Commit 25eb3058 authored by Wei Fang's avatar Wei Fang Committed by Paolo Abeni
Browse files

net: fec: add AF_XDP zero-copy support 



This patch adds AF_XDP zero-copy support for both TX and RX on the FEC
driver. It introduces new functions for XSK buffer allocation, RX/TX
queue processing in zero-copy mode, and XSK pool setup/teardown.

For RX, fec_alloc_rxq_buffers_zc() is added to allocate RX buffers from
XSK pool. And fec_enet_rx_queue_xsk() is used to process the frames from
the RX queue which is bound to the AF_XDP socket. Similar to the copy
mode, the zero-copy mode also supports XDP_TX, XDP_PASS, XDP_DROP and
XDP_REDIRECT actions. In addition, fec_enet_xsk_tx_xmit() is similar to
fec_enet_xdp_tx_xmit() and is used to handle XDP_TX action in zero-copy
mode.

For TX, there are two cases, one is the frames from the AF_XDP socket,
so fec_enet_xsk_xmit() is added to directly transmit the frames from
the socket and the buffer type is marked as FEC_TXBUF_T_XSK_XMIT. The
other one is the frames from the RX queue (XDP_TX action), the buffer
type is marked as FEC_TXBUF_T_XSK_TX. Therefore, fec_enet_tx_queue()
could correctly clean the TX queue base on the buffer type.

Also, some tests have been done on the i.MX93-EVK board with the xdpsock
tool, the following are the results.

Env: i.MX93 connects to a packet generator, the link speed is 1Gbps, and
flow-control is off. The RX packet size is 64 bytes including FCS. Only
one RX queue (CPU) is used to receive frames.

1. MAC swap L2 forwarding
1.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -z
 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 414715         415455
tx                 414715         415455

1.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -c
 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 356396         356609
tx                 356396         356609

2. TX only
2.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -z
 sock0@eth0:0 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 1119573        1126720

2.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -c
sock0@eth0:0 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 406864         407616

Signed-off-by: default avatarWei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-16-wei.fang@nxp.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent fee723a4

drivers/net/ethernet/freescale/fec.h

+12 −1
Original line number Diff line number Diff line
@@ -340,6 +340,7 @@ struct bufdesc_ex { 
#define FEC_ENET_TX_FRPPG	(PAGE_SIZE / FEC_ENET_TX_FRSIZE)

#define TX_RING_SIZE		1024	/* Must be power of two */

#define TX_RING_MOD_MASK	511	/*   for this to work */

#define FEC_XSK_TX_BUDGET_MAX	256



#define BD_ENET_RX_INT		0x00800000

#define BD_ENET_RX_PTP		((ushort)0x0400)
@@ -528,6 +529,8 @@ enum fec_txbuf_type { 
	FEC_TXBUF_T_SKB,

	FEC_TXBUF_T_XDP_NDO,

	FEC_TXBUF_T_XDP_TX,

	FEC_TXBUF_T_XSK_XMIT,

	FEC_TXBUF_T_XSK_TX,

};



struct fec_tx_buffer {
@@ -539,6 +542,7 @@ struct fec_enet_priv_tx_q { 
	struct bufdesc_prop bd;

	unsigned char *tx_bounce[TX_RING_SIZE];

	struct fec_tx_buffer tx_buf[TX_RING_SIZE];

	struct xsk_buff_pool *xsk_pool;



	unsigned short tx_stop_threshold;

	unsigned short tx_wake_threshold;
@@ -548,9 +552,16 @@ struct fec_enet_priv_tx_q { 
	dma_addr_t tso_hdrs_dma;

};



union fec_rx_buffer {

	void *buf_p;

	struct page *page;

	struct xdp_buff *xdp;

};



struct fec_enet_priv_rx_q {

	struct bufdesc_prop bd;

	struct page *rx_buf[RX_RING_SIZE];

	union fec_rx_buffer rx_buf[RX_RING_SIZE];

	struct xsk_buff_pool *xsk_pool;



	/* page_pool */

	struct page_pool *page_pool;

drivers/net/ethernet/freescale/fec_main.c

+742 −43

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