[PATCH net v2 1/5] net: ethernet: mtk_eth_soc: account for vlan in rx header length

[PATCH net v2 1/5] net: ethernet: mtk_eth_soc: account for vlan in rx header length

[Felix Fietkau]

The network stack assumes that devices can handle an extra VLAN tag without
increasing the MTU

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index ee06406e9ff6..628ed72911bd 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -34,7 +34,7 @@
 #define MTK_QDMA_RING_SIZE	2048
 #define MTK_DMA_SIZE		512
 #define MTK_MAC_COUNT		2
-#define MTK_RX_ETH_HLEN		(ETH_HLEN + ETH_FCS_LEN)
+#define MTK_RX_ETH_HLEN		(VLAN_ETH_HLEN + ETH_FCS_LEN)
 #define MTK_RX_HLEN		(NET_SKB_PAD + MTK_RX_ETH_HLEN + NET_IP_ALIGN)
 #define MTK_DMA_DUMMY_DESC	0xffffffff
 #define MTK_DEFAULT_MSG_ENABLE	(NETIF_MSG_DRV | \
-- 
2.38.1

[PATCH net v2 2/5] net: ethernet: mtk_eth_soc: work around issue with sending small fragments

[Felix Fietkau]

When lots of frames are sent with a number of very small fragments, an
internal FIFO can overflow, causing the DMA engine to lock up lock up and
transmit attempts time out.

Fix this on MT7986 by increasing the reserved FIFO space.
Fix this on older chips by detecting the presence of small fragments and use
skb_gso_segment + skb_linearize to deal with them.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
v2: add proper fix for MT7986, limit workaround to NETSYS v1

 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 38 +++++++++++++++++++--
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  2 +-
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index e3de9a53b2d9..8245cddccb5a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1441,12 +1441,28 @@ static void mtk_wake_queue(struct mtk_eth *eth)
 	}
 }
 
+static bool mtk_skb_has_small_frag(struct sk_buff *skb)
+{
+	int min_size = 16;
+	int i;
+
+	if (skb_headlen(skb) < min_size)
+		return true;
+
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
+		if (skb_frag_size(&skb_shinfo(skb)->frags[i]) < min_size)
+			return true;
+
+	return false;
+}
+
 static netdev_tx_t mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct mtk_mac *mac = netdev_priv(dev);
 	struct mtk_eth *eth = mac->hw;
 	struct mtk_tx_ring *ring = &eth->tx_ring;
 	struct net_device_stats *stats = &dev->stats;
+	struct sk_buff *segs, *next;
 	bool gso = false;
 	int tx_num;
 
@@ -1468,6 +1484,18 @@ static netdev_tx_t mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		return NETDEV_TX_BUSY;
 	}
 
+	if (!MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2) &&
+	    skb_is_gso(skb) && mtk_skb_has_small_frag(skb)) {
+		segs = skb_gso_segment(skb, dev->features & ~NETIF_F_ALL_TSO);
+		if (IS_ERR(segs))
+			goto drop;
+
+		if (segs) {
+			consume_skb(skb);
+			skb = segs;
+		}
+	}
+
 	/* TSO: fill MSS info in tcp checksum field */
 	if (skb_is_gso(skb)) {
 		if (skb_cow_head(skb, 0)) {
@@ -1483,8 +1511,14 @@ static netdev_tx_t mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		}
 	}
 
-	if (mtk_tx_map(skb, dev, tx_num, ring, gso) < 0)
-		goto drop;
+	if (!MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2))
+		skb_list_walk_safe(skb, skb, next) {
+			if ((mtk_skb_has_small_frag(skb) && skb_linearize(skb)) ||
+			    mtk_tx_map(skb, dev, tx_num, ring, gso) < 0) {
+				stats->tx_dropped++;
+				dev_kfree_skb_any(skb);
+			}
+		}
 
 	if (unlikely(atomic_read(&ring->free_count) <= ring->thresh))
 		netif_tx_stop_all_queues(dev);
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 628ed72911bd..ce8044e8b3f7 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -246,7 +246,7 @@
 #define MTK_CHK_DDONE_EN	BIT(28)
 #define MTK_DMAD_WR_WDONE	BIT(26)
 #define MTK_WCOMP_EN		BIT(24)
-#define MTK_RESV_BUF		(0x40 << 16)
+#define MTK_RESV_BUF		(0x80 << 16)
 #define MTK_MUTLI_CNT		(0x4 << 12)
 #define MTK_LEAKY_BUCKET_EN	BIT(11)
 
