sfc: check recirc_id match caps before MAE offload

Offloaded TC rules always match on recirc_id in the MAE, so we should
 check that the MAE reported support for this match before attempting
 to insert the rule.
These checks allow us to fail early, avoiding the PCIe round-trip to
 firmware for an MC_CMD_MAE_ACTION_RULE_INSERT that will only fail,
 and more importantly providing a more informative error message that
 identifies which match field is unsupported.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/sfc/mae.c b/drivers/net/ethernet/sfc/mae.c
index 6f472ea..cd01495 100644 (file)
--- a/drivers/net/ethernet/sfc/mae.c
+++ b/drivers/net/ethernet/sfc/mae.c
@@ -250,6 +250,20 @@ static int efx_mae_match_check_cap_typ(u8 support, enum mask_type typ)
        }
 }
 
+/* Validate field mask against hardware capabilities.  Captures caller's 'rc' */
+#define CHECK(_mcdi, _field)   ({                                             \
+       enum mask_type typ = classify_mask((const u8 *)&mask->_field,          \
+                                          sizeof(mask->_field));              \
+                                                                              \
+       rc = efx_mae_match_check_cap_typ(supported_fields[MAE_FIELD_ ## _mcdi],\
+                                        typ);                                 \
+       if (rc)                                                                \
+               NL_SET_ERR_MSG_FMT_MOD(extack,                                 \
+                                      "No support for %s mask in field %s",   \
+                                      mask_type_name(typ), #_field);          \
+       rc;                                                                    \
+})
+
 int efx_mae_match_check_caps(struct efx_nic *efx,
                             const struct efx_tc_match_fields *mask,
                             struct netlink_ext_ack *extack)
@@ -269,8 +283,11 @@ int efx_mae_match_check_caps(struct efx_nic *efx,
                                       mask_type_name(ingress_port_mask_type));
                return rc;
        }
+       if (CHECK(RECIRC_ID, recirc_id))
+               return rc;
        return 0;
 }
+#undef CHECK
 
 static bool efx_mae_asl_id(u32 id)
 {