[PATCH net-next v4 04/14] sfc: evaluate vdpa support based on FW capability CLIENT_CMD_VF_PROXY

[Gautam Dawar]

Add and update vdpa_supported field to struct efx_nic to true if
running Firmware supports CLIENT_CMD_VF_PROXY capability. This is
required to ensure DMA isolation between MCDI command buffer and guest
buffers.
Also, split efx_ef100_init_datapath_caps() into a generic API that vDPA
can use, and the netdev (TSO) specific code is moved to a new function
efx_ef100_update_tso_features()

Signed-off-by: Gautam Dawar <gautam.dawar@xxxxxxx>
---
 drivers/net/ethernet/sfc/ef100_netdev.c | 26 +++++++++++++--
 drivers/net/ethernet/sfc/ef100_nic.c    | 42 ++++++++++++-------------
 drivers/net/ethernet/sfc/ef100_nic.h    |  6 ++--
 3 files changed, 48 insertions(+), 26 deletions(-)

diff --git a/drivers/net/ethernet/sfc/ef100_netdev.c b/drivers/net/ethernet/sfc/ef100_netdev.c
index d916877b5a9a..5d93e870d9b7 100644
--- a/drivers/net/ethernet/sfc/ef100_netdev.c
+++ b/drivers/net/ethernet/sfc/ef100_netdev.c
@@ -355,6 +355,28 @@ void ef100_remove_netdev(struct efx_probe_data *probe_data)
 	efx->state = STATE_PROBED;
 }
 
+static void efx_ef100_update_tso_features(struct efx_nic *efx)
+{
+	struct ef100_nic_data *nic_data = efx->nic_data;
+	struct net_device *net_dev = efx->net_dev;
+	netdev_features_t tso;
+
+	if (!efx_ef100_has_cap(nic_data->datapath_caps2, TX_TSO_V3))
+		return;
+
+	tso = NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_GSO_PARTIAL |
+	      NETIF_F_GSO_UDP_TUNNEL | NETIF_F_GSO_UDP_TUNNEL_CSUM |
+	      NETIF_F_GSO_GRE | NETIF_F_GSO_GRE_CSUM;
+
+	net_dev->features |= tso;
+	net_dev->hw_features |= tso;
+	net_dev->hw_enc_features |= tso;
+	/* EF100 HW can only offload outer checksums if they are UDP,
+	 * so for GRE_CSUM we have to use GSO_PARTIAL.
+	 */
+	net_dev->gso_partial_features |= NETIF_F_GSO_GRE_CSUM;
+}
+
 int ef100_probe_netdev(struct efx_probe_data *probe_data)
 {
 	struct efx_nic *efx = &probe_data->efx;
@@ -387,9 +409,7 @@ int ef100_probe_netdev(struct efx_probe_data *probe_data)
 			       ESE_EF100_DP_GZ_TSO_MAX_HDR_NUM_SEGS_DEFAULT);
 	efx->mdio.dev = net_dev;
 
-	rc = efx_ef100_init_datapath_caps(efx);
-	if (rc < 0)
-		goto fail;
+	efx_ef100_update_tso_features(efx);
 
 	rc = ef100_phy_probe(efx);
 	if (rc)
diff --git a/drivers/net/ethernet/sfc/ef100_nic.c b/drivers/net/ethernet/sfc/ef100_nic.c
index 54b2ee7a5be6..e6e67a50610f 100644
--- a/drivers/net/ethernet/sfc/ef100_nic.c
+++ b/drivers/net/ethernet/sfc/ef100_nic.c
@@ -162,7 +162,7 @@ int ef100_get_mac_address(struct efx_nic *efx, u8 *mac_address,
 	return 0;
 }
 
-int efx_ef100_init_datapath_caps(struct efx_nic *efx)
+static int efx_ef100_init_datapath_caps(struct efx_nic *efx)
 {
 	MCDI_DECLARE_BUF(outbuf, MC_CMD_GET_CAPABILITIES_V7_OUT_LEN);
 	struct ef100_nic_data *nic_data = efx->nic_data;
@@ -198,25 +198,21 @@ int efx_ef100_init_datapath_caps(struct efx_nic *efx)
 	if (rc)
 		return rc;
 
