octeontx2-af: Avoid duplicate unicast rule in mcam_rules list

A mcam rule described by mcam_rule struct has all the info
such as the hardware MCAM entry number, match criteria and
corresponding action etc. All mcam rules are stored in a
linked list mcam->rules. When adding/updating a rule to the
mcam->rules it is checked if a rule already exists for the
mcam entry. If the rule already exists, the same rule is
updated instead of creating new rule. This way only one
mcam_rule exists for the only one default unicast entry
installed by AF. But a PF/VF can get different NIXLF
(or default unicast entry number) after a attach-detach-attach
sequence. When that happens mcam_rules list end up with two
default unicast rules. Fix the problem by deleting the default
unicast rule list node always when disabling mcam rules.
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c

@@ -3637,9 +3637,7 @@ int rvu_mbox_handler_nix_lf_stop_rx(struct rvu *rvu, struct msg_req *req,
 	if (err)
 		return err;
 
-	rvu_npc_disable_default_entries(rvu, pcifunc, nixlf);
-
-	npc_mcam_disable_flows(rvu, pcifunc);
+	rvu_npc_disable_mcam_entries(rvu, pcifunc, nixlf);
 
 	return rvu_cgx_start_stop_io(rvu, pcifunc, false);
 }

drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c

@@ -988,7 +988,7 @@ void rvu_npc_disable_mcam_entries(struct rvu *rvu, u16 pcifunc, int nixlf)
 {
 	struct rvu_pfvf *pfvf = rvu_get_pfvf(rvu, pcifunc);
 	struct npc_mcam *mcam = &rvu->hw->mcam;
-	struct rvu_npc_mcam_rule *rule;
+	struct rvu_npc_mcam_rule *rule, *tmp;
 	int blkaddr;
 
 	blkaddr = rvu_get_blkaddr(rvu, BLKTYPE_NPC, 0);
@@ -998,15 +998,18 @@ void rvu_npc_disable_mcam_entries(struct rvu *rvu, u16 pcifunc, int nixlf)
 	mutex_lock(&mcam->lock);
 
 	/* Disable MCAM entries directing traffic to this 'pcifunc' */
-	list_for_each_entry(rule, &mcam->mcam_rules, list) {
+	list_for_each_entry_safe(rule, tmp, &mcam->mcam_rules, list) {
 		if (is_npc_intf_rx(rule->intf) &&
 		    rule->rx_action.pf_func == pcifunc) {
 			npc_enable_mcam_entry(rvu, mcam, blkaddr,
 					      rule->entry, false);
 			rule->enable = false;
 			/* Indicate that default rule is disabled */
-			if (rule->default_rule)
+			if (rule->default_rule) {
 				pfvf->def_ucast_rule = NULL;
+				list_del(&rule->list);
+				kfree(rule);
+			}
 		}
 	}