Commit eb9a36be authored by Charles McLachlan's avatar Charles McLachlan Committed by David S. Miller
Browse files

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: default avatarCharles McLachlan <cmclachlan@solarflare.com>
Acked-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8c423501

drivers/net/ethernet/sfc/efx.c

+4 −1
Original line number Diff line number Diff line
@@ -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)

drivers/net/ethernet/sfc/net_driver.h

+12 −0
Original line number Diff line number Diff line
@@ -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 */

drivers/net/ethernet/sfc/rx.c

+129 −1
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 
#include <linux/iommu.h>

#include <net/ip.h>

#include <net/checksum.h>

#include <net/xdp.h>

#include <linux/bpf_trace.h>

#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)

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