-- 
2.38.1

[PATCH net v2 3/5] net: ethernet: mtk_eth_soc: fix flow_offload related refcount bug

[Felix Fietkau]

Since we call flow_block_cb_decref on FLOW_BLOCK_UNBIND, we need to call
flow_block_cb_incref unconditionally, even for a newly allocated cb.
Fixes a use-after-free bug

Fixes: 502e84e2382d ("net: ethernet: mtk_eth_soc: add flow offloading support")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 .../net/ethernet/mediatek/mtk_ppe_offload.c   | 21 ++++++++++++-------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
index 81afd5ee3fbf..412d215b9571 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
@@ -554,6 +554,7 @@ mtk_eth_setup_tc_block(struct net_device *dev, struct flow_block_offload *f)
 	struct mtk_eth *eth = mac->hw;
 	static LIST_HEAD(block_cb_list);
 	struct flow_block_cb *block_cb;
+	bool register_block = false;
 	flow_setup_cb_t *cb;
 
 	if (!eth->soc->offload_version)
@@ -568,16 +569,20 @@ mtk_eth_setup_tc_block(struct net_device *dev, struct flow_block_offload *f)
 	switch (f->command) {
 	case FLOW_BLOCK_BIND:
 		block_cb = flow_block_cb_lookup(f->block, cb, dev);
-		if (block_cb) {
-			flow_block_cb_incref(block_cb);
-			return 0;
+		if (!block_cb) {
+			block_cb = flow_block_cb_alloc(cb, dev, dev, NULL);
+			if (IS_ERR(block_cb))
+				return PTR_ERR(block_cb);
+
+			register_block = true;
 		}
-		block_cb = flow_block_cb_alloc(cb, dev, dev, NULL);
-		if (IS_ERR(block_cb))
-			return PTR_ERR(block_cb);
 
-		flow_block_cb_add(block_cb, f);
-		list_add_tail(&block_cb->driver_list, &block_cb_list);
+		flow_block_cb_incref(block_cb);
+
+		if (register_block) {
+			flow_block_cb_add(block_cb, f);
+			list_add_tail(&block_cb->driver_list, &block_cb_list);
+		}
 		return 0;
 	case FLOW_BLOCK_UNBIND:
 		block_cb = flow_block_cb_lookup(f->block, cb, dev);
-- 
2.38.1

[PATCH net v2 4/5] net: ethernet: mtk_eth_soc: drop generic vlan rx offload, only use DSA untagging

[Felix Fietkau]

Through testing I found out that hardware vlan rx offload support seems to
have some hardware issues. At least when using multiple MACs and when receiving
tagged packets on the secondary MAC, the hardware can sometimes start to emit
wrong tags on the first MAC as well.

In order to avoid such issues, drop the feature configuration and use the
offload feature only for DSA hardware untagging on MT7621/MT7622 devices which
only use one MAC.

Tested-By: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 101 ++++++++------------
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |   1 -
 2 files changed, 39 insertions(+), 63 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 8245cddccb5a..214cd80a19a0 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2042,29 +2042,16 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 		if (reason == MTK_PPE_CPU_REASON_HIT_UNBIND_RATE_REACHED)
 			mtk_ppe_check_skb(eth->ppe[0], skb, hash);
 
-		if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX) {
-			if (MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2)) {
-				if (trxd.rxd3 & RX_DMA_VTAG_V2)
-					__vlan_hwaccel_put_tag(skb,
-						htons(RX_DMA_VPID(trxd.rxd4)),
-						RX_DMA_VID(trxd.rxd4));
-			} else if (trxd.rxd2 & RX_DMA_VTAG) {
-				__vlan_hwaccel_put_tag(skb, htons(RX_DMA_VPID(trxd.rxd3)),
-						       RX_DMA_VID(trxd.rxd3));
-			}
-		}
-
 		/* When using VLAN untagging in combination with DSA, the
 		 * hardware treats the MTK special tag as a VLAN and untags it.
 		 */
-		if (skb_vlan_tag_present(skb) && netdev_uses_dsa(netdev)) {
-			unsigned int port = ntohs(skb->vlan_proto) & GENMASK(2, 0);
+		if (!MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2) &&
+		    (trxd.rxd2 & RX_DMA_VTAG) && netdev_uses_dsa(netdev)) {
+			unsigned int port = RX_DMA_VPID(trxd.rxd3) & GENMASK(2, 0);
 
