// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2018 Intel Corporation. */

#include <linux/bpf_trace.h>
#include <net/xdp_sock.h>
#include <net/xdp.h>

#include "i40e.h"
#include "i40e_txrx_common.h"
#include "i40e_xsk.h"

/**
 * i40e_xsk_umem_dma_map - DMA maps all UMEM memory for the netdev
 * @vsi: Current VSI
 * @umem: UMEM to DMA map
 *
 * Returns 0 on success, <0 on failure
 **/
static int i40e_xsk_umem_dma_map(struct i40e_vsi *vsi, struct xdp_umem *umem)
{
        struct i40e_pf *pf = vsi->back;
        struct device *dev;
        unsigned int i, j;
        dma_addr_t dma;

        dev = &pf->pdev->dev;
        for (i = 0; i < umem->npgs; i++) {
                dma = dma_map_page_attrs(dev, umem->pgs[i], 0, PAGE_SIZE,
                                         DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR);
                if (dma_mapping_error(dev, dma))
                        goto out_unmap;

                umem->pages[i].dma = dma;
        }

        return 0;

out_unmap:
        for (j = 0; j < i; j++) {
                dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE,
                                     DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR);
                umem->pages[i].dma = 0;
        }

        return -1;
}

/**
 * i40e_xsk_umem_dma_unmap - DMA unmaps all UMEM memory for the netdev
 * @vsi: Current VSI
 * @umem: UMEM to DMA map
 **/
static void i40e_xsk_umem_dma_unmap(struct i40e_vsi *vsi, struct xdp_umem *umem)
{
        struct i40e_pf *pf = vsi->back;
        struct device *dev;
        unsigned int i;

        dev = &pf->pdev->dev;

        for (i = 0; i < umem->npgs; i++) {
                dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE,
                                     DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR);

                umem->pages[i].dma = 0;
        }
}

/**
 * i40e_xsk_umem_enable - Enable/associate a UMEM to a certain ring/qid
 * @vsi: Current VSI
 * @umem: UMEM
 * @qid: Rx ring to associate UMEM to
 *
 * Returns 0 on success, <0 on failure
 **/
static int i40e_xsk_umem_enable(struct i40e_vsi *vsi, struct xdp_umem *umem,
                                u16 qid)
{
        struct net_device *netdev = vsi->netdev;
        struct xdp_umem_fq_reuse *reuseq;
        bool if_running;
        int err;

        if (vsi->type != I40E_VSI_MAIN)
                return -EINVAL;

        if (qid >= vsi->num_queue_pairs)
                return -EINVAL;

        if (qid >= netdev->real_num_rx_queues ||
            qid >= netdev->real_num_tx_queues)
                return -EINVAL;

        reuseq = xsk_reuseq_prepare(vsi->rx_rings[0]->count);
        if (!reuseq)
                return -ENOMEM;

        xsk_reuseq_free(xsk_reuseq_swap(umem, reuseq));

        err = i40e_xsk_umem_dma_map(vsi, umem);
        if (err)
                return err;

        set_bit(qid, vsi->af_xdp_zc_qps);

        if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);

        if (if_running) {
                err = i40e_queue_pair_disable(vsi, qid);
                if (err)
                        return err;

                err = i40e_queue_pair_enable(vsi, qid);
                if (err)
                        return err;

                /* Kick start the NAPI context so that receiving will start */
                err = i40e_xsk_wakeup(vsi->netdev, qid, XDP_WAKEUP_RX);
                if (err)
                        return err;
        }

        return 0;
}

/**
 * i40e_xsk_umem_disable - Disassociate a UMEM from a certain ring/qid
 * @vsi: Current VSI
 * @qid: Rx ring to associate UMEM to
 *
 * Returns 0 on success, <0 on failure
 **/
static int i40e_xsk_umem_disable(struct i40e_vsi *vsi, u16 qid)
{
        struct net_device *netdev = vsi->netdev;
        struct xdp_umem *umem;
        bool if_running;
        int err;

        umem = xdp_get_umem_from_qid(netdev, qid);
        if (!umem)
                return -EINVAL;

