On Mon, Oct 07, 2024 at 02:31:26PM +0200, Kurt Kanzenbach wrote:
> From: Sriram Yagnaraman <sriram.yagnara...@est.tech>
> 
> Add support for AF_XDP zero-copy receive path.
> 
> When AF_XDP zero-copy is enabled, the rx buffers are allocated from the
> xsk buff pool using igb_alloc_rx_buffers_zc().
> 
> Use xsk_pool_get_rx_frame_size() to set SRRCTL rx buf size when zero-copy
> is enabled.
> 
> Signed-off-by: Sriram Yagnaraman <sriram.yagnara...@est.tech>
> [Kurt: Port to v6.10 and provide napi_id for xdp_rxq_info_reg(),
>        RCT, remove NETDEV_XDP_ACT_XSK_ZEROCOPY, update NTC handling,
>        move stats update and xdp finalize to common functions,
>        READ_ONCE() xsk_pool, likelyfy for XDP_REDIRECT case]
> Signed-off-by: Kurt Kanzenbach <k...@linutronix.de>

Hi Kurt,

Sorry but still have comments :< see below.

> ---
>  drivers/net/ethernet/intel/igb/igb.h      |   8 +
>  drivers/net/ethernet/intel/igb/igb_main.c | 132 +++++++++----
>  drivers/net/ethernet/intel/igb/igb_xsk.c  | 296 
> +++++++++++++++++++++++++++++-
>  3 files changed, 398 insertions(+), 38 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb.h 
> b/drivers/net/ethernet/intel/igb/igb.h
> index c30d6f9708f8..ea3977b313fc 100644
> --- a/drivers/net/ethernet/intel/igb/igb.h
> +++ b/drivers/net/ethernet/intel/igb/igb.h
> @@ -88,6 +88,7 @@ struct igb_adapter;
>  #define IGB_XDP_CONSUMED     BIT(0)
>  #define IGB_XDP_TX           BIT(1)
>  #define IGB_XDP_REDIR                BIT(2)
> +#define IGB_XDP_EXIT         BIT(3)
>  
>  struct vf_data_storage {
>       unsigned char vf_mac_addresses[ETH_ALEN];
> @@ -740,6 +741,9 @@ void igb_clean_tx_ring(struct igb_ring *tx_ring);
>  void igb_clean_rx_ring(struct igb_ring *rx_ring);
>  void igb_configure_tx_ring(struct igb_adapter *, struct igb_ring *);
>  void igb_configure_rx_ring(struct igb_adapter *, struct igb_ring *);
> +void igb_finalize_xdp(struct igb_adapter *adapter, unsigned int status);
> +void igb_update_rx_stats(struct igb_q_vector *q_vector, unsigned int packets,
> +                      unsigned int bytes);
>  void igb_setup_tctl(struct igb_adapter *);
>  void igb_setup_rctl(struct igb_adapter *);
>  void igb_setup_srrctl(struct igb_adapter *, struct igb_ring *);
> @@ -850,6 +854,10 @@ struct xsk_buff_pool *igb_xsk_pool(struct igb_adapter 
> *adapter,
>  int igb_xsk_pool_setup(struct igb_adapter *adapter,
>                      struct xsk_buff_pool *pool,
>                      u16 qid);
> +bool igb_alloc_rx_buffers_zc(struct igb_ring *rx_ring, u16 count);
> +void igb_clean_rx_ring_zc(struct igb_ring *rx_ring);
> +int igb_clean_rx_irq_zc(struct igb_q_vector *q_vector,
> +                     struct xsk_buff_pool *xsk_pool, const int budget);
>  int igb_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags);
>  
>  #endif /* _IGB_H_ */
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c 
> b/drivers/net/ethernet/intel/igb/igb_main.c
> index bdba5c5861be..449ee794b3c9 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -472,12 +472,17 @@ static void igb_dump(struct igb_adapter *adapter)
>  
>               for (i = 0; i < rx_ring->count; i++) {
>                       const char *next_desc;
> -                     struct igb_rx_buffer *buffer_info;
> -                     buffer_info = &rx_ring->rx_buffer_info[i];
> +                     dma_addr_t dma = (dma_addr_t)0;
> +                     struct igb_rx_buffer *buffer_info = NULL;
>                       rx_desc = IGB_RX_DESC(rx_ring, i);
>                       u0 = (struct my_u0 *)rx_desc;
