mlxsw: spectrum_router: Query number of LPM trees from firmware

Instead of hard coding the number of LPM trees in the driver, query it
from the firmware, as it may change in future devices.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index fe4a55e..2c666f9 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -206,8 +206,8 @@
 	static struct mlxsw_sp_lpm_tree *lpm_tree;
 	int i;
 
-	for (i = 0; i < MLXSW_SP_LPM_TREE_COUNT; i++) {
-		lpm_tree = &mlxsw_sp->router.lpm_trees[i];
+	for (i = 0; i < mlxsw_sp->router.lpm.tree_count; i++) {
+		lpm_tree = &mlxsw_sp->router.lpm.trees[i];
 		if (lpm_tree->ref_count == 0)
 			return lpm_tree;
 	}
@@ -303,8 +303,8 @@
 	struct mlxsw_sp_lpm_tree *lpm_tree;
 	int i;
 
-	for (i = 0; i < MLXSW_SP_LPM_TREE_COUNT; i++) {
-		lpm_tree = &mlxsw_sp->router.lpm_trees[i];
+	for (i = 0; i < mlxsw_sp->router.lpm.tree_count; i++) {
+		lpm_tree = &mlxsw_sp->router.lpm.trees[i];
 		if (lpm_tree->ref_count != 0 &&
 		    lpm_tree->proto == proto &&
 		    mlxsw_sp_prefix_usage_eq(&lpm_tree->prefix_usage,
@@ -329,15 +329,36 @@
 	return 0;
 }
 
-static void mlxsw_sp_lpm_init(struct mlxsw_sp *mlxsw_sp)
+#define MLXSW_SP_LPM_TREE_MIN 2 /* trees 0 and 1 are reserved */
+
+static int mlxsw_sp_lpm_init(struct mlxsw_sp *mlxsw_sp)
 {
 	struct mlxsw_sp_lpm_tree *lpm_tree;
+	u64 max_trees;
 	int i;
 
-	for (i = 0; i < MLXSW_SP_LPM_TREE_COUNT; i++) {
-		lpm_tree = &mlxsw_sp->router.lpm_trees[i];
+	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, MAX_LPM_TREES))
+		return -EIO;
+
+	max_trees = MLXSW_CORE_RES_GET(mlxsw_sp->core, MAX_LPM_TREES);
+	mlxsw_sp->router.lpm.tree_count = max_trees - MLXSW_SP_LPM_TREE_MIN;
+	mlxsw_sp->router.lpm.trees = kcalloc(mlxsw_sp->router.lpm.tree_count,
+					     sizeof(struct mlxsw_sp_lpm_tree),
+					     GFP_KERNEL);
+	if (!mlxsw_sp->router.lpm.trees)
+		return -ENOMEM;
+
+	for (i = 0; i < mlxsw_sp->router.lpm.tree_count; i++) {
+		lpm_tree = &mlxsw_sp->router.lpm.trees[i];
 		lpm_tree->id = i + MLXSW_SP_LPM_TREE_MIN;
 	}
+
+	return 0;
+}
+
+static void mlxsw_sp_lpm_fini(struct mlxsw_sp *mlxsw_sp)
+{
+	kfree(mlxsw_sp->router.lpm.trees);
 }
 
 static bool mlxsw_sp_vr_is_used(const struct mlxsw_sp_vr *vr)
@@ -3372,7 +3393,10 @@
 	if (err)
 		goto err_nexthop_group_ht_init;
 
-	mlxsw_sp_lpm_init(mlxsw_sp);
+	err = mlxsw_sp_lpm_init(mlxsw_sp);
+	if (err)
+		goto err_lpm_init;
+
 	err = mlxsw_sp_vrs_init(mlxsw_sp);
 	if (err)
 		goto err_vrs_init;
@@ -3394,6 +3418,8 @@
 err_neigh_init:
 	mlxsw_sp_vrs_fini(mlxsw_sp);
 err_vrs_init:
+	mlxsw_sp_lpm_fini(mlxsw_sp);
+err_lpm_init:
 	rhashtable_destroy(&mlxsw_sp->router.nexthop_group_ht);
 err_nexthop_group_ht_init:
 	rhashtable_destroy(&mlxsw_sp->router.nexthop_ht);
@@ -3407,6 +3433,7 @@
 	unregister_fib_notifier(&mlxsw_sp->fib_nb);
 	mlxsw_sp_neigh_fini(mlxsw_sp);
 	mlxsw_sp_vrs_fini(mlxsw_sp);
+	mlxsw_sp_lpm_fini(mlxsw_sp);
 	rhashtable_destroy(&mlxsw_sp->router.nexthop_group_ht);
 	rhashtable_destroy(&mlxsw_sp->router.nexthop_ht);
 	__mlxsw_sp_router_fini(mlxsw_sp);