        if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);

        if (if_running) {
                err = i40e_queue_pair_disable(vsi, qid);
                if (err)
                        return err;
        }

        clear_bit(qid, vsi->af_xdp_zc_qps);
        i40e_xsk_umem_dma_unmap(vsi, umem);

        if (if_running) {
                err = i40e_queue_pair_enable(vsi, qid);
                if (err)
                        return err;
        }

        return 0;
}

/**
 * i40e_xsk_umem_setup - Enable/disassociate a UMEM to/from a ring/qid
 * @vsi: Current VSI
 * @umem: UMEM to enable/associate to a ring, or NULL to disable
 * @qid: Rx ring to (dis)associate UMEM (from)to
 *
 * This function enables or disables a UMEM to a certain ring.
 *
 * Returns 0 on success, <0 on failure
 **/
int i40e_xsk_umem_setup(struct i40e_vsi *vsi, struct xdp_umem *umem,
                        u16 qid)
{
        return umem ? i40e_xsk_umem_enable(vsi, umem, qid) :
                i40e_xsk_umem_disable(vsi, qid);
}

/**
 * i40e_run_xdp_zc - Executes an XDP program on an xdp_buff
 * @rx_ring: Rx ring
 * @xdp: xdp_buff used as input to the XDP program
 *
 * This function enables or disables a UMEM to a certain ring.
 *
 * Returns any of I40E_XDP_{PASS, CONSUMED, TX, REDIR}
 **/
static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
{
        struct xdp_umem *umem = rx_ring->xsk_umem;
        int err, result = I40E_XDP_PASS;
        struct i40e_ring *xdp_ring;
        struct bpf_prog *xdp_prog;
        u64 offset;
        u32 act;

        rcu_read_lock();
        /* NB! xdp_prog will always be !NULL, due to the fact that
         * this path is enabled by setting an XDP program.
         */
        xdp_prog = READ_ONCE(rx_ring->xdp_prog);
        act = bpf_prog_run_xdp(xdp_prog, xdp);
        offset = xdp->data - xdp->data_hard_start;

        xdp->handle = xsk_umem_adjust_offset(umem, xdp->handle, offset);

        switch (act) {
        case XDP_PASS:
                break;
        case XDP_TX:
                xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index];
                result = i40e_xmit_xdp_tx_ring(xdp, xdp_ring);
                break;
        case XDP_REDIRECT:
                err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
                result = !err ? I40E_XDP_REDIR : I40E_XDP_CONSUMED;
                break;
        default:
                bpf_warn_invalid_xdp_action(act);
                /* fall through */
        case XDP_ABORTED:
                trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
                /* fallthrough -- handle aborts by dropping packet */
        case XDP_DROP:
                result = I40E_XDP_CONSUMED;
                break;
        }
        rcu_read_unlock();
        return result;
}

/**
 * i40e_alloc_buffer_zc - Allocates an i40e_rx_buffer
 * @rx_ring: Rx ring
 * @bi: Rx buffer to populate
 *
 * This function allocates an Rx buffer. The buffer can come from fill
 * queue, or via the recycle queue (next_to_alloc).
 *
 * Returns true for a successful allocation, false otherwise
 **/
static bool i40e_alloc_buffer_zc(struct i40e_ring *rx_ring,
                                 struct i40e_rx_buffer *bi)
{
        struct xdp_umem *umem = rx_ring->xsk_umem;
        void *addr = bi->addr;
        u64 handle, hr;

        if (addr) {
                rx_ring->rx_stats.page_reuse_count++;
                return true;
        }

        if (!xsk_umem_peek_addr(umem, &handle)) {
                rx_ring->rx_stats.alloc_page_failed++;
                return false;
        }

        hr = umem->headroom + XDP_PACKET_HEADROOM;

        bi->dma = xdp_umem_get_dma(umem, handle);
        bi->dma += hr;

        bi->addr = xdp_umem_get_data(umem, handle);
        bi->addr += hr;

        bi->handle = xsk_umem_adjust_offset(umem, handle, umem->headroom);