>                       staterr = le32_to_cpu(rx_desc->wb.upper.status_error);
>  
> +                     if (!rx_ring->xsk_pool) {
> +                             buffer_info = &rx_ring->rx_buffer_info[i];
> +                             dma = buffer_info->dma;
> +                     }
> +
>                       if (i == rx_ring->next_to_use)
>                               next_desc = " NTU";
>                       else if (i == rx_ring->next_to_clean)
> @@ -497,11 +502,11 @@ static void igb_dump(struct igb_adapter *adapter)
>                                       "R  ", i,
>                                       le64_to_cpu(u0->a),
>                                       le64_to_cpu(u0->b),
> -                                     (u64)buffer_info->dma,
> +                                     (u64)dma,
>                                       next_desc);
>  
>                               if (netif_msg_pktdata(adapter) &&
> -                                 buffer_info->dma && buffer_info->page) {
> +                                 buffer_info && dma && buffer_info->page) {
>                                       print_hex_dump(KERN_INFO, "",
>                                         DUMP_PREFIX_ADDRESS,
>                                         16, 1,
> @@ -1983,7 +1988,10 @@ static void igb_configure(struct igb_adapter *adapter)
>        */
>       for (i = 0; i < adapter->num_rx_queues; i++) {
>               struct igb_ring *ring = adapter->rx_ring[i];
> -             igb_alloc_rx_buffers(ring, igb_desc_unused(ring));
> +             if (ring->xsk_pool)
> +                     igb_alloc_rx_buffers_zc(ring, igb_desc_unused(ring));
> +             else
> +                     igb_alloc_rx_buffers(ring, igb_desc_unused(ring));
>       }
>  }
>  
> @@ -4405,7 +4413,8 @@ int igb_setup_rx_resources(struct igb_ring *rx_ring)
>       if (xdp_rxq_info_is_reg(&rx_ring->xdp_rxq))
>               xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
>       res = xdp_rxq_info_reg(&rx_ring->xdp_rxq, rx_ring->netdev,
> -                            rx_ring->queue_index, 0);
> +                            rx_ring->queue_index,
> +                            rx_ring->q_vector->napi.napi_id);
>       if (res < 0) {
>               dev_err(dev, "Failed to register xdp_rxq index %u\n",
>                       rx_ring->queue_index);
> @@ -4701,12 +4710,17 @@ void igb_setup_srrctl(struct igb_adapter *adapter, 
> struct igb_ring *ring)
>       struct e1000_hw *hw = &adapter->hw;
>       int reg_idx = ring->reg_idx;
>       u32 srrctl = 0;
> +     u32 buf_size;
>  
> -     srrctl = IGB_RX_HDR_LEN << E1000_SRRCTL_BSIZEHDRSIZE_SHIFT;
> -     if (ring_uses_large_buffer(ring))
> -             srrctl |= IGB_RXBUFFER_3072 >> E1000_SRRCTL_BSIZEPKT_SHIFT;
> +     if (ring->xsk_pool)
> +             buf_size = xsk_pool_get_rx_frame_size(ring->xsk_pool);
> +     else if (ring_uses_large_buffer(ring))
> +             buf_size = IGB_RXBUFFER_3072;
>       else
> -             srrctl |= IGB_RXBUFFER_2048 >> E1000_SRRCTL_BSIZEPKT_SHIFT;
> +             buf_size = IGB_RXBUFFER_2048;
> +
> +     srrctl = IGB_RX_HDR_LEN << E1000_SRRCTL_BSIZEHDRSIZE_SHIFT;
> +     srrctl |= buf_size >> E1000_SRRCTL_BSIZEPKT_SHIFT;
>       srrctl |= E1000_SRRCTL_DESCTYPE_ADV_ONEBUF;
>       if (hw->mac.type >= e1000_82580)
>               srrctl |= E1000_SRRCTL_TIMESTAMP;
> @@ -4738,9 +4752,17 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
>       u32 rxdctl = 0;
>  
>       xdp_rxq_info_unreg_mem_model(&ring->xdp_rxq);
