From 4a9b052a590d6217237502efde7d598156966080 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Thu, 14 May 2020 12:49:53 +0200 Subject: [PATCH] dpaa2-eth: Add XDP frame size The dpaa2-eth driver reserve some headroom used for hardware and software annotation area in RX/TX buffers. Thus, xdp.data_hard_start doesn't start at page boundary. When XDP is configured the area reserved via dpaa2_fd_get_offset(fd) is 448 bytes of which XDP have reserved 256 bytes. As frame_sz is calculated as an offset from xdp_buff.data_hard_start, an adjust from the full PAGE_SIZE == DPAA2_ETH_RX_BUF_RAW_SIZE. When doing XDP_REDIRECT, the driver doesn't need this reserved headroom any-longer and allows xdp_do_redirect() to use it. This is an advantage for the drivers own ndo-xdp_xmit, as it uses part of this headroom for itself. Patch also adjust frame_sz in this case. The driver cannot support XDP data_meta, because it uses the headroom just before xdp.data for struct dpaa2_eth_swa (DPAA2_ETH_SWA_SIZE=64), when transmitting the packet. When transmitting a xdp_frame in dpaa2_eth_xdp_xmit_frame (call via ndo_xdp_xmit) is uses this area to store a pointer to xdp_frame and dma_size, which is used in TX completion (free_tx_fd) to return frame via xdp_return_frame(). Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov Cc: Ioana Radulescu Link: https://lore.kernel.org/bpf/158945339348.97035.8562488847066908856.stgit@firesoul --- drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c index 0f3e842..8c8d95a 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c @@ -331,6 +331,9 @@ static u32 run_xdp(struct dpaa2_eth_priv *priv, xdp_set_data_meta_invalid(&xdp); xdp.rxq = &ch->xdp_rxq; + xdp.frame_sz = DPAA2_ETH_RX_BUF_RAW_SIZE - + (dpaa2_fd_get_offset(fd) - XDP_PACKET_HEADROOM); + xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp); /* xdp.data pointer may have changed */ @@ -366,7 +369,11 @@ static u32 run_xdp(struct dpaa2_eth_priv *priv, dma_unmap_page(priv->net_dev->dev.parent, addr, DPAA2_ETH_RX_BUF_SIZE, DMA_BIDIRECTIONAL); ch->buf_count--; + + /* Allow redirect use of full headroom */ xdp.data_hard_start = vaddr; + xdp.frame_sz = DPAA2_ETH_RX_BUF_RAW_SIZE; + err = xdp_do_redirect(priv->net_dev, &xdp, xdp_prog); if (unlikely(err)) ch->stats.xdp_drop++; -- 2.7.4