Provide an ndo_bpf function to efx_netdev_ops that allows setting and
querying of xdp programs on an interface.
Also check that the MTU size isn't too big when setting a program or
when the MTU is explicitly set.
Signed-off-by: Charles McLachlan <cmclach...@solarflare.com>
---
drivers/net/ethernet/sfc/efx.c | 64 ++++++++++++++++++++++++++++++++++
1 file changed, 64 insertions(+)
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 2f1d851c7fd2..e382129617f9 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -226,6 +226,8 @@ static void efx_fini_napi_channel(struct efx_channel
*channel);
static void efx_fini_struct(struct efx_nic *efx);
static void efx_start_all(struct efx_nic *efx);
static void efx_stop_all(struct efx_nic *efx);
+static int efx_xdp_setup_prog(struct efx_nic *efx, struct bpf_prog *prog);
+static int efx_xdp(struct net_device *dev, struct netdev_bpf *xdp);
#define EFX_ASSERT_RESET_SERIALISED(efx) \
do { \
@@ -2024,6 +2026,10 @@ static void efx_stop_all(struct efx_nic *efx)
static void efx_remove_all(struct efx_nic *efx)
{
+ rtnl_lock();
+ efx_xdp_setup_prog(efx, NULL);
+ rtnl_unlock();
+
efx_remove_channels(efx);
efx_remove_filters(efx);
#ifdef CONFIG_SFC_SRIOV
@@ -2279,6 +2285,17 @@ static void efx_watchdog(struct net_device *net_dev)
efx_schedule_reset(efx, RESET_TYPE_TX_WATCHDOG);
}
+static unsigned int efx_xdp_max_mtu(struct efx_nic *efx)
+{
+ /* The maximum MTU that we can fit in a single page, allowing for
+ * framing, overhead and XDP headroom.
+ */
+ int overhead = EFX_MAX_FRAME_LEN(0) + sizeof(struct efx_rx_page_state) +
+ efx->rx_prefix_size + efx->type->rx_buffer_padding +
+ efx->rx_ip_align + XDP_PACKET_HEADROOM;
+
+ return PAGE_SIZE - overhead;
+}
/* Context: process, rtnl_lock() held. */
static int efx_change_mtu(struct net_device *net_dev, int new_mtu)
@@ -2290,6 +2307,14 @@ static int efx_change_mtu(struct net_device *net_dev,
int new_mtu)
if (rc)
return rc;
+ if (rtnl_dereference(efx->xdp_prog) &&
+ new_mtu > efx_xdp_max_mtu(efx)) {
+ netif_err(efx, drv, efx->net_dev,
+ "Requested MTU of %d too big for XDP (max: %d)\n",
+ new_mtu, efx_xdp_max_mtu(efx));
+ return -EINVAL;
+ }
+
netif_dbg(efx, drv, efx->net_dev, "changing MTU to %d\n", new_mtu);
efx_device_detach_sync(efx);
@@ -2491,8 +2516,47 @@ static const struct net_device_ops efx_netdev_ops = {
#endif
.ndo_udp_tunnel_add = efx_udp_tunnel_add,
.ndo_udp_tunnel_del = efx_udp_tunnel_del,
+ .ndo_bpf = efx_xdp
};
+static int efx_xdp_setup_prog(struct efx_nic *efx, struct bpf_prog *prog)
+{
+ struct bpf_prog *old_prog;
+
+ if (prog && efx->net_dev->mtu > efx_xdp_max_mtu(efx)) {
+ netif_err(efx, drv, efx->net_dev,
+ "Unable to configure XDP with MTU of %d (max: %d)\n",
+ efx->net_dev->mtu, efx_xdp_max_mtu(efx));
+ return -EINVAL;
+ }
+
+ old_prog = rtnl_dereference(efx->xdp_prog);
+ rcu_assign_pointer(efx->xdp_prog, prog);
+ /* Release the reference that was originally passed by the caller. */
+ if (old_prog)
+ bpf_prog_put(old_prog);
+
+ return 0;
+}
+
+/* Context: process, rtnl_lock() held. */
+static int efx_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+ struct efx_nic *efx = netdev_priv(dev);
+ struct bpf_prog *xdp_prog;
+
+ switch (xdp->command) {
+ case XDP_SETUP_PROG:
+ return efx_xdp_setup_prog(efx, xdp->prog);
+ case XDP_QUERY_PROG:
+ xdp_prog = rtnl_dereference(efx->xdp_prog);
+ xdp->prog_id = xdp_prog ? xdp_prog->aux->id : 0;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
static void efx_update_name(struct efx_nic *efx)
{
strcpy(efx->name, efx->net_dev->name);