> -     WARN_ON(xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
> -                                        MEM_TYPE_PAGE_SHARED, NULL));
>       WRITE_ONCE(ring->xsk_pool, igb_xsk_pool(adapter, ring));
> +     if (ring->xsk_pool) {
> +             WARN_ON(xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
> +                                                MEM_TYPE_XSK_BUFF_POOL,
> +                                                NULL));
> +             xsk_pool_set_rxq_info(ring->xsk_pool, &ring->xdp_rxq);
> +     } else {
> +             WARN_ON(xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
> +                                                MEM_TYPE_PAGE_SHARED,
> +                                                NULL));
> +     }
>  
>       /* disable the queue */
>       wr32(E1000_RXDCTL(reg_idx), 0);
> @@ -4767,9 +4789,12 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
>       rxdctl |= IGB_RX_HTHRESH << 8;
>       rxdctl |= IGB_RX_WTHRESH << 16;
>  
> -     /* initialize rx_buffer_info */
> -     memset(ring->rx_buffer_info, 0,
> -            sizeof(struct igb_rx_buffer) * ring->count);
> +     if (ring->xsk_pool)
> +             memset(ring->rx_buffer_info_zc, 0,
> +                    sizeof(*ring->rx_buffer_info_zc) * ring->count);
> +     else
> +             memset(ring->rx_buffer_info, 0,
> +                    sizeof(*ring->rx_buffer_info) * ring->count);
>  
>       /* initialize Rx descriptor 0 */
>       rx_desc = IGB_RX_DESC(ring, 0);
> @@ -4957,8 +4982,13 @@ void igb_free_rx_resources(struct igb_ring *rx_ring)
>  
>       rx_ring->xdp_prog = NULL;
>       xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
> -     vfree(rx_ring->rx_buffer_info);
> -     rx_ring->rx_buffer_info = NULL;
> +     if (rx_ring->xsk_pool) {
> +             vfree(rx_ring->rx_buffer_info_zc);
> +             rx_ring->rx_buffer_info_zc = NULL;
> +     } else {
> +             vfree(rx_ring->rx_buffer_info);
> +             rx_ring->rx_buffer_info = NULL;
> +     }
>  
>       /* if not set, then don't free */
>       if (!rx_ring->desc)
> @@ -4996,6 +5026,11 @@ void igb_clean_rx_ring(struct igb_ring *rx_ring)
>       dev_kfree_skb(rx_ring->skb);
>       rx_ring->skb = NULL;
>  
> +     if (rx_ring->xsk_pool) {
> +             igb_clean_rx_ring_zc(rx_ring);
> +             goto skip_for_xsk;
> +     }
> +
>       /* Free all the Rx ring sk_buffs */
>       while (i != rx_ring->next_to_alloc) {
>               struct igb_rx_buffer *buffer_info = &rx_ring->rx_buffer_info[i];
> @@ -5023,6 +5058,7 @@ void igb_clean_rx_ring(struct igb_ring *rx_ring)
>                       i = 0;
>       }
>  
> +skip_for_xsk:
>       rx_ring->next_to_alloc = 0;
>       rx_ring->next_to_clean = 0;
>       rx_ring->next_to_use = 0;
> @@ -8177,6 +8213,7 @@ static int igb_poll(struct napi_struct *napi, int 
> budget)
>       struct igb_q_vector *q_vector = container_of(napi,
>                                                    struct igb_q_vector,
>                                                    napi);
> +     struct xsk_buff_pool *xsk_pool;
>       bool clean_complete = true;
>       int work_done = 0;
>  
> @@ -8188,7 +8225,12 @@ static int igb_poll(struct napi_struct *napi, int 
> budget)
>               clean_complete = igb_clean_tx_irq(q_vector, budget);
>  
>       if (q_vector->rx.ring) {
> -             int cleaned = igb_clean_rx_irq(q_vector, budget);
> +             int cleaned;
> +
> +             xsk_pool = READ_ONCE(q_vector->rx.ring->xsk_pool);
> +             cleaned = xsk_pool ?
