[Intel-wired-lan] [PATCH iwl-next 1/1] igc: Allow hot-swapping XDP program

[Song Yoong Siang]

Currently, the driver would always close and reopen the network interface
when setting/removing the XDP program, regardless of the presence of XDP
resources. This could cause unnecessary disruptions.

To avoid this, introduces a check to determine if there is a need to
close and reopen the interface, allowing for seamless hot-swapping of
XDP programs.

Signed-off-by: Song Yoong Siang <yoong.siang.song at intel.com>
---
 drivers/net/ethernet/intel/igc/igc_xdp.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.c b/drivers/net/ethernet/intel/igc/igc_xdp.c
index e27af72aada8..869815f48ac1 100644
--- a/drivers/net/ethernet/intel/igc/igc_xdp.c
+++ b/drivers/net/ethernet/intel/igc/igc_xdp.c
@@ -13,6 +13,7 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
 	struct net_device *dev = adapter->netdev;
 	bool if_running = netif_running(dev);
 	struct bpf_prog *old_prog;
+	bool need_update;
 
 	if (dev->mtu > ETH_DATA_LEN) {
 		/* For now, the driver doesn't support XDP functionality with
@@ -22,7 +23,8 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
 		return -EOPNOTSUPP;
 	}
 
-	if (if_running)
+	need_update = !!adapter->xdp_prog != !!prog;
+	if (if_running && need_update)
 		igc_close(dev);
 
 	old_prog = xchg(&adapter->xdp_prog, prog);
@@ -34,7 +36,7 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
 	else
 		xdp_features_clear_redirect_target(dev);
 
-	if (if_running)
+	if (if_running && need_update)
 		igc_open(dev);
 
 	return 0;
-- 
2.34.1