2 files changed, 150 insertions, 67 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 919a93a52390..8ba8f03e1ce0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -265,8 +265,9 @@ struct stmmac_priv {
 	u32 rx_coal_frames[MTL_MAX_RX_QUEUES];
 
 	int hwts_tx_en;
+	/* skb_shinfo(skb)->gso_type types that we handle */
+	unsigned int gso_enabled_types;
 	bool tx_path_in_lpi_mode;
-	bool tso;
 	bool sph_active;
 	bool sph_capable;
 	u32 sarc_type;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 35cf4491ec16..01a983001ab4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3619,6 +3619,17 @@ static void stmmac_safety_feat_configuration(struct stmmac_priv *priv)
 	}
 }
 
+/* STM32MP25xx (dwmac v5.3) states "Do not enable time-based scheduling for
+ * channels on which the TSO feature is enabled." If we have a skb for a
+ * channel which has TBS enabled, fall back to software GSO.
+ */
+static bool stmmac_tso_channel_permitted(struct stmmac_priv *priv,
+					 unsigned int chan)
+{
+	/* TSO and TBS cannot co-exist */
+	return !(priv->dma_conf.tx_queue[chan].tbs & STMMAC_TBS_AVAIL);
+}
+
 /**
  * stmmac_hw_setup - setup mac in a usable state.
  *  @dev : pointer to the device structure.
@@ -3705,12 +3716,9 @@ static int stmmac_hw_setup(struct net_device *dev)
 	stmmac_set_rings_length(priv);
 
 	/* Enable TSO */
-	if (priv->tso) {
+	if (priv->dma_cap.tsoen && priv->plat->flags & STMMAC_FLAG_TSO_EN) {
 		for (chan = 0; chan < tx_cnt; chan++) {
-			struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[chan];
-
-			/* TSO and TBS cannot co-exist */
-			if (tx_q->tbs & STMMAC_TBS_AVAIL)
+			if (!stmmac_tso_channel_permitted(priv, chan))
 				continue;
 
 			stmmac_enable_tso(priv, priv->ioaddr, 1, chan);
@@ -4365,6 +4373,89 @@ static void stmmac_flush_tx_descriptors(struct stmmac_priv *priv, int queue)
 	stmmac_set_queue_tx_tail_ptr(priv, tx_q, queue, tx_q->cur_tx);
 }
 
+static void stmmac_set_gso_types(struct stmmac_priv *priv, bool tso)
+{
+	if (!tso) {
+		priv->gso_enabled_types = 0;
+	} else {
+		/* Manage oversized TCP frames for GMAC4 device */
+		priv->gso_enabled_types = SKB_GSO_TCPV4 | SKB_GSO_TCPV6;
+		if (priv->plat->core_type == DWMAC_CORE_GMAC4)
+			priv->gso_enabled_types |= SKB_GSO_UDP_L4;
+	}
+}
+
+static void stmmac_set_gso_features(struct net_device *ndev)
+{
+	struct stmmac_priv *priv = netdev_priv(ndev);
+	const struct stmmac_dma_cfg *dma_cfg;
+	int txpbl;
+
+	if (priv->dma_cap.tsoen)
+		dev_info(priv->device, "TSO supported\n");
+
+	if (!(priv->plat->flags & STMMAC_FLAG_TSO_EN))
+		return;
+
+	if (!priv->dma_cap.tsoen) {
+		dev_warn(priv->device, "platform requests unsupported TSO\n");
+		return;
+	}
+
+	/* FIXME:
+	 *  STM32MP151 (v4.2 userver v4.0) states that TxPBL must be >= 4. It
+	 *  is not clear whether PBLx8 (which multiplies the PBL value by 8)
+	 *  influences this.
+	 */
+	dma_cfg = priv->plat->dma_cfg;
+	txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
+	if (txpbl < 4) {
+		dev_warn(priv->device, "txpbl(%d) is too low for TSO\n", txpbl);
+		return;
+	}
+
+	ndev->hw_features |= NETIF_F_TSO | NETIF_F_TSO6;
+	if (priv->plat->core_type == DWMAC_CORE_GMAC4)
+		ndev->hw_features |= NETIF_F_GSO_UDP_L4;
+
+	stmmac_set_gso_types(priv, true);
+
+	dev_info(priv->device, "TSO feature enabled\n");
+}
+
+static size_t stmmac_tso_header_size(struct sk_buff *skb)
+{
+	size_t size;
+
+	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
+		size = skb_transport_offset(skb) + sizeof(struct udphdr);
+	else
+		size = skb_tcp_all_headers(skb);
+
+	return size;
+}
+
+/* STM32MP151 (dwmac v4.2) and STM32MP25xx (dwmac v5.3) states for TDES2 normal
+ * (read format) descriptor that the maximum header length supported for the
+ * TSO feature is 1023 bytes.
+ *
+ * While IPv4 is limited to MAC+VLAN+IPv4+ext+TCP+ext = 138 bytes, the IPv6
+ * extension headers aren't similarly limited.
+ *
+ * Fall back to software GSO for these skbs. Also check that the MSS is >=
+ * the recommended 64 bytes (documented in ETH_DMACxCR register description),
+ * and that a the header plus MSS is not larger than 16383 (documented in
+ * "Building the Descriptor and the packet for the TSO feature").
+ */
+static bool stmmac_tso_valid_packet(struct sk_buff *skb)
+{
+	size_t header_len = stmmac_tso_header_size(skb);
+	unsigned int gso_size = skb_shinfo(skb)->gso_size;
+
+	return header_len <= 1023 && gso_size >= 64 &&
+	       header_len + gso_size < 16383;
+}
+
 /**
  *  stmmac_tso_xmit - Tx entry point of the driver for oversized frames (TSO)
  *  @skb : the socket buffer
@@ -4415,19 +4506,6 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 	u8 proto_hdr_len, hdr;
 	dma_addr_t des;
 
