[v3,1/1] net: fec: add initial XDP support

Message ID 20221031185350.2045675-1-shenwei.wang@nxp.com
State New
Headers
Series [v3,1/1] net: fec: add initial XDP support |

Commit Message

Shenwei Wang Oct. 31, 2022, 6:53 p.m. UTC
  This patch adds the initial XDP support to Freescale driver. It supports
XDP_PASS, XDP_DROP and XDP_REDIRECT actions. Upcoming patches will add
support for XDP_TX and Zero Copy features.

As the patch is rather large, the part of codes to collect the
statistics is separated and will prepare a dedicated patch for that
part.

I just tested with the application of xdpsock.
  -- Native here means running command of "xdpsock -i eth0"
  -- SKB-Mode means running command of "xdpsock -S -i eth0"

The following are the testing result relating to XDP mode:

root@imx8qxpc0mek:~/bpf# ./xdpsock -i eth0
 sock0@eth0:0 rxdrop xdp-drv
                   pps            pkts           1.00
rx                 371347         2717794
tx                 0              0

root@imx8qxpc0mek:~/bpf# ./xdpsock -S -i eth0
 sock0@eth0:0 rxdrop xdp-skb
                   pps            pkts           1.00
rx                 202229         404528
tx                 0              0

root@imx8qxpc0mek:~/bpf# ./xdp2 eth0
proto 0:     496708 pkt/s
proto 0:     505469 pkt/s
proto 0:     505283 pkt/s
proto 0:     505443 pkt/s
proto 0:     505465 pkt/s

root@imx8qxpc0mek:~/bpf# ./xdp2 -S eth0
proto 0:          0 pkt/s
proto 17:     118778 pkt/s
proto 17:     118989 pkt/s
proto 0:          1 pkt/s
proto 17:     118987 pkt/s
proto 0:          0 pkt/s
proto 17:     118943 pkt/s
proto 17:     118976 pkt/s
proto 0:          1 pkt/s
proto 17:     119006 pkt/s
proto 0:          0 pkt/s
proto 17:     119071 pkt/s
proto 17:     119092 pkt/s

Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Reported-by: kernel test robot <lkp@intel.com>
---
 changes in V3:
 - remove the codes to update the RX ring size to avoid potential risk.
 - update the testing data based on the new implementation.

 changes in V2:
 - Get rid of the expensive fec_net_close/open function calls during
   XDP/Normal Mode switch.
 - Update the testing data on i.mx8qxp mek board.
 - fix the compile issue reported by kernel_test_robot

 drivers/net/ethernet/freescale/fec.h      |   4 +-
 drivers/net/ethernet/freescale/fec_main.c | 224 +++++++++++++++++++++-
 2 files changed, 226 insertions(+), 2 deletions(-)

