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

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

#include "ixgbe.h"
#include "ixgbe_txrx_common.h"

struct xsk_buff_pool *ixgbe_xsk_pool(struct ixgbe_adapter *adapter,
                                     struct ixgbe_ring *ring)
{
        bool xdp_on = READ_ONCE(adapter->xdp_prog);
        int qid = ring->ring_idx;

        if (!xdp_on || !test_bit(qid, adapter->af_xdp_zc_qps))
                return NULL;

        return xsk_get_pool_from_qid(adapter->netdev, qid);
}

static int ixgbe_xsk_pool_enable(struct ixgbe_adapter *adapter,
                                 struct xsk_buff_pool *pool,
                                 u16 qid)
{
        struct net_device *netdev = adapter->netdev;
        bool if_running;
        int err;

        if (qid >= adapter->num_rx_queues)
                return -EINVAL;

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

        err = xsk_pool_dma_map(pool, &adapter->pdev->dev, IXGBE_RX_DMA_ATTR);
        if (err)
                return err;

        if_running = netif_running(adapter->netdev) &&
                     ixgbe_enabled_xdp_adapter(adapter);

        if (if_running)
                ixgbe_txrx_ring_disable(adapter, qid);

        set_bit(qid, adapter->af_xdp_zc_qps);

        if (if_running) {
                ixgbe_txrx_ring_enable(adapter, qid);

                /* Kick start the NAPI context so that receiving will start */
                err = ixgbe_xsk_wakeup(adapter->netdev, qid, XDP_WAKEUP_RX);
                if (err) {
                        clear_bit(qid, adapter->af_xdp_zc_qps);
                        xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
                        return err;
                }
        }

        return 0;
}

static int ixgbe_xsk_pool_disable(struct ixgbe_adapter *adapter, u16 qid)
{
        struct xsk_buff_pool *pool;
        bool if_running;

        pool = xsk_get_pool_from_qid(adapter->netdev, qid);
        if (!pool)
                return -EINVAL;

        if_running = netif_running(adapter->netdev) &&
                     ixgbe_enabled_xdp_adapter(adapter);

        if (if_running)
                ixgbe_txrx_ring_disable(adapter, qid);

        clear_bit(qid, adapter->af_xdp_zc_qps);
        xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);

        if (if_running)
                ixgbe_txrx_ring_enable(adapter, qid);

        return 0;
}

int ixgbe_xsk_pool_setup(struct ixgbe_adapter *adapter,
                         struct xsk_buff_pool *pool,
                         u16 qid)
{
        return pool ? ixgbe_xsk_pool_enable(adapter, pool, qid) :
                ixgbe_xsk_pool_disable(adapter, qid);
}

static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
                            struct ixgbe_ring *rx_ring,
                            struct xdp_buff *xdp)
{
        int err, result = IXGBE_XDP_PASS;
        struct bpf_prog *xdp_prog;
        struct ixgbe_ring *ring;
        struct xdp_frame *xdpf;
        u32 act;

        xdp_prog = READ_ONCE(rx_ring->xdp_prog);
        act = bpf_prog_run_xdp(xdp_prog, xdp);

        if (likely(act == XDP_REDIRECT)) {
                err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
                if (!err)
                        return IXGBE_XDP_REDIR;
                if (xsk_uses_need_wakeup(rx_ring->xsk_pool) && err == -ENOBUFS)
                        result = IXGBE_XDP_EXIT;
                else
                        result = IXGBE_XDP_CONSUMED;
                goto out_failure;
        }

        switch (act) {
        case XDP_PASS:
                break;
        case XDP_TX:
                xdpf = xdp_convert_buff_to_frame(xdp);
                if (unlikely(!xdpf))
                        goto out_failure;
                ring = ixgbe_determine_xdp_ring(adapter);
                if (static_branch_unlikely(&ixgbe_xdp_locking_key))
                        spin_lock(&ring->tx_lock);
                result = ixgbe_xmit_xdp_ring(ring, xdpf);
                if (static_branch_unlikely(&ixgbe_xdp_locking_key))
                        spin_unlock(&ring->tx_lock);
                if (result == IXGBE_XDP_CONSUMED)
                        goto out_failure;
                break;
        case XDP_DROP:
                result = IXGBE_XDP_CONSUMED;
                break;
        default:
                bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
                fallthrough;
        case XDP_ABORTED:
                result = IXGBE_XDP_CONSUMED;
out_failure:
                trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
        }
        return result;
}

bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
{
        union ixgbe_adv_rx_desc *rx_desc;
        struct ixgbe_rx_buffer *bi;
        u16 i = rx_ring->next_to_use;
        dma_addr_t dma;
        bool ok = true;

        /* nothing to do */
        if (!count)
                return true;

        rx_desc = IXGBE_RX_DESC(rx_ring, i);
        bi = &rx_ring->rx_buffer_info[i];
        i -= rx_ring->count;

        do {
                bi->xdp = xsk_buff_alloc(rx_ring->xsk_pool);
                if (!bi->xdp) {
                        ok = false;
                        break;
                }

                dma = xsk_buff_xdp_get_dma(bi->xdp);

