nfp: parse metadata prepend before XDP runs

[mirror_ubuntu-artful-kernel.git] / drivers / net / ethernet / netronome / nfp / nfp_net_common.c

/*
 * Copyright (C) 2015-2017 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/*
 * nfp_net_common.c
 * Netronome network device driver: Common functions between PF and VF
 * Authors: Jakub Kicinski <jakub.kicinski@netronome.com>
 *          Jason McMullan <jason.mcmullan@netronome.com>
 *          Rolf Neugebauer <rolf.neugebauer@netronome.com>
 *          Brad Petrus <brad.petrus@netronome.com>
 *          Chris Telfer <chris.telfer@netronome.com>
 */

#include <linux/bitfield.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/interrupt.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/page_ref.h>
#include <linux/pci.h>
#include <linux/pci_regs.h>
#include <linux/msi.h>
#include <linux/ethtool.h>
#include <linux/log2.h>
#include <linux/if_vlan.h>
#include <linux/random.h>

#include <linux/ktime.h>

#include <net/pkt_cls.h>
#include <net/vxlan.h>

#include "nfpcore/nfp_nsp.h"
#include "nfp_net_ctrl.h"
#include "nfp_net.h"

/**
 * nfp_net_get_fw_version() - Read and parse the FW version
 * @fw_ver:     Output fw_version structure to read to
 * @ctrl_bar:   Mapped address of the control BAR
 */
void nfp_net_get_fw_version(struct nfp_net_fw_version *fw_ver,
                            void __iomem *ctrl_bar)
{
        u32 reg;

        reg = readl(ctrl_bar + NFP_NET_CFG_VERSION);
        put_unaligned_le32(reg, fw_ver);
}

static dma_addr_t nfp_net_dma_map_rx(struct nfp_net_dp *dp, void *frag)
{
        return dma_map_single_attrs(dp->dev, frag + NFP_NET_RX_BUF_HEADROOM,
                                    dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA,
                                    dp->rx_dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
}

static void
nfp_net_dma_sync_dev_rx(const struct nfp_net_dp *dp, dma_addr_t dma_addr)
{
        dma_sync_single_for_device(dp->dev, dma_addr,
                                   dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA,
                                   dp->rx_dma_dir);
}

static void nfp_net_dma_unmap_rx(struct nfp_net_dp *dp, dma_addr_t dma_addr)
{
        dma_unmap_single_attrs(dp->dev, dma_addr,
                               dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA,
                               dp->rx_dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
}

static void nfp_net_dma_sync_cpu_rx(struct nfp_net_dp *dp, dma_addr_t dma_addr,
                                    unsigned int len)
{
        dma_sync_single_for_cpu(dp->dev, dma_addr - NFP_NET_RX_BUF_HEADROOM,
                                len, dp->rx_dma_dir);
}

/* Firmware reconfig
 *
 * Firmware reconfig may take a while so we have two versions of it -
 * synchronous and asynchronous (posted).  All synchronous callers are holding
 * RTNL so we don't have to worry about serializing them.
 */
static void nfp_net_reconfig_start(struct nfp_net *nn, u32 update)
{
        nn_writel(nn, NFP_NET_CFG_UPDATE, update);
        /* ensure update is written before pinging HW */
        nn_pci_flush(nn);
        nfp_qcp_wr_ptr_add(nn->qcp_cfg, 1);
}

/* Pass 0 as update to run posted reconfigs. */
static void nfp_net_reconfig_start_async(struct nfp_net *nn, u32 update)
{
        update |= nn->reconfig_posted;
        nn->reconfig_posted = 0;

        nfp_net_reconfig_start(nn, update);

        nn->reconfig_timer_active = true;
        mod_timer(&nn->reconfig_timer, jiffies + NFP_NET_POLL_TIMEOUT * HZ);
}

static bool nfp_net_reconfig_check_done(struct nfp_net *nn, bool last_check)
{
        u32 reg;

        reg = nn_readl(nn, NFP_NET_CFG_UPDATE);
        if (reg == 0)
                return true;
        if (reg & NFP_NET_CFG_UPDATE_ERR) {
                nn_err(nn, "Reconfig error: 0x%08x\n", reg);
                return true;
        } else if (last_check) {
                nn_err(nn, "Reconfig timeout: 0x%08x\n", reg);
                return true;
        }

        return false;
}

static int nfp_net_reconfig_wait(struct nfp_net *nn, unsigned long deadline)
{
        bool timed_out = false;

        /* Poll update field, waiting for NFP to ack the config */
        while (!nfp_net_reconfig_check_done(nn, timed_out)) {
                msleep(1);
                timed_out = time_is_before_eq_jiffies(deadline);
        }

        if (nn_readl(nn, NFP_NET_CFG_UPDATE) & NFP_NET_CFG_UPDATE_ERR)
                return -EIO;

        return timed_out ? -EIO : 0;
}

static void nfp_net_reconfig_timer(unsigned long data)
{
        struct nfp_net *nn = (void *)data;

        spin_lock_bh(&nn->reconfig_lock);

        nn->reconfig_timer_active = false;

        /* If sync caller is present it will take over from us */
        if (nn->reconfig_sync_present)
                goto done;

        /* Read reconfig status and report errors */
        nfp_net_reconfig_check_done(nn, true);

        if (nn->reconfig_posted)
                nfp_net_reconfig_start_async(nn, 0);
done:
        spin_unlock_bh(&nn->reconfig_lock);
}

/**
 * nfp_net_reconfig_post() - Post async reconfig request
 * @nn:      NFP Net device to reconfigure
 * @update:  The value for the update field in the BAR config
 *
 * Record FW reconfiguration request.  Reconfiguration will be kicked off
 * whenever reconfiguration machinery is idle.  Multiple requests can be
 * merged together!
 */
static void nfp_net_reconfig_post(struct nfp_net *nn, u32 update)
{
        spin_lock_bh(&nn->reconfig_lock);

        /* Sync caller will kick off async reconf when it's done, just post */
        if (nn->reconfig_sync_present) {
                nn->reconfig_posted |= update;
                goto done;
        }

        /* Opportunistically check if the previous command is done */
        if (!nn->reconfig_timer_active ||
            nfp_net_reconfig_check_done(nn, false))
                nfp_net_reconfig_start_async(nn, update);
        else
                nn->reconfig_posted |= update;
done:
        spin_unlock_bh(&nn->reconfig_lock);
}

/**
 * nfp_net_reconfig() - Reconfigure the firmware
 * @nn:      NFP Net device to reconfigure
 * @update:  The value for the update field in the BAR config
 *
 * Write the update word to the BAR and ping the reconfig queue.  The
 * poll until the firmware has acknowledged the update by zeroing the
 * update word.
 *
 * Return: Negative errno on error, 0 on success
 */
int nfp_net_reconfig(struct nfp_net *nn, u32 update)
{
        bool cancelled_timer = false;
        u32 pre_posted_requests;
        int ret;

        spin_lock_bh(&nn->reconfig_lock);

        nn->reconfig_sync_present = true;

        if (nn->reconfig_timer_active) {
                del_timer(&nn->reconfig_timer);
                nn->reconfig_timer_active = false;
                cancelled_timer = true;
        }
        pre_posted_requests = nn->reconfig_posted;
        nn->reconfig_posted = 0;

        spin_unlock_bh(&nn->reconfig_lock);

        if (cancelled_timer)
                nfp_net_reconfig_wait(nn, nn->reconfig_timer.expires);

        /* Run the posted reconfigs which were issued before we started */
        if (pre_posted_requests) {
                nfp_net_reconfig_start(nn, pre_posted_requests);
                nfp_net_reconfig_wait(nn, jiffies + HZ * NFP_NET_POLL_TIMEOUT);
        }

        nfp_net_reconfig_start(nn, update);
        ret = nfp_net_reconfig_wait(nn, jiffies + HZ * NFP_NET_POLL_TIMEOUT);

        spin_lock_bh(&nn->reconfig_lock);

        if (nn->reconfig_posted)
                nfp_net_reconfig_start_async(nn, 0);

        nn->reconfig_sync_present = false;

        spin_unlock_bh(&nn->reconfig_lock);

        return ret;
}

/* Interrupt configuration and handling
 */

/**
 * nfp_net_irq_unmask() - Unmask automasked interrupt
 * @nn:       NFP Network structure
 * @entry_nr: MSI-X table entry
 *
 * Clear the ICR for the IRQ entry.
 */
static void nfp_net_irq_unmask(struct nfp_net *nn, unsigned int entry_nr)
{
        nn_writeb(nn, NFP_NET_CFG_ICR(entry_nr), NFP_NET_CFG_ICR_UNMASKED);
        nn_pci_flush(nn);
}

/**
 * nfp_net_irqs_alloc() - allocates MSI-X irqs
 * @pdev:        PCI device structure
 * @irq_entries: Array to be initialized and used to hold the irq entries
 * @min_irqs:    Minimal acceptable number of interrupts
 * @wanted_irqs: Target number of interrupts to allocate
 *
 * Return: Number of irqs obtained or 0 on error.
 */
unsigned int
nfp_net_irqs_alloc(struct pci_dev *pdev, struct msix_entry *irq_entries,
                   unsigned int min_irqs, unsigned int wanted_irqs)
{
        unsigned int i;
        int got_irqs;

        for (i = 0; i < wanted_irqs; i++)
                irq_entries[i].entry = i;

        got_irqs = pci_enable_msix_range(pdev, irq_entries,
                                         min_irqs, wanted_irqs);
        if (got_irqs < 0) {
                dev_err(&pdev->dev, "Failed to enable %d-%d MSI-X (err=%d)\n",
                        min_irqs, wanted_irqs, got_irqs);
                return 0;
        }

        if (got_irqs < wanted_irqs)
                dev_warn(&pdev->dev, "Unable to allocate %d IRQs got only %d\n",
                         wanted_irqs, got_irqs);

        return got_irqs;
}

/**
 * nfp_net_irqs_assign() - Assign interrupts allocated externally to netdev
 * @nn:          NFP Network structure
 * @irq_entries: Table of allocated interrupts
 * @n:           Size of @irq_entries (number of entries to grab)
 *
 * After interrupts are allocated with nfp_net_irqs_alloc() this function
 * should be called to assign them to a specific netdev (port).
 */
void
nfp_net_irqs_assign(struct nfp_net *nn, struct msix_entry *irq_entries,
                    unsigned int n)
{
        struct nfp_net_dp *dp = &nn->dp;

        nn->max_r_vecs = n - NFP_NET_NON_Q_VECTORS;
        dp->num_r_vecs = nn->max_r_vecs;

        memcpy(nn->irq_entries, irq_entries, sizeof(*irq_entries) * n);

        if (dp->num_rx_rings > dp->num_r_vecs ||
            dp->num_tx_rings > dp->num_r_vecs)
                dev_warn(nn->dp.dev, "More rings (%d,%d) than vectors (%d).\n",
                         dp->num_rx_rings, dp->num_tx_rings,
                         dp->num_r_vecs);

        dp->num_rx_rings = min(dp->num_r_vecs, dp->num_rx_rings);
        dp->num_tx_rings = min(dp->num_r_vecs, dp->num_tx_rings);
        dp->num_stack_tx_rings = dp->num_tx_rings;
}

/**
 * nfp_net_irqs_disable() - Disable interrupts
 * @pdev:        PCI device structure
 *
 * Undoes what @nfp_net_irqs_alloc() does.
 */
void nfp_net_irqs_disable(struct pci_dev *pdev)
{
        pci_disable_msix(pdev);
}

/**
 * nfp_net_irq_rxtx() - Interrupt service routine for RX/TX rings.
 * @irq:      Interrupt
 * @data:     Opaque data structure
 *
 * Return: Indicate if the interrupt has been handled.
 */
static irqreturn_t nfp_net_irq_rxtx(int irq, void *data)
{
        struct nfp_net_r_vector *r_vec = data;

        napi_schedule_irqoff(&r_vec->napi);

        /* The FW auto-masks any interrupt, either via the MASK bit in
         * the MSI-X table or via the per entry ICR field.  So there
         * is no need to disable interrupts here.
         */
        return IRQ_HANDLED;
}

bool nfp_net_link_changed_read_clear(struct nfp_net *nn)
{
        unsigned long flags;
        bool ret;

        spin_lock_irqsave(&nn->link_status_lock, flags);
        ret = nn->link_changed;
        nn->link_changed = false;
        spin_unlock_irqrestore(&nn->link_status_lock, flags);

        return ret;
}

/**
 * nfp_net_read_link_status() - Reread link status from control BAR
 * @nn:       NFP Network structure
 */
static void nfp_net_read_link_status(struct nfp_net *nn)
{
        unsigned long flags;
        bool link_up;
        u32 sts;

        spin_lock_irqsave(&nn->link_status_lock, flags);

        sts = nn_readl(nn, NFP_NET_CFG_STS);
        link_up = !!(sts & NFP_NET_CFG_STS_LINK);

        if (nn->link_up == link_up)
                goto out;

        nn->link_up = link_up;
        nn->link_changed = true;

        if (nn->link_up) {
                netif_carrier_on(nn->dp.netdev);
                netdev_info(nn->dp.netdev, "NIC Link is Up\n");
        } else {
                netif_carrier_off(nn->dp.netdev);
                netdev_info(nn->dp.netdev, "NIC Link is Down\n");
        }
out:
        spin_unlock_irqrestore(&nn->link_status_lock, flags);
}

