mlxsw: CFF flood mode: NVE underlay configuration

Recently, support for CFF flood mode (for Compressed FID Flooding) was added to the mlxsw driver. The most recent patchset has a detailed coverage of what CFF is and what has changed and how:

    https://lore.kernel.org/netdev/[email protected]/

In CFF flood mode, each FID allocates a handful (in our implementation two or three) consecutive PGT entries. One entry holds the flood vector for unknown-UC traffic, one for MC, one for BC.

To determine how to look up flood vectors, the CFF flood mode uses a concept of flood profiles, which are IDs that reference mappings from traffic types to offsets. In the case of CFF flood mode, the offset in question is applied to the PGT address configured at a FID. The same mechanism is used by NVE underlay for flooding. Again the profile ID and the traffic type determine the offset to apply, this time to KVD address used to look up flooding entries. Since mlxsw configures NVE underlay flood the same regardless of traffic type, only one offset was ever needed: the zero, which is the default, and thus no explicit configuration was needed.

Now that CFF uses profiles as well, it would be better to configure the profile used by NVE explicitly, to make the configuration visible in the source code.

In this patchset, add the register support (in patch #1), add a new traffic type to refer to "any traffic at all" (in patch #2) and finally configure the NVE profile explicitly for FIDs (in patch #3).

So far, the implicitly configured flood profile was the ID 0. With this patchset, it changes to 3, leaving the 0 free to allow us to spot missed configuration.

Petr Machata (3):
mlxsw: reg: Add nve_flood_prf_id field to SFMR
mlxsw: spectrum_fid: Add an "any" packet type
mlxsw: spectrum_fid: Set NVE flood profile as part of FID
configuration

 drivers/net/ethernet/mellanox/mlxsw/reg.h     |  9 ++++++
 .../net/ethernet/mellanox/mlxsw/spectrum.h    |  2 ++
 .../ethernet/mellanox/mlxsw/spectrum_fid.c    | 29 +++++++++++++++++++
 3 files changed, 40 insertions(+)

2.41.0

The field is used for setting a flood profile for lookup of KVD entry for NVE underlay. As the other uses of flood profile, this references a traffic type-to-offset mapping, except here it is not applied to PGT offsets, but KVD offsets.

---
 drivers/net/ethernet/mellanox/mlxsw/reg.h | 9 +++++++++
 1 file changed, 9 insertions(+)

index 3aae4467e431..8892654c685f 100644
@@ -1954,6 +1954,15 @@ MLXSW_ITEM32(reg, sfmr, irif, 0x14, 0, 16);
  */
 MLXSW_ITEM32(reg, sfmr, cff_mid_base, 0x20, 0, 16);
 
+/* reg_sfmr_nve_flood_prf_id
+ * FID flooding profile_id for NVE Encap
+ * Range 0..(max_cap_nve_flood_prf-1)
+ * Access: RW
+ *
+ * Note: Reserved when SwitchX/-2 and Spectrum-1
+ */
+MLXSW_ITEM32(reg, sfmr, nve_flood_prf_id, 0x24, 8, 2);
+
 /* reg_sfmr_cff_prf_id
  * Compressed Fid Flooding profile_id
  * Range 0..(max_cap_nve_flood_prf-1)

2.41.0

Flood profiles have been used prior to CFF support for NVE underlay. Like is the case with FID flooding, an NVE profile describes at which offset a datum is located given traffic type. mlxsw currently only ever uses one KVD entry for NVE lookup, i.e. regardless of traffic type, the offset is always zero. To be able to describe this, add a traffic type enumerator describing "any traffic type".

---
 drivers/net/ethernet/mellanox/mlxsw/spectrum.h     |  2 ++
 drivers/net/ethernet/mellanox/mlxsw/spectrum_fid.c | 11 +++++++++++
 2 files changed, 13 insertions(+)

index 61612c413310..a0c9775fa955 100644
@@ -515,6 +515,8 @@ enum mlxsw_sp_flood_type {
 	MLXSW_SP_FLOOD_TYPE_MC,
 	/* For RSP FIDs in CFF mode. */
 	MLXSW_SP_FLOOD_TYPE_NOT_UC,
+	/* For NVE traffic. */
+	MLXSW_SP_FLOOD_TYPE_ANY,
 };
 
 int mlxsw_sp_port_get_stats_raw(struct net_device *dev, int grp,

index 401117086235..379a911f463f 100644
@@ -167,11 +167,22 @@ static const int mlxsw_sp_sfgc_not_uc_packet_types[MLXSW_REG_SFGC_TYPE_MAX] = {
 	[MLXSW_REG_SFGC_TYPE_UNREGISTERED_MULTICAST_IPV4]	= 1,
 };
 