--
2.34.1
  

Comments

Shenwei Wang Nov. 3, 2022, 2:07 a.m. UTC | #1
A kind ping. 😊

Regards,
Shenwei

> -----Original Message-----
> From: Shenwei Wang <shenwei.wang@nxp.com>
> Sent: Monday, October 31, 2022 1:54 PM
> To: David S. Miller <davem@davemloft.net>; Eric Dumazet
> <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni
> <pabeni@redhat.com>
> Cc: Alexei Starovoitov <ast@kernel.org>; Daniel Borkmann
> <daniel@iogearbox.net>; Jesper Dangaard Brouer <hawk@kernel.org>; John
> Fastabend <john.fastabend@gmail.com>; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; imx@lists.linux.dev; Shenwei Wang
> <shenwei.wang@nxp.com>; kernel test robot <lkp@intel.com>
> Subject: [PATCH v3 1/1] net: fec: add initial XDP support
> 
> This patch adds the initial XDP support to Freescale driver. It supports XDP_PASS,
> XDP_DROP and XDP_REDIRECT actions. Upcoming patches will add support for
> XDP_TX and Zero Copy features.
> 
> As the patch is rather large, the part of codes to collect the statistics is
> separated and will prepare a dedicated patch for that part.
> 
> I just tested with the application of xdpsock.
>   -- Native here means running command of "xdpsock -i eth0"
>   -- SKB-Mode means running command of "xdpsock -S -i eth0"
> 
> The following are the testing result relating to XDP mode:
> 
> root@imx8qxpc0mek:~/bpf# ./xdpsock -i eth0
>  sock0@eth0:0 rxdrop xdp-drv
>                    pps            pkts           1.00
> rx                 371347         2717794
> tx                 0              0
> 
> root@imx8qxpc0mek:~/bpf# ./xdpsock -S -i eth0
>  sock0@eth0:0 rxdrop xdp-skb
>                    pps            pkts           1.00
> rx                 202229         404528
> tx                 0              0
> 
> root@imx8qxpc0mek:~/bpf# ./xdp2 eth0
> proto 0:     496708 pkt/s
> proto 0:     505469 pkt/s
> proto 0:     505283 pkt/s
> proto 0:     505443 pkt/s
> proto 0:     505465 pkt/s
> 
> root@imx8qxpc0mek:~/bpf# ./xdp2 -S eth0
> proto 0:          0 pkt/s
> proto 17:     118778 pkt/s
> proto 17:     118989 pkt/s
> proto 0:          1 pkt/s
> proto 17:     118987 pkt/s
> proto 0:          0 pkt/s
> proto 17:     118943 pkt/s
> proto 17:     118976 pkt/s
> proto 0:          1 pkt/s
> proto 17:     119006 pkt/s
> proto 0:          0 pkt/s
> proto 17:     119071 pkt/s
> proto 17:     119092 pkt/s
> 
> Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
> Reported-by: kernel test robot <lkp@intel.com>
> ---
>  changes in V3:
>  - remove the codes to update the RX ring size to avoid potential risk.
>  - update the testing data based on the new implementation.
> 
>  changes in V2:
>  - Get rid of the expensive fec_net_close/open function calls during
>    XDP/Normal Mode switch.
>  - Update the testing data on i.mx8qxp mek board.
>  - fix the compile issue reported by kernel_test_robot
> 
>  drivers/net/ethernet/freescale/fec.h      |   4 +-
>  drivers/net/ethernet/freescale/fec_main.c | 224 +++++++++++++++++++++-
>  2 files changed, 226 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/fec.h
> b/drivers/net/ethernet/freescale/fec.h
> index 476e3863a310..61e847b18343 100644
> --- a/drivers/net/ethernet/freescale/fec.h
> +++ b/drivers/net/ethernet/freescale/fec.h
> @@ -348,7 +348,6 @@ struct bufdesc_ex {
>   */
> 
>  #define FEC_ENET_XDP_HEADROOM	(XDP_PACKET_HEADROOM)
> -
>  #define FEC_ENET_RX_PAGES	256
>  #define FEC_ENET_RX_FRSIZE	(PAGE_SIZE - FEC_ENET_XDP_HEADROOM \
>  		- SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) @@ -663,6
> +662,9 @@ struct fec_enet_private {
> 
>  	struct imx_sc_ipc *ipc_handle;
> 
> +	/* XDP BPF Program */
> +	struct bpf_prog *xdp_prog;
> +
>  	u64 ethtool_stats[];
>  };
> 
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index 6986b74fb8af..6b062a0663f4 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -89,6 +89,11 @@ static const u16 fec_enet_vlan_pri_to_queue[8] = {0, 0, 1,
> 1, 1, 2, 2, 2};
>  #define FEC_ENET_OPD_V	0xFFF0
>  #define FEC_MDIO_PM_TIMEOUT  100 /* ms */
> 
> +#define FEC_ENET_XDP_PASS          0
> +#define FEC_ENET_XDP_CONSUMED      BIT(0)
> +#define FEC_ENET_XDP_TX            BIT(1)
> +#define FEC_ENET_XDP_REDIR         BIT(2)
