On Fri, Oct 11, 2024 at 11:01:03AM +0200, Kurt Kanzenbach wrote:
> From: Sriram Yagnaraman <sriram.yagnaraman@xxxxxxxx>
>
> 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.yagnaraman@xxxxxxxx>
> [Kurt: Port to v6.12 and provide napi_id for xdp_rxq_info_reg(),
> RCT, remove NETDEV_XDP_ACT_XSK_ZEROCOPY, update NTC handling,
> READ_ONCE() xsk_pool, likelyfy for XDP_REDIRECT case]
> Signed-off-by: Kurt Kanzenbach <kurt@xxxxxxxxxxxxx>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
> ---
> drivers/net/ethernet/intel/igb/igb.h | 6 +
> drivers/net/ethernet/intel/igb/igb_main.c | 79 ++++++--
> drivers/net/ethernet/intel/igb/igb_xsk.c | 298 +++++++++++++++++++++++++++++-
> 3 files changed, 364 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
> index 1e65b41a48d8..e4a85867aa18 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];
> @@ -853,6 +854,11 @@ 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,
> + struct xsk_buff_pool *xsk_pool, 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 4d3aed6cd848..711b60cab594 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 +1988,11 @@ 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, ring->xsk_pool,
> + igb_desc_unused(ring));
> + else
> + igb_alloc_rx_buffers(ring, igb_desc_unused(ring));
> }
> }
>
> @@ -4405,7 +4414,8 @@ 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 +4711,17 @@ 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 +4753,17 @@ 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 +4790,12 @@ 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 +4983,13 @@ 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 +5027,11 @@ 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 +5059,7 @@ 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 +8214,7 @@ 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 +8226,12 @@ 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)
> diff --git a/drivers/net/ethernet/intel/igb/igb_xsk.c b/drivers/net/ethernet/intel/igb/igb_xsk.c
> index 7b632be3e7e3..22d234db0fab 100644
> --- a/drivers/net/ethernet/intel/igb/igb_xsk.c
> +++ b/drivers/net/ethernet/intel/igb/igb_xsk.c
> @@ -70,7 +70,11 @@ 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, rx_ring->xsk_pool,
> + 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 +173,298 @@ 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,
> + struct xsk_buff_pool *xsk_pool, 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(xsk_pool, xdp, rx_desc,
> + rx_ring->count - ntu);
> + 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(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,
> + ×tamp);
> +
> + 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, xsk_pool,
> + 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
>
