Merge branch 'sfc-encap-offloads-on-EF10'

Edward Cree says:

====================
sfc: encap offloads on EF10

EF10 NICs from the 8000 series onwards support TX offloads (checksumming,
 TSO) on VXLAN- and NVGRE-encapsulated packets.  This series adds driver
 support for these offloads.

Changes from v1:
 * Fix 'no TXQ of type' error handling in patch #1 (and clear up the
   misleading comment that inspired the wrong version)
 * Add comment in patch #5 explaining what the deal with TSOv3 is
====================

Signed-off-by: David S. Miller <[email protected]>

Author: davem330

drivers/net/ethernet/sfc/ef10.c

@@ -601,10 +601,14 @@ static int efx_ef10_probe(struct efx_nic *efx)
 	efx_ef10_read_licensed_features(efx);
 
 	/* We can have one VI for each vi_stride-byte region.
-	 * However, until we use TX option descriptors we need two TX queues
-	 * per channel.
+	 * However, until we use TX option descriptors we need up to four
+	 * TX queues per channel for different checksumming combinations.
 	 */
-	efx->tx_queues_per_channel = 2;
+	if (nic_data->datapath_caps &
+	    (1 << MC_CMD_GET_CAPABILITIES_OUT_VXLAN_NVGRE_LBN))
+		efx->tx_queues_per_channel = 4;
+	else
+		efx->tx_queues_per_channel = 2;
 	efx->max_vis = efx_ef10_mem_map_size(efx) / efx->vi_stride;
 	if (!efx->max_vis) {
 		netif_err(efx, drv, efx->net_dev, "error determining max VIs\n");
@@ -1300,6 +1304,7 @@ static void efx_ef10_fini_nic(struct efx_nic *efx)
 static int efx_ef10_init_nic(struct efx_nic *efx)
 {
 	struct efx_ef10_nic_data *nic_data = efx->nic_data;
+	netdev_features_t hw_enc_features = 0;
 	int rc;
 
 	if (nic_data->must_check_datapath_caps) {
@@ -1344,6 +1349,21 @@ static int efx_ef10_init_nic(struct efx_nic *efx)
 		nic_data->must_restore_piobufs = false;
 	}
 
+	/* add encapsulated checksum offload features */
+	if (efx_has_cap(efx, VXLAN_NVGRE) && !efx_ef10_is_vf(efx))
+		hw_enc_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
+	/* add encapsulated TSO features */
+	if (efx_has_cap(efx, TX_TSO_V2_ENCAP)) {
+		netdev_features_t encap_tso_features;
+
+		encap_tso_features = NETIF_F_GSO_UDP_TUNNEL | NETIF_F_GSO_GRE |
+			NETIF_F_GSO_UDP_TUNNEL_CSUM | NETIF_F_GSO_GRE_CSUM;
+
+		hw_enc_features |= encap_tso_features | NETIF_F_TSO;
+		efx->net_dev->features |= encap_tso_features;
+	}
+	efx->net_dev->hw_enc_features = hw_enc_features;
+
 	/* don't fail init if RSS setup doesn't work */
 	rc = efx->type->rx_push_rss_config(efx, false,
 					   efx->rss_context.rx_indir_table, NULL);
@@ -2146,6 +2166,9 @@ static int efx_ef10_irq_test_generate(struct efx_nic *efx)
 
 static int efx_ef10_tx_probe(struct efx_tx_queue *tx_queue)
 {
+	/* low two bits of label are what we want for type */
+	BUILD_BUG_ON((EFX_TXQ_TYPE_OUTER_CSUM | EFX_TXQ_TYPE_INNER_CSUM) != 3);
+	tx_queue->type = tx_queue->label & 3;
 	return efx_nic_alloc_buffer(tx_queue->efx, &tx_queue->txd.buf,
 				    (tx_queue->ptr_mask + 1) *
 				    sizeof(efx_qword_t),
@@ -2168,15 +2191,15 @@ static inline void efx_ef10_push_tx_desc(struct efx_tx_queue *tx_queue,
 
 /* Add Firmware-Assisted TSO v2 option descriptors to a queue.
  */
-static int efx_ef10_tx_tso_desc(struct efx_tx_queue *tx_queue,
-				struct sk_buff *skb,
-				bool *data_mapped)
+int efx_ef10_tx_tso_desc(struct efx_tx_queue *tx_queue, struct sk_buff *skb,
+			 bool *data_mapped)
 {
 	struct efx_tx_buffer *buffer;
+	u16 inner_ipv4_id = 0;
+	u16 outer_ipv4_id = 0;
 	struct tcphdr *tcp;
 	struct iphdr *ip;
-
-	u16 ipv4_id;
+	u16 ip_tot_len;
 	u32 seqnum;
 	u32 mss;
 