/**
 * nfp_net_irq_lsc() - Interrupt service routine for link state changes
 * @irq:      Interrupt
 * @data:     Opaque data structure
 *
 * Return: Indicate if the interrupt has been handled.
 */
static irqreturn_t nfp_net_irq_lsc(int irq, void *data)
{
        struct nfp_net *nn = data;
        struct msix_entry *entry;

        entry = &nn->irq_entries[NFP_NET_IRQ_LSC_IDX];

        nfp_net_read_link_status(nn);

        nfp_net_irq_unmask(nn, entry->entry);

        return IRQ_HANDLED;
}

/**
 * nfp_net_irq_exn() - Interrupt service routine for exceptions
 * @irq:      Interrupt
 * @data:     Opaque data structure
 *
 * Return: Indicate if the interrupt has been handled.
 */
static irqreturn_t nfp_net_irq_exn(int irq, void *data)
{
        struct nfp_net *nn = data;

        nn_err(nn, "%s: UNIMPLEMENTED.\n", __func__);
        /* XXX TO BE IMPLEMENTED */
        return IRQ_HANDLED;
}

/**
 * nfp_net_tx_ring_init() - Fill in the boilerplate for a TX ring
 * @tx_ring:  TX ring structure
 * @r_vec:    IRQ vector servicing this ring
 * @idx:      Ring index
 */
static void
nfp_net_tx_ring_init(struct nfp_net_tx_ring *tx_ring,
                     struct nfp_net_r_vector *r_vec, unsigned int idx)
{
        struct nfp_net *nn = r_vec->nfp_net;

        tx_ring->idx = idx;
        tx_ring->r_vec = r_vec;

        tx_ring->qcidx = tx_ring->idx * nn->stride_tx;
        tx_ring->qcp_q = nn->tx_bar + NFP_QCP_QUEUE_OFF(tx_ring->qcidx);
}

/**
 * nfp_net_rx_ring_init() - Fill in the boilerplate for a RX ring
 * @rx_ring:  RX ring structure
 * @r_vec:    IRQ vector servicing this ring
 * @idx:      Ring index
 */
static void
nfp_net_rx_ring_init(struct nfp_net_rx_ring *rx_ring,
                     struct nfp_net_r_vector *r_vec, unsigned int idx)
{
        struct nfp_net *nn = r_vec->nfp_net;

        rx_ring->idx = idx;
        rx_ring->r_vec = r_vec;

        rx_ring->fl_qcidx = rx_ring->idx * nn->stride_rx;
        rx_ring->qcp_fl = nn->rx_bar + NFP_QCP_QUEUE_OFF(rx_ring->fl_qcidx);
}

/**
 * nfp_net_vecs_init() - Assign IRQs and setup rvecs.
 * @netdev:   netdev structure
 */
static void nfp_net_vecs_init(struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);
        struct nfp_net_r_vector *r_vec;
        int r;

        nn->lsc_handler = nfp_net_irq_lsc;
        nn->exn_handler = nfp_net_irq_exn;

        for (r = 0; r < nn->max_r_vecs; r++) {
                struct msix_entry *entry;

                entry = &nn->irq_entries[NFP_NET_NON_Q_VECTORS + r];

                r_vec = &nn->r_vecs[r];
                r_vec->nfp_net = nn;
                r_vec->handler = nfp_net_irq_rxtx;
                r_vec->irq_entry = entry->entry;
                r_vec->irq_vector = entry->vector;

                cpumask_set_cpu(r, &r_vec->affinity_mask);
        }
}

/**
 * nfp_net_aux_irq_request() - Request an auxiliary interrupt (LSC or EXN)
 * @nn:         NFP Network structure
 * @ctrl_offset: Control BAR offset where IRQ configuration should be written
 * @format:     printf-style format to construct the interrupt name
 * @name:       Pointer to allocated space for interrupt name
 * @name_sz:    Size of space for interrupt name
 * @vector_idx: Index of MSI-X vector used for this interrupt
 * @handler:    IRQ handler to register for this interrupt
 */
static int
nfp_net_aux_irq_request(struct nfp_net *nn, u32 ctrl_offset,
                        const char *format, char *name, size_t name_sz,
                        unsigned int vector_idx, irq_handler_t handler)
{
        struct msix_entry *entry;
        int err;

        entry = &nn->irq_entries[vector_idx];

        snprintf(name, name_sz, format, netdev_name(nn->dp.netdev));
        err = request_irq(entry->vector, handler, 0, name, nn);
        if (err) {
                nn_err(nn, "Failed to request IRQ %d (err=%d).\n",
                       entry->vector, err);
                return err;
        }
        nn_writeb(nn, ctrl_offset, entry->entry);

        return 0;
}

/**
 * nfp_net_aux_irq_free() - Free an auxiliary interrupt (LSC or EXN)
 * @nn:         NFP Network structure
 * @ctrl_offset: Control BAR offset where IRQ configuration should be written
 * @vector_idx: Index of MSI-X vector used for this interrupt
 */
static void nfp_net_aux_irq_free(struct nfp_net *nn, u32 ctrl_offset,
                                 unsigned int vector_idx)
{
        nn_writeb(nn, ctrl_offset, 0xff);
        free_irq(nn->irq_entries[vector_idx].vector, nn);
}

/* Transmit
 *
 * One queue controller peripheral queue is used for transmit.  The
 * driver en-queues packets for transmit by advancing the write
 * pointer.  The device indicates that packets have transmitted by
 * advancing the read pointer.  The driver maintains a local copy of
 * the read and write pointer in @struct nfp_net_tx_ring.  The driver
 * keeps @wr_p in sync with the queue controller write pointer and can
 * determine how many packets have been transmitted by comparing its
 * copy of the read pointer @rd_p with the read pointer maintained by
 * the queue controller peripheral.
 */

/**
 * nfp_net_tx_full() - Check if the TX ring is full
 * @tx_ring: TX ring to check
 * @dcnt:    Number of descriptors that need to be enqueued (must be >= 1)
 *
 * This function checks, based on the *host copy* of read/write
 * pointer if a given TX ring is full.  The real TX queue may have
 * some newly made available slots.
 *
 * Return: True if the ring is full.
 */
static int nfp_net_tx_full(struct nfp_net_tx_ring *tx_ring, int dcnt)
{
        return (tx_ring->wr_p - tx_ring->rd_p) >= (tx_ring->cnt - dcnt);
}

/* Wrappers for deciding when to stop and restart TX queues */
static int nfp_net_tx_ring_should_wake(struct nfp_net_tx_ring *tx_ring)
{
        return !nfp_net_tx_full(tx_ring, MAX_SKB_FRAGS * 4);
}

static int nfp_net_tx_ring_should_stop(struct nfp_net_tx_ring *tx_ring)
{
        return nfp_net_tx_full(tx_ring, MAX_SKB_FRAGS + 1);
}

/**
 * nfp_net_tx_ring_stop() - stop tx ring
 * @nd_q:    netdev queue
 * @tx_ring: driver tx queue structure
 *
 * Safely stop TX ring.  Remember that while we are running .start_xmit()
 * someone else may be cleaning the TX ring completions so we need to be
 * extra careful here.
 */
static void nfp_net_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_net_tx_ring_should_wake(tx_ring)))
                netif_tx_start_queue(nd_q);
}

/**
 * nfp_net_tx_tso() - Set up Tx descriptor for LSO
 * @r_vec: per-ring structure
 * @txbuf: Pointer to driver soft TX descriptor
 * @txd: Pointer to HW TX descriptor
 * @skb: Pointer to SKB
 *
 * Set up Tx descriptor for LSO, do nothing for non-LSO skbs.
 * Return error on packet header greater than maximum supported LSO header size.
 */
static void nfp_net_tx_tso(struct nfp_net_r_vector *r_vec,
                           struct nfp_net_tx_buf *txbuf,
                           struct nfp_net_tx_desc *txd, struct sk_buff *skb)
{
        u32 hdrlen;
        u16 mss;

        if (!skb_is_gso(skb))
                return;

        if (!skb->encapsulation)
                hdrlen = skb_transport_offset(skb) + tcp_hdrlen(skb);
        else
                hdrlen = skb_inner_transport_header(skb) - skb->data +
                        inner_tcp_hdrlen(skb);

        txbuf->pkt_cnt = skb_shinfo(skb)->gso_segs;
        txbuf->real_len += hdrlen * (txbuf->pkt_cnt - 1);

        mss = skb_shinfo(skb)->gso_size & PCIE_DESC_TX_MSS_MASK;
        txd->l4_offset = hdrlen;
        txd->mss = cpu_to_le16(mss);
        txd->flags |= PCIE_DESC_TX_LSO;

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

/**
 * nfp_net_tx_csum() - Set TX CSUM offload flags in TX descriptor
 * @dp:  NFP Net data path struct
 * @r_vec: per-ring structure
 * @txbuf: Pointer to driver soft TX descriptor
 * @txd: Pointer to TX descriptor
 * @skb: Pointer to SKB
 *
 * This function sets the TX checksum flags in the TX descriptor based
 * on the configuration and the protocol of the packet to be transmitted.
 */
static void nfp_net_tx_csum(struct nfp_net_dp *dp,
                            struct nfp_net_r_vector *r_vec,
                            struct nfp_net_tx_buf *txbuf,
                            struct nfp_net_tx_desc *txd, struct sk_buff *skb)
{
        struct ipv6hdr *ipv6h;
        struct iphdr *iph;
        u8 l4_hdr;

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

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

        txd->flags |= PCIE_DESC_TX_CSUM;
        if (skb->encapsulation)
                txd->flags |= PCIE_DESC_TX_ENCAP;

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

        if (iph->version == 4) {
                txd->flags |= PCIE_DESC_TX_IP4_CSUM;
                l4_hdr = iph->protocol;
        } else if (ipv6h->version == 6) {
                l4_hdr = ipv6h->nexthdr;
        } else {
                nn_dp_warn(dp, "partial checksum but ipv=%x!\n", iph->version);
                return;
        }

        switch (l4_hdr) {
        case IPPROTO_TCP:
                txd->flags |= PCIE_DESC_TX_TCP_CSUM;
                break;
        case IPPROTO_UDP:
                txd->flags |= PCIE_DESC_TX_UDP_CSUM;
                break;
        default:
                nn_dp_warn(dp, "partial checksum but l4 proto=%x!\n", l4_hdr);
                return;
        }

        u64_stats_update_begin(&r_vec->tx_sync);
        if (skb->encapsulation)
                r_vec->hw_csum_tx_inner += txbuf->pkt_cnt;
        else
                r_vec->hw_csum_tx += txbuf->pkt_cnt;
        u64_stats_update_end(&r_vec->tx_sync);
}

static void nfp_net_tx_xmit_more_flush(struct nfp_net_tx_ring *tx_ring)
{
        wmb();
        nfp_qcp_wr_ptr_add(tx_ring->qcp_q, tx_ring->wr_ptr_add);
        tx_ring->wr_ptr_add = 0;
}

/**
 * nfp_net_tx() - Main transmit entry point
 * @skb:    SKB to transmit
 * @netdev: netdev structure
 *
 * Return: NETDEV_TX_OK on success.
 */
static int nfp_net_tx(struct sk_buff *skb, struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);
        const struct skb_frag_struct *frag;
        struct nfp_net_tx_desc *txd, txdg;
        struct nfp_net_tx_ring *tx_ring;
        struct nfp_net_r_vector *r_vec;
        struct nfp_net_tx_buf *txbuf;
        struct netdev_queue *nd_q;
        struct nfp_net_dp *dp;
        dma_addr_t dma_addr;
        unsigned int fsize;
        int f, nr_frags;
        int wr_idx;
        u16 qidx;

        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);

        nr_frags = skb_shinfo(skb)->nr_frags;

        if (unlikely(nfp_net_tx_full(tx_ring, nr_frags + 1))) {
                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;
        }

        /* Start with the head skbuf */
        dma_addr = dma_map_single(dp->dev, skb->data, skb_headlen(skb),
                                  DMA_TO_DEVICE);
        if (dma_mapping_error(dp->dev, dma_addr))
                goto err_free;

        wr_idx = tx_ring->wr_p & (tx_ring->cnt - 1);

        /* Stash the soft descriptor of the head then initialize it */
        txbuf = &tx_ring->txbufs[wr_idx];
        txbuf->skb = skb;
        txbuf->dma_addr = dma_addr;
        txbuf->fidx = -1;
        txbuf->pkt_cnt = 1;
        txbuf->real_len = skb->len;

        /* Build TX descriptor */
        txd = &tx_ring->txds[wr_idx];
        txd->offset_eop = (nr_frags == 0) ? PCIE_DESC_TX_EOP : 0;
        txd->dma_len = cpu_to_le16(skb_headlen(skb));
        nfp_desc_set_dma_addr(txd, dma_addr);
        txd->data_len = cpu_to_le16(skb->len);

        txd->flags = 0;
        txd->mss = 0;
        txd->l4_offset = 0;

        nfp_net_tx_tso(r_vec, txbuf, txd, skb);

        nfp_net_tx_csum(dp, r_vec, txbuf, txd, skb);

        if (skb_vlan_tag_present(skb) && dp->ctrl & NFP_NET_CFG_CTRL_TXVLAN) {
                txd->flags |= PCIE_DESC_TX_VLAN;
                txd->vlan = cpu_to_le16(skb_vlan_tag_get(skb));
        }

