From: Shalom Toledo <shalomt@mellanox.com>
Date: Thu, 1 Mar 2018 11:37:05 +0100
Subject: mlxsw: spectrum_switchdev: Check success of FDB add operation
Patch-mainline: v4.16-rc5
Git-commit: 0a8a1bf17e3af34f1f8d2368916a6327f8b3bfd5
References: bsc#1112374

Until now, we assumed that in case of error when adding FDB entries, the
write operation will fail, but this is not the case. Instead, we need to
check that the number of entries reported in the response is equal to
the number of entries specified in the request.

Fixes: 56ade8fe3fe1 ("mlxsw: spectrum: Add initial support for Spectrum ASIC")
Reported-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Shalom Toledo <shalomt@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c |   29 +++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -1203,6 +1203,7 @@ static int __mlxsw_sp_port_fdb_uc_op(str
 				     bool dynamic)
 {
 	char *sfd_pl;
+	u8 num_rec;
 	int err;
 
 	sfd_pl = kmalloc(MLXSW_REG_SFD_LEN, GFP_KERNEL);
@@ -1212,9 +1213,16 @@ static int __mlxsw_sp_port_fdb_uc_op(str
 	mlxsw_reg_sfd_pack(sfd_pl, mlxsw_sp_sfd_op(adding), 0);
 	mlxsw_reg_sfd_uc_pack(sfd_pl, 0, mlxsw_sp_sfd_rec_policy(dynamic),
 			      mac, fid, action, local_port);
+	num_rec = mlxsw_reg_sfd_num_rec_get(sfd_pl);
 	err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sfd), sfd_pl);
-	kfree(sfd_pl);
+	if (err)
+		goto out;
+
+	if (num_rec != mlxsw_reg_sfd_num_rec_get(sfd_pl))
+		err = -EBUSY;
 
+out:
+	kfree(sfd_pl);
 	return err;
 }
 
@@ -1239,6 +1247,7 @@ static int mlxsw_sp_port_fdb_uc_lag_op(s
 				       bool adding, bool dynamic)
 {
 	char *sfd_pl;
+	u8 num_rec;
 	int err;
 
 	sfd_pl = kmalloc(MLXSW_REG_SFD_LEN, GFP_KERNEL);
@@ -1249,9 +1258,16 @@ static int mlxsw_sp_port_fdb_uc_lag_op(s
 	mlxsw_reg_sfd_uc_lag_pack(sfd_pl, 0, mlxsw_sp_sfd_rec_policy(dynamic),
 				  mac, fid, MLXSW_REG_SFD_REC_ACTION_NOP,
 				  lag_vid, lag_id);
+	num_rec = mlxsw_reg_sfd_num_rec_get(sfd_pl);
 	err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sfd), sfd_pl);
-	kfree(sfd_pl);
+	if (err)
+		goto out;
 
+	if (num_rec != mlxsw_reg_sfd_num_rec_get(sfd_pl))
+		err = -EBUSY;
+
+out:
+	kfree(sfd_pl);
 	return err;
 }
 
@@ -1296,6 +1312,7 @@ static int mlxsw_sp_port_mdb_op(struct m
 				u16 fid, u16 mid_idx, bool adding)
 {
 	char *sfd_pl;
+	u8 num_rec;
 	int err;
 
 	sfd_pl = kmalloc(MLXSW_REG_SFD_LEN, GFP_KERNEL);
@@ -1305,7 +1322,15 @@ static int mlxsw_sp_port_mdb_op(struct m
 	mlxsw_reg_sfd_pack(sfd_pl, mlxsw_sp_sfd_op(adding), 0);
 	mlxsw_reg_sfd_mc_pack(sfd_pl, 0, addr, fid,
 			      MLXSW_REG_SFD_REC_ACTION_NOP, mid_idx);
+	num_rec = mlxsw_reg_sfd_num_rec_get(sfd_pl);
 	err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sfd), sfd_pl);
+	if (err)
+		goto out;
+
+	if (num_rec != mlxsw_reg_sfd_num_rec_get(sfd_pl))
+		err = -EBUSY;
+
+out:
 	kfree(sfd_pl);
 	return err;
 }