> +
>  struct fec_devinfo {
>  	u32 quirks;
>  };
> @@ -418,13 +423,14 @@ static int
>  fec_enet_create_page_pool(struct fec_enet_private *fep,
>  			  struct fec_enet_priv_rx_q *rxq, int size)  {
> +	struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
>  	struct page_pool_params pp_params = {
>  		.order = 0,
>  		.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
>  		.pool_size = size,
>  		.nid = dev_to_node(&fep->pdev->dev),
>  		.dev = &fep->pdev->dev,
> -		.dma_dir = DMA_FROM_DEVICE,
> +		.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL :
> DMA_FROM_DEVICE,
>  		.offset = FEC_ENET_XDP_HEADROOM,
>  		.max_len = FEC_ENET_RX_FRSIZE,
>  	};
> @@ -1499,6 +1505,59 @@ static void fec_enet_update_cbd(struct
> fec_enet_priv_rx_q *rxq,
>  	bdp->cbd_bufaddr = cpu_to_fec32(phys_addr);  }
> 
> +static u32
> +fec_enet_run_xdp(struct fec_enet_private *fep, struct bpf_prog *prog,
> +		 struct xdp_buff *xdp, struct fec_enet_priv_rx_q *rxq, int index)
> {
> +	unsigned int sync, len = xdp->data_end - xdp->data;
> +	u32 ret = FEC_ENET_XDP_PASS;
> +	struct page *page;
> +	int err;
> +	u32 act;
> +
> +	act = bpf_prog_run_xdp(prog, xdp);
> +
> +	/* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch
> */
> +	sync = xdp->data_end - xdp->data_hard_start -
> FEC_ENET_XDP_HEADROOM;
> +	sync = max(sync, len);
> +
> +	switch (act) {
> +	case XDP_PASS:
> +		ret = FEC_ENET_XDP_PASS;
> +		break;
> +
> +	case XDP_REDIRECT:
> +		err = xdp_do_redirect(fep->netdev, xdp, prog);
> +		if (!err) {
> +			ret = FEC_ENET_XDP_REDIR;
> +		} else {
> +			ret = FEC_ENET_XDP_CONSUMED;
> +			page = virt_to_head_page(xdp->data);
> +			page_pool_put_page(rxq->page_pool, page, sync, true);
> +		}
> +		break;
> +
> +	default:
> +		bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
> +		fallthrough;
> +
> +	case XDP_TX:
> +		bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
> +		fallthrough;
> +
> +	case XDP_ABORTED:
> +		fallthrough;    /* handle aborts by dropping packet */
> +
> +	case XDP_DROP:
> +		ret = FEC_ENET_XDP_CONSUMED;
> +		page = virt_to_head_page(xdp->data);
> +		page_pool_put_page(rxq->page_pool, page, sync, true);
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
>  /* During a receive, the bd_rx.cur points to the current incoming buffer.
>   * When we update through the ring, if the next incoming buffer has
>   * not been given to the system, we just set the empty indicator, @@ -1520,6
> +1579,9 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16
> queue_id)
>  	u16	vlan_tag;
>  	int	index = 0;
>  	bool	need_swap = fep->quirks & FEC_QUIRK_SWAP_FRAME;
> +	struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
> +	u32 ret, xdp_result = FEC_ENET_XDP_PASS;
> +	struct xdp_buff xdp;
>  	struct page *page;
> 
>  #ifdef CONFIG_M532x
> @@ -1531,6 +1593,7 @@ fec_enet_rx_queue(struct net_device *ndev, int
> budget, u16 queue_id)
>  	 * These get messed up if we get called due to a busy condition.
>  	 */
>  	bdp = rxq->bd.cur;
> +	xdp_init_buff(&xdp, PAGE_SIZE, &rxq->xdp_rxq);
> 
>  	while (!((status = fec16_to_cpu(bdp->cbd_sc)) & BD_ENET_RX_EMPTY))
> {
> 
> @@ -1580,6 +1643,17 @@ fec_enet_rx_queue(struct net_device *ndev, int
> budget, u16 queue_id)
>  		prefetch(page_address(page));
>  		fec_enet_update_cbd(rxq, bdp, index);
> 
> +		if (xdp_prog) {
> +			xdp_buff_clear_frags_flag(&xdp);
> +			xdp_prepare_buff(&xdp, page_address(page),
> +					 FEC_ENET_XDP_HEADROOM, pkt_len,
> false);
> +
> +			ret = fec_enet_run_xdp(fep, xdp_prog, &xdp, rxq,
> index);
> +			xdp_result |= ret;
> +			if (ret != FEC_ENET_XDP_PASS)
> +				goto rx_processing_done;
> +		}
> +
>  		/* The packet length includes FCS, but we don't want to
>  		 * include that when passing upstream as it messes up
>  		 * bridging applications.
> @@ -1675,6 +1749,10 @@ fec_enet_rx_queue(struct net_device *ndev, int
> budget, u16 queue_id)
>  		writel(0, rxq->bd.reg_desc_active);
>  	}
>  	rxq->bd.cur = bdp;
> +
> +	if (xdp_result & FEC_ENET_XDP_REDIR)
> +		xdp_do_flush_map();
> +
>  	return pkt_received;
>  }
> 
> @@ -3476,6 +3554,148 @@ static u16 fec_enet_select_queue(struct
> net_device *ndev, struct sk_buff *skb,
