mlxsw: spectrum_fid: Add an op to get PGT allocation size

In the CFF flood mode, the PGT allocation size of RFID family will not
depend on number of FIDs, but rather number of ports and LAGs. Therefore
introduce a FID family operation to calculate the PGT allocation size.

The way that size is calculated in the CFF mode depends on calling fallible
functions. Thus express the op as returning an int, with the size returned
via a pointer argument.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/1174651b7160fcedbef50010ae4b68201112fe6f.1701183892.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: pmachata

drivers/net/ethernet/mellanox/mlxsw/spectrum_fid.c

@@ -97,6 +97,8 @@ struct mlxsw_sp_fid_ops {
 				     const struct mlxsw_sp_rif *rif);
 	int (*flood_table_init)(struct mlxsw_sp_fid_family *fid_family,
 				const struct mlxsw_sp_flood_table *flood_table);
+	int (*pgt_size)(const struct mlxsw_sp_fid_family *fid_family,
+			u16 *p_pgt_size);
 };
 
 struct mlxsw_sp_fid_family {
@@ -322,12 +324,14 @@ mlxsw_sp_fid_family_num_fids(const struct mlxsw_sp_fid_family *fid_family)
 	return fid_family->end_index - fid_family->start_index + 1;
 }
 
-static u16
-mlxsw_sp_fid_family_pgt_size(const struct mlxsw_sp_fid_family *fid_family)
+static int
+mlxsw_sp_fid_8021d_pgt_size(const struct mlxsw_sp_fid_family *fid_family,
+			    u16 *p_pgt_size)
 {
 	u16 num_fids = mlxsw_sp_fid_family_num_fids(fid_family);
 
-	return num_fids * fid_family->nr_flood_tables;
+	*p_pgt_size = num_fids * fid_family->nr_flood_tables;
+	return 0;
 }
 
 static u16
@@ -1124,6 +1128,7 @@ static const struct mlxsw_sp_fid_ops mlxsw_sp_fid_8021d_ops_ctl = {
 	.fdb_clear_offload	= mlxsw_sp_fid_8021d_fdb_clear_offload,
 	.vid_to_fid_rif_update  = mlxsw_sp_fid_8021d_vid_to_fid_rif_update,
 	.flood_table_init	= mlxsw_sp_fid_flood_table_init_ctl,
+	.pgt_size		= mlxsw_sp_fid_8021d_pgt_size,
 };
 
 #define MLXSW_SP_FID_8021Q_MAX (VLAN_N_VID - 2)
@@ -1466,6 +1471,7 @@ static const struct mlxsw_sp_fid_ops mlxsw_sp_fid_8021q_ops_ctl = {
 	.fdb_clear_offload	= mlxsw_sp_fid_8021q_fdb_clear_offload,
 	.vid_to_fid_rif_update  = mlxsw_sp_fid_8021q_vid_to_fid_rif_update,
 	.flood_table_init	= mlxsw_sp_fid_flood_table_init_ctl,
+	.pgt_size		= mlxsw_sp_fid_8021d_pgt_size,
 };
 
 /* There are 4K-2 802.1Q FIDs */
@@ -1717,7 +1723,10 @@ mlxsw_sp_fid_flood_tables_init(struct mlxsw_sp_fid_family *fid_family)
 	int err;
 	int i;
 
-	pgt_size = mlxsw_sp_fid_family_pgt_size(fid_family);
+	err = fid_family->ops->pgt_size(fid_family, &pgt_size);
+	if (err)
+		return err;
+
 	err = mlxsw_sp_pgt_mid_alloc_range(mlxsw_sp, &fid_family->pgt_base,
 					   pgt_size);
 	if (err)
@@ -1747,8 +1756,12 @@ mlxsw_sp_fid_flood_tables_fini(struct mlxsw_sp_fid_family *fid_family)
 {
 	struct mlxsw_sp *mlxsw_sp = fid_family->mlxsw_sp;
 	u16 pgt_size;
+	int err;
+
+	err = fid_family->ops->pgt_size(fid_family, &pgt_size);
+	if (WARN_ON_ONCE(err))
+		return;
 
-	pgt_size = mlxsw_sp_fid_family_pgt_size(fid_family);
 	mlxsw_sp_pgt_mid_free_range(mlxsw_sp, fid_family->pgt_base, pgt_size);
 }