 			if (port < ARRAY_SIZE(eth->dsa_meta) &&
 			    eth->dsa_meta[port])
 				skb_dst_set_noref(skb, &eth->dsa_meta[port]->dst);
-
-			__vlan_hwaccel_clear_tag(skb);
 		}
 
 		skb_record_rx_queue(skb, 0);
@@ -2889,29 +2876,11 @@ static netdev_features_t mtk_fix_features(struct net_device *dev,
 
 static int mtk_set_features(struct net_device *dev, netdev_features_t features)
 {
-	struct mtk_mac *mac = netdev_priv(dev);
-	struct mtk_eth *eth = mac->hw;
 	netdev_features_t diff = dev->features ^ features;
-	int i;
 
 	if ((diff & NETIF_F_LRO) && !(features & NETIF_F_LRO))
 		mtk_hwlro_netdev_disable(dev);
 
-	/* Set RX VLAN offloading */
-	if (!(diff & NETIF_F_HW_VLAN_CTAG_RX))
-		return 0;
-
-	mtk_w32(eth, !!(features & NETIF_F_HW_VLAN_CTAG_RX),
-		MTK_CDMP_EG_CTRL);
-
-	/* sync features with other MAC */
-	for (i = 0; i < MTK_MAC_COUNT; i++) {
-		if (!eth->netdev[i] || eth->netdev[i] == dev)
-			continue;
-		eth->netdev[i]->features &= ~NETIF_F_HW_VLAN_CTAG_RX;
-		eth->netdev[i]->features |= features & NETIF_F_HW_VLAN_CTAG_RX;
-	}
-
 	return 0;
 }
 
@@ -3211,30 +3180,6 @@ static int mtk_open(struct net_device *dev)
 	struct mtk_eth *eth = mac->hw;
 	int i, err;
 
-	if (mtk_uses_dsa(dev) && !eth->prog) {
-		for (i = 0; i < ARRAY_SIZE(eth->dsa_meta); i++) {
-			struct metadata_dst *md_dst = eth->dsa_meta[i];
-
-			if (md_dst)
-				continue;
-
-			md_dst = metadata_dst_alloc(0, METADATA_HW_PORT_MUX,
-						    GFP_KERNEL);
-			if (!md_dst)
-				return -ENOMEM;
-
-			md_dst->u.port_info.port_id = i;
-			eth->dsa_meta[i] = md_dst;
-		}
-	} else {
-		/* Hardware special tag parsing needs to be disabled if at least
-		 * one MAC does not use DSA.
-		 */
-		u32 val = mtk_r32(eth, MTK_CDMP_IG_CTRL);
-		val &= ~MTK_CDMP_STAG_EN;
-		mtk_w32(eth, val, MTK_CDMP_IG_CTRL);
-	}
-
 	err = phylink_of_phy_connect(mac->phylink, mac->of_node, 0);
 	if (err) {
 		netdev_err(dev, "%s: could not attach PHY: %d\n", __func__,
@@ -3273,6 +3218,39 @@ static int mtk_open(struct net_device *dev)
 	phylink_start(mac->phylink);
 	netif_tx_start_all_queues(dev);
 
+	if (MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2))
+		return 0;
+
+	if (mtk_uses_dsa(dev) && !eth->prog) {
+		for (i = 0; i < ARRAY_SIZE(eth->dsa_meta); i++) {
+			struct metadata_dst *md_dst = eth->dsa_meta[i];
+
+			if (md_dst)
+				continue;
+
+			md_dst = metadata_dst_alloc(0, METADATA_HW_PORT_MUX,
+						    GFP_KERNEL);
+			if (!md_dst)
+				return -ENOMEM;
+
+			md_dst->u.port_info.port_id = i;
+			eth->dsa_meta[i] = md_dst;
+		}
+	} else {
+		/* Hardware special tag parsing needs to be disabled if at least
+		 * one MAC does not use DSA.
+		 */
+		u32 val = mtk_r32(eth, MTK_CDMP_IG_CTRL);
+		val &= ~MTK_CDMP_STAG_EN;
+		mtk_w32(eth, val, MTK_CDMP_IG_CTRL);
+
+		val = mtk_r32(eth, MTK_CDMQ_IG_CTRL);
+		val &= ~MTK_CDMQ_STAG_EN;
+		mtk_w32(eth, val, MTK_CDMQ_IG_CTRL);
+
+		mtk_w32(eth, 0, MTK_CDMP_EG_CTRL);
+	}
+
 	return 0;
 }
 