> +                     igb_clean_rx_irq_zc(q_vector, xsk_pool, budget) :
> +                     igb_clean_rx_irq(q_vector, budget);
>  
>               work_done += cleaned;
>               if (cleaned >= budget)
> @@ -8852,6 +8894,38 @@ static void igb_put_rx_buffer(struct igb_ring *rx_ring,
>       rx_buffer->page = NULL;
>  }
>  
> +void igb_finalize_xdp(struct igb_adapter *adapter, unsigned int status)
> +{
> +     int cpu = smp_processor_id();
> +     struct netdev_queue *nq;
> +
> +     if (status & IGB_XDP_REDIR)
> +             xdp_do_flush();
> +
> +     if (status & IGB_XDP_TX) {
> +             struct igb_ring *tx_ring = igb_xdp_tx_queue_mapping(adapter);
> +
> +             nq = txring_txq(tx_ring);
> +             __netif_tx_lock(nq, cpu);
> +             igb_xdp_ring_update_tail(tx_ring);
> +             __netif_tx_unlock(nq);
> +     }
> +}
> +
> +void igb_update_rx_stats(struct igb_q_vector *q_vector, unsigned int packets,
> +                      unsigned int bytes)
> +{
> +     struct igb_ring *ring = q_vector->rx.ring;
> +
> +     u64_stats_update_begin(&ring->rx_syncp);
> +     ring->rx_stats.packets += packets;
> +     ring->rx_stats.bytes += bytes;
> +     u64_stats_update_end(&ring->rx_syncp);
> +
> +     q_vector->rx.total_packets += packets;
> +     q_vector->rx.total_bytes += bytes;
> +}
> +
>  static int igb_clean_rx_irq(struct igb_q_vector *q_vector, const int budget)
>  {
>       unsigned int total_bytes = 0, total_packets = 0;
> @@ -8859,9 +8933,7 @@ static int igb_clean_rx_irq(struct igb_q_vector 
> *q_vector, const int budget)
>       struct igb_ring *rx_ring = q_vector->rx.ring;
>       u16 cleaned_count = igb_desc_unused(rx_ring);
>       struct sk_buff *skb = rx_ring->skb;
> -     int cpu = smp_processor_id();
>       unsigned int xdp_xmit = 0;
> -     struct netdev_queue *nq;
>       struct xdp_buff xdp;
>       u32 frame_sz = 0;
>       int rx_buf_pgcnt;
> @@ -8983,24 +9055,10 @@ static int igb_clean_rx_irq(struct igb_q_vector 
> *q_vector, const int budget)
>       /* place incomplete frames back on ring for completion */
>       rx_ring->skb = skb;
>  
> -     if (xdp_xmit & IGB_XDP_REDIR)
> -             xdp_do_flush();
> -
> -     if (xdp_xmit & IGB_XDP_TX) {
> -             struct igb_ring *tx_ring = igb_xdp_tx_queue_mapping(adapter);
> -
> -             nq = txring_txq(tx_ring);
> -             __netif_tx_lock(nq, cpu);
> -             igb_xdp_ring_update_tail(tx_ring);
> -             __netif_tx_unlock(nq);
> -     }
> +     if (xdp_xmit)
> +             igb_finalize_xdp(adapter, xdp_xmit);

Nit: given you would be sending next revision, IMHO this is a candidate
for a separate patch. Not a big deal but would reduce the noise in this
one.

