[PATCH net-next v3 2/2] net: stmmac: dwxgmac2: Add support for HW-accelerated VLAN stripping

[Boon Khai Ng]

This patch adds support for MAC level VLAN tag stripping for the
dwxgmac2 IP. This feature can be configured through ethtool.
If the rx-vlan-offload is off, then the VLAN tag will be stripped
by the driver. If the rx-vlan-offload is on then the VLAN tag
will be stripped by the MAC.

Signed-off-by: Boon Khai Ng <boon.khai.ng at altera.com>
Reviewed-by: Matthew Gerlach <matthew.gerlach at altera.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h | 12 ++++++++++++
 .../ethernet/stmicro/stmmac/dwxgmac2_core.c    |  2 ++
 .../ethernet/stmicro/stmmac/dwxgmac2_descs.c   | 18 ++++++++++++++++++
 .../net/ethernet/stmicro/stmmac/stmmac_main.c  |  2 +-
 4 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
index 5e369a9a2595..0d408ee17f33 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
@@ -464,6 +464,7 @@
 #define XGMAC_RDES3_RSV			BIT(26)
 #define XGMAC_RDES3_L34T		GENMASK(23, 20)
 #define XGMAC_RDES3_L34T_SHIFT		20
+#define XGMAC_RDES3_ET_LT		GENMASK(19, 16)
 #define XGMAC_L34T_IP4TCP		0x1
 #define XGMAC_L34T_IP4UDP		0x2
 #define XGMAC_L34T_IP6TCP		0x9
@@ -473,6 +474,17 @@
 #define XGMAC_RDES3_TSD			BIT(6)
 #define XGMAC_RDES3_TSA			BIT(4)
 
+/* RDES0 (write back format) */
+#define XGMAC_RDES0_VLAN_TAG_MASK	GENMASK(15, 0)
+
+/* Error Type or L2 Type(ET/LT) Field Number */
+#define XGMAC_ET_LT_VLAN_STAG		8
+#define XGMAC_ET_LT_VLAN_CTAG		9
+#define XGMAC_ET_LT_DVLAN_CTAG_CTAG	10
+#define XGMAC_ET_LT_DVLAN_STAG_STAG	11
+#define XGMAC_ET_LT_DVLAN_CTAG_STAG	12
+#define XGMAC_ET_LT_DVLAN_STAG_CTAG	13
+
 extern const struct stmmac_ops dwxgmac210_ops;
 extern const struct stmmac_ops dwxlgmac2_ops;
 extern const struct stmmac_dma_ops dwxgmac210_dma_ops;
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index d9f41c047e5e..6cadf8de4fdf 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -10,6 +10,7 @@
 #include "stmmac.h"
 #include "stmmac_fpe.h"
 #include "stmmac_ptp.h"
+#include "stmmac_vlan.h"
 #include "dwxlgmac2.h"
 #include "dwxgmac2.h"
 
@@ -1551,6 +1552,7 @@ int dwxgmac2_setup(struct stmmac_priv *priv)
 	mac->mii.reg_mask = GENMASK(15, 0);
 	mac->mii.clk_csr_shift = 19;
 	mac->mii.clk_csr_mask = GENMASK(21, 19);
+	mac->num_vlan = stmmac_get_num_vlan(priv->ioaddr);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
index 389aad7b5c1e..55921c88efd0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
@@ -4,6 +4,7 @@
  * stmmac XGMAC support.
  */
 
+#include <linux/bitfield.h>
 #include <linux/stmmac.h>
 #include "common.h"
 #include "dwxgmac2.h"
@@ -69,6 +70,21 @@ static int dwxgmac2_get_tx_ls(struct dma_desc *p)
 	return (le32_to_cpu(p->des3) & XGMAC_RDES3_LD) > 0;
 }
 
+static u16 dwxgmac2_wrback_get_rx_vlan_tci(struct dma_desc *p)
+{
+	return (le32_to_cpu(p->des0) & XGMAC_RDES0_VLAN_TAG_MASK);
+}
+
+static inline bool dwxgmac2_wrback_get_rx_vlan_valid(struct dma_desc *p)
+{
+	u32 et_lt;
+
+	et_lt = FIELD_GET(XGMAC_RDES3_ET_LT, le32_to_cpu(p->des3));
+
+	return et_lt >= XGMAC_ET_LT_VLAN_STAG &&
+	       et_lt <= XGMAC_ET_LT_DVLAN_STAG_CTAG;
+}
+
 static int dwxgmac2_get_rx_frame_len(struct dma_desc *p, int rx_coe)
 {
 	return (le32_to_cpu(p->des3) & XGMAC_RDES3_PL);
@@ -351,6 +367,8 @@ const struct stmmac_desc_ops dwxgmac210_desc_ops = {
 	.set_tx_owner = dwxgmac2_set_tx_owner,
 	.set_rx_owner = dwxgmac2_set_rx_owner,
 	.get_tx_ls = dwxgmac2_get_tx_ls,
+	.get_rx_vlan_tci = dwxgmac2_wrback_get_rx_vlan_tci,
+	.get_rx_vlan_valid = dwxgmac2_wrback_get_rx_vlan_valid,
 	.get_rx_frame_len = dwxgmac2_get_rx_frame_len,
 	.enable_tx_timestamp = dwxgmac2_enable_tx_timestamp,
 	.get_tx_timestamp_status = dwxgmac2_get_tx_timestamp_status,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 279532609707..eb03d6950903 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7644,7 +7644,7 @@ 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;
-	if (priv->plat->has_gmac4) {
+	if (priv->plat->has_gmac4 || priv->plat->has_xgmac) {
 		ndev->hw_features |= NETIF_F_HW_VLAN_CTAG_RX;
 		priv->hw->hw_vlan_en = true;
 	}
-- 
2.25.1