net/mlx5e: Support multi buffer XDP_TX

This commit enables passing multi buffer XDP frames to the TX handlers
on XDP_TX. Fragments are DMA synchronized to the device and queued to
the xdpi_fifo for a subsequent unmapping.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index 368e549..f35b62c 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -59,20 +59,17 @@ static inline bool
 mlx5e_xmit_xdp_buff(struct mlx5e_xdpsq *sq, struct mlx5e_rq *rq,
                    struct page *page, struct xdp_buff *xdp)
 {
+       struct skb_shared_info *sinfo = NULL;
        struct mlx5e_xmit_data xdptxd;
        struct mlx5e_xdp_info xdpi;
        struct xdp_frame *xdpf;
        dma_addr_t dma_addr;
+       int i;
 
        xdpf = xdp_convert_buff_to_frame(xdp);
        if (unlikely(!xdpf))
                return false;
 
-       if (unlikely(xdp_frame_has_frags(xdpf))) {
-               xdp_return_frame(xdpf);
-               return false;
-       }
-
        xdptxd.data = xdpf->data;
        xdptxd.len  = xdpf->len;
 
@@ -117,19 +114,45 @@ mlx5e_xmit_xdp_buff(struct mlx5e_xdpsq *sq, struct mlx5e_rq *rq,
         */
 
        xdpi.mode = MLX5E_XDP_XMIT_MODE_PAGE;
+       xdpi.page.rq = rq;
 
        dma_addr = page_pool_get_dma_addr(page) + (xdpf->data - (void *)xdpf);
        dma_sync_single_for_device(sq->pdev, dma_addr, xdptxd.len, DMA_TO_DEVICE);
 
+       if (unlikely(xdp_frame_has_frags(xdpf))) {
+               sinfo = xdp_get_shared_info_from_frame(xdpf);
+
+               for (i = 0; i < sinfo->nr_frags; i++) {
+                       skb_frag_t *frag = &sinfo->frags[i];
+                       dma_addr_t addr;
+                       u32 len;
+
+                       addr = page_pool_get_dma_addr(skb_frag_page(frag)) +
+                               skb_frag_off(frag);
+                       len = skb_frag_size(frag);
+                       dma_sync_single_for_device(sq->pdev, addr, len,
+                                                  DMA_TO_DEVICE);
+               }
+       }
+
        xdptxd.dma_addr = dma_addr;
-       xdpi.page.rq = rq;
-       xdpi.page.page = page;
 
        if (unlikely(!INDIRECT_CALL_2(sq->xmit_xdp_frame, mlx5e_xmit_xdp_frame_mpwqe,
-                                     mlx5e_xmit_xdp_frame, sq, &xdptxd, NULL, 0)))
+                                     mlx5e_xmit_xdp_frame, sq, &xdptxd, sinfo, 0)))
                return false;
 
+       xdpi.page.page = page;
        mlx5e_xdpi_fifo_push(&sq->db.xdpi_fifo, &xdpi);
+
+       if (unlikely(xdp_frame_has_frags(xdpf))) {
+               for (i = 0; i < sinfo->nr_frags; i++) {
+                       skb_frag_t *frag = &sinfo->frags[i];
+
+                       xdpi.page.page = skb_frag_page(frag);
+                       mlx5e_xdpi_fifo_push(&sq->db.xdpi_fifo, &xdpi);
+               }
+       }
+
        return true;
 }