-	/* Always insert VLAN tag to SKB payload for TSO frames.
-	 *
-	 * Never insert VLAN tag by HW, since segments split by
-	 * TSO engine will be un-tagged by mistake.
-	 */
-	if (skb_vlan_tag_present(skb)) {
-		skb = __vlan_hwaccel_push_inside(skb);
-		if (unlikely(!skb)) {
-			priv->xstats.tx_dropped++;
-			return NETDEV_TX_OK;
-		}
-	}
-
 	nfrags = skb_shinfo(skb)->nr_frags;
 	queue = skb_get_queue_mapping(skb);
 
@@ -4436,13 +4514,11 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 	first_tx = tx_q->cur_tx;
 
 	/* Compute header lengths */
-	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
-		proto_hdr_len = skb_transport_offset(skb) + sizeof(struct udphdr);
+	proto_hdr_len = stmmac_tso_header_size(skb);
+	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
 		hdr = sizeof(struct udphdr);
-	} else {
-		proto_hdr_len = skb_tcp_all_headers(skb);
+	else
 		hdr = tcp_hdrlen(skb);
-	}
 
 	/* Desc availability based on threshold should be enough safe */
 	if (unlikely(stmmac_tx_avail(priv, queue) <
@@ -4680,7 +4756,6 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	u32 queue = skb_get_queue_mapping(skb);
 	int nfrags = skb_shinfo(skb)->nr_frags;
 	unsigned int first_entry, tx_packets;
-	int gso = skb_shinfo(skb)->gso_type;
 	struct stmmac_txq_stats *txq_stats;
 	struct dma_desc *desc, *first_desc;
 	struct stmmac_tx_queue *tx_q;
@@ -4692,14 +4767,9 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (priv->tx_path_in_lpi_mode && priv->eee_sw_timer_en)
 		stmmac_stop_sw_lpi(priv);
 
-	/* Manage oversized TCP frames for GMAC4 device */
-	if (skb_is_gso(skb) && priv->tso) {
-		if (gso & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))
-			return stmmac_tso_xmit(skb, dev);
-		if (priv->plat->core_type == DWMAC_CORE_GMAC4 &&
-		    (gso & SKB_GSO_UDP_L4))
-			return stmmac_tso_xmit(skb, dev);
-	}
+	if (skb_is_gso(skb) &&
+	    skb_shinfo(skb)->gso_type & priv->gso_enabled_types)
+		return stmmac_tso_xmit(skb, dev);
 
 	if (priv->est && priv->est->enable &&
 	    priv->est->max_sdu[queue]) {
@@ -4731,22 +4801,6 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	/* Check if VLAN can be inserted by HW */
 	has_vlan = stmmac_vlan_insert(priv, skb, tx_q);
 
-	csum_insertion = (skb->ip_summed == CHECKSUM_PARTIAL);
-	/* DWMAC IPs can be synthesized to support tx coe only for a few tx
-	 * queues. In that case, checksum offloading for those queues that don't
-	 * support tx coe needs to fallback to software checksum calculation.
-	 *
-	 * Packets that won't trigger the COE e.g. most DSA-tagged packets will
-	 * also have to be checksummed in software.
-	 */
-	if (csum_insertion &&
-	    (priv->plat->tx_queues_cfg[queue].coe_unsupported ||
-	     !stmmac_has_ip_ethertype(skb))) {
-		if (unlikely(skb_checksum_help(skb)))
-			goto dma_map_err;
-		csum_insertion = !csum_insertion;
-	}
-
 	entry = tx_q->cur_tx;
 	first_entry = entry;
 	WARN_ON(tx_q->tx_skbuff[first_entry]);
@@ -4762,6 +4816,8 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (enh_desc)
 		is_jumbo = stmmac_is_jumbo_frm(priv, skb->len, enh_desc);
 
