ice: Avoid RTNL lock when re-creating auxiliary device

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@intel.com>
Reviewed-by: Jonathan Toppins <jtoppins@redhat.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index 4e16d185077de32e6a09116850b29640995cdf78..a9fa701aaa951958f2432e2bb2ff0080b3c71306 100644 (file)
--- 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 */
 };
 
@@ -887,7 +888,7 @@ 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 3b751d8b405655fe664d2212abb55ebb9e6b94a1..17a9bb461dc3a33961915b4ddb86f231aefca2ec 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -2253,6 +2253,9 @@ 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);