        xsk_umem_release_addr(umem);
        return true;
}

/**
 * i40e_alloc_buffer_slow_zc - Allocates an i40e_rx_buffer
 * @rx_ring: Rx ring
 * @bi: Rx buffer to populate
 *
 * This function allocates an Rx buffer. The buffer can come from fill
 * queue, or via the reuse queue.
 *
 * Returns true for a successful allocation, false otherwise
 **/
static bool i40e_alloc_buffer_slow_zc(struct i40e_ring *rx_ring,
                                      struct i40e_rx_buffer *bi)
{
        struct xdp_umem *umem = rx_ring->xsk_umem;
        u64 handle, hr;

        if (!xsk_umem_peek_addr_rq(umem, &handle)) {
                rx_ring->rx_stats.alloc_page_failed++;
                return false;
        }

        handle &= rx_ring->xsk_umem->chunk_mask;

        hr = umem->headroom + XDP_PACKET_HEADROOM;

        bi->dma = xdp_umem_get_dma(umem, handle);
        bi->dma += hr;

        bi->addr = xdp_umem_get_data(umem, handle);
        bi->addr += hr;

        bi->handle = xsk_umem_adjust_offset(umem, handle, umem->headroom);

        xsk_umem_release_addr_rq(umem);
        return true;
}

static __always_inline bool
__i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count,
                           bool alloc(struct i40e_ring *rx_ring,
                                      struct i40e_rx_buffer *bi))
{
        u16 ntu = rx_ring->next_to_use;
        union i40e_rx_desc *rx_desc;
        struct i40e_rx_buffer *bi;
        bool ok = true;

        rx_desc = I40E_RX_DESC(rx_ring, ntu);
        bi = &rx_ring->rx_bi[ntu];
        do {
                if (!alloc(rx_ring, bi)) {
                        ok = false;
                        goto no_buffers;
                }

                dma_sync_single_range_for_device(rx_ring->dev, bi->dma, 0,
                                                 rx_ring->rx_buf_len,
                                                 DMA_BIDIRECTIONAL);

                rx_desc->read.pkt_addr = cpu_to_le64(bi->dma);

                rx_desc++;
                bi++;
                ntu++;

                if (unlikely(ntu == rx_ring->count)) {
                        rx_desc = I40E_RX_DESC(rx_ring, 0);
                        bi = rx_ring->rx_bi;
                        ntu = 0;
                }

                rx_desc->wb.qword1.status_error_len = 0;
                count--;
        } while (count);

no_buffers:
        if (rx_ring->next_to_use != ntu)
                i40e_release_rx_desc(rx_ring, ntu);

        return ok;
}

/**
 * i40e_alloc_rx_buffers_zc - Allocates a number of Rx buffers
 * @rx_ring: Rx ring
 * @count: The number of buffers to allocate
 *
 * This function allocates a number of Rx buffers from the reuse queue
 * or fill ring and places them on the Rx ring.
 *
 * Returns true for a successful allocation, false otherwise
 **/
bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
{
        return __i40e_alloc_rx_buffers_zc(rx_ring, count,
                                          i40e_alloc_buffer_slow_zc);
}

/**
 * i40e_alloc_rx_buffers_fast_zc - Allocates a number of Rx buffers
 * @rx_ring: Rx ring
 * @count: The number of buffers to allocate
 *
 * This function allocates a number of Rx buffers from the fill ring
 * or the internal recycle mechanism and places them on the Rx ring.
 *
 * Returns true for a successful allocation, false otherwise
 **/
static bool i40e_alloc_rx_buffers_fast_zc(struct i40e_ring *rx_ring, u16 count)
{
        return __i40e_alloc_rx_buffers_zc(rx_ring, count,
                                          i40e_alloc_buffer_zc);
}

