[PATCH net-next v2 1/1] net: stmmac: Add support for HW-accelerated VLAN stripping

From: Gan Yi Fang
Date: Tue Nov 21 2023 - 00:42:29 EST


From: "Gan, Yi Fang" <yi.fang.gan@xxxxxxxxx>

Current implementation supports driver level VLAN tag stripping only.
The features is always on if CONFIG_VLAN_8021Q is enabled in kernel
config and is not user configurable.

This patch add support to MAC level VLAN tag stripping and can be
configured through ethtool. If the rx-vlan-offload is off, the VLAN tag
will be stripped by driver. If the rx-vlan-offload is on, the VLAN tag
will be stripped by MAC.

Command: ethtool -K <interface> rx-vlan-offload off | on

Signed-off-by: Lai Peter Jun Ann <jun.ann.lai@xxxxxxxxx>
Signed-off-by: Gan, Yi Fang <yi.fang.gan@xxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/common.h | 1 +
.../net/ethernet/stmicro/stmmac/dwmac4_core.c | 35 +++++++++++++++++++
.../ethernet/stmicro/stmmac/dwmac4_descs.c | 13 +++++++
drivers/net/ethernet/stmicro/stmmac/hwif.h | 15 ++++++++
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 28 +++++++++++++--
5 files changed, 90 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index e3f650e88f82..6b935922054d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -580,6 +580,7 @@ struct mac_device_info {
u32 vlan_filter[32];
bool vlan_fail_q_en;
u8 vlan_fail_q;
+ bool hw_vlan_en;
};

struct stmmac_rx_routing {
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index c6ff1fa0e04d..5f35faf90963 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -1134,6 +1134,35 @@ static int dwmac4_config_l4_filter(struct mac_device_info *hw, u32 filter_no,
return 0;
}

+static void dwmac4_rx_hw_vlan(struct mac_device_info *hw,
+ struct dma_desc *rx_desc, struct sk_buff *skb)
+{
+ if (hw->desc->get_rx_vlan_valid(rx_desc)) {
+ u16 vid = hw->desc->get_rx_vlan_tci(rx_desc);
+
+ __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vid);
+ }
+}
+
+static void dwmac4_set_hw_vlan_mode(struct mac_device_info *hw)
+{
+ void __iomem *ioaddr = hw->pcsr;
+ u32 value = readl(ioaddr + GMAC_VLAN_TAG);
+
+ value &= ~GMAC_VLAN_TAG_CTRL_EVLS_MASK;
+
+ if (hw->hw_vlan_en)
+ /* Always strip VLAN on Receive */
+ value |= GMAC_VLAN_TAG_STRIP_ALL;
+ else
+ /* Do not strip VLAN on Receive */
+ value |= GMAC_VLAN_TAG_STRIP_NONE;
+
+ /* Enable outer VLAN Tag in Rx DMA descriptor */
+ value |= GMAC_VLAN_TAG_CTRL_EVLRXS;
+ writel(value, ioaddr + GMAC_VLAN_TAG);
+}
+
const struct stmmac_ops dwmac4_ops = {
.core_init = dwmac4_core_init,
.phylink_get_caps = dwmac4_phylink_get_caps,
@@ -1175,6 +1204,8 @@ const struct stmmac_ops dwmac4_ops = {
.add_hw_vlan_rx_fltr = dwmac4_add_hw_vlan_rx_fltr,
.del_hw_vlan_rx_fltr = dwmac4_del_hw_vlan_rx_fltr,
.restore_hw_vlan_rx_fltr = dwmac4_restore_hw_vlan_rx_fltr,
+ .rx_hw_vlan = dwmac4_rx_hw_vlan,
+ .set_hw_vlan_mode = dwmac4_set_hw_vlan_mode,
};

const struct stmmac_ops dwmac410_ops = {
@@ -1224,6 +1255,8 @@ const struct stmmac_ops dwmac410_ops = {
.add_hw_vlan_rx_fltr = dwmac4_add_hw_vlan_rx_fltr,
.del_hw_vlan_rx_fltr = dwmac4_del_hw_vlan_rx_fltr,
.restore_hw_vlan_rx_fltr = dwmac4_restore_hw_vlan_rx_fltr,
+ .rx_hw_vlan = dwmac4_rx_hw_vlan,
+ .set_hw_vlan_mode = dwmac4_set_hw_vlan_mode,
};