@@ -2189,21 +2212,43 @@ static int efx_ef10_tx_tso_desc(struct efx_tx_queue *tx_queue,
 		return -EINVAL;
 	}
 
-	ip = ip_hdr(skb);
+	if (skb->encapsulation) {
+		if (!tx_queue->tso_encap)
+			return -EINVAL;
+		ip = ip_hdr(skb);
+		if (ip->version == 4)
+			outer_ipv4_id = ntohs(ip->id);
+
+		ip = inner_ip_hdr(skb);
+		tcp = inner_tcp_hdr(skb);
+	} else {
+		ip = ip_hdr(skb);
+		tcp = tcp_hdr(skb);
+	}
+
+	/* 8000-series EF10 hardware requires that IP Total Length be
+	 * greater than or equal to the value it will have in each segment
+	 * (which is at most mss + 208 + TCP header length), but also less
+	 * than (0x10000 - inner_network_header).  Otherwise the TCP
+	 * checksum calculation will be broken for encapsulated packets.
+	 * We fill in ip->tot_len with 0xff30, which should satisfy the
+	 * first requirement unless the MSS is ridiculously large (which
+	 * should be impossible as the driver max MTU is 9216); it is
+	 * guaranteed to satisfy the second as we only attempt TSO if
+	 * inner_network_header <= 208.
+	 */
+	ip_tot_len = -EFX_TSO2_MAX_HDRLEN;
+	EFX_WARN_ON_ONCE_PARANOID(mss + EFX_TSO2_MAX_HDRLEN +
+				  (tcp->doff << 2u) > ip_tot_len);
+
 	if (ip->version == 4) {
-		/* Modify IPv4 header if needed. */
-		ip->tot_len = 0;
+		ip->tot_len = htons(ip_tot_len);
 		ip->check = 0;
-		ipv4_id = ntohs(ip->id);
+		inner_ipv4_id = ntohs(ip->id);
 	} else {
-		/* Modify IPv6 header if needed. */
-		struct ipv6hdr *ipv6 = ipv6_hdr(skb);
-
-		ipv6->payload_len = 0;
-		ipv4_id = 0;
+		((struct ipv6hdr *)ip)->payload_len = htons(ip_tot_len);
 	}
 
-	tcp = tcp_hdr(skb);
 	seqnum = ntohl(tcp->seq);
 
 	buffer = efx_tx_queue_get_insert_buffer(tx_queue);
@@ -2216,7 +2261,7 @@ static int efx_ef10_tx_tso_desc(struct efx_tx_queue *tx_queue,
 			ESF_DZ_TX_OPTION_TYPE, ESE_DZ_TX_OPTION_DESC_TSO,
 			ESF_DZ_TX_TSO_OPTION_TYPE,
 			ESE_DZ_TX_TSO_OPTION_DESC_FATSO2A,
-			ESF_DZ_TX_TSO_IP_ID, ipv4_id,
+			ESF_DZ_TX_TSO_IP_ID, inner_ipv4_id,
 			ESF_DZ_TX_TSO_TCP_SEQNO, seqnum
 			);
 	++tx_queue->insert_count;
@@ -2226,11 +2271,12 @@ static int efx_ef10_tx_tso_desc(struct efx_tx_queue *tx_queue,
 	buffer->flags = EFX_TX_BUF_OPTION;
 	buffer->len = 0;
 	buffer->unmap_len = 0;
-	EFX_POPULATE_QWORD_4(buffer->option,
+	EFX_POPULATE_QWORD_5(buffer->option,
 			ESF_DZ_TX_DESC_IS_OPT, 1,
 			ESF_DZ_TX_OPTION_TYPE, ESE_DZ_TX_OPTION_DESC_TSO,
 			ESF_DZ_TX_TSO_OPTION_TYPE,
 			ESE_DZ_TX_TSO_OPTION_DESC_FATSO2B,
+			ESF_DZ_TX_TSO_OUTER_IPID, outer_ipv4_id,
 			ESF_DZ_TX_TSO_TCP_MSS, mss
 			);
 	++tx_queue->insert_count;
@@ -2254,11 +2300,11 @@ static u32 efx_ef10_tso_versions(struct efx_nic *efx)
 