+static const int mlxsw_sp_sfgc_any_packet_types[MLXSW_REG_SFGC_TYPE_MAX] = {
+	[MLXSW_REG_SFGC_TYPE_UNKNOWN_UNICAST]			= 1,
+	[MLXSW_REG_SFGC_TYPE_BROADCAST]				= 1,
+	[MLXSW_REG_SFGC_TYPE_UNREGISTERED_MULTICAST_NON_IP]	= 1,
+	[MLXSW_REG_SFGC_TYPE_IPV4_LINK_LOCAL]			= 1,
+	[MLXSW_REG_SFGC_TYPE_IPV6_ALL_HOST]			= 1,
+	[MLXSW_REG_SFGC_TYPE_UNREGISTERED_MULTICAST_IPV6]	= 1,
+	[MLXSW_REG_SFGC_TYPE_UNREGISTERED_MULTICAST_IPV4]	= 1,
+};
+
 static const int *mlxsw_sp_packet_type_sfgc_types[] = {
 	[MLXSW_SP_FLOOD_TYPE_UC]	= mlxsw_sp_sfgc_uc_packet_types,
 	[MLXSW_SP_FLOOD_TYPE_BC]	= mlxsw_sp_sfgc_bc_packet_types,
 	[MLXSW_SP_FLOOD_TYPE_MC]	= mlxsw_sp_sfgc_mc_packet_types,
 	[MLXSW_SP_FLOOD_TYPE_NOT_UC]	= mlxsw_sp_sfgc_not_uc_packet_types,
+	[MLXSW_SP_FLOOD_TYPE_ANY]	= mlxsw_sp_sfgc_any_packet_types,
 };
 
 struct mlxsw_sp_fid *mlxsw_sp_fid_lookup_by_index(struct mlxsw_sp *mlxsw_sp,

2.41.0

The NVE flood profile is used for determining of offset applied to KVD address for NVE flood. We currently do not set it, leaving it at the default value of 0. That is not an issue: all the traffic-type-to-offset mappings (as configured by SFFP) default to offset of 0. This is what we need anyway, as mlxsw only allocates a single KVD entry for NVE underlay.

The field is only relevant on Spectrum-2 and above. So to be fully consistent, we should split the existing controlled ops to Spectrum-1 and Spectrum>1 variants, with only the latter setting the field. But that seems like a lot of overhead for a single field whose meaning is "everything is the default". So instead pretend that the NVE flood profile does not exist in the controlled flood mode, like we have so far, and only set it when flood mode is CFF.

Setting this at all serves dual purpose. First, it is now clear which profile belongs to NVE, because in the CFF mode, we have multiple users. This should prevent bugs in flood profile management. Second, using specifically non-zero value means there will be no valid uses of the profile 0, which we can therefore use as a sentinel.

---
 .../net/ethernet/mellanox/mlxsw/spectrum_fid.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

index 379a911f463f..65562ab208b3 100644
@@ -117,6 +117,7 @@ struct mlxsw_sp_fid_ops {
 enum mlxsw_sp_fid_flood_profile_id {
 	MLXSW_SP_FID_FLOOD_PROFILE_ID_BRIDGE = 1,
 	MLXSW_SP_FID_FLOOD_PROFILE_ID_RSP,
+	MLXSW_SP_FID_FLOOD_PROFILE_ID_NVE,
 };
 
 struct mlxsw_sp_fid_flood_profile {

@@ -560,6 +561,8 @@ static void mlxsw_sp_fid_fid_pack_cff(char *sfmr_pl,
 	mlxsw_reg_sfmr_cff_mid_base_set(sfmr_pl, pgt_base);
 	mlxsw_reg_sfmr_cff_prf_id_set(sfmr_pl,
 				      fid_family->flood_profile->profile_id);
+	mlxsw_reg_sfmr_nve_flood_prf_id_set(sfmr_pl,
+					    MLXSW_SP_FID_FLOOD_PROFILE_ID_NVE);
 }
 
 static u16 mlxsw_sp_fid_rfid_fid_offset_cff(struct mlxsw_sp *mlxsw_sp,

@@ -1321,6 +1324,20 @@ struct mlxsw_sp_fid_flood_profile mlxsw_sp_fid_rsp_flood_profile_cff = {
 	.profile_id		= MLXSW_SP_FID_FLOOD_PROFILE_ID_RSP,
 };
 
+static const struct mlxsw_sp_flood_table mlxsw_sp_fid_nve_flood_tables_cff[] = {
+	{
+		.packet_type	= MLXSW_SP_FLOOD_TYPE_ANY,
+		.table_index	= 0,
+	},
+};
+
+static const
+struct mlxsw_sp_fid_flood_profile mlxsw_sp_fid_nve_flood_profile_cff = {
+	.flood_tables		= mlxsw_sp_fid_nve_flood_tables_cff,
+	.nr_flood_tables	= ARRAY_SIZE(mlxsw_sp_fid_nve_flood_tables_cff),
+	.profile_id		= MLXSW_SP_FID_FLOOD_PROFILE_ID_NVE,
+};
+
 static bool
 mlxsw_sp_fid_8021q_compare(const struct mlxsw_sp_fid *fid, const void *arg)
 {

@@ -2422,6 +2439,7 @@ static const
 struct mlxsw_sp_fid_flood_profile *mlxsw_sp_fid_flood_profiles[] = {
 	&mlxsw_sp_fid_8021d_flood_profile,
 	&mlxsw_sp_fid_rsp_flood_profile_cff,
+	&mlxsw_sp_fid_nve_flood_profile_cff,
 };
 
 static int

2.41.0