Re: [PATCH net-next v4 10/10] tsnep: Support XDP BPF program setup
From: Alexander H Duyck <hidden>
Date: 2023-01-10 17:34:05
On Mon, 2023-01-09 at 20:15 +0100, Gerhard Engleder wrote:
Implement setup of BPF programs for XDP RX path with command
XDP_SETUP_PROG of ndo_bpf(). This is the final step for XDP RX path
support.
tsnep_netdev_close() is called directly during BPF program setup. Add
netif_carrier_off() and netif_tx_stop_all_queues() calls to signal to
network stack that device is down. Otherwise network stack would
continue transmitting pakets.
Return value of tsnep_netdev_open() is not checked during BPF program
setup like in other drivers. Forwarding the return value would result in
a bpf_prog_put() call in dev_xdp_install(), which would make removal of
BPF program necessary.
If tsnep_netdev_open() fails during BPF program setup, then the network
stack would call tsnep_netdev_close() anyway. Thus, tsnep_netdev_close()
checks now if device is already down.
Additionally remove $(tsnep-y) from $(tsnep-objs) because it is added
automatically.
Test results with A53 1.2GHz:
XDP_DROP (samples/bpf/xdp1)
proto 17: 883878 pkt/s
XDP_TX (samples/bpf/xdp2)
proto 17: 255693 pkt/s
XDP_REDIRECT (samples/bpf/xdpsock)
sock0@eth2:0 rxdrop xdp-drv
pps pkts 1.00
rx 855,582 5,404,523
tx 0 0
XDP_REDIRECT (samples/bpf/xdp_redirect)
eth2->eth1 613,267 rx/s 0 err,drop/s 613,272 xmit/s
Signed-off-by: Gerhard Engleder <redacted>
---
drivers/net/ethernet/engleder/Makefile | 2 +-
drivers/net/ethernet/engleder/tsnep.h | 6 +++++
drivers/net/ethernet/engleder/tsnep_main.c | 25 ++++++++++++++++---
drivers/net/ethernet/engleder/tsnep_xdp.c | 29 ++++++++++++++++++++++
4 files changed, 58 insertions(+), 4 deletions(-)
create mode 100644 drivers/net/ethernet/engleder/tsnep_xdp.c
<...>
quoted hunk ↗ jump to hunk
--- a/drivers/net/ethernet/engleder/tsnep_main.c +++ b/drivers/net/ethernet/engleder/tsnep_main.c@@ -1373,7 +1373,7 @@ static void tsnep_free_irq(struct tsnep_queue *queue, bool first) memset(queue->name, 0, sizeof(queue->name)); } -static int tsnep_netdev_open(struct net_device *netdev) +int tsnep_netdev_open(struct net_device *netdev) { struct tsnep_adapter *adapter = netdev_priv(netdev); int tx_queue_index = 0;@@ -1436,6 +1436,8 @@ static int tsnep_netdev_open(struct net_device *netdev) tsnep_enable_irq(adapter, adapter->queue[i].irq_mask); } + netif_tx_start_all_queues(adapter->netdev); + clear_bit(__TSNEP_DOWN, &adapter->state); return 0;@@ -1457,12 +1459,16 @@ static int tsnep_netdev_open(struct net_device *netdev) return retval; } -static int tsnep_netdev_close(struct net_device *netdev) +int tsnep_netdev_close(struct net_device *netdev) { struct tsnep_adapter *adapter = netdev_priv(netdev); int i; - set_bit(__TSNEP_DOWN, &adapter->state); + if (test_and_set_bit(__TSNEP_DOWN, &adapter->state)) + return 0; + + netif_carrier_off(netdev); + netif_tx_stop_all_queues(netdev);
As I called out earlier the __TSNEP_DOWN is just !IFF_UP so you don't need that bit. The fact that netif_carrier_off is here also points out the fact that the code in the Tx path isn't needed regarding __TSNEP_DOWN and you can probably just check netif_carrier_ok if you need the check.
quoted hunk ↗ jump to hunk
tsnep_disable_irq(adapter, ECM_INT_LINK); tsnep_phy_close(adapter);@@ -1627,6 +1633,18 @@ static ktime_t tsnep_netdev_get_tstamp(struct net_device *netdev, return ns_to_ktime(timestamp); } +static int tsnep_netdev_bpf(struct net_device *dev, struct netdev_bpf *bpf) +{ + struct tsnep_adapter *adapter = netdev_priv(dev); + + switch (bpf->command) { + case XDP_SETUP_PROG: + return tsnep_xdp_setup_prog(adapter, bpf->prog, bpf->extack); + default: + return -EOPNOTSUPP; + } +} + static int tsnep_netdev_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **xdp, u32 flags) {@@ -1677,6 +1695,7 @@ static const struct net_device_ops tsnep_netdev_ops = { .ndo_set_features = tsnep_netdev_set_features, .ndo_get_tstamp = tsnep_netdev_get_tstamp, .ndo_setup_tc = tsnep_tc_setup, + .ndo_bpf = tsnep_netdev_bpf, .ndo_xdp_xmit = tsnep_netdev_xdp_xmit, };