 static void efx_ef10_tx_init(struct efx_tx_queue *tx_queue)
 {
-	bool csum_offload = tx_queue->label & EFX_TXQ_TYPE_OFFLOAD;
+	bool csum_offload = tx_queue->type & EFX_TXQ_TYPE_OUTER_CSUM;
+	bool inner_csum = tx_queue->type & EFX_TXQ_TYPE_INNER_CSUM;
 	struct efx_channel *channel = tx_queue->channel;
 	struct efx_nic *efx = tx_queue->efx;
 	struct efx_ef10_nic_data *nic_data;
-	bool tso_v2 = false;
 	efx_qword_t *txd;
 	int rc;
 
@@ -2281,15 +2327,18 @@ static void efx_ef10_tx_init(struct efx_tx_queue *tx_queue)
 	 * TSOv2 cannot be used with Hardware timestamping, and is never needed
 	 * for XDP tx.
 	 */
-	if (csum_offload && (nic_data->datapath_caps2 &
-			(1 << MC_CMD_GET_CAPABILITIES_V2_OUT_TX_TSO_V2_LBN)) &&
-	    !tx_queue->timestamping && !tx_queue->xdp_tx) {
-		tso_v2 = true;
-		netif_dbg(efx, hw, efx->net_dev, "Using TSOv2 for channel %u\n",
-				channel->channel);
+	if (efx_has_cap(efx, TX_TSO_V2)) {
+		if ((csum_offload || inner_csum) &&
+		    !tx_queue->timestamping && !tx_queue->xdp_tx) {
+			tx_queue->tso_version = 2;
+			netif_dbg(efx, hw, efx->net_dev, "Using TSOv2 for channel %u\n",
+				  channel->channel);
+		}
+	} else if (efx_has_cap(efx, TX_TSO)) {
+		tx_queue->tso_version = 1;
 	}
 
-	rc = efx_mcdi_tx_init(tx_queue, tso_v2);
+	rc = efx_mcdi_tx_init(tx_queue);
 	if (rc)
 		goto fail;
 
@@ -2302,22 +2351,19 @@ static void efx_ef10_tx_init(struct efx_tx_queue *tx_queue)
 	tx_queue->buffer[0].flags = EFX_TX_BUF_OPTION;
 	tx_queue->insert_count = 1;
 	txd = efx_tx_desc(tx_queue, 0);
-	EFX_POPULATE_QWORD_5(*txd,
+	EFX_POPULATE_QWORD_7(*txd,
 			     ESF_DZ_TX_DESC_IS_OPT, true,
 			     ESF_DZ_TX_OPTION_TYPE,
 			     ESE_DZ_TX_OPTION_DESC_CRC_CSUM,
 			     ESF_DZ_TX_OPTION_UDP_TCP_CSUM, csum_offload,
-			     ESF_DZ_TX_OPTION_IP_CSUM, csum_offload,
+			     ESF_DZ_TX_OPTION_IP_CSUM, csum_offload && tx_queue->tso_version != 2,
+			     ESF_DZ_TX_OPTION_INNER_UDP_TCP_CSUM, inner_csum,
+			     ESF_DZ_TX_OPTION_INNER_IP_CSUM, inner_csum && tx_queue->tso_version != 2,
 			     ESF_DZ_TX_TIMESTAMP, tx_queue->timestamping);
 	tx_queue->write_count = 1;
 
-	if (tso_v2) {
-		tx_queue->handle_tso = efx_ef10_tx_tso_desc;
-		tx_queue->tso_version = 2;
-	} else if (nic_data->datapath_caps &
-			(1 << MC_CMD_GET_CAPABILITIES_OUT_TX_TSO_LBN)) {
-		tx_queue->tso_version = 1;
-	}
+	if (tx_queue->tso_version == 2 && efx_has_cap(efx, TX_TSO_V2_ENCAP))
+		tx_queue->tso_encap = true;
 
 	wmb();
 	efx_ef10_push_tx_desc(tx_queue, txd);
@@ -2880,7 +2926,7 @@ efx_ef10_handle_tx_event(struct efx_channel *channel, efx_qword_t *event)
 	/* Get the transmit queue */
 	tx_ev_q_label = EFX_QWORD_FIELD(*event, ESF_DZ_TX_QLABEL);
 	tx_queue = efx_channel_get_tx_queue(channel,
-					    tx_ev_q_label % EFX_TXQ_TYPES);
+					    tx_ev_q_label % EFX_MAX_TXQ_PER_CHANNEL);
 
 	if (!tx_queue->timestamping) {
 		/* Transmit completion */

drivers/net/ethernet/sfc/ef100_tx.c

@@ -37,7 +37,14 @@ void ef100_tx_init(struct efx_tx_queue *tx_queue)
 				    tx_queue->channel->channel -
 				    tx_queue->efx->tx_channel_offset);
 
