TX_DESC_STOP_CNT * 2);
}

static int nfp_nfdk_tx_ring_should_stop(struct nfp_net_tx_ring *tx_ring)
{
        return nfp_net_tx_full(tx_ring, NFDK_TX_DESC_STOP_CNT);
}

static void nfp_nfdk_tx_ring_stop(struct netdev_queue *nd_q,
                                  struct nfp_net_tx_ring *tx_ring)
{
        netif_tx_stop_queue(nd_q);

        /* We can race with the TX completion out of NAPI so recheck */
        smp_mb();
        if (unlikely(nfp_nfdk_tx_ring_should_wake(tx_ring)))
                netif_tx_start_queue(nd_q);
}

static __le64
nfp_nfdk_tx_tso(struct nfp_net_r_vector *r_vec, struct nfp_nfdk_tx_buf *txbuf,
                struct sk_buff *skb)
{
        u32 segs, hdrlen, l3_offset, l4_offset, l4_hdrlen;
        struct nfp_nfdk_tx_desc txd;
        u16 mss;

        if (!skb->encapsulation) {
                l3_offset = skb_network_offset(skb);
                l4_offset = skb_transport_offset(skb);
                l4_hdrlen = (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) ?
                            sizeof(struct udphdr) : tcp_hdrlen(skb);
        } else {
                l3_offset = skb_inner_network_offset(skb);
                l4_offset = skb_inner_transport_offset(skb);
                l4_hdrlen = (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) ?
                            sizeof(struct udphdr) : inner_tcp_hdrlen(skb);
        }

        hdrlen = l4_offset + l4_hdrlen;
        segs = skb_shinfo(skb)->gso_segs;
        mss = skb_shinfo(skb)->gso_size & NFDK_DESC_TX_MSS_MASK;

        txd.l3_offset = l3_offset;
        txd.l4_offset = l4_offset;
        txd.lso_meta_res = 0;
        txd.mss = cpu_to_le16(mss);
        txd.lso_hdrlen = hdrlen;
        txd.lso_totsegs = segs;

        txbuf->pkt_cnt = segs;
        txbuf->real_len = skb->len + hdrlen * (txbuf->pkt_cnt - 1);

        u64_stats_update_begin(&r_vec->tx_sync);
        r_vec->tx_lso++;
        u64_stats_update_end(&r_vec->tx_sync);

        return txd.raw;
}

static u8
nfp_nfdk_tx_csum(struct nfp_net_dp *dp, struct nfp_net_r_vector *r_vec,
                 unsigned int pkt_cnt, struct sk_buff *skb, u64 flags)
{
        struct ipv6hdr *ipv6h;
        struct iphdr *iph;

        if (!(dp->ctrl & NFP_NET_CFG_CTRL_TXCSUM))
                return flags;

        if (skb->ip_summed != CHECKSUM_PARTIAL)
                return flags;

        flags |= NFDK_DESC_TX_L4_CSUM;

        iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
        ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);

        /* L3 checksum offloading flag is not required for ipv6 */
        if (iph->version == 4) {
                flags |= NFDK_DESC_TX_L3_CSUM;
        } else if (ipv6h->version != 6) {
                nn_dp_warn(dp, "partial checksum but ipv=%x!\n", iph->version);
                return flags;
        }

        u64_stats_update_begin(&r_vec->tx_sync);
        if (!skb->encapsulation) {
                r_vec->hw_csum_tx += pkt_cnt;
        } else {
                flags |= NFDK_DESC_TX_ENCAP;
                r_vec->hw_csum_tx_inner += pkt_cnt;
        }
        u64_stats_update_end(&r_vec->tx_sync);

        return flags;
}

static int
nfp_nfdk_tx_maybe_close_block(struct nfp_net_tx_ring *tx_ring,
                              struct sk_buff *skb)
{
        unsigned int n_descs, wr_p, nop_slots;
        const skb_frag_t *frag, *fend;
        struct nfp_nfdk_tx_desc *txd;
        unsigned int nr_frags;
        unsigned int wr_idx;
        int err;

recount_descs:
        n_descs = nfp_nfdk_headlen_to_segs(skb_headlen(skb));
        nr_frags = skb_shinfo(skb)->nr_frags;
        frag = skb_shinfo(skb)->frags;
        fend = frag + nr_frags;
        for (; frag < fend; frag++)
                n_descs += DIV_ROUND_UP(skb_frag_size(frag),
                                        NFDK_TX_MAX_DATA_PER_DESC);

        if (unlikely(n_descs > NFDK_TX_DESC_GATHER_MAX)) {
                if (skb_is_nonlinear(skb)) {
                        err = skb_linearize(skb);
                        if (err)
                                return err;
                        goto recount_descs;
                }
                return -EINVAL;
        }

        /* Under count by 1 (don't count meta) for the round down to work out */
        n_descs += !!skb_is_gso(skb);

        if (round_down(tx_ring->wr_p, NFDK_TX_DESC_BLOCK_CNT) !=
            round_down(tx_ring->wr_p + n_descs, NFDK_TX_DESC_BLOCK_CNT))
                goto close_block;

        if ((u32)tx_ring->data_pending + skb->len > NFDK_TX_MAX_DATA_PER_BLOCK)
                goto close_block;

        return 0;

close_block:
        wr_p = tx_ring->wr_p;
        nop_slots = D_BLOCK_CPL(wr_p);

        wr_idx = D_IDX(tx_ring, wr_p);
        tx_ring->ktxbufs[wr_idx].skb = NULL;
        txd = &tx_ring->ktxds[wr_idx];

        memset(txd, 0, array_size(nop_slots, sizeof(struct nfp_nfdk_tx_desc)));

        tx_ring->data_pending = 0;
        tx_ring->wr_p += nop_slots;
        tx_ring->wr_ptr_add += nop_slots;

        return 0;
}

static int
nfp_nfdk_prep_tx_meta(struct nfp_net_dp *dp, struct nfp_app *app,
                      struct sk_buff *skb, bool *ipsec)
{
        struct metadata_dst *md_dst = skb_metadata_dst(skb);
        struct nfp_ipsec_offload offload_info;
        unsigned char *data;
        bool vlan_insert;
        u32 meta_id = 0;
        int md_bytes;

#ifdef CONFIG_NFP_NET_IPSEC
        if (xfrm_offload(skb))
                *ipsec = nfp_net_ipsec_tx_prep(dp, skb, &offload_info);
#endif

        if (unlikely(md_dst && md_dst->type != METADATA_HW_PORT_MUX))
                md_dst = NULL;

        vlan_insert = skb_vlan_tag_present(skb) && (dp->ctrl & NFP_NET_CFG_CTRL_TXVLAN_V2);

        if (!(md_dst || vlan_insert || *ipsec))
                return 0;

        md_bytes = sizeof(meta_id) +
                   (!!md_dst ? NFP_NET_META_PORTID_SIZE : 0) +
                   (vlan_insert ? NFP_NET_META_VLAN_SIZE : 0) +
                   (*ipsec ? NFP_NET_META_IPSEC_FIELD_SIZE : 0);

        if (unlikely(skb_cow_head(skb, md_bytes)))
                return -ENOMEM;

