mlxsw: spectrum_ptp: Increase parsing depth when PTP is enabled

Spectrum systems have a configurable limit on how far into the packet they
parse. By default, the limit is 96 bytes.

An IPv6 PTP packet is layered as Ethernet/IPv6/UDP (14+40+8 bytes), and
sequence ID of a PTP event is only available 32 bytes into payload, for a
total of 94 bytes. When an additional 802.1q header is present as
well (such as when ptp4l is running on a VLAN port), the parsing limit is
exceeded. Such packets are not recognized as PTP, and are not timestamped.

Therefore generalize the current VXLAN-specific parsing depth setting to
allow reference-counted requests from other modules as well. Keep it in the
VXLAN module, because the MPRS register also configures UDP destination
port number used for VXLAN, and is thus closely tied to the VXLAN code
anyway.

Then invoke the new interfaces from both VXLAN (in obvious places), as well
as from PTP code, when the (global) timestamping configuration changes from
disabled to enabled or vice versa.

Fixes: 8748642751ed ("mlxsw: spectrum: PTP: Support SIOCGHWTSTAMP, SIOCSHWTSTAMP ioctls")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 59 insertions, 17 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c
index 93ccd9fc2266..05517c7feaa5 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c
@@ -103,9 +103,9 @@ static void mlxsw_sp_nve_vxlan_config(const struct mlxsw_sp_nve *nve,
 	config->udp_dport = cfg->dst_port;
 }
 
-static int mlxsw_sp_nve_parsing_set(struct mlxsw_sp *mlxsw_sp,
-				    unsigned int parsing_depth,
-				    __be16 udp_dport)
+static int __mlxsw_sp_nve_parsing_set(struct mlxsw_sp *mlxsw_sp,
+				      unsigned int parsing_depth,
+				      __be16 udp_dport)
 {
 	char mprs_pl[MLXSW_REG_MPRS_LEN];
 
@@ -113,6 +113,56 @@ static int mlxsw_sp_nve_parsing_set(struct mlxsw_sp *mlxsw_sp,
 	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mprs), mprs_pl);
 }
 
+static int mlxsw_sp_nve_parsing_set(struct mlxsw_sp *mlxsw_sp,
+				    __be16 udp_dport)
+{
+	int parsing_depth = mlxsw_sp->nve->inc_parsing_depth_refs ?
+				MLXSW_SP_NVE_VXLAN_PARSING_DEPTH :
+				MLXSW_SP_NVE_DEFAULT_PARSING_DEPTH;
+
+	return __mlxsw_sp_nve_parsing_set(mlxsw_sp, parsing_depth, udp_dport);
+}
+
+static int
+__mlxsw_sp_nve_inc_parsing_depth_get(struct mlxsw_sp *mlxsw_sp,
+				     __be16 udp_dport)
+{
+	int err;
+
+	mlxsw_sp->nve->inc_parsing_depth_refs++;
+
+	err = mlxsw_sp_nve_parsing_set(mlxsw_sp, udp_dport);
+	if (err)
+		goto err_nve_parsing_set;
+	return 0;
+
+err_nve_parsing_set:
+	mlxsw_sp->nve->inc_parsing_depth_refs--;
+	return err;
+}
+
+static void
+__mlxsw_sp_nve_inc_parsing_depth_put(struct mlxsw_sp *mlxsw_sp,
+				     __be16 udp_dport)
+{
+	mlxsw_sp->nve->inc_parsing_depth_refs--;
+	mlxsw_sp_nve_parsing_set(mlxsw_sp, udp_dport);
+}
+
+int mlxsw_sp_nve_inc_parsing_depth_get(struct mlxsw_sp *mlxsw_sp)
+{
+	__be16 udp_dport = mlxsw_sp->nve->config.udp_dport;
+
+	return __mlxsw_sp_nve_inc_parsing_depth_get(mlxsw_sp, udp_dport);
+}
+
+void mlxsw_sp_nve_inc_parsing_depth_put(struct mlxsw_sp *mlxsw_sp)
+{
+	__be16 udp_dport = mlxsw_sp->nve->config.udp_dport;
+
+	__mlxsw_sp_nve_inc_parsing_depth_put(mlxsw_sp, udp_dport);
+}
+
 static void
 mlxsw_sp_nve_vxlan_config_prepare(char *tngcr_pl,
 				  const struct mlxsw_sp_nve_config *config)
@@ -176,9 +226,7 @@ static int mlxsw_sp1_nve_vxlan_init(struct mlxsw_sp_nve *nve,
 	struct mlxsw_sp *mlxsw_sp = nve->mlxsw_sp;
 	int err;
 
