Merge branch 'dsa-MT7530-vlan'

Sean Wang says:

====================
add VLAN support to DSA MT7530

Changes sicne v2:
update to the latest code base from net-next and fix up all building
errors with -Werror.

Changes since v1:
- fix up the typo
- prefer ordering declarations longest to shortest
- update that vlan_prepare callback should not change any state
- use lower case letter for function naming

The patchset extends DSA MT7530 to VLAN support through filling required
callbacks in patch 1 and merging the special tag with VLAN tag in patch 2
for allowing that the hardware can handle these packets with VID from the
CPU port.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 400 insertions, 16 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index a5c0fd3bed32..856029896eec 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8728,6 +8728,13 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/ethernet/mediatek/
 
+MEDIATEK SWITCH DRIVER
+M:	Sean Wang <sean.wang@mediatek.com>
+L:	netdev@vger.kernel.org
+S:	Maintained
+F:	drivers/net/dsa/mt7530.*
+F:	net/dsa/tag_mtk.c
+
 MEDIATEK JPEG DRIVER
 M:	Rick Chang <rick.chang@mediatek.com>
 M:	Bin Liu <bin.liu@mediatek.com>
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 2820d69810b3..8a0bb000d056 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -805,6 +805,69 @@ mt7530_port_bridge_join(struct dsa_switch *ds, int port,
 }
 
 static void
+mt7530_port_set_vlan_unaware(struct dsa_switch *ds, int port)
+{
+	struct mt7530_priv *priv = ds->priv;
+	bool all_user_ports_removed = true;
+	int i;
+
+	/* When a port is removed from the bridge, the port would be set up
+	 * back to the default as is at initial boot which is a VLAN-unaware
+	 * port.
+	 */
+	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
+		   MT7530_PORT_MATRIX_MODE);
+	mt7530_rmw(priv, MT7530_PVC_P(port), VLAN_ATTR_MASK,
+		   VLAN_ATTR(MT7530_VLAN_TRANSPARENT));
+
+	priv->ports[port].vlan_filtering = false;
+
+	for (i = 0; i < MT7530_NUM_PORTS; i++) {
+		if (dsa_is_user_port(ds, i) &&
+		    priv->ports[i].vlan_filtering) {
+			all_user_ports_removed = false;
+			break;
+		}
+	}
+
+	/* CPU port also does the same thing until all user ports belonging to
+	 * the CPU port get out of VLAN filtering mode.
+	 */
+	if (all_user_ports_removed) {
+		mt7530_write(priv, MT7530_PCR_P(MT7530_CPU_PORT),
+			     PCR_MATRIX(dsa_user_ports(priv->ds)));
+		mt7530_write(priv, MT7530_PVC_P(MT7530_CPU_PORT),
+			     PORT_SPEC_TAG);
+	}
+}
+
+static void
+mt7530_port_set_vlan_aware(struct dsa_switch *ds, int port)
+{
+	struct mt7530_priv *priv = ds->priv;
+
+	/* The real fabric path would be decided on the membership in the
+	 * entry of VLAN table. PCR_MATRIX set up here with ALL_MEMBERS
+	 * means potential VLAN can be consisting of certain subset of all
+	 * ports.
+	 */
+	mt7530_rmw(priv, MT7530_PCR_P(port),
+		   PCR_MATRIX_MASK, PCR_MATRIX(MT7530_ALL_MEMBERS));
+
+	/* Trapped into security mode allows packet forwarding through VLAN
+	 * table lookup.
+	 */
+	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
+		   MT7530_PORT_SECURITY_MODE);
+
+	/* Set the port as a user port which is to be able to recognize VID
+	 * from incoming packets before fetching entry within the VLAN table.
+	 */
+	mt7530_rmw(priv, MT7530_PVC_P(port), VLAN_ATTR_MASK,
+		   VLAN_ATTR(MT7530_VLAN_USER));
+}
+
+static void
 mt7530_port_bridge_leave(struct dsa_switch *ds, int port,
 			 struct net_device *bridge)
 {
@@ -817,8 +880,11 @@ mt7530_port_bridge_leave(struct dsa_switch *ds, int port,
 		/* Remove this port from the port matrix of the other ports
 		 * in the same bridge. If the port is disabled, port matrix
 		 * is kept and not being setup until the port becomes enabled.
+		 * And the other port's port matrix cannot be broken when the
+		 * other port is still a VLAN-aware port.
 		 */
-		if (dsa_is_user_port(ds, i) && i != port) {
+		if (!priv->ports[i].vlan_filtering &&
+		    dsa_is_user_port(ds, i) && i != port) {
 			if (dsa_to_port(ds, i)->bridge_dev != bridge)
 				continue;
 			if (priv->ports[i].enable)
@@ -836,6 +902,8 @@ mt7530_port_bridge_leave(struct dsa_switch *ds, int port,
 			   PCR_MATRIX(BIT(MT7530_CPU_PORT)));
 	priv->ports[port].pm = PCR_MATRIX(BIT(MT7530_CPU_PORT));
 