        data = skb_push(skb, md_bytes) + md_bytes;
        if (md_dst) {
                data -= NFP_NET_META_PORTID_SIZE;
                put_unaligned_be32(md_dst->u.port_info.port_id, data);
                meta_id = NFP_NET_META_PORTID;
        }
        if (vlan_insert) {
                data -= NFP_NET_META_VLAN_SIZE;
                /* data type of skb->vlan_proto is __be16
                 * so it fills metadata without calling put_unaligned_be16
                 */
                memcpy(data, &skb->vlan_proto, sizeof(skb->vlan_proto));
                put_unaligned_be16(skb_vlan_tag_get(skb), data + sizeof(skb->vlan_proto));
                meta_id <<= NFP_NET_META_FIELD_SIZE;
                meta_id |= NFP_NET_META_VLAN;
        }

        if (*ipsec) {
                data -= NFP_NET_META_IPSEC_SIZE;
                put_unaligned_be32(offload_info.seq_hi, data);
                data -= NFP_NET_META_IPSEC_SIZE;
                put_unaligned_be32(offload_info.seq_low, data);
                data -= NFP_NET_META_IPSEC_SIZE;
                put_unaligned_be32(offload_info.handle - 1, data);
                meta_id <<= NFP_NET_META_IPSEC_FIELD_SIZE;
                meta_id |= NFP_NET_META_IPSEC << 8 | NFP_NET_META_IPSEC << 4 | NFP_NET_META_IPSEC;
        }

        meta_id = FIELD_PREP(NFDK_META_LEN, md_bytes) |
                  FIELD_PREP(NFDK_META_FIELDS, meta_id);

        data -= sizeof(meta_id);
        put_unaligned_be32(meta_id, data);

        return NFDK_DESC_TX_CHAIN_META;
}

/**
 * nfp_nfdk_tx() - Main transmit entry point
 * @skb:    SKB to transmit
 * @netdev: netdev structure
 *
 * Return: NETDEV_TX_OK on success.
 */
netdev_tx_t nfp_nfdk_tx(struct sk_buff *skb, struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);
        struct nfp_nfdk_tx_buf *txbuf, *etxbuf;
        u32 cnt, tmp_dlen, dlen_type = 0;
        struct nfp_net_tx_ring *tx_ring;
        struct nfp_net_r_vector *r_vec;
        const skb_frag_t *frag, *fend;
        struct nfp_nfdk_tx_desc *txd;
        unsigned int real_len, qidx;
        unsigned int dma_len, type;
        struct netdev_queue *nd_q;
        struct nfp_net_dp *dp;
        int nr_frags, wr_idx;
        dma_addr_t dma_addr;
        bool ipsec = false;
        u64 metadata;

        dp = &nn->dp;
        qidx = skb_get_queue_mapping(skb);
        tx_ring = &dp->tx_rings[qidx];
        r_vec = tx_ring->r_vec;
        nd_q = netdev_get_tx_queue(dp->netdev, qidx);

        /* Don't bother counting frags, assume the worst */
        if (unlikely(nfp_net_tx_full(tx_ring, NFDK_TX_DESC_STOP_CNT))) {
                nn_dp_warn(dp, "TX ring %d busy. wrp=%u rdp=%u\n",
                           qidx, tx_ring->wr_p, tx_ring->rd_p);
                netif_tx_stop_queue(nd_q);
                nfp_net_tx_xmit_more_flush(tx_ring);
                u64_stats_update_begin(&r_vec->tx_sync);
                r_vec->tx_busy++;
                u64_stats_update_end(&r_vec->tx_sync);
                return NETDEV_TX_BUSY;
        }

        metadata = nfp_nfdk_prep_tx_meta(dp, nn->app, skb, &ipsec);
        if (unlikely((int)metadata < 0))
                goto err_flush;

        if (nfp_nfdk_tx_maybe_close_block(tx_ring, skb))
                goto err_flush;

        /* nr_frags will change after skb_linearize so we get nr_frags after
         * nfp_nfdk_tx_maybe_close_block function
         */
        nr_frags = skb_shinfo(skb)->nr_frags;
        /* DMA map all */
        wr_idx = D_IDX(tx_ring, tx_ring->wr_p);
        txd = &tx_ring->ktxds[wr_idx];
        txbuf = &tx_ring->ktxbufs[wr_idx];

        dma_len = skb_headlen(skb);
        if (skb_is_gso(skb))
                type = NFDK_DESC_TX_TYPE_TSO;
        else if (!nr_frags && dma_len <= NFDK_TX_MAX_DATA_PER_HEAD)
                type = NFDK_DESC_TX_TYPE_SIMPLE;
        else
                type = NFDK_DESC_TX_TYPE_GATHER;

        dma_addr = dma_map_single(dp->dev, skb->data, dma_len, DMA_TO_DEVICE);
        if (dma_mapping_error(dp->dev, dma_addr))
                goto err_warn_dma;

        txbuf->skb = skb;
        txbuf++;

        txbuf->dma_addr = dma_addr;
        txbuf++;

        /* FIELD_PREP() implicitly truncates to chunk */
        dma_len -= 1;

        /* We will do our best to pass as much data as we can in descriptor
         * and we need to make sure the first descriptor includes whole head
         * since there is limitation in firmware side. Sometimes the value of
         * dma_len bitwise and NFDK_DESC_TX_DMA_LEN_HEAD will less than
         * headlen.
         */
        dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD,
                               dma_len > NFDK_DESC_TX_DMA_LEN_HEAD ?
                               NFDK_DESC_TX_DMA_LEN_HEAD : dma_len) |
                    FIELD_PREP(NFDK_DESC_TX_TYPE_HEAD, type);

        txd->dma_len_type = cpu_to_le16(dlen_type);
        nfp_desc_set_dma_addr_48b(txd, dma_addr);

        /* starts at bit 0 */
        BUILD_BUG_ON(!(NFDK_DESC_TX_DMA_LEN_HEAD & 1));

        /* Preserve the original dlen_type, this way below the EOP logic
         * can use dlen_type.
         */
        tmp_dlen = dlen_type & NFDK_DESC_TX_DMA_LEN_HEAD;
        dma_len -= tmp_dlen;
        dma_addr += tmp_dlen + 1;
        txd++;

        /* The rest of the data (if any) will be in larger dma descritors
         * and is handled with the fragment loop.
         */
        frag = skb_shinfo(skb)->frags;
        fend = frag + nr_frags;

        while (true) {
                while (dma_len > 0) {
                        dma_len -= 1;
                        dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN, dma_len);

                        txd->dma_len_type = cpu_to_le16(dlen_type);
                        nfp_desc_set_dma_addr_48b(txd, dma_addr);

                        dma_len -= dlen_type;
                        dma_addr += dlen_type + 1;
                        txd++;
                }

                if (frag >= fend)
                        break;

                dma_len = skb_frag_size(frag);
                dma_addr = skb_frag_dma_map(dp->dev, frag, 0, dma_len,
                                            DMA_TO_DEVICE);
                if (dma_mapping_error(dp->dev, dma_addr))
                        goto err_unmap;

                txbuf->dma_addr = dma_addr;
                txbuf++;

                frag++;
        }

        (txd - 1)->dma_len_type = cpu_to_le16(dlen_type | NFDK_DESC_TX_EOP);

        if (ipsec)
                metadata = nfp_nfdk_ipsec_tx(metadata, skb);

        if (!skb_is_gso(skb)) {
                real_len = skb->len;
                /* Metadata desc */
                if (!ipsec)
                        metadata = nfp_nfdk_tx_csum(dp, r_vec, 1, skb, metadata);
                txd->raw = cpu_to_le64(metadata);
                txd++;
        } else {
                /* lso desc should be placed after metadata desc */
                (txd + 1)->raw = nfp_nfdk_tx_tso(r_vec, txbuf, skb);
                real_len = txbuf->real_len;
                /* Metadata desc */
                if (!ipsec)
                        metadata = nfp_nfdk_tx_csum(dp, r_vec, txbuf->pkt_cnt, skb, metadata);
                txd->raw = cpu_to_le64(metadata);
                txd += 2;
                txbuf++;
        }