        /* Gather DMA */
        if (nr_frags > 0) {
                /* all descs must match except for in addr, length and eop */
                txdg = *txd;

                for (f = 0; f < nr_frags; f++) {
                        frag = &skb_shinfo(skb)->frags[f];
                        fsize = skb_frag_size(frag);

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

                        wr_idx = (wr_idx + 1) & (tx_ring->cnt - 1);
                        tx_ring->txbufs[wr_idx].skb = skb;
                        tx_ring->txbufs[wr_idx].dma_addr = dma_addr;
                        tx_ring->txbufs[wr_idx].fidx = f;

                        txd = &tx_ring->txds[wr_idx];
                        *txd = txdg;
                        txd->dma_len = cpu_to_le16(fsize);
                        nfp_desc_set_dma_addr(txd, dma_addr);
                        txd->offset_eop =
                                (f == nr_frags - 1) ? PCIE_DESC_TX_EOP : 0;
                }

                u64_stats_update_begin(&r_vec->tx_sync);
                r_vec->tx_gather++;
                u64_stats_update_end(&r_vec->tx_sync);
        }

        netdev_tx_sent_queue(nd_q, txbuf->real_len);

        tx_ring->wr_p += nr_frags + 1;
        if (nfp_net_tx_ring_should_stop(tx_ring))
                nfp_net_tx_ring_stop(nd_q, tx_ring);

        tx_ring->wr_ptr_add += nr_frags + 1;
        if (!skb->xmit_more || netif_xmit_stopped(nd_q))
                nfp_net_tx_xmit_more_flush(tx_ring);

        skb_tx_timestamp(skb);

        return NETDEV_TX_OK;

err_unmap:
        --f;
        while (f >= 0) {
                frag = &skb_shinfo(skb)->frags[f];
                dma_unmap_page(dp->dev, tx_ring->txbufs[wr_idx].dma_addr,
                               skb_frag_size(frag), DMA_TO_DEVICE);
                tx_ring->txbufs[wr_idx].skb = NULL;
                tx_ring->txbufs[wr_idx].dma_addr = 0;
                tx_ring->txbufs[wr_idx].fidx = -2;
                wr_idx = wr_idx - 1;
                if (wr_idx < 0)
                        wr_idx += tx_ring->cnt;
        }
        dma_unmap_single(dp->dev, tx_ring->txbufs[wr_idx].dma_addr,
                         skb_headlen(skb), DMA_TO_DEVICE);
        tx_ring->txbufs[wr_idx].skb = NULL;
        tx_ring->txbufs[wr_idx].dma_addr = 0;
        tx_ring->txbufs[wr_idx].fidx = -2;
err_free:
        nn_dp_warn(dp, "Failed to map DMA TX buffer\n");
        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_net_tx_complete() - Handled completed TX packets
 * @tx_ring:   TX ring structure
 *
 * Return: Number of completed TX descriptors
 */
static void nfp_net_tx_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;
        const struct skb_frag_struct *frag;
        struct netdev_queue *nd_q;
        u32 done_pkts = 0, done_bytes = 0;
        struct sk_buff *skb;
        int todo, nr_frags;
        u32 qcp_rd_p;
        int fidx;
        int idx;

        /* Work out how many descriptors have been transmitted */
        qcp_rd_p = nfp_qcp_rd_ptr_read(tx_ring->qcp_q);

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

        if (qcp_rd_p > tx_ring->qcp_rd_p)
                todo = qcp_rd_p - tx_ring->qcp_rd_p;
        else
                todo = qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p;

        while (todo--) {
                idx = tx_ring->rd_p & (tx_ring->cnt - 1);
                tx_ring->rd_p++;

                skb = tx_ring->txbufs[idx].skb;
                if (!skb)
                        continue;

                nr_frags = skb_shinfo(skb)->nr_frags;
                fidx = tx_ring->txbufs[idx].fidx;

                if (fidx == -1) {
                        /* unmap head */
                        dma_unmap_single(dp->dev, tx_ring->txbufs[idx].dma_addr,
                                         skb_headlen(skb), DMA_TO_DEVICE);

                        done_pkts += tx_ring->txbufs[idx].pkt_cnt;
                        done_bytes += tx_ring->txbufs[idx].real_len;
                } else {
                        /* unmap fragment */
                        frag = &skb_shinfo(skb)->frags[fidx];
                        dma_unmap_page(dp->dev, tx_ring->txbufs[idx].dma_addr,
                                       skb_frag_size(frag), DMA_TO_DEVICE);
                }

                /* check for last gather fragment */
                if (fidx == nr_frags - 1)
                        dev_kfree_skb_any(skb);

                tx_ring->txbufs[idx].dma_addr = 0;
                tx_ring->txbufs[idx].skb = NULL;
                tx_ring->txbufs[idx].fidx = -2;
        }

        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);

        nd_q = netdev_get_tx_queue(dp->netdev, tx_ring->idx);
        netdev_tx_completed_queue(nd_q, done_pkts, done_bytes);
        if (nfp_net_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);
}

static void nfp_net_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;
        u32 done_pkts = 0, done_bytes = 0;
        int idx, todo;
        u32 qcp_rd_p;

        /* Work out how many descriptors have been transmitted */
        qcp_rd_p = nfp_qcp_rd_ptr_read(tx_ring->qcp_q);

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

        if (qcp_rd_p > tx_ring->qcp_rd_p)
                todo = qcp_rd_p - tx_ring->qcp_rd_p;
        else
                todo = qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p;

        while (todo--) {
                idx = tx_ring->rd_p & (tx_ring->cnt - 1);
                tx_ring->rd_p++;

                if (!tx_ring->txbufs[idx].frag)
                        continue;

                nfp_net_dma_unmap_rx(dp, tx_ring->txbufs[idx].dma_addr);
                __free_page(virt_to_page(tx_ring->txbufs[idx].frag));

                done_pkts++;
                done_bytes += tx_ring->txbufs[idx].real_len;

                tx_ring->txbufs[idx].dma_addr = 0;
                tx_ring->txbufs[idx].frag = NULL;
                tx_ring->txbufs[idx].fidx = -2;
        }

        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);

        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);
}

/**
 * nfp_net_tx_ring_reset() - Free any untransmitted buffers and reset pointers
 * @dp:         NFP Net data path struct
 * @tx_ring:    TX ring structure
 *
 * Assumes that the device is stopped
 */
static void
nfp_net_tx_ring_reset(struct nfp_net_dp *dp, struct nfp_net_tx_ring *tx_ring)
{
        struct nfp_net_r_vector *r_vec = tx_ring->r_vec;
        const struct skb_frag_struct *frag;
        struct netdev_queue *nd_q;

        while (tx_ring->rd_p != tx_ring->wr_p) {
                struct nfp_net_tx_buf *tx_buf;
                int idx;

                idx = tx_ring->rd_p & (tx_ring->cnt - 1);
                tx_buf = &tx_ring->txbufs[idx];

                if (tx_ring == r_vec->xdp_ring) {
                        nfp_net_dma_unmap_rx(dp, tx_buf->dma_addr);
                        __free_page(virt_to_page(tx_ring->txbufs[idx].frag));
                } else {
                        struct sk_buff *skb = tx_ring->txbufs[idx].skb;
                        int nr_frags = skb_shinfo(skb)->nr_frags;

                        if (tx_buf->fidx == -1) {
                                /* unmap head */
                                dma_unmap_single(dp->dev, tx_buf->dma_addr,
                                                 skb_headlen(skb),
                                                 DMA_TO_DEVICE);
                        } else {
                                /* unmap fragment */
                                frag = &skb_shinfo(skb)->frags[tx_buf->fidx];
                                dma_unmap_page(dp->dev, tx_buf->dma_addr,
                                               skb_frag_size(frag),
                                               DMA_TO_DEVICE);
                        }

                        /* check for last gather fragment */
                        if (tx_buf->fidx == nr_frags - 1)
                                dev_kfree_skb_any(skb);
                }

                tx_buf->dma_addr = 0;
                tx_buf->skb = NULL;
                tx_buf->fidx = -2;

                tx_ring->qcp_rd_p++;
                tx_ring->rd_p++;
        }

        memset(tx_ring->txds, 0, sizeof(*tx_ring->txds) * tx_ring->cnt);
        tx_ring->wr_p = 0;
        tx_ring->rd_p = 0;
        tx_ring->qcp_rd_p = 0;
        tx_ring->wr_ptr_add = 0;

        if (tx_ring == r_vec->xdp_ring)
                return;

        nd_q = netdev_get_tx_queue(dp->netdev, tx_ring->idx);
        netdev_tx_reset_queue(nd_q);
}

static void nfp_net_tx_timeout(struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);
        int i;

        for (i = 0; i < nn->dp.netdev->real_num_tx_queues; i++) {
                if (!netif_tx_queue_stopped(netdev_get_tx_queue(netdev, i)))
                        continue;
                nn_warn(nn, "TX timeout on ring: %d\n", i);
        }
        nn_warn(nn, "TX watchdog timeout\n");
}

/* Receive processing
 */
static unsigned int
nfp_net_calc_fl_bufsz(struct nfp_net_dp *dp)
{
        unsigned int fl_bufsz;

        fl_bufsz = NFP_NET_RX_BUF_HEADROOM;
        fl_bufsz += dp->rx_dma_off;
        if (dp->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC)
                fl_bufsz += NFP_NET_MAX_PREPEND;
        else
                fl_bufsz += dp->rx_offset;
        fl_bufsz += ETH_HLEN + VLAN_HLEN * 2 + dp->mtu;

        fl_bufsz = SKB_DATA_ALIGN(fl_bufsz);
        fl_bufsz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

        return fl_bufsz;
}

static void
nfp_net_free_frag(void *frag, bool xdp)
{
        if (!xdp)
                skb_free_frag(frag);
        else
                __free_page(virt_to_page(frag));
}

/**
 * nfp_net_rx_alloc_one() - Allocate and map page frag for RX
 * @dp:         NFP Net data path struct
 * @rx_ring:    RX ring structure of the skb
 * @dma_addr:   Pointer to storage for DMA address (output param)
 *
 * This function will allcate a new page frag, map it for DMA.
 *
 * Return: allocated page frag or NULL on failure.
 */
static void *
nfp_net_rx_alloc_one(struct nfp_net_dp *dp, struct nfp_net_rx_ring *rx_ring,
                     dma_addr_t *dma_addr)
{
        void *frag;

        if (!dp->xdp_prog)
                frag = netdev_alloc_frag(dp->fl_bufsz);
        else
                frag = page_address(alloc_page(GFP_KERNEL | __GFP_COLD));
        if (!frag) {
                nn_dp_warn(dp, "Failed to alloc receive page frag\n");
                return NULL;
        }

        *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;
}

static void *nfp_net_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);
        else
                frag = page_address(alloc_page(GFP_ATOMIC | __GFP_COLD));
        if (!frag) {
                nn_dp_warn(dp, "Failed to alloc receive page frag\n");
                return NULL;
        }

        *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_net_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_net_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 = rx_ring->wr_p & (rx_ring->cnt - 1);

        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(&rx_ring->rxds[wr_idx].fld,
                              dma_addr + dp->rx_dma_off);

        rx_ring->wr_p++;
        rx_ring->wr_ptr_add++;
        if (rx_ring->wr_ptr_add >= 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, rx_ring->wr_ptr_add);
                rx_ring->wr_ptr_add = 0;
        }
}

/**
 * nfp_net_rx_ring_reset() - Reflect in SW state of freelist after disable
 * @rx_ring:    RX ring structure
 *
 * Warning: Do *not* call if ring buffers were never put on the FW freelist
 *          (i.e. device was not enabled)!
 */
static void nfp_net_rx_ring_reset(struct nfp_net_rx_ring *rx_ring)
{
        unsigned int wr_idx, last_idx;

        /* Move the empty entry to the end of the list */
        wr_idx = rx_ring->wr_p & (rx_ring->cnt - 1);
        last_idx = rx_ring->cnt - 1;
        rx_ring->rxbufs[wr_idx].dma_addr = rx_ring->rxbufs[last_idx].dma_addr;
        rx_ring->rxbufs[wr_idx].frag = rx_ring->rxbufs[last_idx].frag;
        rx_ring->rxbufs[last_idx].dma_addr = 0;
        rx_ring->rxbufs[last_idx].frag = NULL;

        memset(rx_ring->rxds, 0, sizeof(*rx_ring->rxds) * rx_ring->cnt);
        rx_ring->wr_p = 0;
        rx_ring->rd_p = 0;
        rx_ring->wr_ptr_add = 0;
}

/**
 * nfp_net_rx_ring_bufs_free() - Free any buffers currently on the RX ring
 * @dp:         NFP Net data path struct
 * @rx_ring:    RX ring to remove buffers from
 *
 * Assumes that the device is stopped and buffers are in [0, ring->cnt - 1)
 * entries.  After device is disabled nfp_net_rx_ring_reset() must be called
 * to restore required ring geometry.
 */
static void
nfp_net_rx_ring_bufs_free(struct nfp_net_dp *dp,
                          struct nfp_net_rx_ring *rx_ring)
{
        unsigned int i;

        for (i = 0; i < rx_ring->cnt - 1; i++) {
                /* NULL skb can only happen when initial filling of the ring
                 * fails to allocate enough buffers and calls here to free
                 * already allocated ones.
                 */
                if (!rx_ring->rxbufs[i].frag)
                        continue;

                nfp_net_dma_unmap_rx(dp, rx_ring->rxbufs[i].dma_addr);
                nfp_net_free_frag(rx_ring->rxbufs[i].frag, dp->xdp_prog);
                rx_ring->rxbufs[i].dma_addr = 0;
                rx_ring->rxbufs[i].frag = NULL;
        }
}