>  
> -     u64_stats_update_begin(&rx_ring->rx_syncp);
> -     rx_ring->rx_stats.packets += total_packets;
> -     rx_ring->rx_stats.bytes += total_bytes;
> -     u64_stats_update_end(&rx_ring->rx_syncp);
> -     q_vector->rx.total_packets += total_packets;
> -     q_vector->rx.total_bytes += total_bytes;
> +     igb_update_rx_stats(q_vector, total_packets, total_bytes);

This also.

>  
>       if (cleaned_count)
>               igb_alloc_rx_buffers(rx_ring, cleaned_count);
> diff --git a/drivers/net/ethernet/intel/igb/igb_xsk.c 
> b/drivers/net/ethernet/intel/igb/igb_xsk.c
> index 7b632be3e7e3..9fd094a799fa 100644
> --- a/drivers/net/ethernet/intel/igb/igb_xsk.c
> +++ b/drivers/net/ethernet/intel/igb/igb_xsk.c
> @@ -70,7 +70,10 @@ static void igb_txrx_ring_enable(struct igb_adapter 
> *adapter, u16 qid)
>        * at least 1 descriptor unused to make sure
>        * next_to_use != next_to_clean
>        */
> -     igb_alloc_rx_buffers(rx_ring, igb_desc_unused(rx_ring));
> +     if (rx_ring->xsk_pool)
> +             igb_alloc_rx_buffers_zc(rx_ring, igb_desc_unused(rx_ring));
> +     else
> +             igb_alloc_rx_buffers(rx_ring, igb_desc_unused(rx_ring));
>  
>       /* Rx/Tx share the same napi context. */
>       napi_enable(&rx_ring->q_vector->napi);
> @@ -169,6 +172,297 @@ int igb_xsk_pool_setup(struct igb_adapter *adapter,
>               igb_xsk_pool_disable(adapter, qid);
>  }
>  
> +static u16 igb_fill_rx_descs(struct xsk_buff_pool *pool, struct xdp_buff 
> **xdp,
> +                          union e1000_adv_rx_desc *rx_desc, u16 count)
> +{
> +     dma_addr_t dma;
> +     u16 buffs;
> +     int i;
> +
> +     /* nothing to do */
> +     if (!count)
> +             return 0;
> +
> +     buffs = xsk_buff_alloc_batch(pool, xdp, count);
> +     for (i = 0; i < buffs; i++) {
> +             dma = xsk_buff_xdp_get_dma(*xdp);
> +             rx_desc->read.pkt_addr = cpu_to_le64(dma);
> +             rx_desc->wb.upper.length = 0;
> +
> +             rx_desc++;
> +             xdp++;
> +     }
> +
> +     return buffs;
> +}
> +
> +bool igb_alloc_rx_buffers_zc(struct igb_ring *rx_ring, u16 count)
> +{
> +     u32 nb_buffs_extra = 0, nb_buffs = 0;
> +     union e1000_adv_rx_desc *rx_desc;
> +     u16 ntu = rx_ring->next_to_use;
> +     u16 total_count = count;
> +     struct xdp_buff **xdp;
> +
> +     rx_desc = IGB_RX_DESC(rx_ring, ntu);
> +     xdp = &rx_ring->rx_buffer_info_zc[ntu];
> +
> +     if (ntu + count >= rx_ring->count) {
> +             nb_buffs_extra = igb_fill_rx_descs(rx_ring->xsk_pool, xdp,
> +                                                rx_desc,
> +                                                rx_ring->count - ntu);

Ehh wanted to ack this finally, but I believe that here you need to work
on the pool pointer that was READ_ONCE() in igb_poll() in hot path and
in igb_configure() pass rx_ring->xsk_pool as an argument.

I did the same scheme for ice FWIW.