        cnt = txd - tx_ring->ktxds - wr_idx;
        if (unlikely(round_down(wr_idx, NFDK_TX_DESC_BLOCK_CNT) !=
                     round_down(wr_idx + cnt - 1, NFDK_TX_DESC_BLOCK_CNT)))
                goto err_warn_overflow;

        skb_tx_timestamp(skb);

        tx_ring->wr_p += cnt;
        if (tx_ring->wr_p % NFDK_TX_DESC_BLOCK_CNT)
                tx_ring->data_pending += skb->len;
        else
                tx_ring->data_pending = 0;

        if (nfp_nfdk_tx_ring_should_stop(tx_ring))
                nfp_nfdk_tx_ring_stop(nd_q, tx_ring);

        tx_ring->wr_ptr_add += cnt;
        if (__netdev_tx_sent_queue(nd_q, real_len, netdev_xmit_more()))
                nfp_net_tx_xmit_more_flush(tx_ring);

        return NETDEV_TX_OK;

err_warn_overflow:
        WARN_ONCE(1, "unable to fit packet into a descriptor wr_idx:%d head:%d frags:%d cnt:%d",
                  wr_idx, skb_headlen(skb), nr_frags, cnt);
        if (skb_is_gso(skb))
                txbuf--;
err_unmap:
        /* txbuf pointed to the next-to-use */
        etxbuf = txbuf;
        /* first txbuf holds the skb */
        txbuf = &tx_ring->ktxbufs[wr_idx + 1];
        if (txbuf < etxbuf) {
                dma_unmap_single(dp->dev, txbuf->dma_addr,
                                 skb_headlen(skb), DMA_TO_DEVICE);
                txbuf->raw = 0;
                txbuf++;
        }
        frag = skb_shinfo(skb)->frags;
        while (etxbuf < txbuf) {
                dma_unmap_page(dp->dev, txbuf->dma_addr,
                               skb_frag_size(frag), DMA_TO_DEVICE);
                txbuf->raw = 0;
                frag++;
                txbuf++;
        }
err_warn_dma:
        nn_dp_warn(dp, "Failed to map DMA TX buffer\n");
err_flush:
        nfp_net_tx_xmit_more_flush(tx_ring);
        u64_stats_update_begin(&r_vec->tx_sync);
        r_vec->tx_errors++;
        u64_stats_update_end(&r_vec->tx_sync);
        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
}

/**
 * nfp_nfdk_tx_complete() - Handled completed TX packets
 * @tx_ring:    TX ring structure
 * @budget:     NAPI budget (only used as bool to determine if in NAPI context)
 */
static void nfp_nfdk_tx_complete(struct nfp_net_tx_ring *tx_ring, int budget)
{
        struct nfp_net_r_vector *r_vec = tx_ring->r_vec;
        struct nfp_net_dp *dp = &r_vec->nfp_net->dp;
        u32 done_pkts = 0, done_bytes = 0;
        struct nfp_nfdk_tx_buf *ktxbufs;
        struct device *dev = dp->dev;
        struct netdev_queue *nd_q;
        u32 rd_p, qcp_rd_p;
        int todo;

        rd_p = tx_ring->rd_p;
        if (tx_ring->wr_p == rd_p)
                return;

        /* Work out how many descriptors have been transmitted */
        qcp_rd_p = nfp_net_read_tx_cmpl(tx_ring, dp);

        if (qcp_rd_p == tx_ring->qcp_rd_p)
                return;

        todo = D_IDX(tx_ring, qcp_rd_p - tx_ring->qcp_rd_p);
        ktxbufs = tx_ring->ktxbufs;

        while (todo > 0) {
                const skb_frag_t *frag, *fend;
                unsigned int size, n_descs = 1;
                struct nfp_nfdk_tx_buf *txbuf;
                struct sk_buff *skb;

                txbuf = &ktxbufs[D_IDX(tx_ring, rd_p)];
                skb = txbuf->skb;
                txbuf++;

                /* Closed block */
                if (!skb) {
                        n_descs = D_BLOCK_CPL(rd_p);
                        goto next;
                }

                /* Unmap head */
                size = skb_headlen(skb);
                n_descs += nfp_nfdk_headlen_to_segs(size);
                dma_unmap_single(dev, txbuf->dma_addr, size, DMA_TO_DEVICE);
                txbuf++;

                /* Unmap frags */
                frag = skb_shinfo(skb)->frags;
                fend = frag + skb_shinfo(skb)->nr_frags;
                for (; frag < fend; frag++) {
                        size = skb_frag_size(frag);
                        n_descs += DIV_ROUND_UP(size,
                                                NFDK_TX_MAX_DATA_PER_DESC);
                        dma_unmap_page(dev, txbuf->dma_addr,
                                       skb_frag_size(frag), DMA_TO_DEVICE);
                        txbuf++;
                }

                if (!skb_is_gso(skb)) {
                        done_bytes += skb->len;
                        done_pkts++;
                } else {
                        done_bytes += txbuf->real_len;
                        done_pkts += txbuf->pkt_cnt;
                        n_descs++;
                }

                napi_consume_skb(skb, budget);
next:
                rd_p += n_descs;
                todo -= n_descs;
        }

        tx_ring->rd_p = rd_p;
        tx_ring->qcp_rd_p = qcp_rd_p;

        u64_stats_update_begin(&r_vec->tx_sync);
        r_vec->tx_bytes += done_bytes;
        r_vec->tx_pkts += done_pkts;
        u64_stats_update_end(&r_vec->tx_sync);

        if (!dp->netdev)
                return;

        nd_q = netdev_get_tx_queue(dp->netdev, tx_ring->idx);
        netdev_tx_completed_queue(nd_q, done_pkts, done_bytes);
        if (nfp_nfdk_tx_ring_should_wake(tx_ring)) {
                /* Make sure TX thread will see updated tx_ring->rd_p */
                smp_mb();

                if (unlikely(netif_tx_queue_stopped(nd_q)))
                        netif_tx_wake_queue(nd_q);
        }

        WARN_ONCE(tx_ring->wr_p - tx_ring->rd_p > tx_ring->cnt,
                  "TX ring corruption rd_p=%u wr_p=%u cnt=%u\n",
                  tx_ring->rd_p, tx_ring->wr_p, tx_ring->cnt);
}

/* Receive processing */
static void *
nfp_nfdk_napi_alloc_one(struct nfp_net_dp *dp, dma_addr_t *dma_addr)
{
        void *frag;

        if (!dp->xdp_prog) {
                frag = napi_alloc_frag(dp->fl_bufsz);
                if (unlikely(!frag))
                        return NULL;
        } else {
                struct page *page;

                page = dev_alloc_page();
                if (unlikely(!page))
                        return NULL;
                frag = page_address(page);
        }

        *dma_addr = nfp_net_dma_map_rx(dp, frag);
        if (dma_mapping_error(dp->dev, *dma_addr)) {
                nfp_net_free_frag(frag, dp->xdp_prog);
                nn_dp_warn(dp, "Failed to map DMA RX buffer\n");
                return NULL;
        }

        return frag;
}

/**
 * nfp_nfdk_rx_give_one() - Put mapped skb on the software and hardware rings
 * @dp:         NFP Net data path struct
 * @rx_ring:    RX ring structure
 * @frag:       page fragment buffer
 * @dma_addr:   DMA address of skb mapping
 */
static void
nfp_nfdk_rx_give_one(const struct nfp_net_dp *dp,
                     struct nfp_net_rx_ring *rx_ring,
                     void *frag, dma_addr_t dma_addr)
{
        unsigned int wr_idx;

        wr_idx = D_IDX(rx_ring, rx_ring->wr_p);

        nfp_net_dma_sync_dev_rx(dp, dma_addr);