/**
 * nfp_net_rx_ring_bufs_alloc() - Fill RX ring with buffers (don't give to FW)
 * @dp:         NFP Net data path struct
 * @rx_ring:    RX ring to remove buffers from
 */
static int
nfp_net_rx_ring_bufs_alloc(struct nfp_net_dp *dp,
                           struct nfp_net_rx_ring *rx_ring)
{
        struct nfp_net_rx_buf *rxbufs;
        unsigned int i;

        rxbufs = rx_ring->rxbufs;

        for (i = 0; i < rx_ring->cnt - 1; i++) {
                rxbufs[i].frag =
                        nfp_net_rx_alloc_one(dp, rx_ring, &rxbufs[i].dma_addr);
                if (!rxbufs[i].frag) {
                        nfp_net_rx_ring_bufs_free(dp, rx_ring);
                        return -ENOMEM;
                }
        }

        return 0;
}

/**
 * nfp_net_rx_ring_fill_freelist() - Give buffers from the ring to FW
 * @dp:      NFP Net data path struct
 * @rx_ring: RX ring to fill
 */
static void
nfp_net_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_net_rx_give_one(dp, rx_ring, rx_ring->rxbufs[i].frag,
                                    rx_ring->rxbufs[i].dma_addr);
}

/**
 * nfp_net_rx_csum_has_errors() - group check if rxd has any csum errors
 * @flags: RX descriptor flags field in CPU byte order
 */
static int nfp_net_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_net_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
 * @skb: Pointer to SKB
 */
static void nfp_net_rx_csum(struct nfp_net_dp *dp,
                            struct nfp_net_r_vector *r_vec,
                            struct nfp_net_rx_desc *rxd, struct sk_buff *skb)
{
        skb_checksum_none_assert(skb);

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

        if (nfp_net_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_net_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 void
nfp_net_set_hash_desc(struct net_device *netdev, struct nfp_meta_parsed *meta,
                      void *data, struct nfp_net_rx_desc *rxd)
{
        struct nfp_net_rx_hash *rx_hash = data;

        if (!(rxd->rxd.flags & PCIE_DESC_RX_RSS))
                return;

        nfp_net_set_hash(netdev, meta, get_unaligned_be32(&rx_hash->hash_type),
                         &rx_hash->hash);
}

static void *
nfp_net_parse_meta(struct net_device *netdev, struct nfp_meta_parsed *meta,
                   void *data, int meta_len)
{
        u32 meta_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_net_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;
                default:
                        return NULL;
                }

                meta_info >>= NFP_NET_META_FIELD_SIZE;
        }

        return data;
}

static void
nfp_net_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++;
        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_net_rx_give_one(dp, rx_ring, rxbuf->frag, rxbuf->dma_addr);
        if (skb)
                dev_kfree_skb_any(skb);
}

static bool
nfp_net_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)
{
        struct nfp_net_tx_buf *txbuf;
        struct nfp_net_tx_desc *txd;
        dma_addr_t new_dma_addr;
        void *new_frag;
        int wr_idx;

        if (unlikely(nfp_net_tx_full(tx_ring, 1))) {
                nfp_net_rx_drop(dp, rx_ring->r_vec, rx_ring, rxbuf, NULL);
                return false;
        }

        new_frag = nfp_net_napi_alloc_one(dp, &new_dma_addr);
        if (unlikely(!new_frag)) {
                nfp_net_rx_drop(dp, rx_ring->r_vec, rx_ring, rxbuf, NULL);
                return false;
        }
        nfp_net_rx_give_one(dp, rx_ring, new_frag, new_dma_addr);

        wr_idx = tx_ring->wr_p & (tx_ring->cnt - 1);

        /* Stash the soft descriptor of the head then initialize it */
        txbuf = &tx_ring->txbufs[wr_idx];
        txbuf->frag = rxbuf->frag;
        txbuf->dma_addr = rxbuf->dma_addr;
        txbuf->fidx = -1;
        txbuf->pkt_cnt = 1;
        txbuf->real_len = pkt_len;

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

        /* Build TX descriptor */
        txd = &tx_ring->txds[wr_idx];
        txd->offset_eop = PCIE_DESC_TX_EOP;
        txd->dma_len = cpu_to_le16(pkt_len);
        nfp_desc_set_dma_addr(txd, rxbuf->dma_addr + dma_off);
        txd->data_len = cpu_to_le16(pkt_len);

        txd->flags = 0;
        txd->mss = 0;
        txd->l4_offset = 0;

        tx_ring->wr_p++;
        tx_ring->wr_ptr_add++;
        return true;
}

static int nfp_net_run_xdp(struct bpf_prog *prog, void *data, void *hard_start,
                           unsigned int *off, unsigned int *len)
{
        struct xdp_buff xdp;
        void *orig_data;
        int ret;

        xdp.data_hard_start = hard_start;
        xdp.data = data + *off;
        xdp.data_end = data + *off + *len;

        orig_data = xdp.data;
        ret = bpf_prog_run_xdp(prog, &xdp);

        *len -= xdp.data - orig_data;
        *off += xdp.data - orig_data;

        return ret;
}

/**
 * nfp_net_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_net_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;
        unsigned int true_bufsz;
        struct sk_buff *skb;
        int pkts_polled = 0;
        int idx;

        rcu_read_lock();
        xdp_prog = READ_ONCE(dp->xdp_prog);
        true_bufsz = xdp_prog ? PAGE_SIZE : dp->fl_bufsz;
        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;
                dma_addr_t new_dma_addr;
                void *new_frag;

                idx = rx_ring->rd_p & (rx_ring->cnt - 1);

                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_net_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 (!dp->chained_metadata_format) {
                        nfp_net_set_hash_desc(dp->netdev, &meta,
                                              rxbuf->frag + meta_off, rxd);
                } else if (meta_len) {
                        void *end;

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

                if (xdp_prog && !(rxd->rxd.flags & PCIE_DESC_RX_BPF &&
                                  dp->bpf_offload_xdp)) {
                        unsigned int dma_off;
                        void *hard_start;
                        int act;

                        hard_start = rxbuf->frag + NFP_NET_RX_BUF_HEADROOM;

                        act = nfp_net_run_xdp(xdp_prog, rxbuf->frag, hard_start,
                                              &pkt_off, &pkt_len);
                        switch (act) {
                        case XDP_PASS:
                                break;
                        case XDP_TX:
                                dma_off = pkt_off - NFP_NET_RX_BUF_HEADROOM;
                                if (unlikely(!nfp_net_tx_xdp_buf(dp, rx_ring,
                                                                 tx_ring, rxbuf,
                                                                 dma_off,
                                                                 pkt_len)))
                                        trace_xdp_exception(dp->netdev,
                                                            xdp_prog, act);
                                continue;
                        default:
                                bpf_warn_invalid_xdp_action(act);
                        case XDP_ABORTED:
                                trace_xdp_exception(dp->netdev, xdp_prog, act);
                        case XDP_DROP:
                                nfp_net_rx_give_one(dp, rx_ring, rxbuf->frag,
                                                    rxbuf->dma_addr);
                                continue;
                        }
                }

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

                nfp_net_dma_unmap_rx(dp, rxbuf->dma_addr);

                nfp_net_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, dp->netdev);

                nfp_net_rx_csum(dp, r_vec, rxd, skb);

                if (rxd->rxd.flags & PCIE_DESC_RX_VLAN)
                        __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
                                               le16_to_cpu(rxd->rxd.vlan));

                napi_gro_receive(&rx_ring->r_vec->napi, skb);
        }

        if (xdp_prog && tx_ring->wr_ptr_add)
                nfp_net_tx_xmit_more_flush(tx_ring);
        rcu_read_unlock();

        return pkts_polled;
}

/**
 * nfp_net_poll() - napi poll function
 * @napi:    NAPI structure
 * @budget:  NAPI budget
 *
 * Return: number of packets polled.
 */
static int nfp_net_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_net_tx_complete(r_vec->tx_ring);
        if (r_vec->rx_ring) {
                pkts_polled = nfp_net_rx(r_vec->rx_ring, budget);
                if (r_vec->xdp_ring)
                        nfp_net_xdp_complete(r_vec->xdp_ring);
        }

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

        return pkts_polled;
}

/* Setup and Configuration
 */

/**
 * nfp_net_tx_ring_free() - Free resources allocated to a TX ring
 * @tx_ring:   TX ring to free
 */
static void nfp_net_tx_ring_free(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;

        kfree(tx_ring->txbufs);

        if (tx_ring->txds)
                dma_free_coherent(dp->dev, tx_ring->size,
                                  tx_ring->txds, tx_ring->dma);

        tx_ring->cnt = 0;
        tx_ring->txbufs = NULL;
        tx_ring->txds = NULL;
        tx_ring->dma = 0;
        tx_ring->size = 0;
}

/**
 * nfp_net_tx_ring_alloc() - Allocate resource for a TX ring
 * @dp:        NFP Net data path struct
 * @tx_ring:   TX Ring structure to allocate
 * @is_xdp:    True if ring will be used for XDP
 *
 * Return: 0 on success, negative errno otherwise.
 */
static int
nfp_net_tx_ring_alloc(struct nfp_net_dp *dp, struct nfp_net_tx_ring *tx_ring,
                      bool is_xdp)
{
        struct nfp_net_r_vector *r_vec = tx_ring->r_vec;
        int sz;

        tx_ring->cnt = dp->txd_cnt;

        tx_ring->size = sizeof(*tx_ring->txds) * tx_ring->cnt;
        tx_ring->txds = dma_zalloc_coherent(dp->dev, tx_ring->size,
                                            &tx_ring->dma, GFP_KERNEL);
        if (!tx_ring->txds)
                goto err_alloc;

        sz = sizeof(*tx_ring->txbufs) * tx_ring->cnt;
        tx_ring->txbufs = kzalloc(sz, GFP_KERNEL);
        if (!tx_ring->txbufs)
                goto err_alloc;

        if (!is_xdp)
                netif_set_xps_queue(dp->netdev, &r_vec->affinity_mask,
                                    tx_ring->idx);

        return 0;

err_alloc:
        nfp_net_tx_ring_free(tx_ring);
        return -ENOMEM;
}

static int nfp_net_tx_rings_prepare(struct nfp_net *nn, struct nfp_net_dp *dp)
{
        unsigned int r;

        dp->tx_rings = kcalloc(dp->num_tx_rings, sizeof(*dp->tx_rings),
                               GFP_KERNEL);
        if (!dp->tx_rings)
                return -ENOMEM;

        for (r = 0; r < dp->num_tx_rings; r++) {
                int bias = 0;

                if (r >= dp->num_stack_tx_rings)
                        bias = dp->num_stack_tx_rings;

                nfp_net_tx_ring_init(&dp->tx_rings[r], &nn->r_vecs[r - bias],
                                     r);

                if (nfp_net_tx_ring_alloc(dp, &dp->tx_rings[r], bias))
                        goto err_free_prev;
        }

        return 0;

err_free_prev:
        while (r--)
                nfp_net_tx_ring_free(&dp->tx_rings[r]);
        kfree(dp->tx_rings);
        return -ENOMEM;
}

static void nfp_net_tx_rings_free(struct nfp_net_dp *dp)
{
        unsigned int r;

        for (r = 0; r < dp->num_tx_rings; r++)
                nfp_net_tx_ring_free(&dp->tx_rings[r]);

        kfree(dp->tx_rings);
}

/**
 * nfp_net_rx_ring_free() - Free resources allocated to a RX ring
 * @rx_ring:  RX ring to free
 */
static void nfp_net_rx_ring_free(struct nfp_net_rx_ring *rx_ring)
{
        struct nfp_net_r_vector *r_vec = rx_ring->r_vec;
        struct nfp_net_dp *dp = &r_vec->nfp_net->dp;

        kfree(rx_ring->rxbufs);

        if (rx_ring->rxds)
                dma_free_coherent(dp->dev, rx_ring->size,
                                  rx_ring->rxds, rx_ring->dma);

        rx_ring->cnt = 0;
        rx_ring->rxbufs = NULL;
        rx_ring->rxds = NULL;
        rx_ring->dma = 0;
        rx_ring->size = 0;
}