>  	return fec_enet_vlan_pri_to_queue[vlan_tag >> 13];  }
> 
> +static int fec_enet_bpf(struct net_device *dev, struct netdev_bpf *bpf)
> +{
> +	struct fec_enet_private *fep = netdev_priv(dev);
> +	bool is_run = netif_running(dev);
> +	struct bpf_prog *old_prog;
> +
> +	switch (bpf->command) {
> +	case XDP_SETUP_PROG:
> +		if (is_run) {
> +			napi_disable(&fep->napi);
> +			netif_tx_disable(dev);
> +		}
> +
> +		old_prog = xchg(&fep->xdp_prog, bpf->prog);
> +		fec_restart(dev);
> +
> +		if (is_run) {
> +			napi_enable(&fep->napi);
> +			netif_tx_start_all_queues(dev);
> +		}
> +
> +		if (old_prog)
> +			bpf_prog_put(old_prog);
> +
> +		return 0;
> +
> +	case XDP_SETUP_XSK_POOL:
> +		return -EOPNOTSUPP;
> +
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int
> +fec_enet_xdp_get_tx_queue(struct fec_enet_private *fep, int cpu) {
> +	int index = cpu;
> +
> +	if (unlikely(index < 0))
> +		index = 0;
> +
> +	while (index >= fep->num_tx_queues)
> +		index -= fep->num_tx_queues;
> +
> +	return index;
> +}
> +
> +static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
> +				   struct fec_enet_priv_tx_q *txq,
> +				   struct xdp_frame *frame)
> +{
> +	unsigned int index, status, estatus;
> +	struct bufdesc *bdp, *last_bdp;
> +	dma_addr_t dma_addr;
> +	int entries_free;
> +
> +	entries_free = fec_enet_get_free_txdesc_num(txq);
> +	if (entries_free < MAX_SKB_FRAGS + 1) {
> +		netdev_err(fep->netdev, "NOT enough BD for SG!\n");
> +		return NETDEV_TX_OK;
> +	}
> +
> +	/* Fill in a Tx ring entry */
> +	bdp = txq->bd.cur;
> +	last_bdp = bdp;
> +	status = fec16_to_cpu(bdp->cbd_sc);
> +	status &= ~BD_ENET_TX_STATS;
> +
> +	index = fec_enet_get_bd_index(bdp, &txq->bd);
> +
> +	dma_addr = dma_map_single(&fep->pdev->dev, frame->data,
> +				  frame->len, DMA_TO_DEVICE);
> +	if (dma_mapping_error(&fep->pdev->dev, dma_addr))
> +		return FEC_ENET_XDP_CONSUMED;
> +
> +	status |= (BD_ENET_TX_INTR | BD_ENET_TX_LAST);
> +	if (fep->bufdesc_ex)
> +		estatus = BD_ENET_TX_INT;
> +
> +	bdp->cbd_bufaddr = cpu_to_fec32(dma_addr);
> +	bdp->cbd_datlen = cpu_to_fec16(frame->len);
> +
> +	if (fep->bufdesc_ex) {
> +		struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
> +
> +		if (fep->quirks & FEC_QUIRK_HAS_AVB)
> +			estatus |= FEC_TX_BD_FTYPE(txq->bd.qid);
> +
> +		ebdp->cbd_bdu = 0;
> +		ebdp->cbd_esc = cpu_to_fec32(estatus);
> +	}
> +
> +	index = fec_enet_get_bd_index(last_bdp, &txq->bd);
> +	txq->tx_skbuff[index] = NULL;
> +
> +	/* Send it on its way.  Tell FEC it's ready, interrupt when done,
> +	 * it's the last BD of the frame, and to put the CRC on the end.
> +	 */
> +	status |= (BD_ENET_TX_READY | BD_ENET_TX_TC);
> +	bdp->cbd_sc = cpu_to_fec16(status);
> +
> +	/* If this was the last BD in the ring, start at the beginning again. */
> +	bdp = fec_enet_get_nextdesc(last_bdp, &txq->bd);
> +
> +	txq->bd.cur = bdp;
> +
> +	return 0;
> +}
> +
> +static int fec_enet_xdp_xmit(struct net_device *dev,
> +			     int num_frames,
> +			     struct xdp_frame **frames,
> +			     u32 flags)
> +{
> +	struct fec_enet_private *fep = netdev_priv(dev);
> +	struct fec_enet_priv_tx_q *txq;
> +	int cpu = smp_processor_id();
> +	struct netdev_queue *nq;
> +	unsigned int queue;
> +	int i;
> +
> +	queue = fec_enet_xdp_get_tx_queue(fep, cpu);
> +	txq = fep->tx_queue[queue];
> +	nq = netdev_get_tx_queue(fep->netdev, queue);
> +
> +	__netif_tx_lock(nq, cpu);
> +
> +	for (i = 0; i < num_frames; i++)
> +		fec_enet_txq_xmit_frame(fep, txq, frames[i]);
> +
> +	/* Make sure the update to bdp and tx_skbuff are performed. */
> +	wmb();
> +
> +	/* Trigger transmission start */
> +	writel(0, txq->bd.reg_desc_active);
> +
> +	__netif_tx_unlock(nq);
> +
> +	return num_frames;
> +}
> +
>  static const struct net_device_ops fec_netdev_ops = {
>  	.ndo_open		= fec_enet_open,
>  	.ndo_stop		= fec_enet_close,
> @@ -3490,6 +3710,8 @@ static const struct net_device_ops fec_netdev_ops = {
>  	.ndo_poll_controller	= fec_poll_controller,
>  #endif
>  	.ndo_set_features	= fec_set_features,
> +	.ndo_bpf		= fec_enet_bpf,
> +	.ndo_xdp_xmit		= fec_enet_xdp_xmit,
>  };
> 
>  static const unsigned short offset_des_active_rxq[] = {
> --
> 2.34.1
  