        /* Stash SKB and DMA address away */
        rx_ring->rxbufs[wr_idx].frag = frag;
        rx_ring->rxbufs[wr_idx].dma_addr = dma_addr;

        /* Fill freelist descriptor */
        rx_ring->rxds[wr_idx].fld.reserved = 0;
        rx_ring->rxds[wr_idx].fld.meta_len_dd = 0;
        nfp_desc_set_dma_addr_48b(&rx_ring->rxds[wr_idx].fld,
                                  dma_addr + dp->rx_dma_off);

        rx_ring->wr_p++;
        if (!(rx_ring->wr_p % NFP_NET_FL_BATCH)) {
                /* Update write pointer of the freelist queue. Make
                 * sure all writes are flushed before telling the hardware.
                 */
                wmb();
                nfp_qcp_wr_ptr_add(rx_ring->qcp_fl, NFP_NET_FL_BATCH);
        }
}

/**
 * nfp_nfdk_rx_ring_fill_freelist() - Give buffers from the ring to FW
 * @dp:      NFP Net data path struct
 * @rx_ring: RX ring to fill
 */
void nfp_nfdk_rx_ring_fill_freelist(struct nfp_net_dp *dp,
                                    struct nfp_net_rx_ring *rx_ring)
{
        unsigned int i;

        for (i = 0; i < rx_ring->cnt - 1; i++)
                nfp_nfdk_rx_give_one(dp, rx_ring, rx_ring->rxbufs[i].frag,
                                     rx_ring->rxbufs[i].dma_addr);
}

/**
 * nfp_nfdk_rx_csum_has_errors() - group check if rxd has any csum errors
 * @flags: RX descriptor flags field in CPU byte order
 */
static int nfp_nfdk_rx_csum_has_errors(u16 flags)
{
        u16 csum_all_checked, csum_all_ok;

        csum_all_checked = flags & __PCIE_DESC_RX_CSUM_ALL;
        csum_all_ok = flags & __PCIE_DESC_RX_CSUM_ALL_OK;

        return csum_all_checked != (csum_all_ok << PCIE_DESC_RX_CSUM_OK_SHIFT);
}

/**
 * nfp_nfdk_rx_csum() - set SKB checksum field based on RX descriptor flags
 * @dp:  NFP Net data path struct
 * @r_vec: per-ring structure
 * @rxd: Pointer to RX descriptor
 * @meta: Parsed metadata prepend
 * @skb: Pointer to SKB
 */
static void
nfp_nfdk_rx_csum(struct nfp_net_dp *dp, struct nfp_net_r_vector *r_vec,
                 struct nfp_net_rx_desc *rxd, struct nfp_meta_parsed *meta,
                 struct sk_buff *skb)
{
        skb_checksum_none_assert(skb);

        if (!(dp->netdev->features & NETIF_F_RXCSUM))
                return;

        if (meta->csum_type) {
                skb->ip_summed = meta->csum_type;
                skb->csum = meta->csum;
                u64_stats_update_begin(&r_vec->rx_sync);
                r_vec->hw_csum_rx_complete++;
                u64_stats_update_end(&r_vec->rx_sync);
                return;
        }

        if (nfp_nfdk_rx_csum_has_errors(le16_to_cpu(rxd->rxd.flags))) {
                u64_stats_update_begin(&r_vec->rx_sync);
                r_vec->hw_csum_rx_error++;
                u64_stats_update_end(&r_vec->rx_sync);
                return;
        }

        /* Assume that the firmware will never report inner CSUM_OK unless outer
         * L4 headers were successfully parsed. FW will always report zero UDP
         * checksum as CSUM_OK.
         */
        if (rxd->rxd.flags & PCIE_DESC_RX_TCP_CSUM_OK ||
            rxd->rxd.flags & PCIE_DESC_RX_UDP_CSUM_OK) {
                __skb_incr_checksum_unnecessary(skb);
                u64_stats_update_begin(&r_vec->rx_sync);
                r_vec->hw_csum_rx_ok++;
                u64_stats_update_end(&r_vec->rx_sync);
        }

        if (rxd->rxd.flags & PCIE_DESC_RX_I_TCP_CSUM_OK ||
            rxd->rxd.flags & PCIE_DESC_RX_I_UDP_CSUM_OK) {
                __skb_incr_checksum_unnecessary(skb);
                u64_stats_update_begin(&r_vec->rx_sync);
                r_vec->hw_csum_rx_inner_ok++;
                u64_stats_update_end(&r_vec->rx_sync);
        }
}

static void
nfp_nfdk_set_hash(struct net_device *netdev, struct nfp_meta_parsed *meta,
                  unsigned int type, __be32 *hash)
{
        if (!(netdev->features & NETIF_F_RXHASH))
                return;

        switch (type) {
        case NFP_NET_RSS_IPV4:
        case NFP_NET_RSS_IPV6:
        case NFP_NET_RSS_IPV6_EX:
                meta->hash_type = PKT_HASH_TYPE_L3;
                break;
        default:
                meta->hash_type = PKT_HASH_TYPE_L4;
                break;
        }

        meta->hash = get_unaligned_be32(hash);
}

static bool
nfp_nfdk_parse_meta(struct net_device *netdev, struct nfp_meta_parsed *meta,
                    void *data, void *pkt, unsigned int pkt_len, int meta_len)
{
        u32 meta_info, vlan_info;

        meta_info = get_unaligned_be32(data);
        data += 4;

        while (meta_info) {
                switch (meta_info & NFP_NET_META_FIELD_MASK) {
                case NFP_NET_META_HASH:
                        meta_info >>= NFP_NET_META_FIELD_SIZE;
                        nfp_nfdk_set_hash(netdev, meta,
                                          meta_info & NFP_NET_META_FIELD_MASK,
                                          (__be32 *)data);
                        data += 4;
                        break;
                case NFP_NET_META_MARK:
                        meta->mark = get_unaligned_be32(data);
                        data += 4;
                        break;
                case NFP_NET_META_VLAN:
                        vlan_info = get_unaligned_be32(data);
                        if (FIELD_GET(NFP_NET_META_VLAN_STRIP, vlan_info)) {
                                meta->vlan.stripped = true;
                                meta->vlan.tpid = FIELD_GET(NFP_NET_META_VLAN_TPID_MASK,
                                                            vlan_info);
                                meta->vlan.tci = FIELD_GET(NFP_NET_META_VLAN_TCI_MASK,
                                                           vlan_info);
                        }
                        data += 4;
                        break;
                case NFP_NET_META_PORTID:
                        meta->portid = get_unaligned_be32(data);
                        data += 4;
                        break;
                case NFP_NET_META_CSUM:
                        meta->csum_type = CHECKSUM_COMPLETE;
                        meta->csum =
                                (__force __wsum)get_unaligned((u32 *)data);
                        data += 4;
                        break;
                case NFP_NET_META_RESYNC_INFO:
                        if (nfp_net_tls_rx_resync_req(netdev, data, pkt,
                                                      pkt_len))
                                return false;
                        data += sizeof(struct nfp_net_tls_resync_req);
                        break;
#ifdef CONFIG_NFP_NET_IPSEC
                case NFP_NET_META_IPSEC:
                        /* Note: IPsec packet could have zero saidx, so need add 1
                         * to indicate packet is IPsec packet within driver.
                         */
                        meta->ipsec_saidx = get_unaligned_be32(data) + 1;
                        data += 4;
                        break;
#endif
                default:
                        return true;
                }

                meta_info >>= NFP_NET_META_FIELD_SIZE;
        }

        return data != pkt;
}

static void
nfp_nfdk_rx_drop(const struct nfp_net_dp *dp, struct nfp_net_r_vector *r_vec,
                 struct nfp_net_rx_ring *rx_ring, struct nfp_net_rx_buf *rxbuf,
                 struct sk_buff *skb)
{
        u64_stats_update_begin(&r_vec->rx_sync);
        r_vec->rx_drops++;
        /* If we have both skb and rxbuf the replacement buffer allocation
         * must have failed, count this as an alloc failure.
         */
        if (skb && rxbuf)
                r_vec->rx_replace_buf_alloc_fail++;
        u64_stats_update_end(&r_vec->rx_sync);