/**
 * i40e_get_rx_buffer_zc - Return the current Rx buffer
 * @rx_ring: Rx ring
 * @size: The size of the rx buffer (read from descriptor)
 *
 * This function returns the current, received Rx buffer, and also
 * does DMA synchronization.  the Rx ring.
 *
 * Returns the received Rx buffer
 **/
static struct i40e_rx_buffer *i40e_get_rx_buffer_zc(struct i40e_ring *rx_ring,
                                                    const unsigned int size)
{
        struct i40e_rx_buffer *bi;

        bi = &rx_ring->rx_bi[rx_ring->next_to_clean];

        /* we are reusing so sync this buffer for CPU use */
        dma_sync_single_range_for_cpu(rx_ring->dev,
                                      bi->dma, 0,
                                      size,
                                      DMA_BIDIRECTIONAL);

        return bi;
}

/**
 * i40e_reuse_rx_buffer_zc - Recycle an Rx buffer
 * @rx_ring: Rx ring
 * @old_bi: The Rx buffer to recycle
 *
 * This function recycles a finished Rx buffer, and places it on the
 * recycle queue (next_to_alloc).
 **/
static void i40e_reuse_rx_buffer_zc(struct i40e_ring *rx_ring,
                                    struct i40e_rx_buffer *old_bi)
{
        struct i40e_rx_buffer *new_bi = &rx_ring->rx_bi[rx_ring->next_to_alloc];
        u16 nta = rx_ring->next_to_alloc;

        /* update, and store next to alloc */
        nta++;
        rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;

        /* transfer page from old buffer to new buffer */
        new_bi->dma = old_bi->dma;
        new_bi->addr = old_bi->addr;
        new_bi->handle = old_bi->handle;

        old_bi->addr = NULL;
}

/**
 * i40e_zca_free - Free callback for MEM_TYPE_ZERO_COPY allocations
 * @alloc: Zero-copy allocator
 * @handle: Buffer handle
 **/
void i40e_zca_free(struct zero_copy_allocator *alloc, unsigned long handle)
{
        struct i40e_rx_buffer *bi;
        struct i40e_ring *rx_ring;
        u64 hr, mask;
        u16 nta;

        rx_ring = container_of(alloc, struct i40e_ring, zca);
        hr = rx_ring->xsk_umem->headroom + XDP_PACKET_HEADROOM;
        mask = rx_ring->xsk_umem->chunk_mask;

        nta = rx_ring->next_to_alloc;
        bi = &rx_ring->rx_bi[nta];

        nta++;
        rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;

        handle &= mask;

        bi->dma = xdp_umem_get_dma(rx_ring->xsk_umem, handle);
        bi->dma += hr;

        bi->addr = xdp_umem_get_data(rx_ring->xsk_umem, handle);
        bi->addr += hr;

        bi->handle = xsk_umem_adjust_offset(rx_ring->xsk_umem, (u64)handle,
                                            rx_ring->xsk_umem->headroom);
}

/**
 * i40e_construct_skb_zc - Create skbufff from zero-copy Rx buffer
 * @rx_ring: Rx ring
 * @bi: Rx buffer
 * @xdp: xdp_buff
 *
 * This functions allocates a new skb from a zero-copy Rx buffer.
 *
 * Returns the skb, or NULL on failure.
 **/
static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
                                             struct i40e_rx_buffer *bi,
                                             struct xdp_buff *xdp)
{
        unsigned int metasize = xdp->data - xdp->data_meta;
        unsigned int datasize = xdp->data_end - xdp->data;
        struct sk_buff *skb;

        /* allocate a skb to store the frags */
        skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
                               xdp->data_end - xdp->data_hard_start,
                               GFP_ATOMIC | __GFP_NOWARN);
        if (unlikely(!skb))
                return NULL;

        skb_reserve(skb, xdp->data - xdp->data_hard_start);
        memcpy(__skb_put(skb, datasize), xdp->data, datasize);
        if (metasize)
                skb_metadata_set(skb, metasize);

        i40e_reuse_rx_buffer_zc(rx_ring, bi);
        return skb;
}

/**
 * i40e_inc_ntc: Advance the next_to_clean index
 * @rx_ring: Rx ring
 **/
static void i40e_inc_ntc(struct i40e_ring *rx_ring)
{
        u32 ntc = rx_ring->next_to_clean + 1;

        ntc = (ntc < rx_ring->count) ? ntc : 0;
        rx_ring->next_to_clean = ntc;
        prefetch(I40E_RX_DESC(rx_ring, ntc));
}

