net: enetc: set up XDP program under enetc_reconfigure()

Offloading a BPF program to the RX path of the driver suffers from the
same problems as the PTP reconfiguration - improper error checking can
leave the driver in an invalid state, and the link on the PHY is lost.

Reuse the enetc_reconfigure() procedure, but here, we need to run some
code in the middle of the ring reconfiguration procedure - while the
interface is still down. Introduce a callback which makes that possible.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index ce3319f55573d57bd75d52d131b3308f598778bd..eeff69336a803ba3188c49909b679a660ef6e09f 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -2489,16 +2489,24 @@ int enetc_close(struct net_device *ndev)
        return 0;
 }
 
-static int enetc_reconfigure(struct enetc_ndev_priv *priv, bool extended)
+static int enetc_reconfigure(struct enetc_ndev_priv *priv, bool extended,
+                            int (*cb)(struct enetc_ndev_priv *priv, void *ctx),
+                            void *ctx)
 {
        struct enetc_bdr_resource *tx_res, *rx_res;
        int err;
 
        ASSERT_RTNL();
 
-       /* If the interface is down, do nothing. */
-       if (!netif_running(priv->ndev))
+       /* If the interface is down, run the callback right away,
+        * without reconfiguration.
+        */
+       if (!netif_running(priv->ndev)) {
+               if (cb)
+                       cb(priv, ctx);
+
                return 0;
+       }
 
        tx_res = enetc_alloc_tx_resources(priv);
        if (IS_ERR(tx_res)) {
@@ -2516,6 +2524,10 @@ static int enetc_reconfigure(struct enetc_ndev_priv *priv, bool extended)
        enetc_clear_bdrs(priv);
        enetc_free_rxtx_rings(priv);
 
+       /* Interface is down, run optional callback now */
+       if (cb)
+               cb(priv, ctx);
+
        enetc_assign_tx_resources(priv, tx_res);
        enetc_assign_rx_resources(priv, rx_res);
        enetc_setup_bdrs(priv, extended);
@@ -2586,21 +2598,11 @@ int enetc_setup_tc_mqprio(struct net_device *ndev, void *type_data)
        return 0;
 }
 
-static int enetc_setup_xdp_prog(struct net_device *ndev, struct bpf_prog *prog,
-                               struct netlink_ext_ack *extack)
+static int enetc_reconfigure_xdp_cb(struct enetc_ndev_priv *priv, void *ctx)
 {
-       struct enetc_ndev_priv *priv = netdev_priv(ndev);
-       struct bpf_prog *old_prog;
-       bool is_up;
+       struct bpf_prog *old_prog, *prog = ctx;
        int i;
 
-       /* The buffer layout is changing, so we need to drain the old
-        * RX buffers and seed new ones.
-        */
-       is_up = netif_running(ndev);
-       if (is_up)
-               dev_close(ndev);
-
        old_prog = xchg(&priv->xdp_prog, prog);
        if (old_prog)
                bpf_prog_put(old_prog);
@@ -2616,12 +2618,23 @@ static int enetc_setup_xdp_prog(struct net_device *ndev, struct bpf_prog *prog,
                        rx_ring->buffer_offset = ENETC_RXB_PAD;
        }
 
-       if (is_up)
-               return dev_open(ndev, extack);
-
        return 0;
 }
 
+static int enetc_setup_xdp_prog(struct net_device *ndev, struct bpf_prog *prog,
+                               struct netlink_ext_ack *extack)
+{
+       struct enetc_ndev_priv *priv = netdev_priv(ndev);
+       bool extended;
+
+       extended = !!(priv->active_offloads & ENETC_F_RX_TSTAMP);
+
+       /* The buffer layout is changing, so we need to drain the old
+        * RX buffers and seed new ones.
+        */
+       return enetc_reconfigure(priv, extended, enetc_reconfigure_xdp_cb, prog);
+}
+
 int enetc_setup_bpf(struct net_device *ndev, struct netdev_bpf *bpf)
 {
        switch (bpf->command) {
@@ -2755,7 +2768,7 @@ static int enetc_hwtstamp_set(struct net_device *ndev, struct ifreq *ifr)
        if ((new_offloads ^ priv->active_offloads) & ENETC_F_RX_TSTAMP) {
                bool extended = !!(new_offloads & ENETC_F_RX_TSTAMP);
 
-               err = enetc_reconfigure(priv, extended);
+               err = enetc_reconfigure(priv, extended, NULL, NULL);
                if (err)
                        return err;
        }