[Intel-wired-lan] [PATCH net-next] igc: add xdp frags support to ndo_xdp_xmit
Lorenzo Bianconi
lorenzo at kernel.org
Wed Jul 20 07:57:17 UTC 2022
> On 7/6/2022 10:54, Lorenzo Bianconi wrote:
> > Add the capability to map non-linear xdp frames in XDP_TX and
> > ndo_xdp_xmit callback.
> >
> > Signed-off-by: Lorenzo Bianconi <lorenzo at kernel.org>
> > ---
> > Please note this patch is only compiled tested since I do not have
> > access to a igc NIC
> > ---
> > drivers/net/ethernet/intel/igc/igc_main.c | 128 ++++++++++++++--------
> > 1 file changed, 83 insertions(+), 45 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> > index ae17af44fe02..71657d03da03 100644
> > --- a/drivers/net/ethernet/intel/igc/igc_main.c
> > +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> > @@ -2129,65 +2129,102 @@ static bool igc_alloc_rx_buffers_zc(struct igc_ring *ring, u16 count)
> > return ok;
> > }
> > -static int igc_xdp_init_tx_buffer(struct igc_tx_buffer *buffer,
> > - struct xdp_frame *xdpf,
> > - struct igc_ring *ring)
> > -{
> > - dma_addr_t dma;
> > -
> > - dma = dma_map_single(ring->dev, xdpf->data, xdpf->len, DMA_TO_DEVICE);
> > - if (dma_mapping_error(ring->dev, dma)) {
> > - netdev_err_once(ring->netdev, "Failed to map DMA for TX\n");
> > - return -ENOMEM;
> > - }
> > -
> > - buffer->type = IGC_TX_BUFFER_TYPE_XDP;
> > - buffer->xdpf = xdpf;
> > - buffer->protocol = 0;
> > - buffer->bytecount = xdpf->len;
> > - buffer->gso_segs = 1;
> > - buffer->time_stamp = jiffies;
> > - dma_unmap_len_set(buffer, len, xdpf->len);
> > - dma_unmap_addr_set(buffer, dma, dma);
> > - return 0;
> > -}
> > -
> > /* This function requires __netif_tx_lock is held by the caller. */
> > static int igc_xdp_init_tx_descriptor(struct igc_ring *ring,
> > struct xdp_frame *xdpf)
> > {
> > - struct igc_tx_buffer *buffer;
> > - union igc_adv_tx_desc *desc;
> > - u32 cmd_type, olinfo_status;
> > - int err;
> > + struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf);
> > + u8 nr_frags = unlikely(xdp_frame_has_frags(xdpf)) ? sinfo->nr_frags : 0;
> > + u16 count, index = ring->next_to_use;
> > + struct igc_tx_buffer *head = &ring->tx_buffer_info[index];
> > + struct igc_tx_buffer *buffer = head;
> > + union igc_adv_tx_desc *desc = IGC_TX_DESC(ring, index);
> > + u32 olinfo_status, len = xdpf->len, cmd_type;
> > + void *data = xdpf->data;
> > + u16 i;
> > - if (!igc_desc_unused(ring))
> > - return -EBUSY;
> > + count = TXD_USE_COUNT(len);
> > + for (i = 0; i < nr_frags; i++)
> > + count += TXD_USE_COUNT(skb_frag_size(&sinfo->frags[i]));
> > - buffer = &ring->tx_buffer_info[ring->next_to_use];
> > - err = igc_xdp_init_tx_buffer(buffer, xdpf, ring);
> > - if (err)
> > - return err;
> > + if (igc_maybe_stop_tx(ring, count + 3)) {
> > + /* this is a hard error */
> > + return -EBUSY;
> > + }
> > - cmd_type = IGC_ADVTXD_DTYP_DATA | IGC_ADVTXD_DCMD_DEXT |
> > - IGC_ADVTXD_DCMD_IFCS | IGC_TXD_DCMD |
> > - buffer->bytecount;
> > - olinfo_status = buffer->bytecount << IGC_ADVTXD_PAYLEN_SHIFT;
