mlxsw: spectrum_fid: Allocate PGT for the whole FID family in one go

PGT blocks are allocated through the function
mlxsw_sp_pgt_mid_alloc_range(). The interface assumes that the caller knows
which piece of PGT exactly they want to get. That was fine while the FID
code was the only client allocating blocks of PGT. However for SW-allocated
LAG table, there will be an additional client: mlxsw_sp_lag_init(). The
interface should therefore be changed to not require particular
coordinates, but to take just the requested size, allocate the block
wherever, and give back the PGT address.

The current FID mode has one place where PGT address can be stored: the FID
family's pgt_base. The allocation scheme should therefore be changed from
allocating a block per FID flood table, to allocating a block per FID
family.

Do just that in this patch.

The per-family allocation is going to be useful for another related feature
as well: the CFF mode.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -320,6 +320,14 @@ 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)
+{
+	u16 num_fids = mlxsw_sp_fid_family_num_fids(fid_family);
+
+	return num_fids * fid_family->nr_flood_tables;
+}
+
 static u16
 mlxsw_sp_fid_flood_table_mid(const struct mlxsw_sp_fid_family *fid_family,
 			     const struct mlxsw_sp_flood_table *flood_table,
@@ -1654,14 +1662,10 @@ mlxsw_sp_fid_flood_table_init(struct mlxsw_sp_fid_family *fid_family,
 	enum mlxsw_sp_flood_type packet_type = flood_table->packet_type;
 	struct mlxsw_sp *mlxsw_sp = fid_family->mlxsw_sp;
 	const int *sfgc_packet_types;
-	u16 num_fids, mid_base;
+	u16 mid_base;
 	int err, i;
 
 	mid_base = mlxsw_sp_fid_flood_table_mid(fid_family, flood_table, 0);
-	num_fids = mlxsw_sp_fid_family_num_fids(fid_family);
-	err = mlxsw_sp_pgt_mid_alloc_range(mlxsw_sp, mid_base, num_fids);
-	if (err)
-		return err;
 
 	sfgc_packet_types = mlxsw_sp_packet_type_sfgc_types[packet_type];
 	for (i = 0; i < MLXSW_REG_SFGC_TYPE_MAX; i++) {
@@ -1675,57 +1679,56 @@ mlxsw_sp_fid_flood_table_init(struct mlxsw_sp_fid_family *fid_family,
 
 		err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sfgc), sfgc_pl);
 		if (err)
-			goto err_reg_write;
+			return err;
 	}
 
 	return 0;
-
-err_reg_write:
-	mlxsw_sp_pgt_mid_free_range(mlxsw_sp, mid_base, num_fids);
-	return err;
-}
-
-static void
-mlxsw_sp_fid_flood_table_fini(struct mlxsw_sp_fid_family *fid_family,
-			      const struct mlxsw_sp_flood_table *flood_table)
-{
-	struct mlxsw_sp *mlxsw_sp = fid_family->mlxsw_sp;
-	u16 num_fids, mid_base;
-
-	mid_base = mlxsw_sp_fid_flood_table_mid(fid_family, flood_table, 0);
-	num_fids = mlxsw_sp_fid_family_num_fids(fid_family);
-	mlxsw_sp_pgt_mid_free_range(mlxsw_sp, mid_base, num_fids);
 }
 
 static int
 mlxsw_sp_fid_flood_tables_init(struct mlxsw_sp_fid_family *fid_family)
 {
+	struct mlxsw_sp *mlxsw_sp = fid_family->mlxsw_sp;
+	u16 pgt_size;
+	int err;
 	int i;
 
+	if (!fid_family->nr_flood_tables)
+		return 0;
+
+	pgt_size = mlxsw_sp_fid_family_pgt_size(fid_family);
+	err = mlxsw_sp_pgt_mid_alloc_range(mlxsw_sp, fid_family->pgt_base,
+					   pgt_size);
+	if (err)
+		return err;
+
 	for (i = 0; i < fid_family->nr_flood_tables; i++) {
 		const struct mlxsw_sp_flood_table *flood_table;
-		int err;
 
 		flood_table = &fid_family->flood_tables[i];
 		err = mlxsw_sp_fid_flood_table_init(fid_family, flood_table);
 		if (err)
-			return err;
+			goto err_flood_table_init;
 	}
 
 	return 0;
+
+err_flood_table_init:
+	mlxsw_sp_pgt_mid_free_range(mlxsw_sp, fid_family->pgt_base, pgt_size);
+	return err;
 }
 
 static void
 mlxsw_sp_fid_flood_tables_fini(struct mlxsw_sp_fid_family *fid_family)
 {
-	int i;
+	struct mlxsw_sp *mlxsw_sp = fid_family->mlxsw_sp;
+	u16 pgt_size;
 
-	for (i = 0; i < fid_family->nr_flood_tables; i++) {
-		const struct mlxsw_sp_flood_table *flood_table;
+	if (!fid_family->nr_flood_tables)
+		return;
 
-		flood_table = &fid_family->flood_tables[i];
-		mlxsw_sp_fid_flood_table_fini(fid_family, flood_table);
-	}
+	pgt_size = mlxsw_sp_fid_family_pgt_size(fid_family);
+	mlxsw_sp_pgt_mid_free_range(mlxsw_sp, fid_family->pgt_base, pgt_size);
 }
 
 static int mlxsw_sp_fid_family_register(struct mlxsw_sp *mlxsw_sp,