From dfe44c1f52eed6020df74e83d21d617308164a68 Mon Sep 17 00:00:00 2001 From: Charles McLachlan Date: Thu, 31 Oct 2019 10:24:12 +0000 Subject: [PATCH] sfc: handle XDP_TX outcomes of XDP eBPF programs Provide an ndo_xdp_xmit function that uses the XDP tx queue for this CPU to send the packet. Signed-off-by: Charles McLachlan Acked-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/efx.c | 14 ++++++ drivers/net/ethernet/sfc/efx.h | 3 ++ drivers/net/ethernet/sfc/rx.c | 12 ++++- drivers/net/ethernet/sfc/tx.c | 88 ++++++++++++++++++++++++++++++++++ 4 files changed, 116 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index 10c9b1ede799..0fa9972027db 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -228,6 +228,8 @@ static void efx_start_all(struct efx_nic *efx); static void efx_stop_all(struct efx_nic *efx); static int efx_xdp_setup_prog(struct efx_nic *efx, struct bpf_prog *prog); static int efx_xdp(struct net_device *dev, struct netdev_bpf *xdp); +static int efx_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **xdpfs, + u32 flags); #define EFX_ASSERT_RESET_SERIALISED(efx) \ do { \ @@ -2633,6 +2635,7 @@ static const struct net_device_ops efx_netdev_ops = { #endif .ndo_udp_tunnel_add = efx_udp_tunnel_add, .ndo_udp_tunnel_del = efx_udp_tunnel_del, + .ndo_xdp_xmit = efx_xdp_xmit, .ndo_bpf = efx_xdp }; @@ -2680,6 +2683,17 @@ static int efx_xdp(struct net_device *dev, struct netdev_bpf *xdp) } } +static int efx_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **xdpfs, + u32 flags) +{ + struct efx_nic *efx = netdev_priv(dev); + + if (!netif_running(dev)) + return -EINVAL; + + return efx_xdp_tx_buffers(efx, n, xdpfs, flags & XDP_XMIT_FLUSH); +} + static void efx_update_name(struct efx_nic *efx) { strcpy(efx->name, efx->net_dev->name); diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h index 04fed7c06618..45c7ae4114ec 100644 --- a/drivers/net/ethernet/sfc/efx.h +++ b/drivers/net/ethernet/sfc/efx.h @@ -322,4 +322,7 @@ static inline bool efx_rwsem_assert_write_locked(struct rw_semaphore *sem) return true; } +int efx_xdp_tx_buffers(struct efx_nic *efx, int n, struct xdp_frame **xdpfs, + bool flush); + #endif /* EFX_EFX_H */ diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c index 644d157843c6..91f6d5b9ceac 100644 --- a/drivers/net/ethernet/sfc/rx.c +++ b/drivers/net/ethernet/sfc/rx.c @@ -653,6 +653,7 @@ static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel, u8 rx_prefix[EFX_MAX_RX_PREFIX_SIZE]; struct efx_rx_queue *rx_queue; struct bpf_prog *xdp_prog; + struct xdp_frame *xdpf; struct xdp_buff xdp; u32 xdp_act; s16 offset; @@ -713,7 +714,16 @@ static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel, break; case XDP_TX: - return -EOPNOTSUPP; + /* Buffer ownership passes to tx on success. */ + xdpf = convert_to_xdp_frame(&xdp); + err = efx_xdp_tx_buffers(efx, 1, &xdpf, true); + if (unlikely(err != 1)) { + efx_free_rx_buffers(rx_queue, rx_buf, 1); + if (net_ratelimit()) + netif_err(efx, rx_err, efx->net_dev, + "XDP TX failed (%d)\n", err); + } + break; case XDP_REDIRECT: err = xdp_do_redirect(efx->net_dev, &xdp, xdp_prog); diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c index 8a5bc500d2a1..00c1c4402451 100644 --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -599,6 +599,94 @@ err: return NETDEV_TX_OK; } +static void efx_xdp_return_frames(int n, struct xdp_frame **xdpfs) +{ + int i; + + for (i = 0; i < n; i++) + xdp_return_frame_rx_napi(xdpfs[i]); +} + +/* Transmit a packet from an XDP buffer + * + * Returns number of packets sent on success, error code otherwise. + * Runs in NAPI context, either in our poll (for XDP TX) or a different NIC + * (for XDP redirect). + */ +int efx_xdp_tx_buffers(struct efx_nic *efx, int n, struct xdp_frame **xdpfs, + bool flush) +{ + struct efx_tx_buffer *tx_buffer; + struct efx_tx_queue *tx_queue; + struct xdp_frame *xdpf; + dma_addr_t dma_addr; + unsigned int len; + int space; + int cpu; + int i; + + cpu = raw_smp_processor_id(); + + if (!efx->xdp_tx_queue_count || + unlikely(cpu >= efx->xdp_tx_queue_count)) + return -EINVAL; + + tx_queue = efx->xdp_tx_queues[cpu]; + if (unlikely(!tx_queue)) + return -EINVAL; + + if (unlikely(n && !xdpfs)) + return -EINVAL; + + if (!n) + return 0; + + /* Check for available space. We should never need multiple + * descriptors per frame. + */ + space = efx->txq_entries + + tx_queue->read_count - tx_queue->insert_count; + + for (i = 0; i < n; i++) { + xdpf = xdpfs[i]; + + if (i >= space) + break; + + /* We'll want a descriptor for this tx. */ + prefetchw(__efx_tx_queue_get_insert_buffer(tx_queue)); + + len = xdpf->len; + + /* Map for DMA. */ + dma_addr = dma_map_single(&efx->pci_dev->dev, + xdpf->data, len, + DMA_TO_DEVICE); + if (dma_mapping_error(&efx->pci_dev->dev, dma_addr)) + break; + + /* Create descriptor and set up for unmapping DMA. */ + tx_buffer = efx_tx_map_chunk(tx_queue, dma_addr, len); + tx_buffer->xdpf = xdpf; + tx_buffer->flags = EFX_TX_BUF_XDP | + EFX_TX_BUF_MAP_SINGLE; + tx_buffer->dma_offset = 0; + tx_buffer->unmap_len = len; + tx_queue->tx_packets++; + } + + /* Pass mapped frames to hardware. */ + if (flush && i > 0) + efx_nic_push_buffers(tx_queue); + + if (i == 0) + return -EIO; + + efx_xdp_return_frames(n - i, xdpfs + i); + + return i; +} + /* Remove packets from the TX queue * * This removes packets from the TX queue, up to and including the -- 2.39.5