> > + i = 0;
> > + head->bytecount = xdp_get_frame_len(xdpf);
> > + head->type = IGC_TX_BUFFER_TYPE_XDP;
> > + head->gso_segs = 1;
> > + head->xdpf = xdpf;
> > - desc = IGC_TX_DESC(ring, ring->next_to_use);
> > - desc->read.cmd_type_len = cpu_to_le32(cmd_type);
> > + olinfo_status = head->bytecount << IGC_ADVTXD_PAYLEN_SHIFT;
> > desc->read.olinfo_status = cpu_to_le32(olinfo_status);
> > - desc->read.buffer_addr = cpu_to_le64(dma_unmap_addr(buffer, dma));
> > - netdev_tx_sent_queue(txring_txq(ring), buffer->bytecount);
> > + for (;;) {
> > + dma_addr_t dma;
> > - buffer->next_to_watch = desc;
> > + dma = dma_map_single(ring->dev, data, len, DMA_TO_DEVICE);
> > + if (dma_mapping_error(ring->dev, dma)) {
> > + netdev_err_once(ring->netdev,
> > + "Failed to map DMA for TX\n");
> > + goto unmap;
> > + }
> > - ring->next_to_use++;
> > - if (ring->next_to_use == ring->count)
> > - ring->next_to_use = 0;
> > + dma_unmap_len_set(buffer, len, len);
> > + dma_unmap_addr_set(buffer, dma, dma);
> > +
> > + cmd_type = IGC_ADVTXD_DTYP_DATA | IGC_ADVTXD_DCMD_DEXT |
> > + IGC_ADVTXD_DCMD_IFCS | len;
> > +
> > + desc->read.cmd_type_len = cpu_to_le32(cmd_type);
> > + desc->read.buffer_addr = cpu_to_le64(dma);
> > +
> > + buffer->protocol = 0;
> > +
> > + if (++index == ring->count)
> > + index = 0;
> > +
> > + if (i == nr_frags)
> > + break;
> > +
> > + buffer = &ring->tx_buffer_info[index];
> > + desc = IGC_TX_DESC(ring, index);
> > + desc->read.olinfo_status = 0;
> > +
> > + data = skb_frag_address(&sinfo->frags[i]);
> > + len = skb_frag_size(&sinfo->frags[i]);
> > + i++;
> > + }
> > + desc->read.cmd_type_len |= cpu_to_le32(IGC_TXD_DCMD);
> > +
> > + netdev_tx_sent_queue(txring_txq(ring), head->bytecount);
> > + /* set the timestamp */
> > + head->time_stamp = jiffies;
> > + /* set next_to_watch value indicating a packet is present */
> > + head->next_to_watch = desc;
> > + ring->next_to_use = index;
> > return 0;
> > +
> > +unmap:
> > + for (;;) {
> > + buffer = &ring->tx_buffer_info[index];
> > + if (dma_unmap_len(buffer, len))
> > + dma_unmap_page(ring->dev,
> > + dma_unmap_addr(buffer, dma),
> > + dma_unmap_len(buffer, len),
> > + DMA_TO_DEVICE);
> > + dma_unmap_len_set(buffer, len, 0);
> > + if (buffer == head)
> > + break;
> > +
> > + if (!index)
> > + index += ring->count;
> > + index--;
> > + }
> > +
> > + return -ENOMEM;
> > }
> > static struct igc_ring *igc_xdp_get_tx_ring(struct igc_adapter *adapter,
> > @@ -2369,6 +2406,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
> > xdp_prepare_buff(&xdp, pktbuf - igc_rx_offset(rx_ring),
> > igc_rx_offset(rx_ring) + pkt_offset,
> > size, true);
> > + xdp_buff_clear_frags_flag(&xdp);
> > skb = igc_xdp_run_prog(adapter, &xdp);
> > }
> Hello Lorenzo,
> Could you provide test hints (step by step) on how to test it?
> Sasha
Hi Sasha,
I guess you can just run the script I shared, does it work?
Regards,
Lorenzo
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