[PATCH net-next v2 09/12] net: ethernet: mtk_eth_soc: fix VLAN rx hardware acceleration

From: Felix Fietkau
Date: Wed Nov 09 2022 - 11:35:25 EST

- enable VLAN untagging for PDMA rx
- make it possible to disable the feature via ethtool
- pass VLAN tag to the DSA driver
- untag special tag on PDMA only if no non-DSA devices are in use
- disable special tag untagging on 7986 for now, since it's not working yet

Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 99 ++++++++++++++++-----
drivers/net/ethernet/mediatek/mtk_eth_soc.h | 8 ++
2 files changed, 84 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 92bdd69eed2e..ffaa9fe32b14 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -23,6 +23,7 @@
#include <linux/jhash.h>
#include <linux/bitfield.h>
#include <net/dsa.h>
+#include <net/dst_metadata.h>

#include "mtk_eth_soc.h"
#include "mtk_wed.h"
@@ -2008,23 +2009,27 @@ 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(ETH_P_8021Q),
- RX_DMA_VID(trxd.rxd3));
- }
+ 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 (port < ARRAY_SIZE(eth->dsa_meta) &&
+ eth->dsa_meta[port])
+ skb_dst_set_noref(skb, &eth->dsa_meta[port]->dst);

- /* If the device is attached to a dsa switch, the special
- * tag inserted in VLAN field by hw switch can * be offloaded
- * by RX HW VLAN offload. Clear vlan info.
- */
- if (netdev_uses_dsa(netdev))
- __vlan_hwaccel_clear_tag(skb);
+ __vlan_hwaccel_clear_tag(skb);
}

skb_record_rx_queue(skb, 0);
@@ -2847,15 +2852,19 @@ static netdev_features_t mtk_fix_features(struct net_device *dev,

static int mtk_set_features(struct net_device *dev, netdev_features_t features)
{
- int err = 0;
-
- if (!((dev->features ^ features) & NETIF_F_LRO))
- return 0;
+ struct mtk_mac *mac = netdev_priv(dev);
+ struct mtk_eth *eth = mac->hw;
+ netdev_features_t diff = dev->features ^ features;

- if (!(features & NETIF_F_LRO))
+ if ((diff & NETIF_F_LRO) && !(features & NETIF_F_LRO))
mtk_hwlro_netdev_disable(dev);

- return err;
+ /* Set RX VLAN offloading */
+ if (diff & NETIF_F_HW_VLAN_CTAG_RX)
+ mtk_w32(eth, !!(features & NETIF_F_HW_VLAN_CTAG_RX),
+ MTK_CDMP_EG_CTRL);
+
+ return 0;
}

/* wait for DMA to finish whatever it is doing before we start using it again */
@@ -3137,11 +3146,45 @@ static int mtk_device_event(struct notifier_block *n, unsigned long event, void
return NOTIFY_DONE;
}

+static bool mtk_uses_dsa(struct net_device *dev)
+{
+#if IS_ENABLED(CONFIG_NET_DSA)
+ return netdev_uses_dsa(dev) &&
+ dev->dsa_ptr->tag_ops->proto == DSA_TAG_PROTO_MTK;
+#else
+ return false;
+#endif
+}
+
static int mtk_open(struct net_device *dev)
{
struct mtk_mac *mac = netdev_priv(dev);
struct mtk_eth *eth = mac->hw;
- int err;
+ int i, err;
+
+ if (mtk_uses_dsa(dev)) {
+ 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) {
@@ -3469,6 +3512,10 @@ static int mtk_hw_init(struct mtk_eth *eth)
*/
val = mtk_r32(eth, MTK_CDMQ_IG_CTRL);
mtk_w32(eth, val | MTK_CDMQ_STAG_EN, MTK_CDMQ_IG_CTRL);
+ 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);
@@ -3686,6 +3733,12 @@ static int mtk_free_dev(struct mtk_eth *eth)
free_netdev(eth->netdev[i]);
}

+ for (i = 0; i < ARRAY_SIZE(eth->dsa_meta); i++) {
+ if (!eth->dsa_meta[i])
+ break;
+ metadata_dst_free(eth->dsa_meta[i]);
+ }
+
return 0;
}

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 146437ca044b..1c85fbad5bc1 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -22,6 +22,9 @@
#include <linux/bpf_trace.h>
#include "mtk_ppe.h"

+#define MTK_MAX_DSA_PORTS 7
+#define MTK_DSA_PORT_MASK GENMASK(2, 0)
+
#define MTK_QDMA_NUM_QUEUES 16
#define MTK_QDMA_PAGE_SIZE 2048
#define MTK_MAX_RX_LENGTH 1536
@@ -93,6 +96,9 @@
#define MTK_CDMQ_IG_CTRL 0x1400
#define MTK_CDMQ_STAG_EN BIT(0)

+/* CDMQ Exgress Control Register */
+#define MTK_CDMQ_EG_CTRL 0x1404
+
/* CDMP Ingress Control Register */
#define MTK_CDMP_IG_CTRL 0x400
#define MTK_CDMP_STAG_EN BIT(0)
@@ -1149,6 +1155,8 @@ struct mtk_eth {

int ip_align;

+ struct metadata_dst *dsa_meta[MTK_MAX_DSA_PORTS];
+
struct mtk_ppe *ppe[2];
struct rhashtable flow_table;

--
2.38.1