Subject: [PATCH net] mediathek: mtk_eth_soc: fix netdev inside xdp_rxq_info

From: Til Kaiser <[email-masked]>
Date: Tue, 26 Nov 2024 14:41:54 +0100

Currently, the network device isn't set inside the xdp_rxq_info
of the mtk_rx_ring, which means that an XDP program attached to
the Mediathek ethernet driver cannot retrieve the index of the
interface that received the package since it's always 0 inside
the xdp_md struct.

This patch sets the network device pointer inside the
xdp_rxq_info struct, which is later used to initialize
the xdp_buff struct via xdp_init_buff.

This was tested using the following eBPF/XDP program attached
to a network interface of the mtk_eth_soc driver. As said before,
ingress_ifindex always had a value of zero. After applying the
patch, ingress_ifindex holds the correct interface index.

	#include <linux/bpf.h>
	#include <bpf/bpf_helpers.h>

	SEC("pass")
	int pass_func(struct xdp_md *xdp) {
    		bpf_printk("ingress_ifindex: %u",
			xdp->ingress_ifindex);

		return XDP_PASS;
	}

	char _license[] SEC("license") = "GPL";

Signed-off-by: Til Kaiser <[email-masked]>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 53485142938c..9c6d4477e536 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2069,6 +2069,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 
 		netdev = eth->netdev[mac];
 		ppe_idx = eth->mac[mac]->ppe_idx;
+		ring->xdp_q.dev = netdev;
 
 		if (unlikely(test_bit(MTK_RESETTING, &eth->state)))
 			goto release_desc;
-- 
2.47.1