> +             if (nb_buffs_extra != rx_ring->count - ntu) {
> +                     ntu += nb_buffs_extra;
> +                     goto exit;
> +             }
> +             rx_desc = IGB_RX_DESC(rx_ring, 0);
> +             xdp = rx_ring->rx_buffer_info_zc;
> +             ntu = 0;
> +             count -= nb_buffs_extra;
> +     }
> +
> +     nb_buffs = igb_fill_rx_descs(rx_ring->xsk_pool, xdp, rx_desc, count);
> +     ntu += nb_buffs;
> +     if (ntu == rx_ring->count)
> +             ntu = 0;
> +
> +     /* clear the length for the next_to_use descriptor */
> +     rx_desc = IGB_RX_DESC(rx_ring, ntu);
> +     rx_desc->wb.upper.length = 0;
> +
> +exit:
> +     if (rx_ring->next_to_use != ntu) {
> +             rx_ring->next_to_use = ntu;
> +
> +             /* 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(ntu, rx_ring->tail);
> +     }
> +
> +     return total_count == (nb_buffs + nb_buffs_extra);
> +}
> +
> +void igb_clean_rx_ring_zc(struct igb_ring *rx_ring)
> +{
> +     u16 ntc = rx_ring->next_to_clean;
> +     u16 ntu = rx_ring->next_to_use;
> +
> +     while (ntc != ntu) {
> +             struct xdp_buff *xdp = rx_ring->rx_buffer_info_zc[ntc];
> +
> +             xsk_buff_free(xdp);
> +             ntc++;
> +             if (ntc >= rx_ring->count)
> +                     ntc = 0;
> +     }
> +}
> +
> +static struct sk_buff *igb_construct_skb_zc(struct igb_ring *rx_ring,
> +                                         struct xdp_buff *xdp,
> +                                         ktime_t timestamp)
> +{
> +     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;
> +
> +     if (timestamp)
> +             skb_hwtstamps(skb)->hwtstamp = timestamp;
> +
> +     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 struct sk_buff *igb_run_xdp_zc(struct igb_adapter *adapter,
> +                                   struct igb_ring *rx_ring,
> +                                   struct xdp_buff *xdp,
> +                                   struct xsk_buff_pool *xsk_pool,
> +                                   struct bpf_prog *xdp_prog)
> +{
> +     int err, result = IGB_XDP_PASS;
> +     u32 act;
> +
> +     prefetchw(xdp->data_hard_start); /* xdp_frame write */
> +
> +     act = bpf_prog_run_xdp(xdp_prog, xdp);
> +
> +     if (likely(act == XDP_REDIRECT)) {
> +             err = xdp_do_redirect(adapter->netdev, xdp, xdp_prog);
> +             if (!err) {
> +                     result = IGB_XDP_REDIR;
> +                     goto xdp_out;
> +             }
> +
> +             if (xsk_uses_need_wakeup(xsk_pool) &&
> +                 err == -ENOBUFS)
> +                     result = IGB_XDP_EXIT;
> +             else
> +                     result = IGB_XDP_CONSUMED;
> +             goto out_failure;
> +     }
> +
> +     switch (act) {
> +     case XDP_PASS:
> +             break;
> +     case XDP_TX:
> +             result = igb_xdp_xmit_back(adapter, xdp);
> +             if (result == IGB_XDP_CONSUMED)
> +                     goto out_failure;
> +             break;
> +     default:
> +             bpf_warn_invalid_xdp_action(adapter->netdev, xdp_prog, act);
> +             fallthrough;
> +     case XDP_ABORTED:
> +out_failure:
> +             trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
> +             fallthrough;
> +     case XDP_DROP:
> +             result = IGB_XDP_CONSUMED;
> +             break;
> +     }
> +xdp_out:
> +     return ERR_PTR(-result);
> +}
> +
> +int igb_clean_rx_irq_zc(struct igb_q_vector *q_vector,
> +                     struct xsk_buff_pool *xsk_pool, const int budget)
> +{
> +     struct igb_adapter *adapter = q_vector->adapter;
> +     unsigned int total_bytes = 0, total_packets = 0;
> +     struct igb_ring *rx_ring = q_vector->rx.ring;
> +     u32 ntc = rx_ring->next_to_clean;
> +     struct bpf_prog *xdp_prog;
> +     unsigned int xdp_xmit = 0;
> +     bool failure = false;
> +     u16 entries_to_alloc;
