On Sat, 2022-12-03 at 22:54 +0100, Gerhard Engleder wrote:
> If BPF program is set up, then run BPF program for every received frame
> and execute the selected action.
>
> Test results with A53 1.2GHz:
>
> XDP_DROP (samples/bpf/xdp1)
> proto 17: 865683 pkt/s
>
> XDP_TX (samples/bpf/xdp2)
> proto 17: 253594 pkt/s
>
> XDP_REDIRECT (samples/bpf/xdpsock)
> sock0@eth2:0 rxdrop xdp-drv
> pps pkts 1.00
> rx 862,258 4,514,166
> tx 0 0
>
> XDP_REDIRECT (samples/bpf/xdp_redirect)
> eth2->eth1 608,895 rx/s 0 err,drop/s 608,895 xmit/s
>
> Signed-off-by: Gerhard Engleder <gerhard@xxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/engleder/tsnep_main.c | 100 +++++++++++++++++++++
> 1 file changed, 100 insertions(+)
>
> diff --git a/drivers/net/ethernet/engleder/tsnep_main.c b/drivers/net/ethernet/engleder/tsnep_main.c
> index 725b2a1e7be4..4e3c6bd3dc9f 100644
> --- a/drivers/net/ethernet/engleder/tsnep_main.c
> +++ b/drivers/net/ethernet/engleder/tsnep_main.c
> @@ -27,6 +27,7 @@
> #include <linux/phy.h>
> #include <linux/iopoll.h>
> #include <linux/bpf.h>
> +#include <linux/bpf_trace.h>
>
> #define TSNEP_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN)
> #define TSNEP_HEADROOM ALIGN(max(TSNEP_SKB_PAD, XDP_PACKET_HEADROOM), 4)
> @@ -44,6 +45,11 @@
> #define TSNEP_COALESCE_USECS_MAX ((ECM_INT_DELAY_MASK >> ECM_INT_DELAY_SHIFT) * \
> ECM_INT_DELAY_BASE_US + ECM_INT_DELAY_BASE_US - 1)
>
> +#define TSNEP_XDP_PASS 0
> +#define TSNEP_XDP_CONSUMED BIT(0)
> +#define TSNEP_XDP_TX BIT(1)
> +#define TSNEP_XDP_REDIRECT BIT(2)
> +
> enum {
> __TSNEP_DOWN,
> };
> @@ -819,6 +825,11 @@ static inline unsigned int tsnep_rx_offset(struct tsnep_rx *rx)
> return TSNEP_SKB_PAD;
> }
>
> +static inline unsigned int tsnep_rx_offset_xdp(void)
Please, no 'inline' in c files, the complier will do a better job
without.
> +{
> + return XDP_PACKET_HEADROOM;
> +}
> +
> static void tsnep_rx_ring_cleanup(struct tsnep_rx *rx)
> {
> struct device *dmadev = rx->adapter->dmadev;
> @@ -1024,6 +1035,65 @@ static int tsnep_rx_refill(struct tsnep_rx *rx, int count, bool reuse)
> return i;
> }
>
> +static int tsnep_xdp_run_prog(struct tsnep_rx *rx, struct bpf_prog *prog,
> + struct xdp_buff *xdp)
> +{
> + unsigned int length;
> + unsigned int sync;
> + u32 act;
> +
> + length = xdp->data_end - xdp->data_hard_start - tsnep_rx_offset_xdp();
> +
> + 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 - tsnep_rx_offset_xdp();
> + sync = max(sync, length);
> +
> + switch (act) {
> + case XDP_PASS:
> + return TSNEP_XDP_PASS;
> + case XDP_TX:
> + if (tsnep_xdp_xmit_back(rx->adapter, xdp) < 0)
> + goto out_failure;
> + return TSNEP_XDP_TX;
> + case XDP_REDIRECT:
> + if (xdp_do_redirect(rx->adapter->netdev, xdp, prog) < 0)
> + goto out_failure;
> + return TSNEP_XDP_REDIRECT;
> + default:
> + bpf_warn_invalid_xdp_action(rx->adapter->netdev, prog, act);
> + fallthrough;
> + case XDP_ABORTED:
> +out_failure:
> + trace_xdp_exception(rx->adapter->netdev, prog, act);
> + fallthrough;
> + case XDP_DROP:
> + page_pool_put_page(rx->page_pool, virt_to_head_page(xdp->data),
> + sync, true);
> + return TSNEP_XDP_CONSUMED;
> + }
> +}
> +
> +static void tsnep_finalize_xdp(struct tsnep_adapter *adapter, int status)
> +{
> + int cpu = smp_processor_id();
> + int queue;
> + struct netdev_queue *nq;
> +
> + if (status & TSNEP_XDP_TX) {
> + queue = cpu % adapter->num_tx_queues;
> + nq = netdev_get_tx_queue(adapter->netdev, queue);
> +
> + __netif_tx_lock(nq, cpu);
> + tsnep_xdp_xmit_flush(&adapter->tx[queue]);
> + __netif_tx_unlock(nq);
> + }
> +
> + if (status & TSNEP_XDP_REDIRECT)
> + xdp_do_flush();
> +}
> +
> static struct sk_buff *tsnep_build_skb(struct tsnep_rx *rx, struct page *page,
> int length)
> {
> @@ -1062,12 +1132,17 @@ static int tsnep_rx_poll(struct tsnep_rx *rx, struct napi_struct *napi,
> int desc_available;
> int done = 0;
> enum dma_data_direction dma_dir;
> + struct bpf_prog *prog;
> struct tsnep_rx_entry *entry;
> + struct xdp_buff xdp;
> + int xdp_status = 0;
> struct sk_buff *skb;
> int length;
> + int retval;
>
> desc_available = tsnep_rx_desc_available(rx);
> dma_dir = page_pool_get_dma_dir(rx->page_pool);
> + prog = READ_ONCE(rx->adapter->xdp_prog);
>
> while (likely(done < budget) && (rx->read != rx->write)) {
> entry = &rx->entry[rx->read];
> @@ -1111,6 +1186,28 @@ static int tsnep_rx_poll(struct tsnep_rx *rx, struct napi_struct *napi,
> rx->read = (rx->read + 1) % TSNEP_RING_SIZE;
> desc_available++;
>
> + if (prog) {
> + xdp_init_buff(&xdp, PAGE_SIZE, &rx->xdp_rxq);
> + xdp_prepare_buff(&xdp, page_address(entry->page),
> + tsnep_rx_offset_xdp() + TSNEP_RX_INLINE_METADATA_SIZE,
> + length - TSNEP_RX_INLINE_METADATA_SIZE,
> + false);
> + retval = tsnep_xdp_run_prog(rx, prog, &xdp);
> + } else {
> + retval = TSNEP_XDP_PASS;
> + }
> + if (retval) {
> + if (retval & (TSNEP_XDP_TX | TSNEP_XDP_REDIRECT))
> + xdp_status |= retval;
Here you could avoid a couple of conditionals passing xdp_status as an
additional tsnep_xdp_run_prog() argument, let the latter update it
under the existing switch, returning a single consumed/pass up bool and
testing such value just after tsnep_xdp_run_prog().
Mostly a matter of personal tasted I guess.
Cheers,
Paolo
