[PATCH iwl-net 2/3] ice: fix locking in ice_xsk_pool_setup()

[Larysa Zaremba]

With ICE_CFG_BUSY PF state flag locking used in ice_xdp(), there is no need
to lock with VSI state inside ice_xsk_pool_setup(). For robust
synchronization the state between reset preparation and PF VSI rebuild has
to be handled, in the same way as in ice_xdp_setup_prog().

Remove locking logic from ice_qp_dis() and ice_qp_ena() and skip those
functions, if rebuild is pending.

Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
Reviewed-by: Igor Bagnucki <igor.bagnucki@xxxxxxxxx>
Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
---
 drivers/net/ethernet/intel/ice/ice.h      |  1 +
 drivers/net/ethernet/intel/ice/ice_main.c |  2 +-
 drivers/net/ethernet/intel/ice/ice_xsk.c  | 12 ++----------
 3 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index 701a61d791dd..76590cfcaf68 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -941,6 +941,7 @@ int ice_prepare_xdp_rings(struct ice_vsi *vsi, struct bpf_prog *prog,
 			  enum ice_xdp_cfg cfg_type);
 int ice_destroy_xdp_rings(struct ice_vsi *vsi, enum ice_xdp_cfg cfg_type);
 void ice_map_xdp_rings(struct ice_vsi *vsi);
+bool ice_rebuild_pending(struct ice_vsi *vsi);
 int
 ice_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
 	     u32 flags);
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index dc60d816a345..cd8be3c3b956 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -2994,7 +2994,7 @@ static int ice_max_xdp_frame_size(struct ice_vsi *vsi)
  * so it happens strictly before or after .ndo_bpf().
  * In case it has happened before, we do not have anything attached to rings
  */
-static bool ice_rebuild_pending(struct ice_vsi *vsi)
+bool ice_rebuild_pending(struct ice_vsi *vsi)
 {
 	return ice_is_reset_in_progress(vsi->back->state) &&
 	       !vsi->rx_rings[0]->desc;
diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index 4e2020ab0825..6c95bebd7777 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -163,7 +163,6 @@ static int ice_qp_dis(struct ice_vsi *vsi, u16 q_idx)
 	struct ice_tx_ring *xdp_ring;
 	struct ice_tx_ring *tx_ring;
 	struct ice_rx_ring *rx_ring;
-	int timeout = 50;
 	int fail = 0;
 	int err;
 
@@ -175,13 +174,6 @@ static int ice_qp_dis(struct ice_vsi *vsi, u16 q_idx)
 	xdp_ring = vsi->xdp_rings[q_idx];
 	q_vector = rx_ring->q_vector;
 
-	while (test_and_set_bit(ICE_CFG_BUSY, vsi->state)) {
-		timeout--;
-		if (!timeout)
-			return -EBUSY;
-		usleep_range(1000, 2000);
-	}
-
 	synchronize_net();
 	netif_trans_update(vsi->netdev);
 	netif_carrier_off(vsi->netdev);
@@ -251,7 +243,6 @@ static int ice_qp_ena(struct ice_vsi *vsi, u16 q_idx)
 	synchronize_net();
 	netif_tx_start_queue(netdev_get_tx_queue(vsi->netdev, q_idx));
 	netif_carrier_on(vsi->netdev);
-	clear_bit(ICE_CFG_BUSY, vsi->state);
 
 	return fail;
 }
@@ -379,7 +370,8 @@ int ice_xsk_pool_setup(struct ice_vsi *vsi, struct xsk_buff_pool *pool, u16 qid)
 		return -EINVAL;
 	}
 
-	if_running = netif_running(vsi->netdev) && ice_is_xdp_ena_vsi(vsi);
+	if_running = !ice_rebuild_pending(vsi) &&
+		     netif_running(vsi->netdev) && ice_is_xdp_ena_vsi(vsi);
 
 	if (if_running) {
 		struct ice_rx_ring *rx_ring = vsi->rx_rings[qid];
-- 
2.43.0