Jakub Kicinski Nov. 3, 2022, 2:32 a.m. UTC | #2
On Thu, 3 Nov 2022 02:07:19 +0000 Shenwei Wang wrote:
> A kind ping. 😊

Pong.

Don't top post.
  
Paolo Abeni Nov. 3, 2022, 9:19 a.m. UTC | #3
On Mon, 2022-10-31 at 13:53 -0500, Shenwei Wang wrote:
> This patch adds the initial XDP support to Freescale driver. It supports
> XDP_PASS, XDP_DROP and XDP_REDIRECT actions. Upcoming patches will add
> support for XDP_TX and Zero Copy features.
> 
> As the patch is rather large, the part of codes to collect the
> statistics is separated and will prepare a dedicated patch for that
> part.
> 
> I just tested with the application of xdpsock.
>   -- Native here means running command of "xdpsock -i eth0"
>   -- SKB-Mode means running command of "xdpsock -S -i eth0"
> 
> The following are the testing result relating to XDP mode:
> 
> root@imx8qxpc0mek:~/bpf# ./xdpsock -i eth0
>  sock0@eth0:0 rxdrop xdp-drv
>                    pps            pkts           1.00
> rx                 371347         2717794
> tx                 0              0
> 
> root@imx8qxpc0mek:~/bpf# ./xdpsock -S -i eth0
>  sock0@eth0:0 rxdrop xdp-skb
>                    pps            pkts           1.00
> rx                 202229         404528
> tx                 0              0
> 
> root@imx8qxpc0mek:~/bpf# ./xdp2 eth0
> proto 0:     496708 pkt/s
> proto 0:     505469 pkt/s
> proto 0:     505283 pkt/s
> proto 0:     505443 pkt/s
> proto 0:     505465 pkt/s
> 
> root@imx8qxpc0mek:~/bpf# ./xdp2 -S eth0
> proto 0:          0 pkt/s
> proto 17:     118778 pkt/s
> proto 17:     118989 pkt/s
> proto 0:          1 pkt/s
> proto 17:     118987 pkt/s
> proto 0:          0 pkt/s
> proto 17:     118943 pkt/s
> proto 17:     118976 pkt/s
> proto 0:          1 pkt/s
> proto 17:     119006 pkt/s
> proto 0:          0 pkt/s
> proto 17:     119071 pkt/s
> proto 17:     119092 pkt/s
> 
> Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
> Reported-by: kernel test robot <lkp@intel.com>
> ---
>  changes in V3:
>  - remove the codes to update the RX ring size to avoid potential risk.
>  - update the testing data based on the new implementation.
> 
>  changes in V2:
>  - Get rid of the expensive fec_net_close/open function calls during
>    XDP/Normal Mode switch.
>  - Update the testing data on i.mx8qxp mek board.
>  - fix the compile issue reported by kernel_test_robot
> 
>  drivers/net/ethernet/freescale/fec.h      |   4 +-
>  drivers/net/ethernet/freescale/fec_main.c | 224 +++++++++++++++++++++-
>  2 files changed, 226 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
> index 476e3863a310..61e847b18343 100644
> --- a/drivers/net/ethernet/freescale/fec.h
> +++ b/drivers/net/ethernet/freescale/fec.h
> @@ -348,7 +348,6 @@ struct bufdesc_ex {
>   */
> 
>  #define FEC_ENET_XDP_HEADROOM	(XDP_PACKET_HEADROOM)
> -
>  #define FEC_ENET_RX_PAGES	256
>  #define FEC_ENET_RX_FRSIZE	(PAGE_SIZE - FEC_ENET_XDP_HEADROOM \
>  		- SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
> @@ -663,6 +662,9 @@ struct fec_enet_private {
> 
>  	struct imx_sc_ipc *ipc_handle;
> 
> +	/* XDP BPF Program */
> +	struct bpf_prog *xdp_prog;
> +
>  	u64 ethtool_stats[];
>  };
> 
> diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
> index 6986b74fb8af..6b062a0663f4 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -89,6 +89,11 @@ static const u16 fec_enet_vlan_pri_to_queue[8] = {0, 0, 1, 1, 1, 2, 2, 2};
>  #define FEC_ENET_OPD_V	0xFFF0
>  #define FEC_MDIO_PM_TIMEOUT  100 /* ms */
> 
> +#define FEC_ENET_XDP_PASS          0
> +#define FEC_ENET_XDP_CONSUMED      BIT(0)
> +#define FEC_ENET_XDP_TX            BIT(1)
> +#define FEC_ENET_XDP_REDIR         BIT(2)
> +
>  struct fec_devinfo {
>  	u32 quirks;
>  };
> @@ -418,13 +423,14 @@ static int
>  fec_enet_create_page_pool(struct fec_enet_private *fep,
>  			  struct fec_enet_priv_rx_q *rxq, int size)
>  {
> +	struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
>  	struct page_pool_params pp_params = {
>  		.order = 0,
>  		.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
>  		.pool_size = size,
>  		.nid = dev_to_node(&fep->pdev->dev),
>  		.dev = &fep->pdev->dev,
> -		.dma_dir = DMA_FROM_DEVICE,
> +		.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,
>  		.offset = FEC_ENET_XDP_HEADROOM,
>  		.max_len = FEC_ENET_RX_FRSIZE,
>  	};
> @@ -1499,6 +1505,59 @@ static void fec_enet_update_cbd(struct fec_enet_priv_rx_q *rxq,
>  	bdp->cbd_bufaddr = cpu_to_fec32(phys_addr);
>  }
> 
> +static u32
> +fec_enet_run_xdp(struct fec_enet_private *fep, struct bpf_prog *prog,
> +		 struct xdp_buff *xdp, struct fec_enet_priv_rx_q *rxq, int index)
> +{
> +	unsigned int sync, len = xdp->data_end - xdp->data;
> +	u32 ret = FEC_ENET_XDP_PASS;
> +	struct page *page;
> +	int err;
> +	u32 act;
> +
> +	act = bpf_prog_run_xdp(prog, xdp);
> +
> +	/* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */
> +	sync = xdp->data_end - xdp->data_hard_start - FEC_ENET_XDP_HEADROOM;
> +	sync = max(sync, len);
> +
> +	switch (act) {
> +	case XDP_PASS:
> +		ret = FEC_ENET_XDP_PASS;
> +		break;
> +
> +	case XDP_REDIRECT:
> +		err = xdp_do_redirect(fep->netdev, xdp, prog);
> +		if (!err) {
> +			ret = FEC_ENET_XDP_REDIR;
> +		} else {
> +			ret = FEC_ENET_XDP_CONSUMED;
> +			page = virt_to_head_page(xdp->data);
> +			page_pool_put_page(rxq->page_pool, page, sync, true);
> +		}
> +		break;
> +
> +	default:
> +		bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
> +		fallthrough;
> +
> +	case XDP_TX:
> +		bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
> +		fallthrough;
> +
> +	case XDP_ABORTED:
> +		fallthrough;    /* handle aborts by dropping packet */
> +
> +	case XDP_DROP:
> +		ret = FEC_ENET_XDP_CONSUMED;
> +		page = virt_to_head_page(xdp->data);
> +		page_pool_put_page(rxq->page_pool, page, sync, true);
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
>  /* During a receive, the bd_rx.cur points to the current incoming buffer.
>   * When we update through the ring, if the next incoming buffer has
>   * not been given to the system, we just set the empty indicator,
> @@ -1520,6 +1579,9 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
>  	u16	vlan_tag;
>  	int	index = 0;
>  	bool	need_swap = fep->quirks & FEC_QUIRK_SWAP_FRAME;
> +	struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
> +	u32 ret, xdp_result = FEC_ENET_XDP_PASS;
> +	struct xdp_buff xdp;
>  	struct page *page;
> 
>  #ifdef CONFIG_M532x
> @@ -1531,6 +1593,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
>  	 * These get messed up if we get called due to a busy condition.
>  	 */
>  	bdp = rxq->bd.cur;
> +	xdp_init_buff(&xdp, PAGE_SIZE, &rxq->xdp_rxq);
> 
>  	while (!((status = fec16_to_cpu(bdp->cbd_sc)) & BD_ENET_RX_EMPTY)) {
> 
> @@ -1580,6 +1643,17 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
>  		prefetch(page_address(page));
>  		fec_enet_update_cbd(rxq, bdp, index);
> 
> +		if (xdp_prog) {
> +			xdp_buff_clear_frags_flag(&xdp);
> +			xdp_prepare_buff(&xdp, page_address(page),
> +					 FEC_ENET_XDP_HEADROOM, pkt_len, false);
> +
> +			ret = fec_enet_run_xdp(fep, xdp_prog, &xdp, rxq, index);
> +			xdp_result |= ret;
> +			if (ret != FEC_ENET_XDP_PASS)
> +				goto rx_processing_done;
> +		}
> +
>  		/* The packet length includes FCS, but we don't want to
>  		 * include that when passing upstream as it messes up
>  		 * bridging applications.
> @@ -1675,6 +1749,10 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
>  		writel(0, rxq->bd.reg_desc_active);
>  	}
>  	rxq->bd.cur = bdp;
> +
> +	if (xdp_result & FEC_ENET_XDP_REDIR)
> +		xdp_do_flush_map();
> +
>  	return pkt_received;
>  }
> 
> @@ -3476,6 +3554,148 @@ static u16 fec_enet_select_queue(struct net_device *ndev, struct sk_buff *skb,
>  	return fec_enet_vlan_pri_to_queue[vlan_tag >> 13];
>  }
> 
> +static int fec_enet_bpf(struct net_device *dev, struct netdev_bpf *bpf)
> +{
> +	struct fec_enet_private *fep = netdev_priv(dev);
> +	bool is_run = netif_running(dev);
> +	struct bpf_prog *old_prog;
> +
> +	switch (bpf->command) {
> +	case XDP_SETUP_PROG:
> +		if (is_run) {
> +			napi_disable(&fep->napi);
> +			netif_tx_disable(dev);
> +		}
> +
> +		old_prog = xchg(&fep->xdp_prog, bpf->prog);
> +		fec_restart(dev);
> +
> +		if (is_run) {
> +			napi_enable(&fep->napi);
> +			netif_tx_start_all_queues(dev);
> +		}
> +
> +		if (old_prog)
> +			bpf_prog_put(old_prog);
> +
> +		return 0;
> +
> +	case XDP_SETUP_XSK_POOL:
> +		return -EOPNOTSUPP;
> +
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int
> +fec_enet_xdp_get_tx_queue(struct fec_enet_private *fep, int cpu)
> +{
> +	int index = cpu;
> +
> +	if (unlikely(index < 0))
> +		index = 0;
> +
> +	while (index >= fep->num_tx_queues)
> +		index -= fep->num_tx_queues;

