From eb9a36be7f3ec414700af9a616f035eda1f1e63e Mon Sep 17 00:00:00 2001 From: Charles McLachlan Date: Thu, 31 Oct 2019 10:23:23 +0000 Subject: [PATCH] sfc: perform XDP processing on received packets Adds a field to hold an attached xdp_prog, but never populates it (see following patch). Also, XDP_TX support is deferred to a later patch in the series. Track failures of xdp_rxq_info_reg() via per-queue xdp_rxq_info_valid flags and a per-nic xdp_rxq_info_failed flag. The per-queue flags are needed to prevent attempts to xdp_rxq_info_unreg() structs that failed to register. Possibly the API could be changed in the future to avoid the need for these flags. Signed-off-by: Charles McLachlan Acked-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/efx.c | 5 +- drivers/net/ethernet/sfc/net_driver.h | 12 ++++ drivers/net/ethernet/sfc/rx.c | 130 +++++++++++++++++++++++++++++++++- 3 files changed, 145 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index 2fef740..bd04244 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -340,6 +340,8 @@ static int efx_poll(struct napi_struct *napi, int budget) spent = efx_process_channel(channel, budget); + xdp_do_flush_map(); + if (spent < budget) { if (efx_channel_has_rx_queue(channel) && efx->irq_rx_adaptive && @@ -651,7 +653,7 @@ static void efx_start_datapath(struct efx_nic *efx) efx->rx_dma_len = (efx->rx_prefix_size + EFX_MAX_FRAME_LEN(efx->net_dev->mtu) + efx->type->rx_buffer_padding); - rx_buf_len = (sizeof(struct efx_rx_page_state) + + rx_buf_len = (sizeof(struct efx_rx_page_state) + XDP_PACKET_HEADROOM + efx->rx_ip_align + efx->rx_dma_len); if (rx_buf_len <= PAGE_SIZE) { efx->rx_scatter = efx->type->always_rx_scatter; @@ -774,6 +776,7 @@ static void efx_stop_datapath(struct efx_nic *efx) efx_for_each_possible_channel_tx_queue(tx_queue, channel) efx_fini_tx_queue(tx_queue); } + efx->xdp_rxq_info_failed = false; } static void efx_remove_channel(struct efx_channel *channel) diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h index 7394d90..a5a5055 100644 --- a/drivers/net/ethernet/sfc/net_driver.h +++ b/drivers/net/ethernet/sfc/net_driver.h @@ -369,6 +369,8 @@ struct efx_rx_page_state { * refill was triggered. * @recycle_count: RX buffer recycle counter. * @slow_fill: Timer used to defer efx_nic_generate_fill_event(). + * @xdp_rxq_info: XDP specific RX queue information. + * @xdp_rxq_info_valid: Is xdp_rxq_info valid data?. */ struct efx_rx_queue { struct efx_nic *efx; @@ -400,6 +402,8 @@ struct efx_rx_queue { unsigned int slow_fill_count; /* Statistics to supplement MAC stats */ unsigned long rx_packets; + struct xdp_rxq_info xdp_rxq_info; + bool xdp_rxq_info_valid; }; enum efx_sync_events_state { @@ -900,6 +904,7 @@ struct efx_async_filter_insertion { * @loopback_mode: Loopback status * @loopback_modes: Supported loopback mode bitmask * @loopback_selftest: Offline self-test private state + * @xdp_prog: Current XDP programme for this interface * @filter_sem: Filter table rw_semaphore, protects existence of @filter_state * @filter_state: Architecture-dependent filter table state * @rps_mutex: Protects RPS state of all channels @@ -925,6 +930,8 @@ struct efx_async_filter_insertion { * @ptp_data: PTP state data * @ptp_warned: has this NIC seen and warned about unexpected PTP events? * @vpd_sn: Serial number read from VPD + * @xdp_rxq_info_failed: Have any of the rx queues failed to initialise their + * xdp_rxq_info structures? * @monitor_work: Hardware monitor workitem * @biu_lock: BIU (bus interface unit) lock * @last_irq_cpu: Last CPU to handle a possible test interrupt. This @@ -1059,6 +1066,10 @@ struct efx_nic { u64 loopback_modes; void *loopback_selftest; + /* We access loopback_selftest immediately before running XDP, + * so we want them next to each other. + */ + struct bpf_prog __rcu *xdp_prog; struct rw_semaphore filter_sem; void *filter_state; @@ -1088,6 +1099,7 @@ struct efx_nic { bool ptp_warned; char *vpd_sn; + bool xdp_rxq_info_failed; /* The following fields may be written more often */ diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c index 85ec07f..644d157 100644 --- a/drivers/net/ethernet/sfc/rx.c +++ b/drivers/net/ethernet/sfc/rx.c @@ -17,6 +17,8 @@ #include #include #include +#include +#include #include "net_driver.h" #include "efx.h" #include "filter.h" @@ -27,6 +29,9 @@ /* Preferred number of descriptors to fill at once */ #define EFX_RX_PREFERRED_BATCH 8U +/* Maximum rx prefix used by any architecture. */ +#define EFX_MAX_RX_PREFIX_SIZE 16 + /* Number of RX buffers to recycle pages for. When creating the RX page recycle * ring, this number is divided by the number of buffers per page to calculate * the number of pages to store in the RX page recycle ring. @@ -95,7 +100,7 @@ void efx_rx_config_page_split(struct efx_nic *efx) EFX_RX_BUF_ALIGNMENT); efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 : ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) / - efx->rx_page_buf_step); + (efx->rx_page_buf_step + XDP_PACKET_HEADROOM)); efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) / efx->rx_bufs_per_page; efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH, @@ -185,6 +190,9 @@ static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic) page_offset = sizeof(struct efx_rx_page_state); do { + page_offset += XDP_PACKET_HEADROOM; + dma_addr += XDP_PACKET_HEADROOM; + index = rx_queue->added_count & rx_queue->ptr_mask; rx_buf = efx_rx_buffer(rx_queue, index); rx_buf->dma_addr = dma_addr + efx->rx_ip_align; @@ -635,6 +643,104 @@ static void efx_rx_deliver(struct efx_channel *channel, u8 *eh, netif_receive_skb(skb); } +/** efx_do_xdp: perform XDP processing on a received packet + * + * Returns true if packet should still be delivered. + */ +static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel, + struct efx_rx_buffer *rx_buf, u8 **ehp) +{ + u8 rx_prefix[EFX_MAX_RX_PREFIX_SIZE]; + struct efx_rx_queue *rx_queue; + struct bpf_prog *xdp_prog; + struct xdp_buff xdp; + u32 xdp_act; + s16 offset; + int err; + + rcu_read_lock(); + xdp_prog = rcu_dereference(efx->xdp_prog); + if (!xdp_prog) { + rcu_read_unlock(); + return true; + } + + rx_queue = efx_channel_get_rx_queue(channel); + + if (unlikely(channel->rx_pkt_n_frags > 1)) { + /* We can't do XDP on fragmented packets - drop. */ + rcu_read_unlock(); + efx_free_rx_buffers(rx_queue, rx_buf, + channel->rx_pkt_n_frags); + if (net_ratelimit()) + netif_err(efx, rx_err, efx->net_dev, + "XDP is not possible with multiple receive fragments (%d)\n", + channel->rx_pkt_n_frags); + return false; + } + + dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, + rx_buf->len, DMA_FROM_DEVICE); + + /* Save the rx prefix. */ + EFX_WARN_ON_PARANOID(efx->rx_prefix_size > EFX_MAX_RX_PREFIX_SIZE); + memcpy(rx_prefix, *ehp - efx->rx_prefix_size, + efx->rx_prefix_size); + + xdp.data = *ehp; + xdp.data_hard_start = xdp.data - XDP_PACKET_HEADROOM; + + /* No support yet for XDP metadata */ + xdp_set_data_meta_invalid(&xdp); + xdp.data_end = xdp.data + rx_buf->len; + xdp.rxq = &rx_queue->xdp_rxq_info; + + xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp); + rcu_read_unlock(); + + offset = (u8 *)xdp.data - *ehp; + + switch (xdp_act) { + case XDP_PASS: + /* Fix up rx prefix. */ + if (offset) { + *ehp += offset; + rx_buf->page_offset += offset; + rx_buf->len -= offset; + memcpy(*ehp - efx->rx_prefix_size, rx_prefix, + efx->rx_prefix_size); + } + break; + + case XDP_TX: + return -EOPNOTSUPP; + + case XDP_REDIRECT: + err = xdp_do_redirect(efx->net_dev, &xdp, xdp_prog); + if (unlikely(err)) { + efx_free_rx_buffers(rx_queue, rx_buf, 1); + if (net_ratelimit()) + netif_err(efx, rx_err, efx->net_dev, + "XDP redirect failed (%d)\n", err); + } + break; + + default: + bpf_warn_invalid_xdp_action(xdp_act); + efx_free_rx_buffers(rx_queue, rx_buf, 1); + break; + + case XDP_ABORTED: + trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act); + /* Fall through */ + case XDP_DROP: + efx_free_rx_buffers(rx_queue, rx_buf, 1); + break; + } + + return xdp_act == XDP_PASS; +} + /* Handle a received packet. Second half: Touches packet payload. */ void __efx_rx_packet(struct efx_channel *channel) { @@ -663,6 +769,9 @@ void __efx_rx_packet(struct efx_channel *channel) goto out; } + if (!efx_do_xdp(efx, channel, rx_buf, &eh)) + goto out; + if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM))) rx_buf->flags &= ~EFX_RX_PKT_CSUMMED; @@ -731,6 +840,7 @@ void efx_init_rx_queue(struct efx_rx_queue *rx_queue) { struct efx_nic *efx = rx_queue->efx; unsigned int max_fill, trigger, max_trigger; + int rc = 0; netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev, "initialising RX queue %d\n", efx_rx_queue_index(rx_queue)); @@ -764,6 +874,19 @@ void efx_init_rx_queue(struct efx_rx_queue *rx_queue) rx_queue->fast_fill_trigger = trigger; rx_queue->refill_enabled = true; + /* Initialise XDP queue information */ + rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev, + rx_queue->core_index); + + if (rc) { + netif_err(efx, rx_err, efx->net_dev, + "Failure to initialise XDP queue information rc=%d\n", + rc); + efx->xdp_rxq_info_failed = true; + } else { + rx_queue->xdp_rxq_info_valid = true; + } + /* Set up RX descriptor ring */ efx_nic_init_rx(rx_queue); } @@ -805,6 +928,11 @@ void efx_fini_rx_queue(struct efx_rx_queue *rx_queue) } kfree(rx_queue->page_ring); rx_queue->page_ring = NULL; + + if (rx_queue->xdp_rxq_info_valid) + xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info); + + rx_queue->xdp_rxq_info_valid = false; } void efx_remove_rx_queue(struct efx_rx_queue *rx_queue) -- 2.7.4