        /* skb is build based on the frag, free_skb() would free the frag
         * so to be able to reuse it we need an extra ref.
         */
        if (skb && rxbuf && skb->head == rxbuf->frag)
                page_ref_inc(virt_to_head_page(rxbuf->frag));
        if (rxbuf)
                nfp_nfdk_rx_give_one(dp, rx_ring, rxbuf->frag, rxbuf->dma_addr);
        if (skb)
                dev_kfree_skb_any(skb);
}

static bool nfp_nfdk_xdp_complete(struct nfp_net_tx_ring *tx_ring)
{
        struct nfp_net_r_vector *r_vec = tx_ring->r_vec;
        struct nfp_net_dp *dp = &r_vec->nfp_net->dp;
        struct nfp_net_rx_ring *rx_ring;
        u32 qcp_rd_p, done = 0;
        bool done_all;
        int todo;

        /* Work out how many descriptors have been transmitted */
        qcp_rd_p = nfp_net_read_tx_cmpl(tx_ring, dp);
        if (qcp_rd_p == tx_ring->qcp_rd_p)
                return true;

        todo = D_IDX(tx_ring, qcp_rd_p - tx_ring->qcp_rd_p);

        done_all = todo <= NFP_NET_XDP_MAX_COMPLETE;
        todo = min(todo, NFP_NET_XDP_MAX_COMPLETE);

        rx_ring = r_vec->rx_ring;
        while (todo > 0) {
                int idx = D_IDX(tx_ring, tx_ring->rd_p + done);
                struct nfp_nfdk_tx_buf *txbuf;
                unsigned int step = 1;

                txbuf = &tx_ring->ktxbufs[idx];
                if (!txbuf->raw)
                        goto next;

                if (NFDK_TX_BUF_INFO(txbuf->val) != NFDK_TX_BUF_INFO_SOP) {
                        WARN_ONCE(1, "Unexpected TX buffer in XDP TX ring\n");
                        goto next;
                }

                /* Two successive txbufs are used to stash virtual and dma
                 * address respectively, recycle and clean them here.
                 */
                nfp_nfdk_rx_give_one(dp, rx_ring,
                                     (void *)NFDK_TX_BUF_PTR(txbuf[0].val),
                                     txbuf[1].dma_addr);
                txbuf[0].raw = 0;
                txbuf[1].raw = 0;
                step = 2;

                u64_stats_update_begin(&r_vec->tx_sync);
                /* Note: tx_bytes not accumulated. */
                r_vec->tx_pkts++;
                u64_stats_update_end(&r_vec->tx_sync);
next:
                todo -= step;
                done += step;
        }

        tx_ring->qcp_rd_p = D_IDX(tx_ring, tx_ring->qcp_rd_p + done);
        tx_ring->rd_p += done;

        WARN_ONCE(tx_ring->wr_p - tx_ring->rd_p > tx_ring->cnt,
                  "XDP TX ring corruption rd_p=%u wr_p=%u cnt=%u\n",
                  tx_ring->rd_p, tx_ring->wr_p, tx_ring->cnt);

        return done_all;
}

static bool
nfp_nfdk_tx_xdp_buf(struct nfp_net_dp *dp, struct nfp_net_rx_ring *rx_ring,
                    struct nfp_net_tx_ring *tx_ring,
                    struct nfp_net_rx_buf *rxbuf, unsigned int dma_off,
                    unsigned int pkt_len, bool *completed)
{
        unsigned int dma_map_sz = dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA;
        unsigned int dma_len, type, cnt, dlen_type, tmp_dlen;
        struct nfp_nfdk_tx_buf *txbuf;
        struct nfp_nfdk_tx_desc *txd;
        unsigned int n_descs;
        dma_addr_t dma_addr;
        int wr_idx;

        /* Reject if xdp_adjust_tail grow packet beyond DMA area */
        if (pkt_len + dma_off > dma_map_sz)
                return false;

        /* Make sure there's still at least one block available after
         * aligning to block boundary, so that the txds used below
         * won't wrap around the tx_ring.
         */
        if (unlikely(nfp_net_tx_full(tx_ring, NFDK_TX_DESC_STOP_CNT))) {
                if (!*completed) {
                        nfp_nfdk_xdp_complete(tx_ring);
                        *completed = true;
                }

                if (unlikely(nfp_net_tx_full(tx_ring, NFDK_TX_DESC_STOP_CNT))) {
                        nfp_nfdk_rx_drop(dp, rx_ring->r_vec, rx_ring, rxbuf,
                                         NULL);
                        return false;
                }
        }

        /* Check if cross block boundary */
        n_descs = nfp_nfdk_headlen_to_segs(pkt_len);
        if ((round_down(tx_ring->wr_p, NFDK_TX_DESC_BLOCK_CNT) !=
             round_down(tx_ring->wr_p + n_descs, NFDK_TX_DESC_BLOCK_CNT)) ||
            ((u32)tx_ring->data_pending + pkt_len >
             NFDK_TX_MAX_DATA_PER_BLOCK)) {
                unsigned int nop_slots = D_BLOCK_CPL(tx_ring->wr_p);

                wr_idx = D_IDX(tx_ring, tx_ring->wr_p);
                txd = &tx_ring->ktxds[wr_idx];
                memset(txd, 0,
                       array_size(nop_slots, sizeof(struct nfp_nfdk_tx_desc)));

                tx_ring->data_pending = 0;
                tx_ring->wr_p += nop_slots;
                tx_ring->wr_ptr_add += nop_slots;
        }

        wr_idx = D_IDX(tx_ring, tx_ring->wr_p);

        txbuf = &tx_ring->ktxbufs[wr_idx];

        txbuf[0].val = (unsigned long)rxbuf->frag | NFDK_TX_BUF_INFO_SOP;
        txbuf[1].dma_addr = rxbuf->dma_addr;
        /* Note: pkt len not stored */

        dma_sync_single_for_device(dp->dev, rxbuf->dma_addr + dma_off,
                                   pkt_len, DMA_BIDIRECTIONAL);

        /* Build TX descriptor */
        txd = &tx_ring->ktxds[wr_idx];
        dma_len = pkt_len;
        dma_addr = rxbuf->dma_addr + dma_off;

        if (dma_len <= NFDK_TX_MAX_DATA_PER_HEAD)
                type = NFDK_DESC_TX_TYPE_SIMPLE;
        else
                type = NFDK_DESC_TX_TYPE_GATHER;