Not a big deal, but I think kind of optimizations are not worthy and
potentially dangerous since late '90 ;)

You could consider switching to a simpler '%', but IMHO it's not
blocking.


Cheers,

Paolo
  
patchwork-bot+netdevbpf@kernel.org Nov. 3, 2022, 9:40 a.m. UTC | #4
Hello:

This patch was applied to netdev/net-next.git (master)
by Paolo Abeni <pabeni@redhat.com>:

On Mon, 31 Oct 2022 13:53:50 -0500 you wrote:
> This patch adds the initial XDP support to Freescale driver. It supports
> XDP_PASS, XDP_DROP and XDP_REDIRECT actions. Upcoming patches will add
> support for XDP_TX and Zero Copy features.
> 
> As the patch is rather large, the part of codes to collect the
> statistics is separated and will prepare a dedicated patch for that
> part.
> 
> [...]

Here is the summary with links:
  - [v3,1/1] net: fec: add initial XDP support
    https://git.kernel.org/netdev/net-next/c/6d6b39f180b8

You are awesome, thank you!
  
Shenwei Wang Nov. 3, 2022, 2:53 p.m. UTC | #5
> -----Original Message-----
> From: Paolo Abeni <pabeni@redhat.com>
> > +     if (unlikely(index < 0))
> > +             index = 0;
> > +
> > +     while (index >= fep->num_tx_queues)
> > +             index -= fep->num_tx_queues;
> 
> Not a big deal, but I think kind of optimizations are not worthy and potentially
> dangerous since late '90 ;)
> 
> You could consider switching to a simpler '%', but IMHO it's not blocking.

Agree. Will optimize it in next patch of adding xdp statistics.