                /* Refresh the desc even if buffer_addrs didn't change
                 * because each write-back erases this info.
                 */
                rx_desc->read.pkt_addr = cpu_to_le64(dma);

                rx_desc++;
                bi++;
                i++;
                if (unlikely(!i)) {
                        rx_desc = IXGBE_RX_DESC(rx_ring, 0);
                        bi = rx_ring->rx_buffer_info;
                        i -= rx_ring->count;
                }

                /* clear the length for the next_to_use descriptor */
                rx_desc->wb.upper.length = 0;

                count--;
        } while (count);

        i += rx_ring->count;

        if (rx_ring->next_to_use != i) {
                rx_ring->next_to_use = i;

                /* Force memory writes to complete before letting h/w
                 * know there are new descriptors to fetch.  (Only
                 * applicable for weak-ordered memory model archs,
                 * such as IA-64).
                 */
                wmb();
                writel(i, rx_ring->tail);
        }

        return ok;
}

static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
                                              const struct xdp_buff *xdp)
{
        unsigned int totalsize = xdp->data_end - xdp->data_meta;
        unsigned int metasize = xdp->data - xdp->data_meta;
        struct sk_buff *skb;

        net_prefetch(xdp->data_meta);

        /* allocate a skb to store the frags */
        skb = napi_alloc_skb(&rx_ring->q_vector->napi, totalsize);
        if (unlikely(!skb))
                return NULL;

        memcpy(__skb_put(skb, totalsize), xdp->data_meta,
               ALIGN(totalsize, sizeof(long)));

        if (metasize) {
                skb_metadata_set(skb, metasize);
                __skb_pull(skb, metasize);
        }

        return skb;
}

static void ixgbe_inc_ntc(struct ixgbe_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(IXGBE_RX_DESC(rx_ring, ntc));
}

int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
                          struct ixgbe_ring *rx_ring,
                          const int budget)
{
        unsigned int total_rx_bytes = 0, total_rx_packets = 0;
        struct ixgbe_adapter *adapter = q_vector->adapter;
        u16 cleaned_count = ixgbe_desc_unused(rx_ring);
        unsigned int xdp_res, xdp_xmit = 0;
        bool failure = false;
        struct sk_buff *skb;

        while (likely(total_rx_packets < budget)) {
                union ixgbe_adv_rx_desc *rx_desc;
                struct ixgbe_rx_buffer *bi;
                unsigned int size;

                /* return some buffers to hardware, one at a time is too slow */
                if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
                        failure = failure ||
                                  !ixgbe_alloc_rx_buffers_zc(rx_ring,
                                                             cleaned_count);
                        cleaned_count = 0;
                }

                rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean);
                size = le16_to_cpu(rx_desc->wb.upper.length);
                if (!size)
                        break;

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

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

                if (unlikely(!ixgbe_test_staterr(rx_desc,
                                                 IXGBE_RXD_STAT_EOP))) {
                        struct ixgbe_rx_buffer *next_bi;

                        xsk_buff_free(bi->xdp);
                        bi->xdp = NULL;
                        ixgbe_inc_ntc(rx_ring);
                        next_bi =
                               &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
                        next_bi->discard = true;
                        continue;
                }

                if (unlikely(bi->discard)) {
                        xsk_buff_free(bi->xdp);
                        bi->xdp = NULL;
                        bi->discard = false;
                        ixgbe_inc_ntc(rx_ring);
                        continue;
                }

                bi->xdp->data_end = bi->xdp->data + size;
                xsk_buff_dma_sync_for_cpu(bi->xdp);
                xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);

                if (likely(xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))) {
                        xdp_xmit |= xdp_res;
                } else if (xdp_res == IXGBE_XDP_EXIT) {
                        failure = true;
                        break;
                } else if (xdp_res == IXGBE_XDP_CONSUMED) {
                        xsk_buff_free(bi->xdp);
                } else if (xdp_res == IXGBE_XDP_PASS) {
                        goto construct_skb;
                }

                bi->xdp = NULL;
                total_rx_packets++;
                total_rx_bytes += size;

                cleaned_count++;
                ixgbe_inc_ntc(rx_ring);
                continue;

construct_skb:
                /* XDP_PASS path */
                skb = ixgbe_construct_skb_zc(rx_ring, bi->xdp);
                if (!skb) {
                        rx_ring->rx_stats.alloc_rx_buff_failed++;
                        break;
                }

                xsk_buff_free(bi->xdp);
                bi->xdp = NULL;

                cleaned_count++;
                ixgbe_inc_ntc(rx_ring);

                if (eth_skb_pad(skb))
                        continue;

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

                ixgbe_process_skb_fields(rx_ring, rx_desc, skb);
                ixgbe_rx_skb(q_vector, skb);
        }

        if (xdp_xmit & IXGBE_XDP_REDIR)
                xdp_do_flush();

        if (xdp_xmit & IXGBE_XDP_TX) {
                struct ixgbe_ring *ring = ixgbe_determine_xdp_ring(adapter);

                ixgbe_xdp_ring_update_tail_locked(ring);
        }

        ixgbe_update_rx_ring_stats(rx_ring, q_vector, total_rx_packets,
                                   total_rx_bytes);