        /* FIELD_PREP() implicitly truncates to chunk */
        dma_len -= 1;
        dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD,
                               dma_len > NFDK_DESC_TX_DMA_LEN_HEAD ?
                               NFDK_DESC_TX_DMA_LEN_HEAD : dma_len) |
                    FIELD_PREP(NFDK_DESC_TX_TYPE_HEAD, type);

        txd->dma_len_type = cpu_to_le16(dlen_type);
        nfp_desc_set_dma_addr_48b(txd, dma_addr);

        tmp_dlen = dlen_type & NFDK_DESC_TX_DMA_LEN_HEAD;
        dma_len -= tmp_dlen;
        dma_addr += tmp_dlen + 1;
        txd++;

        while (dma_len > 0) {
                dma_len -= 1;
                dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN, dma_len);
                txd->dma_len_type = cpu_to_le16(dlen_type);
                nfp_desc_set_dma_addr_48b(txd, dma_addr);

                dlen_type &= NFDK_DESC_TX_DMA_LEN;
                dma_len -= dlen_type;
                dma_addr += dlen_type + 1;
                txd++;
        }

        (txd - 1)->dma_len_type = cpu_to_le16(dlen_type | NFDK_DESC_TX_EOP);

        /* Metadata desc */
        txd->raw = 0;
        txd++;

        cnt = txd - tx_ring->ktxds - wr_idx;
        tx_ring->wr_p += cnt;
        if (tx_ring->wr_p % NFDK_TX_DESC_BLOCK_CNT)
                tx_ring->data_pending += pkt_len;
        else
                tx_ring->data_pending = 0;

        tx_ring->wr_ptr_add += cnt;
        return true;
}

/**
 * nfp_nfdk_rx() - receive up to @budget packets on @rx_ring
 * @rx_ring:   RX ring to receive from
 * @budget:    NAPI budget
 *
 * Note, this function is separated out from the napi poll function to
 * more cleanly separate packet receive code from other bookkeeping
 * functions performed in the napi poll function.
 *
 * Return: Number of packets received.
 */
static int nfp_nfdk_rx(struct nfp_net_rx_ring *rx_ring, int budget)
{
        struct nfp_net_r_vector *r_vec = rx_ring->r_vec;
        struct nfp_net_dp *dp = &r_vec->nfp_net->dp;
        struct nfp_net_tx_ring *tx_ring;
        struct bpf_prog *xdp_prog;
        bool xdp_tx_cmpl = false;
        unsigned int true_bufsz;
        struct sk_buff *skb;
        int pkts_polled = 0;
        struct xdp_buff xdp;
        int idx;

        xdp_prog = READ_ONCE(dp->xdp_prog);
        true_bufsz = xdp_prog ? PAGE_SIZE : dp->fl_bufsz;
        xdp_init_buff(&xdp, PAGE_SIZE - NFP_NET_RX_BUF_HEADROOM,
                      &rx_ring->xdp_rxq);
        tx_ring = r_vec->xdp_ring;

        while (pkts_polled < budget) {
                unsigned int meta_len, data_len, meta_off, pkt_len, pkt_off;
                struct nfp_net_rx_buf *rxbuf;
                struct nfp_net_rx_desc *rxd;
                struct nfp_meta_parsed meta;
                bool redir_egress = false;
                struct net_device *netdev;
                dma_addr_t new_dma_addr;
                u32 meta_len_xdp = 0;
                void *new_frag;

                idx = D_IDX(rx_ring, rx_ring->rd_p);

                rxd = &rx_ring->rxds[idx];
                if (!(rxd->rxd.meta_len_dd & PCIE_DESC_RX_DD))
                        break;

                /* Memory barrier to ensure that we won't do other reads
                 * before the DD bit.
                 */
                dma_rmb();

                memset(&meta, 0, sizeof(meta));

                rx_ring->rd_p++;
                pkts_polled++;

                rxbuf = &rx_ring->rxbufs[idx];
                /*         < meta_len >
                 *  <-- [rx_offset] -->
                 *  ---------------------------------------------------------
                 * | [XX] |  metadata  |             packet           | XXXX |
                 *  ---------------------------------------------------------
                 *         <---------------- data_len --------------->
                 *
                 * The rx_offset is fixed for all packets, the meta_len can vary
                 * on a packet by packet basis. If rx_offset is set to zero
                 * (_RX_OFFSET_DYNAMIC) metadata starts at the beginning of the
                 * buffer and is immediately followed by the packet (no [XX]).
                 */
                meta_len = rxd->rxd.meta_len_dd & PCIE_DESC_RX_META_LEN_MASK;
                data_len = le16_to_cpu(rxd->rxd.data_len);
                pkt_len = data_len - meta_len;

                pkt_off = NFP_NET_RX_BUF_HEADROOM + dp->rx_dma_off;
                if (dp->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC)
                        pkt_off += meta_len;
                else
                        pkt_off += dp->rx_offset;
                meta_off = pkt_off - meta_len;

                /* Stats update */
                u64_stats_update_begin(&r_vec->rx_sync);
                r_vec->rx_pkts++;
                r_vec->rx_bytes += pkt_len;
                u64_stats_update_end(&r_vec->rx_sync);

                if (unlikely(meta_len > NFP_NET_MAX_PREPEND ||
                             (dp->rx_offset && meta_len > dp->rx_offset))) {
                        nn_dp_warn(dp, "oversized RX packet metadata %u\n",
                                   meta_len);
                        nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf, NULL);
                        continue;
                }

                nfp_net_dma_sync_cpu_rx(dp, rxbuf->dma_addr + meta_off,
                                        data_len);

                if (meta_len) {
                        if (unlikely(nfp_nfdk_parse_meta(dp->netdev, &meta,
                                                         rxbuf->frag + meta_off,
                                                         rxbuf->frag + pkt_off,
                                                         pkt_len, meta_len))) {
                                nn_dp_warn(dp, "invalid RX packet metadata\n");
                                nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf,
                                                 NULL);
                                continue;
                        }
                }

                if (xdp_prog && !meta.portid) {
                        void *orig_data = rxbuf->frag + pkt_off;
                        unsigned int dma_off;
                        int act;

                        xdp_prepare_buff(&xdp,
                                         rxbuf->frag + NFP_NET_RX_BUF_HEADROOM,
                                         pkt_off - NFP_NET_RX_BUF_HEADROOM,
                                         pkt_len, true);

                        act = bpf_prog_run_xdp(xdp_prog, &xdp);

                        pkt_len = xdp.data_end - xdp.data;
                        pkt_off += xdp.data - orig_data;

                        switch (act) {
                        case XDP_PASS:
                                meta_len_xdp = xdp.data - xdp.data_meta;
                                break;
                        case XDP_TX:
                                dma_off = pkt_off - NFP_NET_RX_BUF_HEADROOM;
                                if (unlikely(!nfp_nfdk_tx_xdp_buf(dp, rx_ring,
                                                                  tx_ring,
                                                                  rxbuf,
                                                                  dma_off,
                                                                  pkt_len,
                                                                  &xdp_tx_cmpl)))
                                        trace_xdp_exception(dp->netdev,
                                                            xdp_prog, act);
                                continue;
                        default:
                                bpf_warn_invalid_xdp_action(dp->netdev, xdp_prog, act);
                                fallthrough;
                        case XDP_ABORTED:
                                trace_xdp_exception(dp->netdev, xdp_prog, act);
                                fallthrough;
                        case XDP_DROP:
                                nfp_nfdk_rx_give_one(dp, rx_ring, rxbuf->frag,
                                                     rxbuf->dma_addr);
                                continue;
                        }
                }

                if (likely(!meta.portid)) {
                        netdev = dp->netdev;
                } else if (meta.portid == NFP_META_PORT_ID_CTRL) {
                        struct nfp_net *nn = netdev_priv(dp->netdev);

