From d4ecdbf7aa2fa4feac09befb04cdaf44e6dc938b Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Thu, 14 May 2020 12:51:10 +0200 Subject: ice: Add XDP frame size to driver This driver uses different memory models depending on PAGE_SIZE at compile time. For PAGE_SIZE 4K it uses page splitting, meaning for normal MTU frame size is 2048 bytes (and headroom 192 bytes). For larger MTUs the driver still use page splitting, by allocating order-1 pages (8192 bytes) for RX frames. For PAGE_SIZE larger than 4K, driver instead advance its rx_buffer->page_offset with the frame size "truesize". For XDP frame size calculations, this mean that in PAGE_SIZE larger than 4K mode the frame_sz change on a per packet basis. For the page split 4K PAGE_SIZE mode, xdp.frame_sz is more constant and can be updated once outside the main NAPI loop. The default setting in the driver uses build_skb(), which provides the necessary headroom and tailroom for XDP-redirect in RX-frame (in both modes). There is one complication, which is legacy-rx mode (configurable via ethtool priv-flags). There are zero headroom in this mode, which is a requirement for XDP-redirect to work. The conversion to xdp_frame (convert_to_xdp_frame) will detect this insufficient space, and xdp_do_redirect() call will fail. This is deemed acceptable, as it allows other XDP actions to still work in legacy-mode. In legacy-mode + larger PAGE_SIZE due to lacking tailroom, we also accept that xdp_adjust_tail shrink doesn't work. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov Cc: intel-wired-lan@lists.osuosl.org Cc: Jeff Kirsher Cc: Alexander Duyck Link: https://lore.kernel.org/bpf/158945347002.97035.328088795813704587.stgit@firesoul --- drivers/net/ethernet/intel/ice/ice_txrx.c | 34 +++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 9 deletions(-) (limited to 'drivers/net/ethernet/intel/ice') diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index f67e8362958c..69b21b436f9a 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -423,6 +423,22 @@ static unsigned int ice_rx_offset(struct ice_ring *rx_ring) return 0; } +static unsigned int ice_rx_frame_truesize(struct ice_ring *rx_ring, + unsigned int size) +{ + unsigned int truesize; + +#if (PAGE_SIZE < 8192) + truesize = ice_rx_pg_size(rx_ring) / 2; /* Must be power-of-2 */ +#else + truesize = ice_rx_offset(rx_ring) ? + SKB_DATA_ALIGN(ice_rx_offset(rx_ring) + size) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) : + SKB_DATA_ALIGN(size); +#endif + return truesize; +} + /** * ice_run_xdp - Executes an XDP program on initialized xdp_buff * @rx_ring: Rx ring @@ -991,6 +1007,10 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget) bool failure; xdp.rxq = &rx_ring->xdp_rxq; + /* Frame size depend on rx_ring setup when PAGE_SIZE=4K */ +#if (PAGE_SIZE < 8192) + xdp.frame_sz = ice_rx_frame_truesize(rx_ring, 0); +#endif /* start the loop to process Rx packets bounded by 'budget' */ while (likely(total_rx_pkts < (unsigned int)budget)) { @@ -1038,6 +1058,10 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget) xdp.data_hard_start = xdp.data - ice_rx_offset(rx_ring); xdp.data_meta = xdp.data; xdp.data_end = xdp.data + size; +#if (PAGE_SIZE > 4096) + /* At larger PAGE_SIZE, frame_sz depend on len size */ + xdp.frame_sz = ice_rx_frame_truesize(rx_ring, size); +#endif rcu_read_lock(); xdp_prog = READ_ONCE(rx_ring->xdp_prog); @@ -1051,16 +1075,8 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget) if (!xdp_res) goto construct_skb; if (xdp_res & (ICE_XDP_TX | ICE_XDP_REDIR)) { - unsigned int truesize; - -#if (PAGE_SIZE < 8192) - truesize = ice_rx_pg_size(rx_ring) / 2; -#else - truesize = SKB_DATA_ALIGN(ice_rx_offset(rx_ring) + - size); -#endif xdp_xmit |= xdp_res; - ice_rx_buf_adjust_pg_offset(rx_buf, truesize); + ice_rx_buf_adjust_pg_offset(rx_buf, xdp.frame_sz); } else { rx_buf->pagecnt_bias++; } -- cgit v1.2.3 From 2a637c5b1aaf3b21418fadffad7e56ff27cee6f7 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Thu, 14 May 2020 12:51:15 +0200 Subject: xdp: For Intel AF_XDP drivers add XDP frame_sz MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Intel drivers implement native AF_XDP zerocopy in separate C-files, that have its own invocation of bpf_prog_run_xdp(). The setup of xdp_buff is also handled in separately from normal code path. This patch update XDP frame_sz for AF_XDP zerocopy drivers i40e, ice and ixgbe, as the code changes needed are very similar. Introduce a helper function xsk_umem_xdp_frame_sz() for calculating frame size. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov Acked-by: Björn Töpel Cc: intel-wired-lan@lists.osuosl.org Cc: Magnus Karlsson Link: https://lore.kernel.org/bpf/158945347511.97035.8536753731329475655.stgit@firesoul --- drivers/net/ethernet/intel/ice/ice_xsk.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/net/ethernet/intel/ice') diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c index 8279db15e870..23e5515d4527 100644 --- a/drivers/net/ethernet/intel/ice/ice_xsk.c +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c @@ -840,11 +840,13 @@ int ice_clean_rx_irq_zc(struct ice_ring *rx_ring, int budget) { unsigned int total_rx_bytes = 0, total_rx_packets = 0; u16 cleaned_count = ICE_DESC_UNUSED(rx_ring); + struct xdp_umem *umem = rx_ring->xsk_umem; unsigned int xdp_xmit = 0; bool failure = false; struct xdp_buff xdp; xdp.rxq = &rx_ring->xdp_rxq; + xdp.frame_sz = xsk_umem_xdp_frame_sz(umem); while (likely(total_rx_packets < (unsigned int)budget)) { union ice_32b_rx_flex_desc *rx_desc; -- cgit v1.2.3