[PATCH 5.16 159/203] ice: Avoid RTNL lock when re-creating auxiliary device

[Greg Kroah-Hartman]

From: Dave Ertman <david.m.ertman@xxxxxxxxx>

[ Upstream commit 5dbbbd01cbba831233c6ea9a3e6bfa133606d3c0 ]

If a call to re-create the auxiliary device happens in a context that has
already taken the RTNL lock, then the call flow that recreates auxiliary
device can hang if there is another attempt to claim the RTNL lock by the
auxiliary driver.

To avoid this, any call to re-create auxiliary devices that comes from
an source that is holding the RTNL lock (e.g. netdev notifier when
interface exits a bond) should execute in a separate thread.  To
accomplish this, add a flag to the PF that will be evaluated in the
service task and dealt with there.

Fixes: f9f5301e7e2d ("ice: Register auxiliary device to provide RDMA")
Signed-off-by: Dave Ertman <david.m.ertman@xxxxxxxxx>
Reviewed-by: Jonathan Toppins <jtoppins@xxxxxxxxxx>
Tested-by: Gurucharan G <gurucharanx.g@xxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/intel/ice/ice.h      | 3 ++-
 drivers/net/ethernet/intel/ice/ice_main.c | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index b2db39ee5f85c..b3e1fc6a0a8eb 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -483,6 +483,7 @@ enum ice_pf_flags {
 	ICE_FLAG_VF_TRUE_PROMISC_ENA,
 	ICE_FLAG_MDD_AUTO_RESET_VF,
 	ICE_FLAG_LINK_LENIENT_MODE_ENA,
+	ICE_FLAG_PLUG_AUX_DEV,
 	ICE_PF_FLAGS_NBITS		/* must be last */
 };
 
@@ -880,7 +881,7 @@ static inline void ice_set_rdma_cap(struct ice_pf *pf)
 	if (pf->hw.func_caps.common_cap.rdma && pf->num_rdma_msix) {
 		set_bit(ICE_FLAG_RDMA_ENA, pf->flags);
 		set_bit(ICE_FLAG_AUX_ENA, pf->flags);
-		ice_plug_aux_dev(pf);
+		set_bit(ICE_FLAG_PLUG_AUX_DEV, pf->flags);
 	}
 }
 
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 68d3de6d42218..5b4be432b60ce 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -2235,6 +2235,9 @@ static void ice_service_task(struct work_struct *work)
 		return;
 	}
 
+	if (test_and_clear_bit(ICE_FLAG_PLUG_AUX_DEV, pf->flags))
+		ice_plug_aux_dev(pf);
+
 	ice_clean_adminq_subtask(pf);
 	ice_check_media_subtask(pf);
 	ice_check_for_hang_subtask(pf);
-- 
2.34.1