+	csum_insertion = skb->ip_summed == CHECKSUM_PARTIAL;
+
 	if (unlikely(is_jumbo)) {
 		entry = stmmac_jumbo_frm(priv, tx_q, skb, csum_insertion);
 		if (unlikely(entry < 0) && (entry != -EINVAL))
@@ -4919,6 +4975,46 @@ max_sdu_err:
 	return NETDEV_TX_OK;
 }
 
+static netdev_features_t stmmac_features_check(struct sk_buff *skb,
+					       struct net_device *dev,
+					       netdev_features_t features)
+{
+	struct stmmac_priv *priv = netdev_priv(dev);
+	u16 queue = skb_get_queue_mapping(skb);
+
+	/* DWMAC IPs can be synthesized to support tx coe only for a few tx
+	 * queues. In that case, checksum offloading for those queues that don't
+	 * support tx coe needs to fallback to software checksum calculation.
+	 *
+	 * Packets that won't trigger the COE e.g. most DSA-tagged packets will
+	 * also have to be checksummed in software.
+	 *
+	 * Note that disabling hardware checksumming also disables TSO. See
+	 * harmonize_features() in net/core/dev.c
+	 */
+	if (priv->plat->tx_queues_cfg[queue].coe_unsupported ||
+	    !stmmac_has_ip_ethertype(skb))
+		features &= ~(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
+
+	if (skb_is_gso(skb)) {
+		if (!stmmac_tso_channel_permitted(priv, queue) ||
+		    !stmmac_tso_valid_packet(skb))
+			features &= ~NETIF_F_GSO_MASK;
+
+		/* If we are going to be using hardware TSO, always insert
+		 * VLAN tag to SKB payload for TSO frames.
+		 *
+		 * Never insert VLAN tag by HW, since segments split by
+		 * TSO engine will be un-tagged by mistake.
+		 */
+		if (features & NETIF_F_GSO_MASK)
+			features &= ~(NETIF_F_HW_VLAN_STAG_TX |
+				      NETIF_F_HW_VLAN_CTAG_TX);
+	}
+
+	return vlan_features_check(skb, features);
+}
+
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
 	struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb);
@@ -6073,14 +6169,6 @@ static netdev_features_t stmmac_fix_features(struct net_device *dev,
 	if (priv->plat->bugged_jumbo && (dev->mtu > ETH_DATA_LEN))
 		features &= ~NETIF_F_CSUM_MASK;
 
-	/* Disable tso if asked by ethtool */
-	if ((priv->plat->flags & STMMAC_FLAG_TSO_EN) && (priv->dma_cap.tsoen)) {
-		if (features & NETIF_F_TSO)
-			priv->tso = true;
-		else
-			priv->tso = false;
-	}
-
 	return features;
 }
 
@@ -6107,6 +6195,8 @@ static int stmmac_set_features(struct net_device *netdev,
 			stmmac_enable_sph(priv, priv->ioaddr, sph_en, chan);
 	}
 
+	stmmac_set_gso_types(priv, features & NETIF_F_TSO);
+
 	if (features & NETIF_F_HW_VLAN_CTAG_RX)
 		priv->hw->hw_vlan_en = true;
 	else
@@ -7214,6 +7304,7 @@ static void stmmac_get_stats64(struct net_device *dev, struct rtnl_link_stats64
 static const struct net_device_ops stmmac_netdev_ops = {
 	.ndo_open = stmmac_open,
 	.ndo_start_xmit = stmmac_xmit,
+	.ndo_features_check = stmmac_features_check,
 	.ndo_stop = stmmac_release,
 	.ndo_change_mtu = stmmac_change_mtu,
 	.ndo_fix_features = stmmac_fix_features,
@@ -7375,9 +7466,6 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
 		devm_pm_set_wake_irq(priv->device, priv->wol_irq);
 	}
 
-	if (priv->dma_cap.tsoen)
-		dev_info(priv->device, "TSO supported\n");
-
 	if (priv->dma_cap.number_rx_queues &&
 	    priv->plat->rx_queues_to_use > priv->dma_cap.number_rx_queues) {
 		dev_warn(priv->device,
@@ -7829,13 +7917,7 @@ static int __stmmac_dvr_probe(struct device *device,
 		ndev->hw_features |= NETIF_F_HW_TC;
 	}
 
-	if ((priv->plat->flags & STMMAC_FLAG_TSO_EN) && (priv->dma_cap.tsoen)) {
-		ndev->hw_features |= NETIF_F_TSO | NETIF_F_TSO6;
-		if (priv->plat->core_type == DWMAC_CORE_GMAC4)
-			ndev->hw_features |= NETIF_F_GSO_UDP_L4;
-		priv->tso = true;
-		dev_info(priv->device, "TSO feature enabled\n");
-	}
+	stmmac_set_gso_features(ndev);
 
 	if (priv->dma_cap.sphen &&
 	    !(priv->plat->flags & STMMAC_FLAG_SPH_DISABLE)) {