/**
 * nfp_net_rx_ring_alloc() - Allocate resource for a RX ring
 * @dp:       NFP Net data path struct
 * @rx_ring:  RX ring to allocate
 *
 * Return: 0 on success, negative errno otherwise.
 */
static int
nfp_net_rx_ring_alloc(struct nfp_net_dp *dp, struct nfp_net_rx_ring *rx_ring)
{
        int sz;

        rx_ring->cnt = dp->rxd_cnt;
        rx_ring->size = sizeof(*rx_ring->rxds) * rx_ring->cnt;
        rx_ring->rxds = dma_zalloc_coherent(dp->dev, rx_ring->size,
                                            &rx_ring->dma, GFP_KERNEL);
        if (!rx_ring->rxds)
                goto err_alloc;

        sz = sizeof(*rx_ring->rxbufs) * rx_ring->cnt;
        rx_ring->rxbufs = kzalloc(sz, GFP_KERNEL);
        if (!rx_ring->rxbufs)
                goto err_alloc;

        return 0;

err_alloc:
        nfp_net_rx_ring_free(rx_ring);
        return -ENOMEM;
}

static int nfp_net_rx_rings_prepare(struct nfp_net *nn, struct nfp_net_dp *dp)
{
        unsigned int r;

        dp->rx_rings = kcalloc(dp->num_rx_rings, sizeof(*dp->rx_rings),
                               GFP_KERNEL);
        if (!dp->rx_rings)
                return -ENOMEM;

        for (r = 0; r < dp->num_rx_rings; r++) {
                nfp_net_rx_ring_init(&dp->rx_rings[r], &nn->r_vecs[r], r);

                if (nfp_net_rx_ring_alloc(dp, &dp->rx_rings[r]))
                        goto err_free_prev;

                if (nfp_net_rx_ring_bufs_alloc(dp, &dp->rx_rings[r]))
                        goto err_free_ring;
        }

        return 0;

err_free_prev:
        while (r--) {
                nfp_net_rx_ring_bufs_free(dp, &dp->rx_rings[r]);
err_free_ring:
                nfp_net_rx_ring_free(&dp->rx_rings[r]);
        }
        kfree(dp->rx_rings);
        return -ENOMEM;
}

static void nfp_net_rx_rings_free(struct nfp_net_dp *dp)
{
        unsigned int r;

        for (r = 0; r < dp->num_rx_rings; r++) {
                nfp_net_rx_ring_bufs_free(dp, &dp->rx_rings[r]);
                nfp_net_rx_ring_free(&dp->rx_rings[r]);
        }

        kfree(dp->rx_rings);
}

static void
nfp_net_vector_assign_rings(struct nfp_net_dp *dp,
                            struct nfp_net_r_vector *r_vec, int idx)
{
        r_vec->rx_ring = idx < dp->num_rx_rings ? &dp->rx_rings[idx] : NULL;
        r_vec->tx_ring =
                idx < dp->num_stack_tx_rings ? &dp->tx_rings[idx] : NULL;

        r_vec->xdp_ring = idx < dp->num_tx_rings - dp->num_stack_tx_rings ?
                &dp->tx_rings[dp->num_stack_tx_rings + idx] : NULL;
}

static int
nfp_net_prepare_vector(struct nfp_net *nn, struct nfp_net_r_vector *r_vec,
                       int idx)
{
        int err;

        /* Setup NAPI */
        netif_napi_add(nn->dp.netdev, &r_vec->napi,
                       nfp_net_poll, NAPI_POLL_WEIGHT);

        snprintf(r_vec->name, sizeof(r_vec->name),
                 "%s-rxtx-%d", nn->dp.netdev->name, idx);
        err = request_irq(r_vec->irq_vector, r_vec->handler, 0, r_vec->name,
                          r_vec);
        if (err) {
                netif_napi_del(&r_vec->napi);
                nn_err(nn, "Error requesting IRQ %d\n", r_vec->irq_vector);
                return err;
        }
        disable_irq(r_vec->irq_vector);

        irq_set_affinity_hint(r_vec->irq_vector, &r_vec->affinity_mask);

        nn_dbg(nn, "RV%02d: irq=%03d/%03d\n", idx, r_vec->irq_vector,
               r_vec->irq_entry);

        return 0;
}

static void
nfp_net_cleanup_vector(struct nfp_net *nn, struct nfp_net_r_vector *r_vec)
{
        irq_set_affinity_hint(r_vec->irq_vector, NULL);
        netif_napi_del(&r_vec->napi);
        free_irq(r_vec->irq_vector, r_vec);
}

/**
 * nfp_net_rss_write_itbl() - Write RSS indirection table to device
 * @nn:      NFP Net device to reconfigure
 */
void nfp_net_rss_write_itbl(struct nfp_net *nn)
{
        int i;

        for (i = 0; i < NFP_NET_CFG_RSS_ITBL_SZ; i += 4)
                nn_writel(nn, NFP_NET_CFG_RSS_ITBL + i,
                          get_unaligned_le32(nn->rss_itbl + i));
}

/**
 * nfp_net_rss_write_key() - Write RSS hash key to device
 * @nn:      NFP Net device to reconfigure
 */
void nfp_net_rss_write_key(struct nfp_net *nn)
{
        int i;

        for (i = 0; i < nfp_net_rss_key_sz(nn); i += 4)
                nn_writel(nn, NFP_NET_CFG_RSS_KEY + i,
                          get_unaligned_le32(nn->rss_key + i));
}

/**
 * nfp_net_coalesce_write_cfg() - Write irq coalescence configuration to HW
 * @nn:      NFP Net device to reconfigure
 */
void nfp_net_coalesce_write_cfg(struct nfp_net *nn)
{
        u8 i;
        u32 factor;
        u32 value;

        /* Compute factor used to convert coalesce '_usecs' parameters to
         * ME timestamp ticks.  There are 16 ME clock cycles for each timestamp
         * count.
         */
        factor = nn->me_freq_mhz / 16;

        /* copy RX interrupt coalesce parameters */
        value = (nn->rx_coalesce_max_frames << 16) |
                (factor * nn->rx_coalesce_usecs);
        for (i = 0; i < nn->dp.num_rx_rings; i++)
                nn_writel(nn, NFP_NET_CFG_RXR_IRQ_MOD(i), value);

        /* copy TX interrupt coalesce parameters */
        value = (nn->tx_coalesce_max_frames << 16) |
                (factor * nn->tx_coalesce_usecs);
        for (i = 0; i < nn->dp.num_tx_rings; i++)
                nn_writel(nn, NFP_NET_CFG_TXR_IRQ_MOD(i), value);
}

/**
 * nfp_net_write_mac_addr() - Write mac address to the device control BAR
 * @nn:      NFP Net device to reconfigure
 *
 * Writes the MAC address from the netdev to the device control BAR.  Does not
 * perform the required reconfig.  We do a bit of byte swapping dance because
 * firmware is LE.
 */
static void nfp_net_write_mac_addr(struct nfp_net *nn)
{
        nn_writel(nn, NFP_NET_CFG_MACADDR + 0,
                  get_unaligned_be32(nn->dp.netdev->dev_addr));
        nn_writew(nn, NFP_NET_CFG_MACADDR + 6,
                  get_unaligned_be16(nn->dp.netdev->dev_addr + 4));
}

static void nfp_net_vec_clear_ring_data(struct nfp_net *nn, unsigned int idx)
{
        nn_writeq(nn, NFP_NET_CFG_RXR_ADDR(idx), 0);
        nn_writeb(nn, NFP_NET_CFG_RXR_SZ(idx), 0);
        nn_writeb(nn, NFP_NET_CFG_RXR_VEC(idx), 0);

        nn_writeq(nn, NFP_NET_CFG_TXR_ADDR(idx), 0);
        nn_writeb(nn, NFP_NET_CFG_TXR_SZ(idx), 0);
        nn_writeb(nn, NFP_NET_CFG_TXR_VEC(idx), 0);
}

/**
 * nfp_net_clear_config_and_disable() - Clear control BAR and disable NFP
 * @nn:      NFP Net device to reconfigure
 */
static void nfp_net_clear_config_and_disable(struct nfp_net *nn)
{
        u32 new_ctrl, update;
        unsigned int r;
        int err;

        new_ctrl = nn->dp.ctrl;
        new_ctrl &= ~NFP_NET_CFG_CTRL_ENABLE;
        update = NFP_NET_CFG_UPDATE_GEN;
        update |= NFP_NET_CFG_UPDATE_MSIX;
        update |= NFP_NET_CFG_UPDATE_RING;

        if (nn->cap & NFP_NET_CFG_CTRL_RINGCFG)
                new_ctrl &= ~NFP_NET_CFG_CTRL_RINGCFG;

        nn_writeq(nn, NFP_NET_CFG_TXRS_ENABLE, 0);
        nn_writeq(nn, NFP_NET_CFG_RXRS_ENABLE, 0);

        nn_writel(nn, NFP_NET_CFG_CTRL, new_ctrl);
        err = nfp_net_reconfig(nn, update);
        if (err)
                nn_err(nn, "Could not disable device: %d\n", err);

        for (r = 0; r < nn->dp.num_rx_rings; r++)
                nfp_net_rx_ring_reset(&nn->dp.rx_rings[r]);
        for (r = 0; r < nn->dp.num_tx_rings; r++)
                nfp_net_tx_ring_reset(&nn->dp, &nn->dp.tx_rings[r]);
        for (r = 0; r < nn->dp.num_r_vecs; r++)
                nfp_net_vec_clear_ring_data(nn, r);

        nn->dp.ctrl = new_ctrl;
}

static void
nfp_net_rx_ring_hw_cfg_write(struct nfp_net *nn,
                             struct nfp_net_rx_ring *rx_ring, unsigned int idx)
{
        /* Write the DMA address, size and MSI-X info to the device */
        nn_writeq(nn, NFP_NET_CFG_RXR_ADDR(idx), rx_ring->dma);
        nn_writeb(nn, NFP_NET_CFG_RXR_SZ(idx), ilog2(rx_ring->cnt));
        nn_writeb(nn, NFP_NET_CFG_RXR_VEC(idx), rx_ring->r_vec->irq_entry);
}

static void
nfp_net_tx_ring_hw_cfg_write(struct nfp_net *nn,
                             struct nfp_net_tx_ring *tx_ring, unsigned int idx)
{
        nn_writeq(nn, NFP_NET_CFG_TXR_ADDR(idx), tx_ring->dma);
        nn_writeb(nn, NFP_NET_CFG_TXR_SZ(idx), ilog2(tx_ring->cnt));
        nn_writeb(nn, NFP_NET_CFG_TXR_VEC(idx), tx_ring->r_vec->irq_entry);
}

/**
 * nfp_net_set_config_and_enable() - Write control BAR and enable NFP
 * @nn:      NFP Net device to reconfigure
 */
static int nfp_net_set_config_and_enable(struct nfp_net *nn)
{
        u32 new_ctrl, update = 0;
        unsigned int r;
        int err;

        new_ctrl = nn->dp.ctrl;

        if (nn->cap & NFP_NET_CFG_CTRL_RSS) {
                nfp_net_rss_write_key(nn);
                nfp_net_rss_write_itbl(nn);
                nn_writel(nn, NFP_NET_CFG_RSS_CTRL, nn->rss_cfg);
                update |= NFP_NET_CFG_UPDATE_RSS;
        }

        if (nn->cap & NFP_NET_CFG_CTRL_IRQMOD) {
                nfp_net_coalesce_write_cfg(nn);

                new_ctrl |= NFP_NET_CFG_CTRL_IRQMOD;
                update |= NFP_NET_CFG_UPDATE_IRQMOD;
        }

        for (r = 0; r < nn->dp.num_tx_rings; r++)
                nfp_net_tx_ring_hw_cfg_write(nn, &nn->dp.tx_rings[r], r);
        for (r = 0; r < nn->dp.num_rx_rings; r++)
                nfp_net_rx_ring_hw_cfg_write(nn, &nn->dp.rx_rings[r], r);

        nn_writeq(nn, NFP_NET_CFG_TXRS_ENABLE, nn->dp.num_tx_rings == 64 ?
                  0xffffffffffffffffULL : ((u64)1 << nn->dp.num_tx_rings) - 1);

        nn_writeq(nn, NFP_NET_CFG_RXRS_ENABLE, nn->dp.num_rx_rings == 64 ?
                  0xffffffffffffffffULL : ((u64)1 << nn->dp.num_rx_rings) - 1);

        nfp_net_write_mac_addr(nn);

        nn_writel(nn, NFP_NET_CFG_MTU, nn->dp.netdev->mtu);
        nn_writel(nn, NFP_NET_CFG_FLBUFSZ,
                  nn->dp.fl_bufsz - NFP_NET_RX_BUF_NON_DATA);

        /* Enable device */
        new_ctrl |= NFP_NET_CFG_CTRL_ENABLE;
        update |= NFP_NET_CFG_UPDATE_GEN;
        update |= NFP_NET_CFG_UPDATE_MSIX;
        update |= NFP_NET_CFG_UPDATE_RING;
        if (nn->cap & NFP_NET_CFG_CTRL_RINGCFG)
                new_ctrl |= NFP_NET_CFG_CTRL_RINGCFG;

        nn_writel(nn, NFP_NET_CFG_CTRL, new_ctrl);
        err = nfp_net_reconfig(nn, update);
        if (err) {
                nfp_net_clear_config_and_disable(nn);
                return err;
        }

        nn->dp.ctrl = new_ctrl;

        for (r = 0; r < nn->dp.num_rx_rings; r++)
                nfp_net_rx_ring_fill_freelist(&nn->dp, &nn->dp.rx_rings[r]);