/**
 * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring
 * @rx_ring: Rx ring
 * @budget: NAPI budget
 *
 * Returns amount of work completed
 **/
int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
{
        unsigned int total_rx_bytes = 0, total_rx_packets = 0;
        u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
        unsigned int xdp_res, xdp_xmit = 0;
        bool failure = false;
        struct sk_buff *skb;
        struct xdp_buff xdp;

        xdp.rxq = &rx_ring->xdp_rxq;

        while (likely(total_rx_packets < (unsigned int)budget)) {
                struct i40e_rx_buffer *bi;
                union i40e_rx_desc *rx_desc;
                unsigned int size;
                u64 qword;

                if (cleaned_count >= I40E_RX_BUFFER_WRITE) {
                        failure = failure ||
                                  !i40e_alloc_rx_buffers_fast_zc(rx_ring,
                                                                 cleaned_count);
                        cleaned_count = 0;
                }

                rx_desc = I40E_RX_DESC(rx_ring, rx_ring->next_to_clean);
                qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);

                /* This memory barrier is needed to keep us from reading
                 * any other fields out of the rx_desc until we have
                 * verified the descriptor has been written back.
                 */
                dma_rmb();

                bi = i40e_clean_programming_status(rx_ring, rx_desc,
                                                   qword);
                if (unlikely(bi)) {
                        i40e_reuse_rx_buffer_zc(rx_ring, bi);
                        cleaned_count++;
                        continue;
                }

                size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
                       I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
                if (!size)
                        break;

                bi = i40e_get_rx_buffer_zc(rx_ring, size);
                xdp.data = bi->addr;
                xdp.data_meta = xdp.data;
                xdp.data_hard_start = xdp.data - XDP_PACKET_HEADROOM;
                xdp.data_end = xdp.data + size;
                xdp.handle = bi->handle;

                xdp_res = i40e_run_xdp_zc(rx_ring, &xdp);
                if (xdp_res) {
                        if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR)) {
                                xdp_xmit |= xdp_res;
                                bi->addr = NULL;
                        } else {
                                i40e_reuse_rx_buffer_zc(rx_ring, bi);
                        }

                        total_rx_bytes += size;
                        total_rx_packets++;

                        cleaned_count++;
                        i40e_inc_ntc(rx_ring);
                        continue;
                }

                /* XDP_PASS path */

                /* NB! We are not checking for errors using
                 * i40e_test_staterr with
                 * BIT(I40E_RXD_QW1_ERROR_SHIFT). This is due to that
                 * SBP is *not* set in PRT_SBPVSI (default not set).
                 */
                skb = i40e_construct_skb_zc(rx_ring, bi, &xdp);
                if (!skb) {
                        rx_ring->rx_stats.alloc_buff_failed++;
                        break;
                }

                cleaned_count++;
                i40e_inc_ntc(rx_ring);

                if (eth_skb_pad(skb))
                        continue;

                total_rx_bytes += skb->len;
                total_rx_packets++;

                i40e_process_skb_fields(rx_ring, rx_desc, skb);
                napi_gro_receive(&rx_ring->q_vector->napi, skb);
        }

        i40e_finalize_xdp_rx(rx_ring, xdp_xmit);
        i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets);

        if (xsk_umem_uses_need_wakeup(rx_ring->xsk_umem)) {
                if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
                        xsk_set_rx_need_wakeup(rx_ring->xsk_umem);
                else
                        xsk_clear_rx_need_wakeup(rx_ring->xsk_umem);

                return (int)total_rx_packets;
        }
        return failure ? budget : (int)total_rx_packets;
}