-	if (efx_ef100_has_cap(nic_data->datapath_caps2, TX_TSO_V3)) {
-		struct net_device *net_dev = efx->net_dev;
-		netdev_features_t tso = NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_GSO_PARTIAL |
-					NETIF_F_GSO_UDP_TUNNEL | NETIF_F_GSO_UDP_TUNNEL_CSUM |
-					NETIF_F_GSO_GRE | NETIF_F_GSO_GRE_CSUM;
-
-		net_dev->features |= tso;
-		net_dev->hw_features |= tso;
-		net_dev->hw_enc_features |= tso;
-		/* EF100 HW can only offload outer checksums if they are UDP,
-		 * so for GRE_CSUM we have to use GSO_PARTIAL.
-		 */
-		net_dev->gso_partial_features |= NETIF_F_GSO_GRE_CSUM;
-	}
 	efx->num_mac_stats = MCDI_WORD(outbuf,
 				       GET_CAPABILITIES_V4_OUT_MAC_STATS_NUM_STATS);
 	netif_dbg(efx, probe, efx->net_dev,
 		  "firmware reports num_mac_stats = %u\n",
 		  efx->num_mac_stats);
+
+	/* Current EF100 hardware supports vDPA on VFs only, requires MCDI v2
+	 * and Firmware's capability to proxy MCDI commands from PF to VF
+	 */
+#ifdef CONFIG_SFC_VDPA
+		nic_data->vdpa_supported = efx->type->is_vf &&
+					   (efx->type->mcdi_max_ver > 1) &&
+				efx_ef100_has_cap(nic_data->datapath_caps3,
+						  CLIENT_CMD_VF_PROXY);
+#endif
 	return 0;
 }
 
@@ -820,14 +816,12 @@ int efx_ef100_set_bar_config(struct efx_nic *efx,
 	if (WARN_ON_ONCE(nic_data->bar_config > EF100_BAR_CONFIG_VDPA))
 		return -EINVAL;
 
-	/* Current EF100 hardware supports vDPA on VFs only */
-	if (IS_ENABLED(CONFIG_SFC_VDPA) &&
-	    new_config == EF100_BAR_CONFIG_VDPA &&
-	    !efx->type->is_vf) {
-		pci_err(efx->pci_dev, "vdpa over PF not supported : %s",
-			efx->name);
+#ifdef CONFIG_SFC_VDPA
+	if (new_config == EF100_BAR_CONFIG_VDPA && !nic_data->vdpa_supported) {
+		pci_err(efx->pci_dev, "vdpa not supported on %s", efx->name);
 		return -EOPNOTSUPP;
 	}
+#endif
 
 	mutex_lock(&nic_data->bar_config_lock);
 	old_config = nic_data->bar_config;
@@ -1203,6 +1197,12 @@ static int ef100_probe_main(struct efx_nic *efx)
 		goto fail;
 	}
 
+	rc = efx_ef100_init_datapath_caps(efx);
+	if (rc) {
+		pci_info(efx->pci_dev, "Unable to initialize datapath caps\n");
+		goto fail;
+	}
+
 	return 0;
 fail:
 	return rc;
diff --git a/drivers/net/ethernet/sfc/ef100_nic.h b/drivers/net/ethernet/sfc/ef100_nic.h
index 02e5ab4e9f1f..a01e9d643ccd 100644
--- a/drivers/net/ethernet/sfc/ef100_nic.h
+++ b/drivers/net/ethernet/sfc/ef100_nic.h
@@ -77,6 +77,9 @@ struct ef100_nic_data {
 	u32 datapath_caps3;
 	unsigned int pf_index;
 	u16 warm_boot_count;
+#ifdef CONFIG_SFC_VDPA
+	bool vdpa_supported; /* true if vdpa is supported on this PCIe FN */
+#endif
 	u8 port_id[ETH_ALEN];
 	DECLARE_BITMAP(evq_phases, EFX_MAX_CHANNELS);
 	enum ef100_bar_config bar_config;
@@ -96,9 +99,8 @@ struct ef100_nic_data {
 };
 
 #define efx_ef100_has_cap(caps, flag) \
-	(!!((caps) & BIT_ULL(MC_CMD_GET_CAPABILITIES_V4_OUT_ ## flag ## _LBN)))
+	(!!((caps) & BIT_ULL(MC_CMD_GET_CAPABILITIES_V7_OUT_ ## flag ## _LBN)))
 
-int efx_ef100_init_datapath_caps(struct efx_nic *efx);
 int ef100_phy_probe(struct efx_nic *efx);
 int ef100_filter_table_probe(struct efx_nic *efx);
 
-- 
2.30.1