mlxsw: spectrum_pgt: Generalize PGT allocation

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.

In this patch, change the interface accordingly. Initialize FID family's
pgt_base from the result of the PGT allocation (note that mlxsw makes a
copy of the family structure, so what gets initialized is not actually the
global structure). Drop the now-unnecessary pgt_base initializations and
the corresponding defines.
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.h

@@ -1480,7 +1480,7 @@ int mlxsw_sp_policer_resources_register(struct mlxsw_core *mlxsw_core);
 /* spectrum_pgt.c */
 int mlxsw_sp_pgt_mid_alloc(struct mlxsw_sp *mlxsw_sp, u16 *p_mid);
 void mlxsw_sp_pgt_mid_free(struct mlxsw_sp *mlxsw_sp, u16 mid_base);
-int mlxsw_sp_pgt_mid_alloc_range(struct mlxsw_sp *mlxsw_sp, u16 mid_base,
+int mlxsw_sp_pgt_mid_alloc_range(struct mlxsw_sp *mlxsw_sp, u16 *mid_base,
 				 u16 count);
 void mlxsw_sp_pgt_mid_free_range(struct mlxsw_sp *mlxsw_sp, u16 mid_base,
 				 u16 count);

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

@@ -1076,8 +1076,6 @@ static const struct mlxsw_sp_fid_ops mlxsw_sp_fid_8021d_ops = {
 
 #define MLXSW_SP_FID_8021Q_MAX (VLAN_N_VID - 2)
 #define MLXSW_SP_FID_RFID_MAX (11 * 1024)
-#define MLXSW_SP_FID_8021Q_PGT_BASE 0
-#define MLXSW_SP_FID_8021D_PGT_BASE (3 * MLXSW_SP_FID_8021Q_MAX)
 
 static const struct mlxsw_sp_flood_table mlxsw_sp_fid_8021d_flood_tables[] = {
 	{
@@ -1442,7 +1440,6 @@ static const struct mlxsw_sp_fid_family mlxsw_sp1_fid_8021q_family = {
 	.ops			= &mlxsw_sp_fid_8021q_ops,
 	.flood_rsp              = false,
 	.bridge_type            = MLXSW_REG_BRIDGE_TYPE_0,
-	.pgt_base		= MLXSW_SP_FID_8021Q_PGT_BASE,
 	.smpe_index_valid	= false,
 };
 
@@ -1456,7 +1453,6 @@ static const struct mlxsw_sp_fid_family mlxsw_sp1_fid_8021d_family = {
 	.rif_type		= MLXSW_SP_RIF_TYPE_FID,
 	.ops			= &mlxsw_sp_fid_8021d_ops,
 	.bridge_type            = MLXSW_REG_BRIDGE_TYPE_1,
-	.pgt_base		= MLXSW_SP_FID_8021D_PGT_BASE,
 	.smpe_index_valid       = false,
 };
 
@@ -1498,7 +1494,6 @@ static const struct mlxsw_sp_fid_family mlxsw_sp2_fid_8021q_family = {
 	.ops			= &mlxsw_sp_fid_8021q_ops,
 	.flood_rsp              = false,
 	.bridge_type            = MLXSW_REG_BRIDGE_TYPE_0,
-	.pgt_base		= MLXSW_SP_FID_8021Q_PGT_BASE,
 	.smpe_index_valid	= true,
 };
 
@@ -1512,7 +1507,6 @@ static const struct mlxsw_sp_fid_family mlxsw_sp2_fid_8021d_family = {
 	.rif_type		= MLXSW_SP_RIF_TYPE_FID,
 	.ops			= &mlxsw_sp_fid_8021d_ops,
 	.bridge_type            = MLXSW_REG_BRIDGE_TYPE_1,
-	.pgt_base		= MLXSW_SP_FID_8021D_PGT_BASE,
 	.smpe_index_valid       = true,
 };
 
@@ -1697,7 +1691,7 @@ mlxsw_sp_fid_flood_tables_init(struct mlxsw_sp_fid_family *fid_family)
 		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,
+	err = mlxsw_sp_pgt_mid_alloc_range(mlxsw_sp, &fid_family->pgt_base,
 					   pgt_size);
 	if (err)
 		return err;

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

@@ -54,25 +54,15 @@ void mlxsw_sp_pgt_mid_free(struct mlxsw_sp *mlxsw_sp, u16 mid_base)
 	mutex_unlock(&mlxsw_sp->pgt->lock);
 }
 
-int
-mlxsw_sp_pgt_mid_alloc_range(struct mlxsw_sp *mlxsw_sp, u16 mid_base, u16 count)
+int mlxsw_sp_pgt_mid_alloc_range(struct mlxsw_sp *mlxsw_sp, u16 *p_mid_base,
+				 u16 count)
 {
-	unsigned int idr_cursor;
+	unsigned int mid_base;
 	int i, err;
 
 	mutex_lock(&mlxsw_sp->pgt->lock);
 
-	/* This function is supposed to be called several times as part of
-	 * driver init, in specific order. Verify that the mid_index is the
-	 * first free index in the idr, to be able to free the indexes in case
-	 * of error.
-	 */
-	idr_cursor = idr_get_cursor(&mlxsw_sp->pgt->pgt_idr);
-	if (WARN_ON(idr_cursor != mid_base)) {
-		err = -EINVAL;
-		goto err_idr_cursor;
-	}
-
+	mid_base = idr_get_cursor(&mlxsw_sp->pgt->pgt_idr);
 	for (i = 0; i < count; i++) {
 		err = idr_alloc_cyclic(&mlxsw_sp->pgt->pgt_idr, NULL,
 				       mid_base, mid_base + count, GFP_KERNEL);
@@ -81,12 +71,12 @@ mlxsw_sp_pgt_mid_alloc_range(struct mlxsw_sp *mlxsw_sp, u16 mid_base, u16 count)
 	}
 
 	mutex_unlock(&mlxsw_sp->pgt->lock);
+	*p_mid_base = mid_base;
 	return 0;
 
 err_idr_alloc_cyclic:
 	for (i--; i >= 0; i--)
 		idr_remove(&mlxsw_sp->pgt->pgt_idr, mid_base + i);
-err_idr_cursor:
 	mutex_unlock(&mlxsw_sp->pgt->lock);
 	return err;
 }