/**
 * i40e_xmit_zc - Performs zero-copy Tx AF_XDP
 * @xdp_ring: XDP Tx ring
 * @budget: NAPI budget
 *
 * Returns true if the work is finished.
 **/
static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
{
        struct i40e_tx_desc *tx_desc = NULL;
        struct i40e_tx_buffer *tx_bi;
        bool work_done = true;
        struct xdp_desc desc;
        dma_addr_t dma;

        while (budget-- > 0) {
                if (!unlikely(I40E_DESC_UNUSED(xdp_ring))) {
                        xdp_ring->tx_stats.tx_busy++;
                        work_done = false;
                        break;
                }

                if (!xsk_umem_consume_tx(xdp_ring->xsk_umem, &desc))
                        break;

                dma = xdp_umem_get_dma(xdp_ring->xsk_umem, desc.addr);

                dma_sync_single_for_device(xdp_ring->dev, dma, desc.len,
                                           DMA_BIDIRECTIONAL);

                tx_bi = &xdp_ring->tx_bi[xdp_ring->next_to_use];
                tx_bi->bytecount = desc.len;

                tx_desc = I40E_TX_DESC(xdp_ring, xdp_ring->next_to_use);
                tx_desc->buffer_addr = cpu_to_le64(dma);
                tx_desc->cmd_type_offset_bsz =
                        build_ctob(I40E_TX_DESC_CMD_ICRC
                                   | I40E_TX_DESC_CMD_EOP,
                                   0, desc.len, 0);

                xdp_ring->next_to_use++;
                if (xdp_ring->next_to_use == xdp_ring->count)
                        xdp_ring->next_to_use = 0;
        }

        if (tx_desc) {
                /* Request an interrupt for the last frame and bump tail ptr. */
                tx_desc->cmd_type_offset_bsz |= (I40E_TX_DESC_CMD_RS <<
                                                 I40E_TXD_QW1_CMD_SHIFT);
                i40e_xdp_ring_update_tail(xdp_ring);

                xsk_umem_consume_tx_done(xdp_ring->xsk_umem);
        }

        return !!budget && work_done;
}

/**
 * i40e_clean_xdp_tx_buffer - Frees and unmaps an XDP Tx entry
 * @tx_ring: XDP Tx ring
 * @tx_bi: Tx buffer info to clean
 **/
static void i40e_clean_xdp_tx_buffer(struct i40e_ring *tx_ring,
                                     struct i40e_tx_buffer *tx_bi)
{
        xdp_return_frame(tx_bi->xdpf);
        dma_unmap_single(tx_ring->dev,
                         dma_unmap_addr(tx_bi, dma),
                         dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
        dma_unmap_len_set(tx_bi, len, 0);
}

/**
 * i40e_clean_xdp_tx_irq - Completes AF_XDP entries, and cleans XDP entries
 * @tx_ring: XDP Tx ring
 * @tx_bi: Tx buffer info to clean
 *
 * Returns true if cleanup/tranmission is done.
 **/
bool i40e_clean_xdp_tx_irq(struct i40e_vsi *vsi,
                           struct i40e_ring *tx_ring, int napi_budget)
{
        unsigned int ntc, total_bytes = 0, budget = vsi->work_limit;
        u32 i, completed_frames, frames_ready, xsk_frames = 0;
        struct xdp_umem *umem = tx_ring->xsk_umem;
        u32 head_idx = i40e_get_head(tx_ring);
        bool work_done = true, xmit_done;
        struct i40e_tx_buffer *tx_bi;

        if (head_idx < tx_ring->next_to_clean)
                head_idx += tx_ring->count;
        frames_ready = head_idx - tx_ring->next_to_clean;

        if (frames_ready == 0) {
                goto out_xmit;
        } else if (frames_ready > budget) {
                completed_frames = budget;
                work_done = false;
        } else {
                completed_frames = frames_ready;
        }

        ntc = tx_ring->next_to_clean;

        for (i = 0; i < completed_frames; i++) {
                tx_bi = &tx_ring->tx_bi[ntc];

                if (tx_bi->xdpf)
                        i40e_clean_xdp_tx_buffer(tx_ring, tx_bi);
                else
                        xsk_frames++;

                tx_bi->xdpf = NULL;
                total_bytes += tx_bi->bytecount;