                        nfp_app_ctrl_rx_raw(nn->app, rxbuf->frag + pkt_off,
                                            pkt_len);
                        nfp_nfdk_rx_give_one(dp, rx_ring, rxbuf->frag,
                                             rxbuf->dma_addr);
                        continue;
                } else {
                        struct nfp_net *nn;

                        nn = netdev_priv(dp->netdev);
                        netdev = nfp_app_dev_get(nn->app, meta.portid,
                                                 &redir_egress);
                        if (unlikely(!netdev)) {
                                nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf,
                                                 NULL);
                                continue;
                        }

                        if (nfp_netdev_is_nfp_repr(netdev))
                                nfp_repr_inc_rx_stats(netdev, pkt_len);
                }

                skb = napi_build_skb(rxbuf->frag, true_bufsz);
                if (unlikely(!skb)) {
                        nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf, NULL);
                        continue;
                }
                new_frag = nfp_nfdk_napi_alloc_one(dp, &new_dma_addr);
                if (unlikely(!new_frag)) {
                        nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf, skb);
                        continue;
                }

                nfp_net_dma_unmap_rx(dp, rxbuf->dma_addr);

                nfp_nfdk_rx_give_one(dp, rx_ring, new_frag, new_dma_addr);

                skb_reserve(skb, pkt_off);
                skb_put(skb, pkt_len);

                skb->mark = meta.mark;
                skb_set_hash(skb, meta.hash, meta.hash_type);

                skb_record_rx_queue(skb, rx_ring->idx);
                skb->protocol = eth_type_trans(skb, netdev);

                nfp_nfdk_rx_csum(dp, r_vec, rxd, &meta, skb);

                if (unlikely(!nfp_net_vlan_strip(skb, rxd, &meta))) {
                        nfp_nfdk_rx_drop(dp, r_vec, rx_ring, NULL, skb);
                        continue;
                }

#ifdef CONFIG_NFP_NET_IPSEC
                if (meta.ipsec_saidx != 0 && unlikely(nfp_net_ipsec_rx(&meta, skb))) {
                        nfp_nfdk_rx_drop(dp, r_vec, rx_ring, NULL, skb);
                        continue;
                }
#endif

                if (meta_len_xdp)
                        skb_metadata_set(skb, meta_len_xdp);

                if (likely(!redir_egress)) {
                        napi_gro_receive(&rx_ring->r_vec->napi, skb);
                } else {
                        skb->dev = netdev;
                        skb_reset_network_header(skb);
                        __skb_push(skb, ETH_HLEN);
                        dev_queue_xmit(skb);
                }
        }

        if (xdp_prog) {
                if (tx_ring->wr_ptr_add)
                        nfp_net_tx_xmit_more_flush(tx_ring);
                else if (unlikely(tx_ring->wr_p != tx_ring->rd_p) &&
                         !xdp_tx_cmpl)
                        if (!nfp_nfdk_xdp_complete(tx_ring))
                                pkts_polled = budget;
        }

        return pkts_polled;
}

/**
 * nfp_nfdk_poll() - napi poll function
 * @napi:    NAPI structure
 * @budget:  NAPI budget
 *
 * Return: number of packets polled.
 */
int nfp_nfdk_poll(struct napi_struct *napi, int budget)
{
        struct nfp_net_r_vector *r_vec =
                container_of(napi, struct nfp_net_r_vector, napi);
        unsigned int pkts_polled = 0;

        if (r_vec->tx_ring)
                nfp_nfdk_tx_complete(r_vec->tx_ring, budget);
        if (r_vec->rx_ring)
                pkts_polled = nfp_nfdk_rx(r_vec->rx_ring, budget);

        if (pkts_polled < budget)
                if (napi_complete_done(napi, pkts_polled))
                        nfp_net_irq_unmask(r_vec->nfp_net, r_vec->irq_entry);

        if (r_vec->nfp_net->rx_coalesce_adapt_on && r_vec->rx_ring) {
                struct dim_sample dim_sample = {};
                u64 pkts, bytes;

                pkts = r_vec->rx_pkts;
                bytes = r_vec->rx_bytes;

                dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample);
                net_dim(&r_vec->rx_dim, &dim_sample);
        }

        if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) {
                struct dim_sample dim_sample = {};
                u64 pkts, bytes;

                pkts = r_vec->tx_pkts;
                bytes = r_vec->tx_bytes;

                dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample);
                net_dim(&r_vec->tx_dim, &dim_sample);
        }

        return pkts_polled;
}

/* Control device data path
 */

bool
nfp_nfdk_ctrl_tx_one(struct nfp_net *nn, struct nfp_net_r_vector *r_vec,
                     struct sk_buff *skb, bool old)
{
        u32 cnt, tmp_dlen, dlen_type = 0;
        struct nfp_net_tx_ring *tx_ring;
        struct nfp_nfdk_tx_buf *txbuf;
        struct nfp_nfdk_tx_desc *txd;
        unsigned int dma_len, type;
        struct nfp_net_dp *dp;
        dma_addr_t dma_addr;
        u64 metadata = 0;
        int wr_idx;

        dp = &r_vec->nfp_net->dp;
        tx_ring = r_vec->tx_ring;

        if (WARN_ON_ONCE(skb_shinfo(skb)->nr_frags)) {
                nn_dp_warn(dp, "Driver's CTRL TX does not implement gather\n");
                goto err_free;
        }

        /* Don't bother counting frags, assume the worst */
        if (unlikely(nfp_net_tx_full(tx_ring, NFDK_TX_DESC_STOP_CNT))) {
                u64_stats_update_begin(&r_vec->tx_sync);
                r_vec->tx_busy++;
                u64_stats_update_end(&r_vec->tx_sync);
                if (!old)
                        __skb_queue_tail(&r_vec->queue, skb);
                else
                        __skb_queue_head(&r_vec->queue, skb);
                return NETDEV_TX_BUSY;
        }

        if (nfp_app_ctrl_has_meta(nn->app)) {
                if (unlikely(skb_headroom(skb) < 8)) {
                        nn_dp_warn(dp, "CTRL TX on skb without headroom\n");
                        goto err_free;
                }
                metadata = NFDK_DESC_TX_CHAIN_META;
                put_unaligned_be32(NFP_META_PORT_ID_CTRL, skb_push(skb, 4));
                put_unaligned_be32(FIELD_PREP(NFDK_META_LEN, 8) |
                                   FIELD_PREP(NFDK_META_FIELDS,
                                              NFP_NET_META_PORTID),
                                   skb_push(skb, 4));
        }

        if (nfp_nfdk_tx_maybe_close_block(tx_ring, skb))
                goto err_free;

