net: mscc: ocelot: establish functions for handling VCAP aux resources

Some VCAP filters utilize resources which are global to the switch, like
for example VCAP IS2 policers take an index into a global policer pool.

In commit c9a7fe12 ("net: mscc: ocelot: add action of police on
vcap_is2"), Xiaoliang expressed this by hooking into the low-level
ocelot_vcap_filter_add_to_block() and ocelot_vcap_block_remove_filter()
functions, and allocating/freeing the policers from there.

Evaluating the code, there probably isn't a better place, but we'll need
to do something similar for the mirror ports, and the code will start to
look even more hacked up than it is right now.

Create two ocelot_vcap_filter_{add,del}_aux_resources() functions to
contain the madness, and pollute less the body of other functions such
as ocelot_vcap_filter_add_to_block().
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mscc/ocelot_vcap.c

@@ -955,12 +955,11 @@ int ocelot_vcap_policer_del(struct ocelot *ocelot, u32 pol_ix)
 }
 EXPORT_SYMBOL(ocelot_vcap_policer_del);
 
-static int ocelot_vcap_filter_add_to_block(struct ocelot *ocelot,
-					   struct ocelot_vcap_block *block,
-					   struct ocelot_vcap_filter *filter)
+static int
+ocelot_vcap_filter_add_aux_resources(struct ocelot *ocelot,
+				     struct ocelot_vcap_filter *filter,
+				     struct netlink_ext_ack *extack)
 {
-	struct ocelot_vcap_filter *tmp;
-	struct list_head *pos, *n;
 	int ret;
 
 	if (filter->block_id == VCAP_IS2 && filter->action.police_ena) {
@@ -970,6 +969,30 @@ static int ocelot_vcap_filter_add_to_block(struct ocelot *ocelot,
 			return ret;
 	}
 
+	return 0;
+}
+
+static void
+ocelot_vcap_filter_del_aux_resources(struct ocelot *ocelot,
+				     struct ocelot_vcap_filter *filter)
+{
+	if (filter->block_id == VCAP_IS2 && filter->action.police_ena)
+		ocelot_vcap_policer_del(ocelot, filter->action.pol_ix);
+}
+
+static int ocelot_vcap_filter_add_to_block(struct ocelot *ocelot,
+					   struct ocelot_vcap_block *block,
+					   struct ocelot_vcap_filter *filter,
+					   struct netlink_ext_ack *extack)
+{
+	struct ocelot_vcap_filter *tmp;
+	struct list_head *pos, *n;
+	int ret;
+
+	ret = ocelot_vcap_filter_add_aux_resources(ocelot, filter, extack);
+	if (ret)
+		return ret;
+
 	block->count++;
 
 	if (list_empty(&block->rules)) {
@@ -1168,7 +1191,7 @@ int ocelot_vcap_filter_add(struct ocelot *ocelot,
 	}
 
 	/* Add filter to the linked list */
-	ret = ocelot_vcap_filter_add_to_block(ocelot, block, filter);
+	ret = ocelot_vcap_filter_add_to_block(ocelot, block, filter, extack);
 	if (ret)
 		return ret;
 
@@ -1199,11 +1222,7 @@ static void ocelot_vcap_block_remove_filter(struct ocelot *ocelot,
 
 	list_for_each_entry_safe(tmp, n, &block->rules, list) {
 		if (ocelot_vcap_filter_equal(filter, tmp)) {
-			if (tmp->block_id == VCAP_IS2 &&
-			    tmp->action.police_ena)
-				ocelot_vcap_policer_del(ocelot,
-							tmp->action.pol_ix);
-
+			ocelot_vcap_filter_del_aux_resources(ocelot, tmp);
 			list_del(&tmp->list);
 			kfree(tmp);
 		}