Thanks,
Shenwei

> 
> 
> Cheers,
> 
> Paolo
  

Patch

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 476e3863a310..61e847b18343 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -348,7 +348,6 @@  struct bufdesc_ex {
  */

 #define FEC_ENET_XDP_HEADROOM	(XDP_PACKET_HEADROOM)
-
 #define FEC_ENET_RX_PAGES	256
 #define FEC_ENET_RX_FRSIZE	(PAGE_SIZE - FEC_ENET_XDP_HEADROOM \
 		- SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
@@ -663,6 +662,9 @@  struct fec_enet_private {

 	struct imx_sc_ipc *ipc_handle;

+	/* XDP BPF Program */
+	struct bpf_prog *xdp_prog;
+
 	u64 ethtool_stats[];
 };

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 6986b74fb8af..6b062a0663f4 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -89,6 +89,11 @@  static const u16 fec_enet_vlan_pri_to_queue[8] = {0, 0, 1, 1, 1, 2, 2, 2};
 #define FEC_ENET_OPD_V	0xFFF0
 #define FEC_MDIO_PM_TIMEOUT  100 /* ms */

+#define FEC_ENET_XDP_PASS          0
+#define FEC_ENET_XDP_CONSUMED      BIT(0)
+#define FEC_ENET_XDP_TX            BIT(1)
+#define FEC_ENET_XDP_REDIR         BIT(2)
+
 struct fec_devinfo {
 	u32 quirks;
 };
@@ -418,13 +423,14 @@  static int
 fec_enet_create_page_pool(struct fec_enet_private *fep,
 			  struct fec_enet_priv_rx_q *rxq, int size)
 {
+	struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
 	struct page_pool_params pp_params = {
 		.order = 0,
 		.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
 		.pool_size = size,
 		.nid = dev_to_node(&fep->pdev->dev),
 		.dev = &fep->pdev->dev,
-		.dma_dir = DMA_FROM_DEVICE,
+		.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,
 		.offset = FEC_ENET_XDP_HEADROOM,
 		.max_len = FEC_ENET_RX_FRSIZE,
 	};
@@ -1499,6 +1505,59 @@  static void fec_enet_update_cbd(struct fec_enet_priv_rx_q *rxq,
 	bdp->cbd_bufaddr = cpu_to_fec32(phys_addr);
 }

+static u32
+fec_enet_run_xdp(struct fec_enet_private *fep, struct bpf_prog *prog,
+		 struct xdp_buff *xdp, struct fec_enet_priv_rx_q *rxq, int index)
+{
+	unsigned int sync, len = xdp->data_end - xdp->data;
+	u32 ret = FEC_ENET_XDP_PASS;
+	struct page *page;
+	int err;
+	u32 act;
+
+	act = bpf_prog_run_xdp(prog, xdp);
+
+	/* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */
+	sync = xdp->data_end - xdp->data_hard_start - FEC_ENET_XDP_HEADROOM;
+	sync = max(sync, len);
+
+	switch (act) {
+	case XDP_PASS:
+		ret = FEC_ENET_XDP_PASS;
+		break;
+
+	case XDP_REDIRECT:
+		err = xdp_do_redirect(fep->netdev, xdp, prog);
+		if (!err) {
+			ret = FEC_ENET_XDP_REDIR;
+		} else {
+			ret = FEC_ENET_XDP_CONSUMED;
+			page = virt_to_head_page(xdp->data);
+			page_pool_put_page(rxq->page_pool, page, sync, true);
+		}
+		break;
+
+	default:
+		bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
+		fallthrough;
+
+	case XDP_TX:
+		bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
+		fallthrough;
+
+	case XDP_ABORTED:
+		fallthrough;    /* handle aborts by dropping packet */
+
+	case XDP_DROP:
+		ret = FEC_ENET_XDP_CONSUMED;
+		page = virt_to_head_page(xdp->data);
+		page_pool_put_page(rxq->page_pool, page, sync, true);
+		break;
+	}
+
+	return ret;
+}
+
 /* During a receive, the bd_rx.cur points to the current incoming buffer.
  * When we update through the ring, if the next incoming buffer has
  * not been given to the system, we just set the empty indicator,
@@ -1520,6 +1579,9 @@  fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
 	u16	vlan_tag;
 	int	index = 0;
 	bool	need_swap = fep->quirks & FEC_QUIRK_SWAP_FRAME;
+	struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
+	u32 ret, xdp_result = FEC_ENET_XDP_PASS;
+	struct xdp_buff xdp;
 	struct page *page;

 #ifdef CONFIG_M532x
@@ -1531,6 +1593,7 @@  fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
 	 * These get messed up if we get called due to a busy condition.
 	 */
 	bdp = rxq->bd.cur;
+	xdp_init_buff(&xdp, PAGE_SIZE, &rxq->xdp_rxq);

 	while (!((status = fec16_to_cpu(bdp->cbd_sc)) & BD_ENET_RX_EMPTY)) {

@@ -1580,6 +1643,17 @@  fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
 		prefetch(page_address(page));
 		fec_enet_update_cbd(rxq, bdp, index);

+		if (xdp_prog) {
+			xdp_buff_clear_frags_flag(&xdp);
+			xdp_prepare_buff(&xdp, page_address(page),
+					 FEC_ENET_XDP_HEADROOM, pkt_len, false);
+
+			ret = fec_enet_run_xdp(fep, xdp_prog, &xdp, rxq, index);
+			xdp_result |= ret;
+			if (ret != FEC_ENET_XDP_PASS)
+				goto rx_processing_done;
+		}
+
 		/* The packet length includes FCS, but we don't want to
 		 * include that when passing upstream as it messes up
 		 * bridging applications.
@@ -1675,6 +1749,10 @@  fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
 		writel(0, rxq->bd.reg_desc_active);
 	}
 	rxq->bd.cur = bdp;
+
+	if (xdp_result & FEC_ENET_XDP_REDIR)
+		xdp_do_flush_map();
+
 	return pkt_received;
 }

@@ -3476,6 +3554,148 @@  static u16 fec_enet_select_queue(struct net_device *ndev, struct sk_buff *skb,
 	return fec_enet_vlan_pri_to_queue[vlan_tag >> 13];
 }

