On Thu, Apr 08, 2021 at 02:50:57PM +0200, Lorenzo Bianconi wrote:
> Introduce the capability to map non-linear xdp buffer running
> mvneta_xdp_submit_frame() for XDP_TX and XDP_REDIRECT
>
> Signed-off-by: Lorenzo Bianconi <lore...@kernel.org>
> ---
> drivers/net/ethernet/marvell/mvneta.c | 94 +++++++++++++++++----------
> 1 file changed, 58 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvneta.c
> b/drivers/net/ethernet/marvell/mvneta.c
> index 94e29cce693a..e95d8df0fcdb 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -1860,8 +1860,8 @@ static void mvneta_txq_bufs_free(struct mvneta_port *pp,
> bytes_compl += buf->skb->len;
> pkts_compl++;
> dev_kfree_skb_any(buf->skb);
> - } else if (buf->type == MVNETA_TYPE_XDP_TX ||
> - buf->type == MVNETA_TYPE_XDP_NDO) {
> + } else if ((buf->type == MVNETA_TYPE_XDP_TX ||
> + buf->type == MVNETA_TYPE_XDP_NDO) && buf->xdpf) {
> if (napi && buf->type == MVNETA_TYPE_XDP_TX)
> xdp_return_frame_rx_napi(buf->xdpf);
> else
> @@ -2057,45 +2057,67 @@ mvneta_xdp_put_buff(struct mvneta_port *pp, struct
> mvneta_rx_queue *rxq,
>
> static int
> mvneta_xdp_submit_frame(struct mvneta_port *pp, struct mvneta_tx_queue *txq,
> - struct xdp_frame *xdpf, bool dma_map)
> + struct xdp_frame *xdpf, int *nxmit_byte, bool dma_map)
> {
> - struct mvneta_tx_desc *tx_desc;
> - struct mvneta_tx_buf *buf;
> - dma_addr_t dma_addr;
> + struct mvneta_tx_desc *tx_desc = NULL;
> + struct xdp_shared_info *xdp_sinfo;
> + struct page *page;
> + int i, num_frames;
> +
> + xdp_sinfo = xdp_get_shared_info_from_frame(xdpf);
> + num_frames = xdpf->mb ? xdp_sinfo->nr_frags + 1 : 1;
>
> - if (txq->count >= txq->tx_stop_threshold)
> + if (txq->count + num_frames >= txq->size)
> return MVNETA_XDP_DROPPED;
>
> - tx_desc = mvneta_txq_next_desc_get(txq);
> + for (i = 0; i < num_frames; i++) {
I get the feeling this is more like num_bufs than num_frames.
> + struct mvneta_tx_buf *buf = &txq->buf[txq->txq_put_index];
> + skb_frag_t *frag = i ? &xdp_sinfo->frags[i - 1] : NULL;
> + int len = i ? xdp_get_frag_size(frag) : xdpf->len;
> + dma_addr_t dma_addr;
>
> - buf = &txq->buf[txq->txq_put_index];
> - if (dma_map) {
> - /* ndo_xdp_xmit */
> - dma_addr = dma_map_single(pp->dev->dev.parent, xdpf->data,
> - xdpf->len, DMA_TO_DEVICE);
> - if (dma_mapping_error(pp->dev->dev.parent, dma_addr)) {
> - mvneta_txq_desc_put(txq);
> - return MVNETA_XDP_DROPPED;
> + tx_desc = mvneta_txq_next_desc_get(txq);
> + if (dma_map) {
> + /* ndo_xdp_xmit */
> + void *data;
> +
> + data = frag ? xdp_get_frag_address(frag) : xdpf->data;
> + dma_addr = dma_map_single(pp->dev->dev.parent, data,
> + len, DMA_TO_DEVICE);
> + if (dma_mapping_error(pp->dev->dev.parent, dma_addr)) {
> + for (; i >= 0; i--)
> + mvneta_txq_desc_put(txq);
Don't you need to unmap the previous buffers too?
