iavf: Introduce new state machines for flow director

New states introduced:

 IAVF_FDIR_FLTR_DIS_REQUEST
 IAVF_FDIR_FLTR_DIS_PENDING
 IAVF_FDIR_FLTR_INACTIVE

Current FDIR state machines (SM) are not adequate to handle a few
scenarios in the link DOWN/UP event, reset event and ntuple-feature.

For example, when VF link goes DOWN and comes back UP administratively,
the expectation is that previously installed filters should also be
restored. But with current SM, filters are not restored.
So with new SM, during link DOWN filters are marked as INACTIVE in
the iavf list but removed from PF. After link UP, SM will transition
from INACTIVE to ADD_REQUEST to restore the filter.

Similarly, with VF reset, filters will be removed from the PF, but
marked as INACTIVE in the iavf list. Filters will be restored after
reset completion.

Steps to reproduce:
-------------------

1. Create a VF. Here VF is enp8s0.

2. Assign IP addresses to VF and link partner and ping continuously
from remote. Here remote IP is 1.1.1.1.

3. Check default RX Queue of traffic.

ethtool -S enp8s0 | grep -E "rx-[[:digit:]]+\.packets"

4. Add filter - change default RX Queue (to 15 here)

ethtool -U ens8s0 flow-type ip4 src-ip 1.1.1.1 action 15 loc 5

5. Ensure filter gets added and traffic is received on RX queue 15 now.

Link event testing:
-------------------
6. Bring VF link down and up. If traffic flows to configured queue 15,
test is success, otherwise it is a failure.

Reset event testing:
--------------------
7. Reset the VF. If traffic flows to configured queue 15, test is success,
otherwise it is a failure.

Fixes: 0dbfbabb840d ("iavf: Add framework to enable ethtool ntuple filters")
Signed-off-by: Piotr Gardocki <piotrx.gardocki@intel.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Ranganatha Rao <ranganatha.rao@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 39 insertions, 9 deletions

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index c862ebcd2e39..567435e23936 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -1353,18 +1353,20 @@ static void iavf_clear_cloud_filters(struct iavf_adapter *adapter)
  **/
 static void iavf_clear_fdir_filters(struct iavf_adapter *adapter)
 {
-	struct iavf_fdir_fltr *fdir, *fdirtmp;
+	struct iavf_fdir_fltr *fdir;
 
 	/* remove all Flow Director filters */
 	spin_lock_bh(&adapter->fdir_fltr_lock);
-	list_for_each_entry_safe(fdir, fdirtmp, &adapter->fdir_list_head,
-				 list) {
+	list_for_each_entry(fdir, &adapter->fdir_list_head, list) {
 		if (fdir->state == IAVF_FDIR_FLTR_ADD_REQUEST) {
-			list_del(&fdir->list);
-			kfree(fdir);
-			adapter->fdir_active_fltr--;
-		} else {
-			fdir->state = IAVF_FDIR_FLTR_DEL_REQUEST;
+			/* Cancel a request, keep filter as inactive */
+			fdir->state = IAVF_FDIR_FLTR_INACTIVE;
+		} else if (fdir->state == IAVF_FDIR_FLTR_ADD_PENDING ||
+			 fdir->state == IAVF_FDIR_FLTR_ACTIVE) {
+			/* Disable filters which are active or have a pending
+			 * request to PF to be added
+			 */
+			fdir->state = IAVF_FDIR_FLTR_DIS_REQUEST;
 		}
 	}
 	spin_unlock_bh(&adapter->fdir_fltr_lock);
@@ -4113,6 +4115,33 @@ static int iavf_setup_tc(struct net_device *netdev, enum tc_setup_type type,
 }
 
 /**
+ * iavf_restore_fdir_filters
+ * @adapter: board private structure
+ *
+ * Restore existing FDIR filters when VF netdev comes back up.
+ **/
+static void iavf_restore_fdir_filters(struct iavf_adapter *adapter)
+{
+	struct iavf_fdir_fltr *f;
+
+	spin_lock_bh(&adapter->fdir_fltr_lock);
+	list_for_each_entry(f, &adapter->fdir_list_head, list) {
+		if (f->state == IAVF_FDIR_FLTR_DIS_REQUEST) {
+			/* Cancel a request, keep filter as active */
+			f->state = IAVF_FDIR_FLTR_ACTIVE;
+		} else if (f->state == IAVF_FDIR_FLTR_DIS_PENDING ||
+			   f->state == IAVF_FDIR_FLTR_INACTIVE) {
+			/* Add filters which are inactive or have a pending
+			 * request to PF to be deleted
+			 */
+			f->state = IAVF_FDIR_FLTR_ADD_REQUEST;
+			adapter->aq_required |= IAVF_FLAG_AQ_ADD_FDIR_FILTER;
+		}
+	}
+	spin_unlock_bh(&adapter->fdir_fltr_lock);
+}
+
+/**
  * iavf_open - Called when a network interface is made active
  * @netdev: network interface device structure
  *
@@ -4179,8 +4208,9 @@ static int iavf_open(struct net_device *netdev)
 
 	spin_unlock_bh(&adapter->mac_vlan_list_lock);
 
-	/* Restore VLAN filters that were removed with IFF_DOWN */
+	/* Restore filters that were removed with IFF_DOWN */
 	iavf_restore_filters(adapter);
+	iavf_restore_fdir_filters(adapter);
 
 	iavf_configure(adapter);