-	err = mlxsw_sp_nve_parsing_set(mlxsw_sp,
-				       MLXSW_SP_NVE_VXLAN_PARSING_DEPTH,
-				       config->udp_dport);
+	err = __mlxsw_sp_nve_inc_parsing_depth_get(mlxsw_sp, config->udp_dport);
 	if (err)
 		return err;
 
@@ -203,8 +251,7 @@ err_promote_decap:
 err_rtdp_set:
 	mlxsw_sp1_nve_vxlan_config_clear(mlxsw_sp);
 err_config_set:
-	mlxsw_sp_nve_parsing_set(mlxsw_sp, MLXSW_SP_NVE_DEFAULT_PARSING_DEPTH,
-				 config->udp_dport);
+	__mlxsw_sp_nve_inc_parsing_depth_put(mlxsw_sp, 0);
 	return err;
 }
 
@@ -216,8 +263,7 @@ static void mlxsw_sp1_nve_vxlan_fini(struct mlxsw_sp_nve *nve)
 	mlxsw_sp_router_nve_demote_decap(mlxsw_sp, config->ul_tb_id,
 					 config->ul_proto, &config->ul_sip);
 	mlxsw_sp1_nve_vxlan_config_clear(mlxsw_sp);
-	mlxsw_sp_nve_parsing_set(mlxsw_sp, MLXSW_SP_NVE_DEFAULT_PARSING_DEPTH,
-				 config->udp_dport);
+	__mlxsw_sp_nve_inc_parsing_depth_put(mlxsw_sp, 0);
 }
 
 static int
@@ -320,9 +366,7 @@ static int mlxsw_sp2_nve_vxlan_init(struct mlxsw_sp_nve *nve,
 	struct mlxsw_sp *mlxsw_sp = nve->mlxsw_sp;
 	int err;
 
-	err = mlxsw_sp_nve_parsing_set(mlxsw_sp,
-				       MLXSW_SP_NVE_VXLAN_PARSING_DEPTH,
-				       config->udp_dport);
+	err = __mlxsw_sp_nve_inc_parsing_depth_get(mlxsw_sp, config->udp_dport);
 	if (err)
 		return err;
 
@@ -348,8 +392,7 @@ err_promote_decap:
 err_rtdp_set:
 	mlxsw_sp2_nve_vxlan_config_clear(mlxsw_sp);
 err_config_set:
-	mlxsw_sp_nve_parsing_set(mlxsw_sp, MLXSW_SP_NVE_DEFAULT_PARSING_DEPTH,
-				 config->udp_dport);
+	__mlxsw_sp_nve_inc_parsing_depth_put(mlxsw_sp, 0);
 	return err;
 }
 
@@ -361,8 +404,7 @@ static void mlxsw_sp2_nve_vxlan_fini(struct mlxsw_sp_nve *nve)
 	mlxsw_sp_router_nve_demote_decap(mlxsw_sp, config->ul_tb_id,
 					 config->ul_proto, &config->ul_sip);
 	mlxsw_sp2_nve_vxlan_config_clear(mlxsw_sp);
-	mlxsw_sp_nve_parsing_set(mlxsw_sp, MLXSW_SP_NVE_DEFAULT_PARSING_DEPTH,
-				 config->udp_dport);
+	__mlxsw_sp_nve_inc_parsing_depth_put(mlxsw_sp, 0);
 }
 
 const struct mlxsw_sp_nve_ops mlxsw_sp2_nve_vxlan_ops = {