+static int fec_enet_bpf(struct net_device *dev, struct netdev_bpf *bpf)
+{
+	struct fec_enet_private *fep = netdev_priv(dev);
+	bool is_run = netif_running(dev);
+	struct bpf_prog *old_prog;
+
+	switch (bpf->command) {
+	case XDP_SETUP_PROG:
+		if (is_run) {
+			napi_disable(&fep->napi);
+			netif_tx_disable(dev);
+		}
+
+		old_prog = xchg(&fep->xdp_prog, bpf->prog);
+		fec_restart(dev);
+
+		if (is_run) {
+			napi_enable(&fep->napi);
+			netif_tx_start_all_queues(dev);
+		}
+
+		if (old_prog)
+			bpf_prog_put(old_prog);
+
+		return 0;
+
+	case XDP_SETUP_XSK_POOL:
+		return -EOPNOTSUPP;
+
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int
+fec_enet_xdp_get_tx_queue(struct fec_enet_private *fep, int cpu)
+{
+	int index = cpu;
+
+	if (unlikely(index < 0))
+		index = 0;
+
+	while (index >= fep->num_tx_queues)
+		index -= fep->num_tx_queues;
+
+	return index;
+}
+
+static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
+				   struct fec_enet_priv_tx_q *txq,
+				   struct xdp_frame *frame)
+{
+	unsigned int index, status, estatus;
+	struct bufdesc *bdp, *last_bdp;
+	dma_addr_t dma_addr;
+	int entries_free;
+
+	entries_free = fec_enet_get_free_txdesc_num(txq);
+	if (entries_free < MAX_SKB_FRAGS + 1) {
+		netdev_err(fep->netdev, "NOT enough BD for SG!\n");
+		return NETDEV_TX_OK;
+	}
+
+	/* Fill in a Tx ring entry */
+	bdp = txq->bd.cur;
+	last_bdp = bdp;
+	status = fec16_to_cpu(bdp->cbd_sc);
+	status &= ~BD_ENET_TX_STATS;
+
+	index = fec_enet_get_bd_index(bdp, &txq->bd);
+
+	dma_addr = dma_map_single(&fep->pdev->dev, frame->data,
+				  frame->len, DMA_TO_DEVICE);
+	if (dma_mapping_error(&fep->pdev->dev, dma_addr))
+		return FEC_ENET_XDP_CONSUMED;
+
+	status |= (BD_ENET_TX_INTR | BD_ENET_TX_LAST);
+	if (fep->bufdesc_ex)
+		estatus = BD_ENET_TX_INT;
+
+	bdp->cbd_bufaddr = cpu_to_fec32(dma_addr);
+	bdp->cbd_datlen = cpu_to_fec16(frame->len);
+
+	if (fep->bufdesc_ex) {
+		struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
+
+		if (fep->quirks & FEC_QUIRK_HAS_AVB)
+			estatus |= FEC_TX_BD_FTYPE(txq->bd.qid);
+
+		ebdp->cbd_bdu = 0;
+		ebdp->cbd_esc = cpu_to_fec32(estatus);
+	}
+
+	index = fec_enet_get_bd_index(last_bdp, &txq->bd);
+	txq->tx_skbuff[index] = NULL;
+
+	/* Send it on its way.  Tell FEC it's ready, interrupt when done,
+	 * it's the last BD of the frame, and to put the CRC on the end.
+	 */
+	status |= (BD_ENET_TX_READY | BD_ENET_TX_TC);
+	bdp->cbd_sc = cpu_to_fec16(status);
+
+	/* If this was the last BD in the ring, start at the beginning again. */
+	bdp = fec_enet_get_nextdesc(last_bdp, &txq->bd);
+
+	txq->bd.cur = bdp;
+
+	return 0;
+}
+
+static int fec_enet_xdp_xmit(struct net_device *dev,
+			     int num_frames,
+			     struct xdp_frame **frames,
+			     u32 flags)
+{
+	struct fec_enet_private *fep = netdev_priv(dev);
+	struct fec_enet_priv_tx_q *txq;
+	int cpu = smp_processor_id();
+	struct netdev_queue *nq;
+	unsigned int queue;
+	int i;
+
+	queue = fec_enet_xdp_get_tx_queue(fep, cpu);
+	txq = fep->tx_queue[queue];
+	nq = netdev_get_tx_queue(fep->netdev, queue);
+
+	__netif_tx_lock(nq, cpu);
+
+	for (i = 0; i < num_frames; i++)
+		fec_enet_txq_xmit_frame(fep, txq, frames[i]);
+
+	/* Make sure the update to bdp and tx_skbuff are performed. */
+	wmb();
+
+	/* Trigger transmission start */
+	writel(0, txq->bd.reg_desc_active);
+
+	__netif_tx_unlock(nq);
+
+	return num_frames;
+}
+
 static const struct net_device_ops fec_netdev_ops = {
 	.ndo_open		= fec_enet_open,
 	.ndo_stop		= fec_enet_close,
@@ -3490,6 +3710,8 @@  static const struct net_device_ops fec_netdev_ops = {
 	.ndo_poll_controller	= fec_poll_controller,
 #endif
 	.ndo_set_features	= fec_set_features,
+	.ndo_bpf		= fec_enet_bpf,
+	.ndo_xdp_xmit		= fec_enet_xdp_xmit,
 };

 static const unsigned short offset_des_active_rxq[] = {