const struct stmmac_ops dwmac510_ops = {
@@ -1277,6 +1310,8 @@ const struct stmmac_ops dwmac510_ops = {
.add_hw_vlan_rx_fltr = dwmac4_add_hw_vlan_rx_fltr,
.del_hw_vlan_rx_fltr = dwmac4_del_hw_vlan_rx_fltr,
.restore_hw_vlan_rx_fltr = dwmac4_restore_hw_vlan_rx_fltr,
+ .rx_hw_vlan = dwmac4_rx_hw_vlan,
+ .set_hw_vlan_mode = dwmac4_set_hw_vlan_mode,
};

static u32 dwmac4_get_num_vlan(void __iomem *ioaddr)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
index 89a14084c611..1c5802e0d7f4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
@@ -198,6 +198,17 @@ static int dwmac4_get_tx_ls(struct dma_desc *p)
>> TDES3_LAST_DESCRIPTOR_SHIFT;
}

+static u16 dwmac4_wrback_get_rx_vlan_tci(struct dma_desc *p)
+{
+ return (le32_to_cpu(p->des0) & RDES0_VLAN_TAG_MASK);
+}
+
+static bool dwmac4_wrback_get_rx_vlan_valid(struct dma_desc *p)
+{
+ return ((le32_to_cpu(p->des3) & RDES3_LAST_DESCRIPTOR) &&
+ (le32_to_cpu(p->des3) & RDES3_RDES0_VALID));
+}
+
static int dwmac4_wrback_get_rx_frame_len(struct dma_desc *p, int rx_coe)
{
return (le32_to_cpu(p->des3) & RDES3_PACKET_SIZE_MASK);
@@ -551,6 +562,8 @@ const struct stmmac_desc_ops dwmac4_desc_ops = {
.set_tx_owner = dwmac4_set_tx_owner,
.set_rx_owner = dwmac4_set_rx_owner,
.get_tx_ls = dwmac4_get_tx_ls,
+ .get_rx_vlan_tci = dwmac4_wrback_get_rx_vlan_tci,
+ .get_rx_vlan_valid = dwmac4_wrback_get_rx_vlan_valid,
.get_rx_frame_len = dwmac4_wrback_get_rx_frame_len,
.enable_tx_timestamp = dwmac4_rd_enable_tx_timestamp,
.get_tx_timestamp_status = dwmac4_wrback_get_tx_timestamp_status,
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index b95d3e137813..1d424c9bf037 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -56,6 +56,10 @@ struct stmmac_desc_ops {
void (*set_tx_ic)(struct dma_desc *p);
/* Last tx segment reports the transmit status */
int (*get_tx_ls)(struct dma_desc *p);
+ /* Get the tag of the descriptor */
+ u16 (*get_rx_vlan_tci)(struct dma_desc *p);
+ /* Get the valid status of descriptor */
+ bool (*get_rx_vlan_valid)(struct dma_desc *p);
/* Return the transmit status looking at the TDES1 */
int (*tx_status)(struct stmmac_extra_stats *x,
struct dma_desc *p, void __iomem *ioaddr);
@@ -117,6 +121,10 @@ struct stmmac_desc_ops {
stmmac_do_void_callback(__priv, desc, set_tx_ic, __args)
#define stmmac_get_tx_ls(__priv, __args...) \
stmmac_do_callback(__priv, desc, get_tx_ls, __args)
+#define stmmac_get_rx_vlan_tci(__priv, __args...) \
+ stmmac_do_callback(__priv, desc, get_rx_vlan_tci, __args)
+#define stmmac_get_rx_vlan_valid(__priv, __args...) \
+ stmmac_do_callback(__priv, desc, get_rx_vlan_valid, __args)
#define stmmac_tx_status(__priv, __args...) \
stmmac_do_callback(__priv, desc, tx_status, __args)
#define stmmac_get_tx_len(__priv, __args...) \
@@ -388,6 +396,9 @@ struct stmmac_ops {
void (*update_vlan_hash)(struct mac_device_info *hw, u32 hash,
__le16 perfect_match, bool is_double);
void (*enable_vlan)(struct mac_device_info *hw, u32 type);
+ void (*rx_hw_vlan)(struct mac_device_info *hw, struct dma_desc *rx_desc,
+ struct sk_buff *skb);
+ void (*set_hw_vlan_mode)(struct mac_device_info *hw);
int (*add_hw_vlan_rx_fltr)(struct net_device *dev,
struct mac_device_info *hw,
__be16 proto, u16 vid);
@@ -497,6 +508,10 @@ struct stmmac_ops {
stmmac_do_void_callback(__priv, mac, update_vlan_hash, __args)
#define stmmac_enable_vlan(__priv, __args...) \
stmmac_do_void_callback(__priv, mac, enable_vlan, __args)
+#define stmmac_rx_hw_vlan(__priv, __args...) \
+ stmmac_do_void_callback(__priv, mac, rx_hw_vlan, __args)
+#define stmmac_set_hw_vlan_mode(__priv, __args...) \
+ stmmac_do_void_callback(__priv, mac, set_hw_vlan_mode, __args)
#define stmmac_add_hw_vlan_rx_fltr(__priv, __args...) \
stmmac_do_callback(__priv, mac, add_hw_vlan_rx_fltr, __args)
#define stmmac_del_hw_vlan_rx_fltr(__priv, __args...) \
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 2afb2bd25977..0323d5ac20f5 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3469,6 +3469,8 @@ static int stmmac_hw_setup(struct net_device *dev, bool ptp_register)
/* Start the ball rolling... */
stmmac_start_all_dma(priv);

