Commit 7822dd4d authored by Zdenek Bouska's avatar Zdenek Bouska Committed by Tony Nguyen
Browse files

igc: Fix HW RX timestamp when passed by ZC XDP 



Fixes HW RX timestamp in the following scenario:
- AF_PACKET socket with enabled HW RX timestamps is created
- AF_XDP socket with enabled zero copy is created
- frame is forwarded to the BPF program, where the timestamp should
  still be readable (extracted by igc_xdp_rx_timestamp(), kfunc
  behind bpf_xdp_metadata_rx_timestamp())
- the frame got XDP_PASS from BPF program, redirecting to the stack
- AF_PACKET socket receives the frame with HW RX timestamp

Moves the skb timestamp setting from igc_dispatch_skb_zc() to
igc_construct_skb_zc() so that igc_construct_skb_zc() is similar to
igc_construct_skb().

This issue can also be reproduced by running:
 # tools/testing/selftests/bpf/xdp_hw_metadata enp1s0
When a frame with the wrong port 9092 (instead of 9091) is used:
 # echo -n xdp | nc -u -q1 192.168.10.9 9092
then the RX timestamp is missing and xdp_hw_metadata prints:
 skb hwtstamp is not found!

With this fix or when copy mode is used:
 # tools/testing/selftests/bpf/xdp_hw_metadata -c enp1s0
then RX timestamp is found and xdp_hw_metadata prints:
 found skb hwtstamp = 1736509937.852786132

Fixes: 069b142f ("igc: Add support for PTP .getcyclesx64()")
Signed-off-by: default avatarZdenek Bouska <zdenek.bouska@siemens.com>
Acked-by: default avatarVinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Reviewed-by: default avatarFlorian Bezdeka <florian.bezdeka@siemens.com>
Reviewed-by: default avatarSong Yoong Siang <yoong.siang.song@intel.com>
Tested-by: default avatarMor Bar-Gabay <morx.bar.gabay@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent 61fb097f

drivers/net/ethernet/intel/igc/igc_main.c

+12 −9
Original line number Diff line number Diff line
@@ -2701,8 +2701,9 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) 
}



static struct sk_buff *igc_construct_skb_zc(struct igc_ring *ring,

					    struct xdp_buff *xdp)

					    struct igc_xdp_buff *ctx)

{

	struct xdp_buff *xdp = &ctx->xdp;

	unsigned int totalsize = xdp->data_end - xdp->data_meta;

	unsigned int metasize = xdp->data - xdp->data_meta;

	struct sk_buff *skb;
@@ -2721,27 +2722,28 @@ static struct sk_buff *igc_construct_skb_zc(struct igc_ring *ring, 
		__skb_pull(skb, metasize);

	}



	if (ctx->rx_ts) {

		skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;

		skb_hwtstamps(skb)->netdev_data = ctx->rx_ts;

	}



	return skb;

}



static void igc_dispatch_skb_zc(struct igc_q_vector *q_vector,

				union igc_adv_rx_desc *desc,

				struct xdp_buff *xdp,

				ktime_t timestamp)

				struct igc_xdp_buff *ctx)

{

	struct igc_ring *ring = q_vector->rx.ring;

	struct sk_buff *skb;



	skb = igc_construct_skb_zc(ring, xdp);

	skb = igc_construct_skb_zc(ring, ctx);

	if (!skb) {

		ring->rx_stats.alloc_failed++;

		set_bit(IGC_RING_FLAG_RX_ALLOC_FAILED, &ring->flags);

		return;

	}



	if (timestamp)

		skb_hwtstamps(skb)->hwtstamp = timestamp;



	if (igc_cleanup_headers(ring, desc, skb))

		return;
@@ -2777,7 +2779,6 @@ static int igc_clean_rx_irq_zc(struct igc_q_vector *q_vector, const int budget) 
		union igc_adv_rx_desc *desc;

		struct igc_rx_buffer *bi;

		struct igc_xdp_buff *ctx;

		ktime_t timestamp = 0;

		unsigned int size;

		int res;
@@ -2807,6 +2808,8 @@ static int igc_clean_rx_irq_zc(struct igc_q_vector *q_vector, const int budget) 
			 */

			bi->xdp->data_meta += IGC_TS_HDR_LEN;

			size -= IGC_TS_HDR_LEN;

		} else {

			ctx->rx_ts = NULL;

		}



		bi->xdp->data_end = bi->xdp->data + size;
@@ -2815,7 +2818,7 @@ static int igc_clean_rx_irq_zc(struct igc_q_vector *q_vector, const int budget) 
		res = __igc_xdp_run_prog(adapter, prog, bi->xdp);

		switch (res) {

		case IGC_XDP_PASS:

			igc_dispatch_skb_zc(q_vector, desc, bi->xdp, timestamp);

			igc_dispatch_skb_zc(q_vector, desc, ctx);

			fallthrough;

		case IGC_XDP_CONSUMED:

			xsk_buff_free(bi->xdp);