                if (++ntc >= tx_ring->count)
                        ntc = 0;
        }

        tx_ring->next_to_clean += completed_frames;
        if (unlikely(tx_ring->next_to_clean >= tx_ring->count))
                tx_ring->next_to_clean -= tx_ring->count;

        if (xsk_frames)
                xsk_umem_complete_tx(umem, xsk_frames);

        i40e_arm_wb(tx_ring, vsi, budget);
        i40e_update_tx_stats(tx_ring, completed_frames, total_bytes);

out_xmit:
        if (xsk_umem_uses_need_wakeup(tx_ring->xsk_umem))
                xsk_set_tx_need_wakeup(tx_ring->xsk_umem);

        xmit_done = i40e_xmit_zc(tx_ring, budget);

        return work_done && xmit_done;
}

/**
 * i40e_xsk_wakeup - Implements the ndo_xsk_wakeup
 * @dev: the netdevice
 * @queue_id: queue id to wake up
 * @flags: ignored in our case since we have Rx and Tx in the same NAPI.
 *
 * Returns <0 for errors, 0 otherwise.
 **/
int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
{
        struct i40e_netdev_priv *np = netdev_priv(dev);
        struct i40e_vsi *vsi = np->vsi;
        struct i40e_pf *pf = vsi->back;
        struct i40e_ring *ring;

        if (test_bit(__I40E_CONFIG_BUSY, pf->state))
                return -EAGAIN;

        if (test_bit(__I40E_VSI_DOWN, vsi->state))
                return -ENETDOWN;

        if (!i40e_enabled_xdp_vsi(vsi))
                return -ENXIO;

        if (queue_id >= vsi->num_queue_pairs)
                return -ENXIO;

        if (!vsi->xdp_rings[queue_id]->xsk_umem)
                return -ENXIO;

        ring = vsi->xdp_rings[queue_id];

        /* The idea here is that if NAPI is running, mark a miss, so
         * it will run again. If not, trigger an interrupt and
         * schedule the NAPI from interrupt context. If NAPI would be
         * scheduled here, the interrupt affinity would not be
         * honored.
         */
        if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi))
                i40e_force_wb(vsi, ring->q_vector);

        return 0;
}

void i40e_xsk_clean_rx_ring(struct i40e_ring *rx_ring)
{
        u16 i;

        for (i = 0; i < rx_ring->count; i++) {
                struct i40e_rx_buffer *rx_bi = &rx_ring->rx_bi[i];

                if (!rx_bi->addr)
                        continue;

                xsk_umem_fq_reuse(rx_ring->xsk_umem, rx_bi->handle);
                rx_bi->addr = NULL;
        }
}

/**
 * i40e_xsk_clean_xdp_ring - Clean the XDP Tx ring on shutdown
 * @xdp_ring: XDP Tx ring
 **/
void i40e_xsk_clean_tx_ring(struct i40e_ring *tx_ring)
{
        u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
        struct xdp_umem *umem = tx_ring->xsk_umem;
        struct i40e_tx_buffer *tx_bi;
        u32 xsk_frames = 0;

        while (ntc != ntu) {
                tx_bi = &tx_ring->tx_bi[ntc];

                if (tx_bi->xdpf)
                        i40e_clean_xdp_tx_buffer(tx_ring, tx_bi);
                else
                        xsk_frames++;

                tx_bi->xdpf = NULL;

                ntc++;
                if (ntc >= tx_ring->count)
                        ntc = 0;
        }

        if (xsk_frames)
                xsk_umem_complete_tx(umem, xsk_frames);
}

/**
 * i40e_xsk_any_rx_ring_enabled - Checks if Rx rings have AF_XDP UMEM attached
 * @vsi: vsi
 *
 * Returns true if any of the Rx rings has an AF_XDP UMEM attached
 **/
bool i40e_xsk_any_rx_ring_enabled(struct i40e_vsi *vsi)
{
        struct net_device *netdev = vsi->netdev;
        int i;

        for (i = 0; i < vsi->num_queue_pairs; i++) {
                if (xdp_get_umem_from_qid(netdev, i))
                        return true;
        }

        return false;
}