net/mlx5e: XDP, Improve dma address calculation of linear part for XDP_TX

When calculating the dma address of the linear part of an XDP frame, the
formula assumes that there is a single XDP buffer per page. Extend the
formula to allow multiple XDP buffers per page by calculating the data
offset in the page.

This is a preparation for the upcoming removal of a single XDP buffer
per page limitation when the formula will no longer be correct.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260403090927.139042-3-tariqt@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index 04e1b5fa482528fb7ddbf923654f5ed1672ef760..d3bab198c99c004d2c9617b5f611bf2621347416 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -123,7 +123,7 @@ mlx5e_xmit_xdp_buff(struct mlx5e_xdpsq *sq, struct mlx5e_rq *rq,
         * mode.
         */
 
-       dma_addr = page_pool_get_dma_addr(page) + (xdpf->data - (void *)xdpf);
+       dma_addr = page_pool_get_dma_addr(page) + offset_in_page(xdpf->data);
        dma_sync_single_for_device(sq->pdev, dma_addr, xdptxd->len, DMA_BIDIRECTIONAL);
 
        if (xdptxd->has_frags) {