        /* Since reconfiguration requests while NFP is down are ignored we
         * have to wipe the entire VXLAN configuration and reinitialize it.
         */
        if (nn->dp.ctrl & NFP_NET_CFG_CTRL_VXLAN) {
                memset(&nn->vxlan_ports, 0, sizeof(nn->vxlan_ports));
                memset(&nn->vxlan_usecnt, 0, sizeof(nn->vxlan_usecnt));
                udp_tunnel_get_rx_info(nn->dp.netdev);
        }

        return 0;
}

/**
 * nfp_net_open_stack() - Start the device from stack's perspective
 * @nn:      NFP Net device to reconfigure
 */
static void nfp_net_open_stack(struct nfp_net *nn)
{
        unsigned int r;

        for (r = 0; r < nn->dp.num_r_vecs; r++) {
                napi_enable(&nn->r_vecs[r].napi);
                enable_irq(nn->r_vecs[r].irq_vector);
        }

        netif_tx_wake_all_queues(nn->dp.netdev);

        enable_irq(nn->irq_entries[NFP_NET_IRQ_LSC_IDX].vector);
        nfp_net_read_link_status(nn);
}

static int nfp_net_netdev_open(struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);
        int err, r;

        /* Step 1: Allocate resources for rings and the like
         * - Request interrupts
         * - Allocate RX and TX ring resources
         * - Setup initial RSS table
         */
        err = nfp_net_aux_irq_request(nn, NFP_NET_CFG_EXN, "%s-exn",
                                      nn->exn_name, sizeof(nn->exn_name),
                                      NFP_NET_IRQ_EXN_IDX, nn->exn_handler);
        if (err)
                return err;
        err = nfp_net_aux_irq_request(nn, NFP_NET_CFG_LSC, "%s-lsc",
                                      nn->lsc_name, sizeof(nn->lsc_name),
                                      NFP_NET_IRQ_LSC_IDX, nn->lsc_handler);
        if (err)
                goto err_free_exn;
        disable_irq(nn->irq_entries[NFP_NET_IRQ_LSC_IDX].vector);

        for (r = 0; r < nn->dp.num_r_vecs; r++) {
                err = nfp_net_prepare_vector(nn, &nn->r_vecs[r], r);
                if (err)
                        goto err_cleanup_vec_p;
        }

        err = nfp_net_rx_rings_prepare(nn, &nn->dp);
        if (err)
                goto err_cleanup_vec;

        err = nfp_net_tx_rings_prepare(nn, &nn->dp);
        if (err)
                goto err_free_rx_rings;

        for (r = 0; r < nn->max_r_vecs; r++)
                nfp_net_vector_assign_rings(&nn->dp, &nn->r_vecs[r], r);

        err = netif_set_real_num_tx_queues(netdev, nn->dp.num_stack_tx_rings);
        if (err)
                goto err_free_rings;

        err = netif_set_real_num_rx_queues(netdev, nn->dp.num_rx_rings);
        if (err)
                goto err_free_rings;

        /* Step 2: Configure the NFP
         * - Enable rings from 0 to tx_rings/rx_rings - 1.
         * - Write MAC address (in case it changed)
         * - Set the MTU
         * - Set the Freelist buffer size
         * - Enable the FW
         */
        err = nfp_net_set_config_and_enable(nn);
        if (err)
                goto err_free_rings;

        /* Step 3: Enable for kernel
         * - put some freelist descriptors on each RX ring
         * - enable NAPI on each ring
         * - enable all TX queues
         * - set link state
         */
        nfp_net_open_stack(nn);

        return 0;

err_free_rings:
        nfp_net_tx_rings_free(&nn->dp);
err_free_rx_rings:
        nfp_net_rx_rings_free(&nn->dp);
err_cleanup_vec:
        r = nn->dp.num_r_vecs;
err_cleanup_vec_p:
        while (r--)
                nfp_net_cleanup_vector(nn, &nn->r_vecs[r]);
        nfp_net_aux_irq_free(nn, NFP_NET_CFG_LSC, NFP_NET_IRQ_LSC_IDX);
err_free_exn:
        nfp_net_aux_irq_free(nn, NFP_NET_CFG_EXN, NFP_NET_IRQ_EXN_IDX);
        return err;
}

/**
 * nfp_net_close_stack() - Quiescent the stack (part of close)
 * @nn:      NFP Net device to reconfigure
 */
static void nfp_net_close_stack(struct nfp_net *nn)
{
        unsigned int r;

        disable_irq(nn->irq_entries[NFP_NET_IRQ_LSC_IDX].vector);
        netif_carrier_off(nn->dp.netdev);
        nn->link_up = false;

        for (r = 0; r < nn->dp.num_r_vecs; r++) {
                disable_irq(nn->r_vecs[r].irq_vector);
                napi_disable(&nn->r_vecs[r].napi);
        }

        netif_tx_disable(nn->dp.netdev);
}

/**
 * nfp_net_close_free_all() - Free all runtime resources
 * @nn:      NFP Net device to reconfigure
 */
static void nfp_net_close_free_all(struct nfp_net *nn)
{
        unsigned int r;

        for (r = 0; r < nn->dp.num_rx_rings; r++) {
                nfp_net_rx_ring_bufs_free(&nn->dp, &nn->dp.rx_rings[r]);
                nfp_net_rx_ring_free(&nn->dp.rx_rings[r]);
        }
        for (r = 0; r < nn->dp.num_tx_rings; r++)
                nfp_net_tx_ring_free(&nn->dp.tx_rings[r]);
        for (r = 0; r < nn->dp.num_r_vecs; r++)
                nfp_net_cleanup_vector(nn, &nn->r_vecs[r]);

        kfree(nn->dp.rx_rings);
        kfree(nn->dp.tx_rings);

        nfp_net_aux_irq_free(nn, NFP_NET_CFG_LSC, NFP_NET_IRQ_LSC_IDX);
        nfp_net_aux_irq_free(nn, NFP_NET_CFG_EXN, NFP_NET_IRQ_EXN_IDX);
}

/**
 * nfp_net_netdev_close() - Called when the device is downed
 * @netdev:      netdev structure
 */
static int nfp_net_netdev_close(struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);

        /* Step 1: Disable RX and TX rings from the Linux kernel perspective
         */
        nfp_net_close_stack(nn);

        /* Step 2: Tell NFP
         */
        nfp_net_clear_config_and_disable(nn);

        /* Step 3: Free resources
         */
        nfp_net_close_free_all(nn);

        nn_dbg(nn, "%s down", netdev->name);
        return 0;
}

static void nfp_net_set_rx_mode(struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);
        u32 new_ctrl;

        new_ctrl = nn->dp.ctrl;

        if (netdev->flags & IFF_PROMISC) {
                if (nn->cap & NFP_NET_CFG_CTRL_PROMISC)
                        new_ctrl |= NFP_NET_CFG_CTRL_PROMISC;
                else
                        nn_warn(nn, "FW does not support promiscuous mode\n");
        } else {
                new_ctrl &= ~NFP_NET_CFG_CTRL_PROMISC;
        }

        if (new_ctrl == nn->dp.ctrl)
                return;

        nn_writel(nn, NFP_NET_CFG_CTRL, new_ctrl);
        nfp_net_reconfig_post(nn, NFP_NET_CFG_UPDATE_GEN);

        nn->dp.ctrl = new_ctrl;
}

static void nfp_net_rss_init_itbl(struct nfp_net *nn)
{
        int i;

        for (i = 0; i < sizeof(nn->rss_itbl); i++)
                nn->rss_itbl[i] =
                        ethtool_rxfh_indir_default(i, nn->dp.num_rx_rings);
}

static void nfp_net_dp_swap(struct nfp_net *nn, struct nfp_net_dp *dp)
{
        struct nfp_net_dp new_dp = *dp;

        *dp = nn->dp;
        nn->dp = new_dp;

        nn->dp.netdev->mtu = new_dp.mtu;

        if (!netif_is_rxfh_configured(nn->dp.netdev))
                nfp_net_rss_init_itbl(nn);
}

static int nfp_net_dp_swap_enable(struct nfp_net *nn, struct nfp_net_dp *dp)
{
        unsigned int r;
        int err;

        nfp_net_dp_swap(nn, dp);

        for (r = 0; r < nn->max_r_vecs; r++)
                nfp_net_vector_assign_rings(&nn->dp, &nn->r_vecs[r], r);

        err = netif_set_real_num_rx_queues(nn->dp.netdev, nn->dp.num_rx_rings);
        if (err)
                return err;

        if (nn->dp.netdev->real_num_tx_queues != nn->dp.num_stack_tx_rings) {
                err = netif_set_real_num_tx_queues(nn->dp.netdev,
                                                   nn->dp.num_stack_tx_rings);
                if (err)
                        return err;
        }

        return nfp_net_set_config_and_enable(nn);
}

struct nfp_net_dp *nfp_net_clone_dp(struct nfp_net *nn)
{
        struct nfp_net_dp *new;

        new = kmalloc(sizeof(*new), GFP_KERNEL);
        if (!new)
                return NULL;

        *new = nn->dp;

        /* Clear things which need to be recomputed */
        new->fl_bufsz = 0;
        new->tx_rings = NULL;
        new->rx_rings = NULL;
        new->num_r_vecs = 0;
        new->num_stack_tx_rings = 0;

        return new;
}

static int nfp_net_check_config(struct nfp_net *nn, struct nfp_net_dp *dp)
{
        /* XDP-enabled tests */
        if (!dp->xdp_prog)
                return 0;
        if (dp->fl_bufsz > PAGE_SIZE) {
                nn_warn(nn, "MTU too large w/ XDP enabled\n");
                return -EINVAL;
        }
        if (dp->num_tx_rings > nn->max_tx_rings) {
                nn_warn(nn, "Insufficient number of TX rings w/ XDP enabled\n");
                return -EINVAL;
        }

        return 0;
}

int nfp_net_ring_reconfig(struct nfp_net *nn, struct nfp_net_dp *dp)
{
        int r, err;

        dp->fl_bufsz = nfp_net_calc_fl_bufsz(dp);

        dp->num_stack_tx_rings = dp->num_tx_rings;
        if (dp->xdp_prog)
                dp->num_stack_tx_rings -= dp->num_rx_rings;

        dp->num_r_vecs = max(dp->num_rx_rings, dp->num_stack_tx_rings);

        err = nfp_net_check_config(nn, dp);
        if (err)
                goto exit_free_dp;

        if (!netif_running(dp->netdev)) {
                nfp_net_dp_swap(nn, dp);
                err = 0;
                goto exit_free_dp;
        }

        /* Prepare new rings */
        for (r = nn->dp.num_r_vecs; r < dp->num_r_vecs; r++) {
                err = nfp_net_prepare_vector(nn, &nn->r_vecs[r], r);
                if (err) {
                        dp->num_r_vecs = r;
                        goto err_cleanup_vecs;
                }
        }

        err = nfp_net_rx_rings_prepare(nn, dp);
        if (err)
                goto err_cleanup_vecs;

        err = nfp_net_tx_rings_prepare(nn, dp);
        if (err)
                goto err_free_rx;

        /* Stop device, swap in new rings, try to start the firmware */
        nfp_net_close_stack(nn);
        nfp_net_clear_config_and_disable(nn);

        err = nfp_net_dp_swap_enable(nn, dp);
        if (err) {
                int err2;

                nfp_net_clear_config_and_disable(nn);

                /* Try with old configuration and old rings */
                err2 = nfp_net_dp_swap_enable(nn, dp);
                if (err2)
                        nn_err(nn, "Can't restore ring config - FW communication failed (%d,%d)\n",
                               err, err2);
        }
        for (r = dp->num_r_vecs - 1; r >= nn->dp.num_r_vecs; r--)
                nfp_net_cleanup_vector(nn, &nn->r_vecs[r]);

        nfp_net_rx_rings_free(dp);
        nfp_net_tx_rings_free(dp);

        nfp_net_open_stack(nn);
exit_free_dp:
        kfree(dp);

        return err;

err_free_rx:
        nfp_net_rx_rings_free(dp);
err_cleanup_vecs:
        for (r = dp->num_r_vecs - 1; r >= nn->dp.num_r_vecs; r--)
                nfp_net_cleanup_vector(nn, &nn->r_vecs[r]);
        kfree(dp);
        return err;
}

static int nfp_net_change_mtu(struct net_device *netdev, int new_mtu)
{
        struct nfp_net *nn = netdev_priv(netdev);
        struct nfp_net_dp *dp;

        dp = nfp_net_clone_dp(nn);
        if (!dp)
                return -ENOMEM;

        dp->mtu = new_mtu;

        return nfp_net_ring_reconfig(nn, dp);
}

static void nfp_net_stat64(struct net_device *netdev,
                           struct rtnl_link_stats64 *stats)
{
        struct nfp_net *nn = netdev_priv(netdev);
        int r;

        for (r = 0; r < nn->dp.num_r_vecs; r++) {
                struct nfp_net_r_vector *r_vec = &nn->r_vecs[r];
                u64 data[3];
                unsigned int start;

                do {
                        start = u64_stats_fetch_begin(&r_vec->rx_sync);
                        data[0] = r_vec->rx_pkts;
                        data[1] = r_vec->rx_bytes;
                        data[2] = r_vec->rx_drops;
                } while (u64_stats_fetch_retry(&r_vec->rx_sync, start));
                stats->rx_packets += data[0];
                stats->rx_bytes += data[1];
                stats->rx_dropped += data[2];

                do {
                        start = u64_stats_fetch_begin(&r_vec->tx_sync);
                        data[0] = r_vec->tx_pkts;
                        data[1] = r_vec->tx_bytes;
                        data[2] = r_vec->tx_errors;
                } while (u64_stats_fetch_retry(&r_vec->tx_sync, start));
                stats->tx_packets += data[0];
                stats->tx_bytes += data[1];
                stats->tx_errors += data[2];
        }
}

static bool nfp_net_ebpf_capable(struct nfp_net *nn)
{
        if (nn->cap & NFP_NET_CFG_CTRL_BPF &&
            nn_readb(nn, NFP_NET_CFG_BPF_ABI) == NFP_NET_BPF_ABI)
                return true;
        return false;
}

static int
nfp_net_setup_tc(struct net_device *netdev, u32 handle, __be16 proto,
                 struct tc_to_netdev *tc)
{
        struct nfp_net *nn = netdev_priv(netdev);

        if (TC_H_MAJ(handle) != TC_H_MAJ(TC_H_INGRESS))
                return -ENOTSUPP;
        if (proto != htons(ETH_P_ALL))
                return -ENOTSUPP;

        if (tc->type == TC_SETUP_CLSBPF && nfp_net_ebpf_capable(nn)) {
                if (!nn->dp.bpf_offload_xdp)
                        return nfp_net_bpf_offload(nn, tc->cls_bpf);
                else
                        return -EBUSY;
        }

        return -EINVAL;
}

static int nfp_net_set_features(struct net_device *netdev,
                                netdev_features_t features)
{
        netdev_features_t changed = netdev->features ^ features;
        struct nfp_net *nn = netdev_priv(netdev);
        u32 new_ctrl;
        int err;