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

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

void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring)
{
        struct ixgbe_rx_buffer *bi;
        u16 i;

        for (i = 0; i < rx_ring->count; i++) {
                bi = &rx_ring->rx_buffer_info[i];

                if (!bi->xdp)
                        continue;

                xsk_buff_free(bi->xdp);
                bi->xdp = NULL;
        }
}

static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
{
        struct xsk_buff_pool *pool = xdp_ring->xsk_pool;
        union ixgbe_adv_tx_desc *tx_desc = NULL;
        struct ixgbe_tx_buffer *tx_bi;
        bool work_done = true;
        struct xdp_desc desc;
        dma_addr_t dma;
        u32 cmd_type;

        while (likely(budget)) {
                if (unlikely(!ixgbe_desc_unused(xdp_ring))) {
                        work_done = false;
                        break;
                }

                if (!netif_carrier_ok(xdp_ring->netdev))
                        break;

                if (!xsk_tx_peek_desc(pool, &desc))
                        break;

                dma = xsk_buff_raw_get_dma(pool, desc.addr);
                xsk_buff_raw_dma_sync_for_device(pool, dma, desc.len);

                tx_bi = &xdp_ring->tx_buffer_info[xdp_ring->next_to_use];
                tx_bi->bytecount = desc.len;
                tx_bi->xdpf = NULL;
                tx_bi->gso_segs = 1;

                tx_desc = IXGBE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
                tx_desc->read.buffer_addr = cpu_to_le64(dma);

                /* put descriptor type bits */
                cmd_type = IXGBE_ADVTXD_DTYP_DATA |
                           IXGBE_ADVTXD_DCMD_DEXT |
                           IXGBE_ADVTXD_DCMD_IFCS;
                cmd_type |= desc.len | IXGBE_TXD_CMD;
                tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
                tx_desc->read.olinfo_status =
                        cpu_to_le32(desc.len << IXGBE_ADVTXD_PAYLEN_SHIFT);

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

                budget--;
        }

        if (tx_desc) {
                ixgbe_xdp_ring_update_tail(xdp_ring);
                xsk_tx_release(pool);
        }

        return !!budget && work_done;
}

static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
                                      struct ixgbe_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);
}

bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
                            struct ixgbe_ring *tx_ring, int napi_budget)
{
        u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
        unsigned int total_packets = 0, total_bytes = 0;
        struct xsk_buff_pool *pool = tx_ring->xsk_pool;
        union ixgbe_adv_tx_desc *tx_desc;
        struct ixgbe_tx_buffer *tx_bi;
        u32 xsk_frames = 0;

        tx_bi = &tx_ring->tx_buffer_info[ntc];
        tx_desc = IXGBE_TX_DESC(tx_ring, ntc);

        while (ntc != ntu) {
                if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
                        break;

                total_bytes += tx_bi->bytecount;
                total_packets += tx_bi->gso_segs;

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

                tx_bi->xdpf = NULL;

                tx_bi++;
                tx_desc++;
                ntc++;
                if (unlikely(ntc == tx_ring->count)) {
                        ntc = 0;
                        tx_bi = tx_ring->tx_buffer_info;
                        tx_desc = IXGBE_TX_DESC(tx_ring, 0);
                }

                /* issue prefetch for next Tx descriptor */
                prefetch(tx_desc);
        }

        tx_ring->next_to_clean = ntc;
        ixgbe_update_tx_ring_stats(tx_ring, q_vector, total_packets,
                                   total_bytes);

        if (xsk_frames)
                xsk_tx_completed(pool, xsk_frames);

        if (xsk_uses_need_wakeup(pool))
                xsk_set_tx_need_wakeup(pool);

        return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
}

int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
{
        struct ixgbe_adapter *adapter = ixgbe_from_netdev(dev);
        struct ixgbe_ring *ring;

        if (test_bit(__IXGBE_DOWN, &adapter->state))
                return -ENETDOWN;

        if (!READ_ONCE(adapter->xdp_prog))
                return -EINVAL;

        if (qid >= adapter->num_xdp_queues)
                return -EINVAL;

        ring = adapter->xdp_ring[qid];

        if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
                return -ENETDOWN;

        if (!ring->xsk_pool)
                return -EINVAL;

        if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
                u64 eics = BIT_ULL(ring->q_vector->v_idx);

                ixgbe_irq_rearm_queues(adapter, eics);
        }

        return 0;
}

void ixgbe_xsk_clean_tx_ring(struct ixgbe_ring *tx_ring)
{
        u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
        struct xsk_buff_pool *pool = tx_ring->xsk_pool;
        struct ixgbe_tx_buffer *tx_bi;
        u32 xsk_frames = 0;

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

                if (tx_bi->xdpf)
                        ixgbe_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_tx_completed(pool, xsk_frames);
}