> +     struct sk_buff *skb;
> +
> +     /* xdp_prog cannot be NULL in the ZC path */
> +     xdp_prog = READ_ONCE(rx_ring->xdp_prog);
> +
> +     while (likely(total_packets < budget)) {
> +             union e1000_adv_rx_desc *rx_desc;
> +             ktime_t timestamp = 0;
> +             struct xdp_buff *xdp;
> +             unsigned int size;
> +
> +             rx_desc = IGB_RX_DESC(rx_ring, ntc);
> +             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();
> +
> +             xdp = rx_ring->rx_buffer_info_zc[ntc];
> +             xsk_buff_set_size(xdp, size);
> +             xsk_buff_dma_sync_for_cpu(xdp);
> +
> +             /* pull rx packet timestamp if available and valid */
> +             if (igb_test_staterr(rx_desc, E1000_RXDADV_STAT_TSIP)) {
> +                     int ts_hdr_len;
> +
> +                     ts_hdr_len = igb_ptp_rx_pktstamp(rx_ring->q_vector,
> +                                                      xdp->data,
> +                                                      &timestamp);
> +
> +                     xdp->data += ts_hdr_len;
> +                     xdp->data_meta += ts_hdr_len;
> +                     size -= ts_hdr_len;
> +             }
> +
> +             skb = igb_run_xdp_zc(adapter, rx_ring, xdp, xsk_pool, xdp_prog);
> +
> +             if (IS_ERR(skb)) {
> +                     unsigned int xdp_res = -PTR_ERR(skb);
> +
> +                     if (likely(xdp_res & (IGB_XDP_TX | IGB_XDP_REDIR))) {
> +                             xdp_xmit |= xdp_res;
> +                     } else if (xdp_res == IGB_XDP_EXIT) {
> +                             failure = true;
> +                             break;
> +                     } else if (xdp_res == IGB_XDP_CONSUMED) {
> +                             xsk_buff_free(xdp);
> +                     }
> +
> +                     total_packets++;
> +                     total_bytes += size;
> +                     ntc++;
> +                     if (ntc == rx_ring->count)
> +                             ntc = 0;
> +                     continue;
> +             }
> +
> +             skb = igb_construct_skb_zc(rx_ring, xdp, timestamp);
> +
> +             /* exit if we failed to retrieve a buffer */
> +             if (!skb) {
> +                     rx_ring->rx_stats.alloc_failed++;
> +                     break;
> +             }
> +
> +             xsk_buff_free(xdp);
> +             ntc++;
> +             if (ntc == rx_ring->count)
> +                     ntc = 0;
> +
> +             if (eth_skb_pad(skb))
> +                     continue;
> +
> +             /* probably a little skewed due to removing CRC */
> +             total_bytes += skb->len;
> +
> +             /* populate checksum, timestamp, VLAN, and protocol */
> +             igb_process_skb_fields(rx_ring, rx_desc, skb);
> +
> +             napi_gro_receive(&q_vector->napi, skb);
> +
> +             /* update budget accounting */
> +             total_packets++;
> +     }
> +
> +     rx_ring->next_to_clean = ntc;
> +
> +     if (xdp_xmit)
> +             igb_finalize_xdp(adapter, xdp_xmit);
> +
> +     igb_update_rx_stats(q_vector, total_packets, total_bytes);
> +
> +     entries_to_alloc = igb_desc_unused(rx_ring);
> +     if (entries_to_alloc >= IGB_RX_BUFFER_WRITE)
> +             failure |= !igb_alloc_rx_buffers_zc(rx_ring, entries_to_alloc);
> +
> +     if (xsk_uses_need_wakeup(xsk_pool)) {
> +             if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
> +                     xsk_set_rx_need_wakeup(xsk_pool);
> +             else
> +                     xsk_clear_rx_need_wakeup(xsk_pool);
> +
> +             return (int)total_packets;
> +     }
> +     return failure ? budget : (int)total_packets;
> +}
> +
>  int igb_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
>  {
>       struct igb_adapter *adapter = netdev_priv(dev);
> 
> -- 
> 2.39.5
> 
> 

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