        /* Assume this is not called with features we have not advertised */

        new_ctrl = nn->dp.ctrl;

        if (changed & NETIF_F_RXCSUM) {
                if (features & NETIF_F_RXCSUM)
                        new_ctrl |= NFP_NET_CFG_CTRL_RXCSUM;
                else
                        new_ctrl &= ~NFP_NET_CFG_CTRL_RXCSUM;
        }

        if (changed & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
                if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM))
                        new_ctrl |= NFP_NET_CFG_CTRL_TXCSUM;
                else
                        new_ctrl &= ~NFP_NET_CFG_CTRL_TXCSUM;
        }

        if (changed & (NETIF_F_TSO | NETIF_F_TSO6)) {
                if (features & (NETIF_F_TSO | NETIF_F_TSO6))
                        new_ctrl |= NFP_NET_CFG_CTRL_LSO;
                else
                        new_ctrl &= ~NFP_NET_CFG_CTRL_LSO;
        }

        if (changed & NETIF_F_HW_VLAN_CTAG_RX) {
                if (features & NETIF_F_HW_VLAN_CTAG_RX)
                        new_ctrl |= NFP_NET_CFG_CTRL_RXVLAN;
                else
                        new_ctrl &= ~NFP_NET_CFG_CTRL_RXVLAN;
        }

        if (changed & NETIF_F_HW_VLAN_CTAG_TX) {
                if (features & NETIF_F_HW_VLAN_CTAG_TX)
                        new_ctrl |= NFP_NET_CFG_CTRL_TXVLAN;
                else
                        new_ctrl &= ~NFP_NET_CFG_CTRL_TXVLAN;
        }

        if (changed & NETIF_F_SG) {
                if (features & NETIF_F_SG)
                        new_ctrl |= NFP_NET_CFG_CTRL_GATHER;
                else
                        new_ctrl &= ~NFP_NET_CFG_CTRL_GATHER;
        }

        if (changed & NETIF_F_HW_TC && nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF) {
                nn_err(nn, "Cannot disable HW TC offload while in use\n");
                return -EBUSY;
        }

        nn_dbg(nn, "Feature change 0x%llx -> 0x%llx (changed=0x%llx)\n",
               netdev->features, features, changed);

        if (new_ctrl == nn->dp.ctrl)
                return 0;

        nn_dbg(nn, "NIC ctrl: 0x%x -> 0x%x\n", nn->dp.ctrl, new_ctrl);
        nn_writel(nn, NFP_NET_CFG_CTRL, new_ctrl);
        err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
        if (err)
                return err;

        nn->dp.ctrl = new_ctrl;

        return 0;
}

static netdev_features_t
nfp_net_features_check(struct sk_buff *skb, struct net_device *dev,
                       netdev_features_t features)
{
        u8 l4_hdr;

        /* We can't do TSO over double tagged packets (802.1AD) */
        features &= vlan_features_check(skb, features);

        if (!skb->encapsulation)
                return features;

        /* Ensure that inner L4 header offset fits into TX descriptor field */
        if (skb_is_gso(skb)) {
                u32 hdrlen;

                hdrlen = skb_inner_transport_header(skb) - skb->data +
                        inner_tcp_hdrlen(skb);

                if (unlikely(hdrlen > NFP_NET_LSO_MAX_HDR_SZ))
                        features &= ~NETIF_F_GSO_MASK;
        }

        /* VXLAN/GRE check */
        switch (vlan_get_protocol(skb)) {
        case htons(ETH_P_IP):
                l4_hdr = ip_hdr(skb)->protocol;
                break;
        case htons(ETH_P_IPV6):
                l4_hdr = ipv6_hdr(skb)->nexthdr;
                break;
        default:
                return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
        }

        if (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
            skb->inner_protocol != htons(ETH_P_TEB) ||
            (l4_hdr != IPPROTO_UDP && l4_hdr != IPPROTO_GRE) ||
            (l4_hdr == IPPROTO_UDP &&
             (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
              sizeof(struct udphdr) + sizeof(struct vxlanhdr))))
                return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);

        return features;
}

static int
nfp_net_get_phys_port_name(struct net_device *netdev, char *name, size_t len)
{
        struct nfp_net *nn = netdev_priv(netdev);
        int err;

        if (!nn->eth_port)
                return -EOPNOTSUPP;

        if (!nn->eth_port->is_split)
                err = snprintf(name, len, "p%d", nn->eth_port->label_port);
        else
                err = snprintf(name, len, "p%ds%d", nn->eth_port->label_port,
                               nn->eth_port->label_subport);
        if (err >= len)
                return -EINVAL;

        return 0;
}

/**
 * nfp_net_set_vxlan_port() - set vxlan port in SW and reconfigure HW
 * @nn:   NFP Net device to reconfigure
 * @idx:  Index into the port table where new port should be written
 * @port: UDP port to configure (pass zero to remove VXLAN port)
 */
static void nfp_net_set_vxlan_port(struct nfp_net *nn, int idx, __be16 port)
{
        int i;

        nn->vxlan_ports[idx] = port;

        if (!(nn->dp.ctrl & NFP_NET_CFG_CTRL_VXLAN))
                return;

        BUILD_BUG_ON(NFP_NET_N_VXLAN_PORTS & 1);
        for (i = 0; i < NFP_NET_N_VXLAN_PORTS; i += 2)
                nn_writel(nn, NFP_NET_CFG_VXLAN_PORT + i * sizeof(port),
                          be16_to_cpu(nn->vxlan_ports[i + 1]) << 16 |
                          be16_to_cpu(nn->vxlan_ports[i]));

        nfp_net_reconfig_post(nn, NFP_NET_CFG_UPDATE_VXLAN);
}

/**
 * nfp_net_find_vxlan_idx() - find table entry of the port or a free one
 * @nn:   NFP Network structure
 * @port: UDP port to look for
 *
 * Return: if the port is already in the table -- it's position;
 *         if the port is not in the table -- free position to use;
 *         if the table is full -- -ENOSPC.
 */
static int nfp_net_find_vxlan_idx(struct nfp_net *nn, __be16 port)
{
        int i, free_idx = -ENOSPC;

        for (i = 0; i < NFP_NET_N_VXLAN_PORTS; i++) {
                if (nn->vxlan_ports[i] == port)
                        return i;
                if (!nn->vxlan_usecnt[i])
                        free_idx = i;
        }

        return free_idx;
}

static void nfp_net_add_vxlan_port(struct net_device *netdev,
                                   struct udp_tunnel_info *ti)
{
        struct nfp_net *nn = netdev_priv(netdev);
        int idx;

        if (ti->type != UDP_TUNNEL_TYPE_VXLAN)
                return;

        idx = nfp_net_find_vxlan_idx(nn, ti->port);
        if (idx == -ENOSPC)
                return;

        if (!nn->vxlan_usecnt[idx]++)
                nfp_net_set_vxlan_port(nn, idx, ti->port);
}

static void nfp_net_del_vxlan_port(struct net_device *netdev,
                                   struct udp_tunnel_info *ti)
{
        struct nfp_net *nn = netdev_priv(netdev);
        int idx;

        if (ti->type != UDP_TUNNEL_TYPE_VXLAN)
                return;

        idx = nfp_net_find_vxlan_idx(nn, ti->port);
        if (idx == -ENOSPC || !nn->vxlan_usecnt[idx])
                return;

        if (!--nn->vxlan_usecnt[idx])
                nfp_net_set_vxlan_port(nn, idx, 0);
}

static int nfp_net_xdp_offload(struct nfp_net *nn, struct bpf_prog *prog)
{
        struct tc_cls_bpf_offload cmd = {
                .prog = prog,
        };
        int ret;

        if (!nfp_net_ebpf_capable(nn))
                return -EINVAL;

        if (nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF) {
                if (!nn->dp.bpf_offload_xdp)
                        return prog ? -EBUSY : 0;
                cmd.command = prog ? TC_CLSBPF_REPLACE : TC_CLSBPF_DESTROY;
        } else {
                if (!prog)
                        return 0;
                cmd.command = TC_CLSBPF_ADD;
        }

        ret = nfp_net_bpf_offload(nn, &cmd);
        /* Stop offload if replace not possible */
        if (ret && cmd.command == TC_CLSBPF_REPLACE)
                nfp_net_xdp_offload(nn, NULL);
        nn->dp.bpf_offload_xdp = prog && !ret;
        return ret;
}

static int nfp_net_xdp_setup(struct nfp_net *nn, struct bpf_prog *prog)
{
        struct bpf_prog *old_prog = nn->dp.xdp_prog;
        struct nfp_net_dp *dp;
        int err;

        if (!prog && !nn->dp.xdp_prog)
                return 0;
        if (prog && nn->dp.xdp_prog) {
                prog = xchg(&nn->dp.xdp_prog, prog);
                bpf_prog_put(prog);
                nfp_net_xdp_offload(nn, nn->dp.xdp_prog);
                return 0;
        }

        dp = nfp_net_clone_dp(nn);
        if (!dp)
                return -ENOMEM;

        dp->xdp_prog = prog;
        dp->num_tx_rings += prog ? nn->dp.num_rx_rings : -nn->dp.num_rx_rings;
        dp->rx_dma_dir = prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE;
        if (prog)
                dp->rx_dma_off = XDP_PACKET_HEADROOM -
                        (nn->dp.rx_offset ?: NFP_NET_MAX_PREPEND);
        else
                dp->rx_dma_off = 0;

        /* We need RX reconfig to remap the buffers (BIDIR vs FROM_DEV) */
        err = nfp_net_ring_reconfig(nn, dp);
        if (err)
                return err;

        if (old_prog)
                bpf_prog_put(old_prog);

        nfp_net_xdp_offload(nn, nn->dp.xdp_prog);

        return 0;
}

static int nfp_net_xdp(struct net_device *netdev, struct netdev_xdp *xdp)
{
        struct nfp_net *nn = netdev_priv(netdev);

        switch (xdp->command) {
        case XDP_SETUP_PROG:
                return nfp_net_xdp_setup(nn, xdp->prog);
        case XDP_QUERY_PROG:
                xdp->prog_attached = !!nn->dp.xdp_prog;
                return 0;
        default:
                return -EINVAL;
        }
}

static const struct net_device_ops nfp_net_netdev_ops = {
        .ndo_open               = nfp_net_netdev_open,
        .ndo_stop               = nfp_net_netdev_close,
        .ndo_start_xmit         = nfp_net_tx,
        .ndo_get_stats64        = nfp_net_stat64,
        .ndo_setup_tc           = nfp_net_setup_tc,
        .ndo_tx_timeout         = nfp_net_tx_timeout,
        .ndo_set_rx_mode        = nfp_net_set_rx_mode,
        .ndo_change_mtu         = nfp_net_change_mtu,
        .ndo_set_mac_address    = eth_mac_addr,
        .ndo_set_features       = nfp_net_set_features,
        .ndo_features_check     = nfp_net_features_check,
        .ndo_get_phys_port_name = nfp_net_get_phys_port_name,
        .ndo_udp_tunnel_add     = nfp_net_add_vxlan_port,
        .ndo_udp_tunnel_del     = nfp_net_del_vxlan_port,
        .ndo_xdp                = nfp_net_xdp,
};