+ stmmac_set_hw_vlan_mode(priv, priv->hw);
+
if (priv->dma_cap.fpesel) {
stmmac_fpe_start_wq(priv);

@@ -4993,7 +4995,12 @@ static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
}

stmmac_get_rx_hwtstamp(priv, p, np, skb);
- stmmac_rx_vlan(priv->dev, skb);
+ if (priv->hw->hw_vlan_en)
+ /* MAC level stripping. */
+ stmmac_rx_hw_vlan(priv, priv->hw, p, skb);
+ else
+ /* Driver level stripping. */
+ stmmac_rx_vlan(priv->dev, skb);
skb->protocol = eth_type_trans(skb, priv->dev);

if (unlikely(!coe))
@@ -5509,7 +5516,14 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
/* Got entire packet into SKB. Finish it. */

stmmac_get_rx_hwtstamp(priv, p, np, skb);
- stmmac_rx_vlan(priv->dev, skb);
+
+ if (priv->hw->hw_vlan_en)
+ /* MAC level stripping. */
+ stmmac_rx_hw_vlan(priv, priv->hw, p, skb);
+ else
+ /* Driver level stripping. */
+ stmmac_rx_vlan(priv->dev, skb);
+
skb->protocol = eth_type_trans(skb, priv->dev);

if (unlikely(!coe))
@@ -5818,6 +5832,13 @@ static int stmmac_set_features(struct net_device *netdev,
stmmac_enable_sph(priv, priv->ioaddr, sph_en, chan);
}

+ if (features & NETIF_F_HW_VLAN_CTAG_RX)
+ priv->hw->hw_vlan_en = true;
+ else
+ priv->hw->hw_vlan_en = false;
+
+ stmmac_set_hw_vlan_mode(priv, priv->hw);
+
return 0;
}

@@ -7516,6 +7537,9 @@ int stmmac_dvr_probe(struct device *device,
#ifdef STMMAC_VLAN_TAG_USED
/* Both mac100 and gmac support receive VLAN tag detection */
ndev->features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX;
+ ndev->hw_features |= NETIF_F_HW_VLAN_CTAG_RX;
+ priv->hw->hw_vlan_en = true;
+
if (priv->dma_cap.vlhash) {
ndev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
ndev->features |= NETIF_F_HW_VLAN_STAG_FILTER;
--
2.34.1