        /* DMA map all */
        wr_idx = D_IDX(tx_ring, tx_ring->wr_p);
        txd = &tx_ring->ktxds[wr_idx];
        txbuf = &tx_ring->ktxbufs[wr_idx];

        dma_len = skb_headlen(skb);
        if (dma_len <= NFDK_TX_MAX_DATA_PER_HEAD)
                type = NFDK_DESC_TX_TYPE_SIMPLE;
        else
                type = NFDK_DESC_TX_TYPE_GATHER;

        dma_addr = dma_map_single(dp->dev, skb->data, dma_len, DMA_TO_DEVICE);
        if (dma_mapping_error(dp->dev, dma_addr))
                goto err_warn_dma;

        txbuf->skb = skb;
        txbuf++;

        txbuf->dma_addr = dma_addr;
        txbuf++;

        dma_len -= 1;
        dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN_HEAD,
                               dma_len > NFDK_DESC_TX_DMA_LEN_HEAD ?
                               NFDK_DESC_TX_DMA_LEN_HEAD : dma_len) |
                    FIELD_PREP(NFDK_DESC_TX_TYPE_HEAD, type);

        txd->dma_len_type = cpu_to_le16(dlen_type);
        nfp_desc_set_dma_addr_48b(txd, dma_addr);

        tmp_dlen = dlen_type & NFDK_DESC_TX_DMA_LEN_HEAD;
        dma_len -= tmp_dlen;
        dma_addr += tmp_dlen + 1;
        txd++;

        while (dma_len > 0) {
                dma_len -= 1;
                dlen_type = FIELD_PREP(NFDK_DESC_TX_DMA_LEN, dma_len);
                txd->dma_len_type = cpu_to_le16(dlen_type);
                nfp_desc_set_dma_addr_48b(txd, dma_addr);

                dlen_type &= NFDK_DESC_TX_DMA_LEN;
                dma_len -= dlen_type;
                dma_addr += dlen_type + 1;
                txd++;
        }

        (txd - 1)->dma_len_type = cpu_to_le16(dlen_type | NFDK_DESC_TX_EOP);

        /* Metadata desc */
        txd->raw = cpu_to_le64(metadata);
        txd++;

        cnt = txd - tx_ring->ktxds - wr_idx;
        if (unlikely(round_down(wr_idx, NFDK_TX_DESC_BLOCK_CNT) !=
                     round_down(wr_idx + cnt - 1, NFDK_TX_DESC_BLOCK_CNT)))
                goto err_warn_overflow;

        tx_ring->wr_p += cnt;
        if (tx_ring->wr_p % NFDK_TX_DESC_BLOCK_CNT)
                tx_ring->data_pending += skb->len;
        else
                tx_ring->data_pending = 0;

        tx_ring->wr_ptr_add += cnt;
        nfp_net_tx_xmit_more_flush(tx_ring);

        return NETDEV_TX_OK;

err_warn_overflow:
        WARN_ONCE(1, "unable to fit packet into a descriptor wr_idx:%d head:%d frags:%d cnt:%d",
                  wr_idx, skb_headlen(skb), 0, cnt);
        txbuf--;
        dma_unmap_single(dp->dev, txbuf->dma_addr,
                         skb_headlen(skb), DMA_TO_DEVICE);
        txbuf->raw = 0;
err_warn_dma:
        nn_dp_warn(dp, "Failed to map DMA TX buffer\n");
err_free:
        u64_stats_update_begin(&r_vec->tx_sync);
        r_vec->tx_errors++;
        u64_stats_update_end(&r_vec->tx_sync);
        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
}

static void __nfp_ctrl_tx_queued(struct nfp_net_r_vector *r_vec)
{
        struct sk_buff *skb;

        while ((skb = __skb_dequeue(&r_vec->queue)))
                if (nfp_nfdk_ctrl_tx_one(r_vec->nfp_net, r_vec, skb, true))
                        return;
}

static bool
nfp_ctrl_meta_ok(struct nfp_net *nn, void *data, unsigned int meta_len)
{
        u32 meta_type, meta_tag;

        if (!nfp_app_ctrl_has_meta(nn->app))
                return !meta_len;

        if (meta_len != 8)
                return false;

        meta_type = get_unaligned_be32(data);
        meta_tag = get_unaligned_be32(data + 4);

        return (meta_type == NFP_NET_META_PORTID &&
                meta_tag == NFP_META_PORT_ID_CTRL);
}

static bool
nfp_ctrl_rx_one(struct nfp_net *nn, struct nfp_net_dp *dp,
                struct nfp_net_r_vector *r_vec, struct nfp_net_rx_ring *rx_ring)
{
        unsigned int meta_len, data_len, meta_off, pkt_len, pkt_off;
        struct nfp_net_rx_buf *rxbuf;
        struct nfp_net_rx_desc *rxd;
        dma_addr_t new_dma_addr;
        struct sk_buff *skb;
        void *new_frag;
        int idx;

        idx = D_IDX(rx_ring, rx_ring->rd_p);

        rxd = &rx_ring->rxds[idx];
        if (!(rxd->rxd.meta_len_dd & PCIE_DESC_RX_DD))
                return false;

        /* Memory barrier to ensure that we won't do other reads
         * before the DD bit.
         */
        dma_rmb();

        rx_ring->rd_p++;

        rxbuf = &rx_ring->rxbufs[idx];
        meta_len = rxd->rxd.meta_len_dd & PCIE_DESC_RX_META_LEN_MASK;
        data_len = le16_to_cpu(rxd->rxd.data_len);
        pkt_len = data_len - meta_len;

        pkt_off = NFP_NET_RX_BUF_HEADROOM + dp->rx_dma_off;
        if (dp->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC)
                pkt_off += meta_len;
        else
                pkt_off += dp->rx_offset;
        meta_off = pkt_off - meta_len;

        /* Stats update */
        u64_stats_update_begin(&r_vec->rx_sync);
        r_vec->rx_pkts++;
        r_vec->rx_bytes += pkt_len;
        u64_stats_update_end(&r_vec->rx_sync);

        nfp_net_dma_sync_cpu_rx(dp, rxbuf->dma_addr + meta_off, data_len);

        if (unlikely(!nfp_ctrl_meta_ok(nn, rxbuf->frag + meta_off, meta_len))) {
                nn_dp_warn(dp, "incorrect metadata for ctrl packet (%d)\n",
                           meta_len);
                nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf, NULL);
                return true;
        }

        skb = build_skb(rxbuf->frag, dp->fl_bufsz);
        if (unlikely(!skb)) {
                nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf, NULL);
                return true;
        }
        new_frag = nfp_nfdk_napi_alloc_one(dp, &new_dma_addr);
        if (unlikely(!new_frag)) {
                nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf, skb);
                return true;
        }

        nfp_net_dma_unmap_rx(dp, rxbuf->dma_addr);

        nfp_nfdk_rx_give_one(dp, rx_ring, new_frag, new_dma_addr);

        skb_reserve(skb, pkt_off);
        skb_put(skb, pkt_len);

        nfp_app_ctrl_rx(nn->app, skb);

        return true;
}

static bool nfp_ctrl_rx(struct nfp_net_r_vector *r_vec)
{
        struct nfp_net_rx_ring *rx_ring = r_vec->rx_ring;
        struct nfp_net *nn = r_vec->nfp_net;
        struct nfp_net_dp *dp = &nn->dp;
        unsigned int budget = 512;

        while (nfp_ctrl_rx_one(nn, dp, r_vec, rx_ring) && budget--)
                continue;

        return budget;
}

void nfp_nfdk_ctrl_poll(struct tasklet_struct *t)
{
        struct nfp_net_r_vector *r_vec = from_tasklet(r_vec, t, tasklet);

        spin_lock(&r_vec->lock);
        nfp_nfdk_tx_complete(r_vec->tx_ring, 0);
        __nfp_ctrl_tx_queued(r_vec);
        spin_unlock(&r_vec->lock);

        if (nfp_ctrl_rx(r_vec)) {
                nfp_net_irq_unmask(r_vec->nfp_net, r_vec->irq_entry);
        } else {
                tasklet_schedule(&r_vec->tasklet);
                nn_dp_warn(&r_vec->nfp_net->dp,
                           "control message budget exceeded!\n");
        }
}