/**
 * nfp_net_info() - Print general info about the NIC
 * @nn:      NFP Net device to reconfigure
 */
void nfp_net_info(struct nfp_net *nn)
{
        nn_info(nn, "Netronome NFP-6xxx %sNetdev: TxQs=%d/%d RxQs=%d/%d\n",
                nn->dp.is_vf ? "VF " : "",
                nn->dp.num_tx_rings, nn->max_tx_rings,
                nn->dp.num_rx_rings, nn->max_rx_rings);
        nn_info(nn, "VER: %d.%d.%d.%d, Maximum supported MTU: %d\n",
                nn->fw_ver.resv, nn->fw_ver.class,
                nn->fw_ver.major, nn->fw_ver.minor,
                nn->max_mtu);
        nn_info(nn, "CAP: %#x %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
                nn->cap,
                nn->cap & NFP_NET_CFG_CTRL_PROMISC  ? "PROMISC "  : "",
                nn->cap & NFP_NET_CFG_CTRL_L2BC     ? "L2BCFILT " : "",
                nn->cap & NFP_NET_CFG_CTRL_L2MC     ? "L2MCFILT " : "",
                nn->cap & NFP_NET_CFG_CTRL_RXCSUM   ? "RXCSUM "   : "",
                nn->cap & NFP_NET_CFG_CTRL_TXCSUM   ? "TXCSUM "   : "",
                nn->cap & NFP_NET_CFG_CTRL_RXVLAN   ? "RXVLAN "   : "",
                nn->cap & NFP_NET_CFG_CTRL_TXVLAN   ? "TXVLAN "   : "",
                nn->cap & NFP_NET_CFG_CTRL_SCATTER  ? "SCATTER "  : "",
                nn->cap & NFP_NET_CFG_CTRL_GATHER   ? "GATHER "   : "",
                nn->cap & NFP_NET_CFG_CTRL_LSO      ? "TSO "      : "",
                nn->cap & NFP_NET_CFG_CTRL_RSS      ? "RSS "      : "",
                nn->cap & NFP_NET_CFG_CTRL_L2SWITCH ? "L2SWITCH " : "",
                nn->cap & NFP_NET_CFG_CTRL_MSIXAUTO ? "AUTOMASK " : "",
                nn->cap & NFP_NET_CFG_CTRL_IRQMOD   ? "IRQMOD "   : "",
                nn->cap & NFP_NET_CFG_CTRL_VXLAN    ? "VXLAN "    : "",
                nn->cap & NFP_NET_CFG_CTRL_NVGRE    ? "NVGRE "    : "",
                nfp_net_ebpf_capable(nn)            ? "BPF "      : "");
}

/**
 * nfp_net_netdev_alloc() - Allocate netdev and related structure
 * @pdev:         PCI device
 * @max_tx_rings: Maximum number of TX rings supported by device
 * @max_rx_rings: Maximum number of RX rings supported by device
 *
 * This function allocates a netdev device and fills in the initial
 * part of the @struct nfp_net structure.
 *
 * Return: NFP Net device structure, or ERR_PTR on error.
 */
struct nfp_net *nfp_net_netdev_alloc(struct pci_dev *pdev,
                                     unsigned int max_tx_rings,
                                     unsigned int max_rx_rings)
{
        struct net_device *netdev;
        struct nfp_net *nn;

        netdev = alloc_etherdev_mqs(sizeof(struct nfp_net),
                                    max_tx_rings, max_rx_rings);
        if (!netdev)
                return ERR_PTR(-ENOMEM);

        SET_NETDEV_DEV(netdev, &pdev->dev);
        nn = netdev_priv(netdev);

        nn->dp.netdev = netdev;
        nn->dp.dev = &pdev->dev;
        nn->pdev = pdev;

        nn->max_tx_rings = max_tx_rings;
        nn->max_rx_rings = max_rx_rings;

        nn->dp.num_tx_rings = min_t(unsigned int,
                                    max_tx_rings, num_online_cpus());
        nn->dp.num_rx_rings = min_t(unsigned int, max_rx_rings,
                                 netif_get_num_default_rss_queues());

        nn->dp.num_r_vecs = max(nn->dp.num_tx_rings, nn->dp.num_rx_rings);
        nn->dp.num_r_vecs = min_t(unsigned int,
                                  nn->dp.num_r_vecs, num_online_cpus());

        nn->dp.txd_cnt = NFP_NET_TX_DESCS_DEFAULT;
        nn->dp.rxd_cnt = NFP_NET_RX_DESCS_DEFAULT;

        spin_lock_init(&nn->reconfig_lock);
        spin_lock_init(&nn->rx_filter_lock);
        spin_lock_init(&nn->link_status_lock);

        setup_timer(&nn->reconfig_timer,
                    nfp_net_reconfig_timer, (unsigned long)nn);
        setup_timer(&nn->rx_filter_stats_timer,
                    nfp_net_filter_stats_timer, (unsigned long)nn);

        return nn;
}

/**
 * nfp_net_netdev_free() - Undo what @nfp_net_netdev_alloc() did
 * @nn:      NFP Net device to reconfigure
 */
void nfp_net_netdev_free(struct nfp_net *nn)
{
        free_netdev(nn->dp.netdev);
}

/**
 * nfp_net_rss_key_sz() - Get current size of the RSS key
 * @nn:         NFP Net device instance
 *
 * Return: size of the RSS key for currently selected hash function.
 */
unsigned int nfp_net_rss_key_sz(struct nfp_net *nn)
{
        switch (nn->rss_hfunc) {
        case ETH_RSS_HASH_TOP:
                return NFP_NET_CFG_RSS_KEY_SZ;
        case ETH_RSS_HASH_XOR:
                return 0;
        case ETH_RSS_HASH_CRC32:
                return 4;
        }

        nn_warn(nn, "Unknown hash function: %u\n", nn->rss_hfunc);
        return 0;
}

/**
 * nfp_net_rss_init() - Set the initial RSS parameters
 * @nn:      NFP Net device to reconfigure
 */
static void nfp_net_rss_init(struct nfp_net *nn)
{
        unsigned long func_bit, rss_cap_hfunc;
        u32 reg;

        /* Read the RSS function capability and select first supported func */
        reg = nn_readl(nn, NFP_NET_CFG_RSS_CAP);
        rss_cap_hfunc = FIELD_GET(NFP_NET_CFG_RSS_CAP_HFUNC, reg);
        if (!rss_cap_hfunc)
                rss_cap_hfunc = FIELD_GET(NFP_NET_CFG_RSS_CAP_HFUNC,
                                          NFP_NET_CFG_RSS_TOEPLITZ);

        func_bit = find_first_bit(&rss_cap_hfunc, NFP_NET_CFG_RSS_HFUNCS);
        if (func_bit == NFP_NET_CFG_RSS_HFUNCS) {
                dev_warn(nn->dp.dev,
                         "Bad RSS config, defaulting to Toeplitz hash\n");
                func_bit = ETH_RSS_HASH_TOP_BIT;
        }
        nn->rss_hfunc = 1 << func_bit;

        netdev_rss_key_fill(nn->rss_key, nfp_net_rss_key_sz(nn));

        nfp_net_rss_init_itbl(nn);

        /* Enable IPv4/IPv6 TCP by default */
        nn->rss_cfg = NFP_NET_CFG_RSS_IPV4_TCP |
                      NFP_NET_CFG_RSS_IPV6_TCP |
                      FIELD_PREP(NFP_NET_CFG_RSS_HFUNC, nn->rss_hfunc) |
                      NFP_NET_CFG_RSS_MASK;
}

/**
 * nfp_net_irqmod_init() - Set the initial IRQ moderation parameters
 * @nn:      NFP Net device to reconfigure
 */
static void nfp_net_irqmod_init(struct nfp_net *nn)
{
        nn->rx_coalesce_usecs      = 50;
        nn->rx_coalesce_max_frames = 64;
        nn->tx_coalesce_usecs      = 50;
        nn->tx_coalesce_max_frames = 64;
}

/**
 * nfp_net_netdev_init() - Initialise/finalise the netdev structure
 * @netdev:      netdev structure
 *
 * Return: 0 on success or negative errno on error.
 */
int nfp_net_netdev_init(struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);
        int err;

        /* XDP calls for 256 byte packet headroom which wouldn't fit in a u8.
         * We, however, reuse the metadata prepend space for XDP buffers which
         * is at least 1 byte long and as long as XDP headroom doesn't increase
         * above 256 the *extra* XDP headroom will fit on 8 bits.
         */
        BUILD_BUG_ON(XDP_PACKET_HEADROOM > 256);

        nn->dp.chained_metadata_format = nn->fw_ver.major > 3;

        nn->dp.rx_dma_dir = DMA_FROM_DEVICE;

        /* Get some of the read-only fields from the BAR */
        nn->cap = nn_readl(nn, NFP_NET_CFG_CAP);
        nn->max_mtu = nn_readl(nn, NFP_NET_CFG_MAX_MTU);

        nfp_net_write_mac_addr(nn);

        /* Determine RX packet/metadata boundary offset */
        if (nn->fw_ver.major >= 2) {
                u32 reg;

                reg = nn_readl(nn, NFP_NET_CFG_RX_OFFSET);
                if (reg > NFP_NET_MAX_PREPEND) {
                        nn_err(nn, "Invalid rx offset: %d\n", reg);
                        return -EINVAL;
                }
                nn->dp.rx_offset = reg;
        } else {
                nn->dp.rx_offset = NFP_NET_RX_OFFSET;
        }

        /* Set default MTU and Freelist buffer size */
        if (nn->max_mtu < NFP_NET_DEFAULT_MTU)
                netdev->mtu = nn->max_mtu;
        else
                netdev->mtu = NFP_NET_DEFAULT_MTU;
        nn->dp.mtu = netdev->mtu;
        nn->dp.fl_bufsz = nfp_net_calc_fl_bufsz(&nn->dp);

        /* Advertise/enable offloads based on capabilities
         *
         * Note: netdev->features show the currently enabled features
         * and netdev->hw_features advertises which features are
         * supported.  By default we enable most features.
         */
        netdev->hw_features = NETIF_F_HIGHDMA;
        if (nn->cap & NFP_NET_CFG_CTRL_RXCSUM) {
                netdev->hw_features |= NETIF_F_RXCSUM;
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_RXCSUM;
        }
        if (nn->cap & NFP_NET_CFG_CTRL_TXCSUM) {
                netdev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_TXCSUM;
        }
        if (nn->cap & NFP_NET_CFG_CTRL_GATHER) {
                netdev->hw_features |= NETIF_F_SG;
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_GATHER;
        }
        if ((nn->cap & NFP_NET_CFG_CTRL_LSO) && nn->fw_ver.major > 2) {
                netdev->hw_features |= NETIF_F_TSO | NETIF_F_TSO6;
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_LSO;
        }
        if (nn->cap & NFP_NET_CFG_CTRL_RSS) {
                netdev->hw_features |= NETIF_F_RXHASH;
                nfp_net_rss_init(nn);
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_RSS;
        }
        if (nn->cap & NFP_NET_CFG_CTRL_VXLAN &&
            nn->cap & NFP_NET_CFG_CTRL_NVGRE) {
                if (nn->cap & NFP_NET_CFG_CTRL_LSO)
                        netdev->hw_features |= NETIF_F_GSO_GRE |
                                               NETIF_F_GSO_UDP_TUNNEL;
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_VXLAN | NFP_NET_CFG_CTRL_NVGRE;

                netdev->hw_enc_features = netdev->hw_features;
        }

        netdev->vlan_features = netdev->hw_features;

        if (nn->cap & NFP_NET_CFG_CTRL_RXVLAN) {
                netdev->hw_features |= NETIF_F_HW_VLAN_CTAG_RX;
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_RXVLAN;
        }
        if (nn->cap & NFP_NET_CFG_CTRL_TXVLAN) {
                netdev->hw_features |= NETIF_F_HW_VLAN_CTAG_TX;
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_TXVLAN;
        }

        netdev->features = netdev->hw_features;

        if (nfp_net_ebpf_capable(nn))
                netdev->hw_features |= NETIF_F_HW_TC;

        /* Advertise but disable TSO by default. */
        netdev->features &= ~(NETIF_F_TSO | NETIF_F_TSO6);

        /* Allow L2 Broadcast and Multicast through by default, if supported */
        if (nn->cap & NFP_NET_CFG_CTRL_L2BC)
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_L2BC;
        if (nn->cap & NFP_NET_CFG_CTRL_L2MC)
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_L2MC;

        /* Allow IRQ moderation, if supported */
        if (nn->cap & NFP_NET_CFG_CTRL_IRQMOD) {
                nfp_net_irqmod_init(nn);
                nn->dp.ctrl |= NFP_NET_CFG_CTRL_IRQMOD;
        }

        /* Stash the re-configuration queue away.  First odd queue in TX Bar */
        nn->qcp_cfg = nn->tx_bar + NFP_QCP_QUEUE_ADDR_SZ;

        /* Make sure the FW knows the netdev is supposed to be disabled here */
        nn_writel(nn, NFP_NET_CFG_CTRL, 0);
        nn_writeq(nn, NFP_NET_CFG_TXRS_ENABLE, 0);
        nn_writeq(nn, NFP_NET_CFG_RXRS_ENABLE, 0);
        err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_RING |
                                   NFP_NET_CFG_UPDATE_GEN);
        if (err)
                return err;

        /* Finalise the netdev setup */
        netdev->netdev_ops = &nfp_net_netdev_ops;
        netdev->watchdog_timeo = msecs_to_jiffies(5 * 1000);

        /* MTU range: 68 - hw-specific max */
        netdev->min_mtu = ETH_MIN_MTU;
        netdev->max_mtu = nn->max_mtu;

        netif_carrier_off(netdev);

        nfp_net_set_ethtool_ops(netdev);
        nfp_net_vecs_init(netdev);

        return register_netdev(netdev);
}

/**
 * nfp_net_netdev_clean() - Undo what nfp_net_netdev_init() did.
 * @netdev:      netdev structure
 */
void nfp_net_netdev_clean(struct net_device *netdev)
{
        struct nfp_net *nn = netdev_priv(netdev);

        unregister_netdev(nn->dp.netdev);

        if (nn->dp.xdp_prog)
                bpf_prog_put(nn->dp.xdp_prog);
        if (nn->dp.bpf_offload_xdp)
                nfp_net_xdp_offload(nn, NULL);
}