-	if (efx_mcdi_tx_init(tx_queue, false))
+	/* This value is purely documentational; as EF100 never passes through
+	 * the switch statement in tx.c:__efx_enqueue_skb(), that switch does
+	 * not handle case 3.  EF100's TSOv3 descriptors are generated by
+	 * ef100_make_tso_desc().
+	 * Meanwhile, all efx_mcdi_tx_init() cares about is that it's not 2.
+	 */
+	tx_queue->tso_version = 3;
+	if (efx_mcdi_tx_init(tx_queue))
 		netdev_WARN(tx_queue->efx->net_dev,
 			    "failed to initialise TXQ %d\n", tx_queue->queue);
 }

drivers/net/ethernet/sfc/efx.c

@@ -596,6 +596,7 @@ static const struct net_device_ops efx_netdev_ops = {
 	.ndo_set_mac_address	= efx_set_mac_address,
 	.ndo_set_rx_mode	= efx_set_rx_mode,
 	.ndo_set_features	= efx_set_features,
+	.ndo_features_check	= efx_features_check,
 	.ndo_vlan_rx_add_vid	= efx_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= efx_vlan_rx_kill_vid,
 #ifdef CONFIG_SFC_SRIOV

drivers/net/ethernet/sfc/efx_channels.c

@@ -151,7 +151,7 @@ static int efx_allocate_msix_channels(struct efx_nic *efx,
 	 */
 
 	n_xdp_tx = num_possible_cpus();
-	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, EFX_TXQ_TYPES);
+	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, EFX_MAX_TXQ_PER_CHANNEL);
 
 	vec_count = pci_msix_vec_count(efx->pci_dev);
 	if (vec_count < 0)
@@ -179,7 +179,7 @@ static int efx_allocate_msix_channels(struct efx_nic *efx,
 		efx->xdp_tx_queue_count = 0;
 	} else {
 		efx->n_xdp_channels = n_xdp_ev;
-		efx->xdp_tx_per_channel = EFX_TXQ_TYPES;
+		efx->xdp_tx_per_channel = EFX_MAX_TXQ_PER_CHANNEL;
 		efx->xdp_tx_queue_count = n_xdp_tx;
 		n_channels += n_xdp_ev;
 		netif_dbg(efx, drv, efx->net_dev,
@@ -520,7 +520,7 @@ static struct efx_channel *efx_alloc_channel(struct efx_nic *efx, int i)
 	channel->channel = i;
 	channel->type = &efx_default_channel_type;
 
-	for (j = 0; j < EFX_TXQ_TYPES; j++) {
+	for (j = 0; j < EFX_MAX_TXQ_PER_CHANNEL; j++) {
 		tx_queue = &channel->tx_queue[j];
 		tx_queue->efx = efx;
 		tx_queue->queue = -1;
@@ -594,7 +594,7 @@ struct efx_channel *efx_copy_channel(const struct efx_channel *old_channel)
 	channel->napi_str.state = 0;
 	memset(&channel->eventq, 0, sizeof(channel->eventq));
 
-	for (j = 0; j < EFX_TXQ_TYPES; j++) {
+	for (j = 0; j < EFX_MAX_TXQ_PER_CHANNEL; j++) {
 		tx_queue = &channel->tx_queue[j];
 		if (tx_queue->channel)
 			tx_queue->channel = channel;
@@ -894,7 +894,7 @@ int efx_set_channels(struct efx_nic *efx)
 						  xdp_queue_number, tx_queue->queue);
 					/* We may have a few left-over XDP TX
 					 * queues owing to xdp_tx_queue_count
-					 * not dividing evenly by EFX_TXQ_TYPES.
+					 * not dividing evenly by EFX_MAX_TXQ_PER_CHANNEL.
 					 * We still allocate and probe those
 					 * TXQs, but never use them.
 					 */