From 5cd4fbeab21b89e08df4590b2020f2e5f60c0d19 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sat, 22 Apr 2017 20:17:52 -0700 Subject: [PATCH] nfp: make use of the DMA_ATTR_SKIP_CPU_SYNC attr DMA unmap may destroy changes CPU made to the buffer. To make XDP run correctly on non-x86 platforms we should use the DMA_ATTR_SKIP_CPU_SYNC attribute. Thanks to using the attribute we can now push the sync operation to the common code path from XDP handler. A little bit of variable name reshuffling is required to bring the code back to readable state. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- .../ethernet/netronome/nfp/nfp_net_common.c | 53 ++++++++++++------- 1 file changed, 35 insertions(+), 18 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index e2197160e4dc..f1128d12cd24 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -87,16 +87,31 @@ void nfp_net_get_fw_version(struct nfp_net_fw_version *fw_ver, static dma_addr_t nfp_net_dma_map_rx(struct nfp_net_dp *dp, void *frag) { - return dma_map_single(dp->dev, frag + NFP_NET_RX_BUF_HEADROOM, - dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA, - dp->rx_dma_dir); + return dma_map_single_attrs(dp->dev, frag + NFP_NET_RX_BUF_HEADROOM, + dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA, + dp->rx_dma_dir, DMA_ATTR_SKIP_CPU_SYNC); +} + +static void +nfp_net_dma_sync_dev_rx(const struct nfp_net_dp *dp, dma_addr_t dma_addr) +{ + dma_sync_single_for_device(dp->dev, dma_addr, + dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA, + dp->rx_dma_dir); } static void nfp_net_dma_unmap_rx(struct nfp_net_dp *dp, dma_addr_t dma_addr) { - dma_unmap_single(dp->dev, dma_addr, - dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA, - dp->rx_dma_dir); + dma_unmap_single_attrs(dp->dev, dma_addr, + dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA, + dp->rx_dma_dir, DMA_ATTR_SKIP_CPU_SYNC); +} + +static void nfp_net_dma_sync_cpu_rx(struct nfp_net_dp *dp, dma_addr_t dma_addr, + unsigned int len) +{ + dma_sync_single_for_cpu(dp->dev, dma_addr - NFP_NET_RX_BUF_HEADROOM, + len, dp->rx_dma_dir); } /* Firmware reconfig @@ -1208,6 +1223,8 @@ static void nfp_net_rx_give_one(const struct nfp_net_dp *dp, wr_idx = rx_ring->wr_p & (rx_ring->cnt - 1); + nfp_net_dma_sync_dev_rx(dp, dma_addr); + /* Stash SKB and DMA address away */ rx_ring->rxbufs[wr_idx].frag = frag; rx_ring->rxbufs[wr_idx].dma_addr = dma_addr; @@ -1569,7 +1586,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) tx_ring = r_vec->xdp_ring; while (pkts_polled < budget) { - unsigned int meta_len, data_len, data_off, pkt_len; + unsigned int meta_len, data_len, meta_off, pkt_len, pkt_off; u8 meta_prepend[NFP_NET_MAX_PREPEND]; struct nfp_net_rx_buf *rxbuf; struct nfp_net_rx_desc *rxd; @@ -1608,11 +1625,12 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) data_len = le16_to_cpu(rxd->rxd.data_len); pkt_len = data_len - meta_len; + pkt_off = NFP_NET_RX_BUF_HEADROOM + dp->rx_dma_off; if (dp->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC) - data_off = NFP_NET_RX_BUF_HEADROOM + meta_len; + pkt_off += meta_len; else - data_off = NFP_NET_RX_BUF_HEADROOM + dp->rx_offset; - data_off += dp->rx_dma_off; + pkt_off += dp->rx_offset; + meta_off = pkt_off - meta_len; /* Stats update */ u64_stats_update_begin(&r_vec->rx_sync); @@ -1621,7 +1639,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) u64_stats_update_end(&r_vec->rx_sync); /* Pointer to start of metadata */ - meta = rxbuf->frag + data_off - meta_len; + meta = rxbuf->frag + meta_off; if (unlikely(meta_len > NFP_NET_MAX_PREPEND || (dp->rx_offset && meta_len > dp->rx_offset))) { @@ -1631,6 +1649,9 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) continue; } + nfp_net_dma_sync_cpu_rx(dp, rxbuf->dma_addr + meta_off, + data_len); + if (xdp_prog && !(rxd->rxd.flags & PCIE_DESC_RX_BPF && dp->bpf_offload_xdp)) { unsigned int dma_off; @@ -1638,10 +1659,6 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) int act; hard_start = rxbuf->frag + NFP_NET_RX_BUF_HEADROOM; - dma_off = data_off - NFP_NET_RX_BUF_HEADROOM; - dma_sync_single_for_cpu(dp->dev, rxbuf->dma_addr, - dma_off + pkt_len, - DMA_BIDIRECTIONAL); /* Move prepend out of the way */ if (xdp_prog->xdp_adjust_head) { @@ -1650,12 +1667,12 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) } act = nfp_net_run_xdp(xdp_prog, rxbuf->frag, hard_start, - &data_off, &pkt_len); + &pkt_off, &pkt_len); switch (act) { case XDP_PASS: break; case XDP_TX: - dma_off = data_off - NFP_NET_RX_BUF_HEADROOM; + dma_off = pkt_off - NFP_NET_RX_BUF_HEADROOM; if (unlikely(!nfp_net_tx_xdp_buf(dp, rx_ring, tx_ring, rxbuf, dma_off, @@ -1689,7 +1706,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) nfp_net_rx_give_one(dp, rx_ring, new_frag, new_dma_addr); - skb_reserve(skb, data_off); + skb_reserve(skb, pkt_off); skb_put(skb, pkt_len); if (!dp->chained_metadata_format) { -- 2.20.1