sfc: determine wire m-port at EF100 PF probe time

Traffic delivered to the (MAE admin) PF could be from either the wire
 or a VF.  The INGRESS_MPORT field of the RX prefix distinguishes these;
 base_mport is the value this field will have for traffic from the wire
 (which should be delivered to the PF's netdevice, not a representor).

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

drivers/net/ethernet/sfc/ef100_nic.c

@@ -24,6 +24,7 @@
 #include "ef100_tx.h"
 #include "ef100_sriov.h"
 #include "ef100_netdev.h"
+#include "mae.h"
 #include "rx_common.h"
 
 #define EF100_MAX_VIS 4096
@@ -704,6 +705,31 @@ static unsigned int efx_ef100_recycle_ring_size(const struct efx_nic *efx)
 	return 10 * EFX_RECYCLE_RING_SIZE_10G;
 }
 
+#ifdef CONFIG_SFC_SRIOV
+static int efx_ef100_get_base_mport(struct efx_nic *efx)
+{
+	struct ef100_nic_data *nic_data = efx->nic_data;
+	u32 selector, id;
+	int rc;
+
+	/* Construct mport selector for "physical network port" */
+	efx_mae_mport_wire(efx, &selector);
+	/* Look up actual mport ID */
+	rc = efx_mae_lookup_mport(efx, selector, &id);
+	if (rc)
+		return rc;
+	/* The ID should always fit in 16 bits, because that's how wide the
+	 * corresponding fields in the RX prefix & TX override descriptor are
+	 */
+	if (id >> 16)
+		netif_warn(efx, probe, efx->net_dev, "Bad base m-port id %#x\n",
+			   id);
+	nic_data->base_mport = id;
+	nic_data->have_mport = true;
+	return 0;
+}
+#endif
+
 static int compare_versions(const char *a, const char *b)
 {
 	int a_major, a_minor, a_point, a_patch;
@@ -1064,6 +1090,17 @@ int ef100_probe_netdev_pf(struct efx_nic *efx)
 	eth_hw_addr_set(net_dev, net_dev->perm_addr);
 	memcpy(nic_data->port_id, net_dev->perm_addr, ETH_ALEN);
 
+	if (!nic_data->grp_mae)
+		return 0;
+
+#ifdef CONFIG_SFC_SRIOV
+	rc = efx_ef100_get_base_mport(efx);
+	if (rc) {
+		netif_warn(efx, probe, net_dev,
+			   "Failed to probe base mport rc %d; representors will not function\n",
+			   rc);
+	}
+#endif
 	return 0;
 
 fail:

drivers/net/ethernet/sfc/ef100_nic.h

@@ -72,6 +72,8 @@ struct ef100_nic_data {
 	u8 port_id[ETH_ALEN];
 	DECLARE_BITMAP(evq_phases, EFX_MAX_CHANNELS);
 	u64 stats[EF100_STAT_COUNT];
+	u32 base_mport;
+	bool have_mport; /* base_mport was populated successfully */
 	bool grp_mae; /* MAE Privilege */
 	u16 tso_max_hdr_len;
 	u16 tso_max_payload_num_segs;

drivers/net/ethernet/sfc/mae.c

@@ -13,6 +13,16 @@
 #include "mcdi.h"
 #include "mcdi_pcol.h"
 
+void efx_mae_mport_wire(struct efx_nic *efx, u32 *out)
+{
+	efx_dword_t mport;
+
+	EFX_POPULATE_DWORD_2(mport,
+			     MAE_MPORT_SELECTOR_TYPE, MAE_MPORT_SELECTOR_TYPE_PPORT,
+			     MAE_MPORT_SELECTOR_PPORT_ID, efx->port_num);
+	*out = EFX_DWORD_VAL(mport);
+}
+
 void efx_mae_mport_vf(struct efx_nic *efx __always_unused, u32 vf_id, u32 *out)
 {
 	efx_dword_t mport;

drivers/net/ethernet/sfc/mae.h

@@ -15,6 +15,7 @@
 
 #include "net_driver.h"
 
+void efx_mae_mport_wire(struct efx_nic *efx, u32 *out);
 void efx_mae_mport_vf(struct efx_nic *efx, u32 vf_id, u32 *out);
 
 int efx_mae_lookup_mport(struct efx_nic *efx, u32 selector, u32 *id);