@@ -3599,10 +3577,9 @@ static int mtk_hw_init(struct mtk_eth *eth)
 	if (!MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2)) {
 		val = mtk_r32(eth, MTK_CDMP_IG_CTRL);
 		mtk_w32(eth, val | MTK_CDMP_STAG_EN, MTK_CDMP_IG_CTRL);
-	}
 
-	/* Enable RX VLan Offloading */
-	mtk_w32(eth, 1, MTK_CDMP_EG_CTRL);
+		mtk_w32(eth, 1, MTK_CDMP_EG_CTRL);
+	}
 
 	/* set interrupt delays based on current Net DIM sample */
 	mtk_dim_rx(&eth->rx_dim.work);
@@ -4203,7 +4180,7 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
 		eth->netdev[id]->hw_features |= NETIF_F_LRO;
 
 	eth->netdev[id]->vlan_features = eth->soc->hw_features &
-		~(NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX);
+		~NETIF_F_HW_VLAN_CTAG_TX;
 	eth->netdev[id]->features |= eth->soc->hw_features;
 	eth->netdev[id]->ethtool_ops = &mtk_ethtool_ops;
 
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index ce8044e8b3f7..00d9a3badf9a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -48,7 +48,6 @@
 #define MTK_HW_FEATURES		(NETIF_F_IP_CSUM | \
 				 NETIF_F_RXCSUM | \
 				 NETIF_F_HW_VLAN_CTAG_TX | \
-				 NETIF_F_HW_VLAN_CTAG_RX | \
 				 NETIF_F_SG | NETIF_F_ALL_TSO | \
 				 NETIF_F_IPV6_CSUM |\
 				 NETIF_F_HW_TC)
-- 
2.38.1

[PATCH net v2 5/5] net: ethernet: mtk_eth_soc: ppe: fix L2 offloading with DSA untagging offload enabled

[Felix Fietkau]

Check for skb metadata in order to detect the case where the DSA header is not
present.

Fixes: 2d7605a72906 ("net: ethernet: mtk_eth_soc: enable hardware DSA untagging")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 6 +++---
 drivers/net/ethernet/mediatek/mtk_ppe.c     | 5 ++++-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 214cd80a19a0..b54248bce501 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2039,9 +2039,6 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 			skb_checksum_none_assert(skb);
 		skb->protocol = eth_type_trans(skb, netdev);
 
-		if (reason == MTK_PPE_CPU_REASON_HIT_UNBIND_RATE_REACHED)
-			mtk_ppe_check_skb(eth->ppe[0], skb, hash);
-
 		/* When using VLAN untagging in combination with DSA, the
 		 * hardware treats the MTK special tag as a VLAN and untags it.
 		 */
@@ -2054,6 +2051,9 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 				skb_dst_set_noref(skb, &eth->dsa_meta[port]->dst);
 		}
 
+		if (reason == MTK_PPE_CPU_REASON_HIT_UNBIND_RATE_REACHED)
+			mtk_ppe_check_skb(eth->ppe[0], skb, hash);
+
 		skb_record_rx_queue(skb, 0);
 		napi_gro_receive(napi, skb);
 
diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
index 269208a841c7..e366a83cf516 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
@@ -8,6 +8,7 @@
 #include <linux/platform_device.h>
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>
+#include <net/dst_metadata.h>
 #include <net/dsa.h>
 #include "mtk_eth_soc.h"
 #include "mtk_ppe.h"
@@ -700,7 +701,9 @@ void __mtk_ppe_check_skb(struct mtk_ppe *ppe, struct sk_buff *skb, u16 hash)
 		    skb->dev->dsa_ptr->tag_ops->proto != DSA_TAG_PROTO_MTK)
 			goto out;
 
-		tag += 4;
+		if (!skb_metadata_dst(skb))
+			tag += 4;
+
 		if (get_unaligned_be16(tag) != ETH_P_8021Q)
 			break;
 
-- 
2.38.1

Re: [PATCH net v2 4/5] net: ethernet: mtk_eth_soc: drop generic vlan rx offload, only use DSA untagging

[Jakub Kicinski]

On Tue, 27 Dec 2022 15:08:06 +0100 Felix Fietkau wrote:
> Through testing I found out that hardware vlan rx offload support seems to
> have some hardware issues. At least when using multiple MACs and when receiving
> tagged packets on the secondary MAC, the hardware can sometimes start to emit
> wrong tags on the first MAC as well.
> 
> In order to avoid such issues, drop the feature configuration and use the
> offload feature only for DSA hardware untagging on MT7621/MT7622 devices which
> only use one MAC.

Does not apply cleanly, could you rebase and repost?