> + return MVNETA_XDP_DROPPED;
> + }
> + buf->type = MVNETA_TYPE_XDP_NDO;
> + } else {
> + page = frag ? xdp_get_frag_page(frag)
> + : virt_to_page(xdpf->data);
> + dma_addr = page_pool_get_dma_addr(page);
> + if (frag)
> + dma_addr += xdp_get_frag_offset(frag);
> + else
> + dma_addr += sizeof(*xdpf) + xdpf->headroom;
> + dma_sync_single_for_device(pp->dev->dev.parent,
> + dma_addr, len,
> + DMA_BIDIRECTIONAL);
> + buf->type = MVNETA_TYPE_XDP_TX;
> }
> - buf->type = MVNETA_TYPE_XDP_NDO;
> - } else {
> - struct page *page = virt_to_page(xdpf->data);
> + buf->xdpf = i ? NULL : xdpf;
>
> - dma_addr = page_pool_get_dma_addr(page) +
> - sizeof(*xdpf) + xdpf->headroom;
> - dma_sync_single_for_device(pp->dev->dev.parent, dma_addr,
> - xdpf->len, DMA_BIDIRECTIONAL);
> - buf->type = MVNETA_TYPE_XDP_TX;
> + tx_desc->command = !i ? MVNETA_TXD_F_DESC : 0;
> + tx_desc->buf_phys_addr = dma_addr;
> + tx_desc->data_size = len;
> + *nxmit_byte += len;
> +
> + mvneta_txq_inc_put(txq);
> }
> - buf->xdpf = xdpf;
>
> - tx_desc->command = MVNETA_TXD_FLZ_DESC;
> - tx_desc->buf_phys_addr = dma_addr;
> - tx_desc->data_size = xdpf->len;
> + /*last descriptor */
> + tx_desc->command |= MVNETA_TXD_L_DESC | MVNETA_TXD_Z_PAD;
>
> - mvneta_txq_inc_put(txq);
> - txq->pending++;
> - txq->count++;
> + txq->pending += num_frames;
> + txq->count += num_frames;
>
> return MVNETA_XDP_TX;
> }
> @@ -2106,8 +2128,8 @@ mvneta_xdp_xmit_back(struct mvneta_port *pp, struct
> xdp_buff *xdp)
> struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);
> struct mvneta_tx_queue *txq;
> struct netdev_queue *nq;
> + int cpu, nxmit_byte = 0;
> struct xdp_frame *xdpf;
> - int cpu;
> u32 ret;
>
> xdpf = xdp_convert_buff_to_frame(xdp);
> @@ -2119,10 +2141,10 @@ mvneta_xdp_xmit_back(struct mvneta_port *pp, struct
> xdp_buff *xdp)
> nq = netdev_get_tx_queue(pp->dev, txq->id);
>
> __netif_tx_lock(nq, cpu);
> - ret = mvneta_xdp_submit_frame(pp, txq, xdpf, false);
> + ret = mvneta_xdp_submit_frame(pp, txq, xdpf, &nxmit_byte, false);
> if (ret == MVNETA_XDP_TX) {
> u64_stats_update_begin(&stats->syncp);
> - stats->es.ps.tx_bytes += xdpf->len;
> + stats->es.ps.tx_bytes += nxmit_byte;
> stats->es.ps.tx_packets++;
> stats->es.ps.xdp_tx++;
> u64_stats_update_end(&stats->syncp);
> @@ -2161,11 +2183,11 @@ mvneta_xdp_xmit(struct net_device *dev, int num_frame,
>
> __netif_tx_lock(nq, cpu);
> for (i = 0; i < num_frame; i++) {
> - ret = mvneta_xdp_submit_frame(pp, txq, frames[i], true);
> + ret = mvneta_xdp_submit_frame(pp, txq, frames[i], &nxmit_byte,
> + true);
> if (ret != MVNETA_XDP_TX)
> break;
>
> - nxmit_byte += frames[i]->len;
> nxmit++;
> }
>
> --
> 2.30.2
>