+	mt7530_port_set_vlan_unaware(ds, port);
+
 	mutex_unlock(&priv->reg_mutex);
 }
 
@@ -906,6 +974,220 @@ err:
 	return 0;
 }
 
+static int
+mt7530_vlan_cmd(struct mt7530_priv *priv, enum mt7530_vlan_cmd cmd, u16 vid)
+{
+	struct mt7530_dummy_poll p;
+	u32 val;
+	int ret;
+
+	val = VTCR_BUSY | VTCR_FUNC(cmd) | vid;
+	mt7530_write(priv, MT7530_VTCR, val);
+
+	INIT_MT7530_DUMMY_POLL(&p, priv, MT7530_VTCR);
+	ret = readx_poll_timeout(_mt7530_read, &p, val,
+				 !(val & VTCR_BUSY), 20, 20000);
+	if (ret < 0) {
+		dev_err(priv->dev, "poll timeout\n");
+		return ret;
+	}
+
+	val = mt7530_read(priv, MT7530_VTCR);
+	if (val & VTCR_INVALID) {
+		dev_err(priv->dev, "read VTCR invalid\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+mt7530_port_vlan_filtering(struct dsa_switch *ds, int port,
+			   bool vlan_filtering)
+{
+	struct mt7530_priv *priv = ds->priv;
+
+	priv->ports[port].vlan_filtering = vlan_filtering;
+
+	if (vlan_filtering) {
+		/* The port is being kept as VLAN-unaware port when bridge is
+		 * set up with vlan_filtering not being set, Otherwise, the
+		 * port and the corresponding CPU port is required the setup
+		 * for becoming a VLAN-aware port.
+		 */
+		mt7530_port_set_vlan_aware(ds, port);
+		mt7530_port_set_vlan_aware(ds, MT7530_CPU_PORT);
+	}
+
+	return 0;
+}
+
+static int
+mt7530_port_vlan_prepare(struct dsa_switch *ds, int port,
+			 const struct switchdev_obj_port_vlan *vlan)
+{
+	/* nothing needed */
+
+	return 0;
+}
+
+static void
+mt7530_hw_vlan_add(struct mt7530_priv *priv,
+		   struct mt7530_hw_vlan_entry *entry)
+{
+	u8 new_members;
+	u32 val;
+
+	new_members = entry->old_members | BIT(entry->port) |
+		      BIT(MT7530_CPU_PORT);
+
+	/* Validate the entry with independent learning, create egress tag per
+	 * VLAN and joining the port as one of the port members.
+	 */
+	val = IVL_MAC | VTAG_EN | PORT_MEM(new_members) | VLAN_VALID;
+	mt7530_write(priv, MT7530_VAWD1, val);
+
+	/* Decide whether adding tag or not for those outgoing packets from the
+	 * port inside the VLAN.
+	 */
+	val = entry->untagged ? MT7530_VLAN_EGRESS_UNTAG :
+				MT7530_VLAN_EGRESS_TAG;
+	mt7530_rmw(priv, MT7530_VAWD2,
+		   ETAG_CTRL_P_MASK(entry->port),
+		   ETAG_CTRL_P(entry->port, val));
+
+	/* CPU port is always taken as a tagged port for serving more than one
+	 * VLANs across and also being applied with egress type stack mode for
+	 * that VLAN tags would be appended after hardware special tag used as
+	 * DSA tag.
+	 */
+	mt7530_rmw(priv, MT7530_VAWD2,
+		   ETAG_CTRL_P_MASK(MT7530_CPU_PORT),
+		   ETAG_CTRL_P(MT7530_CPU_PORT,
+			       MT7530_VLAN_EGRESS_STACK));
+}
+
+static void
+mt7530_hw_vlan_del(struct mt7530_priv *priv,
+		   struct mt7530_hw_vlan_entry *entry)
+{
+	u8 new_members;
+	u32 val;
+
+	new_members = entry->old_members & ~BIT(entry->port);
+
+	val = mt7530_read(priv, MT7530_VAWD1);
+	if (!(val & VLAN_VALID)) {
+		dev_err(priv->dev,
+			"Cannot be deleted due to invalid entry\n");
+		return;
+	}
+
+	/* If certain member apart from CPU port is still alive in the VLAN,
+	 * the entry would be kept valid. Otherwise, the entry is got to be
+	 * disabled.
+	 */
+	if (new_members && new_members != BIT(MT7530_CPU_PORT)) {
+		val = IVL_MAC | VTAG_EN | PORT_MEM(new_members) |
+		      VLAN_VALID;
+		mt7530_write(priv, MT7530_VAWD1, val);
+	} else {
+		mt7530_write(priv, MT7530_VAWD1, 0);
+		mt7530_write(priv, MT7530_VAWD2, 0);
+	}
+}
+
+static void
+mt7530_hw_vlan_update(struct mt7530_priv *priv, u16 vid,
+		      struct mt7530_hw_vlan_entry *entry,
+		      mt7530_vlan_op vlan_op)
+{
+	u32 val;
+
+	/* Fetch entry */
+	mt7530_vlan_cmd(priv, MT7530_VTCR_RD_VID, vid);
+
+	val = mt7530_read(priv, MT7530_VAWD1);
+
+	entry->old_members = (val >> PORT_MEM_SHFT) & PORT_MEM_MASK;
+
+	/* Manipulate entry */
+	vlan_op(priv, entry);
+
+	/* Flush result to hardware */
+	mt7530_vlan_cmd(priv, MT7530_VTCR_WR_VID, vid);
+}
+
+static void
+mt7530_port_vlan_add(struct dsa_switch *ds, int port,
+		     const struct switchdev_obj_port_vlan *vlan)
+{
+	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
+	bool pvid = vlan->flags & BRIDGE_VLAN_INFO_PVID;
+	struct mt7530_hw_vlan_entry new_entry;
+	struct mt7530_priv *priv = ds->priv;
+	u16 vid;
+
+	/* The port is kept as VLAN-unaware if bridge with vlan_filtering not
+	 * being set.
+	 */
+	if (!priv->ports[port].vlan_filtering)
+		return;
+
+	mutex_lock(&priv->reg_mutex);
+
+	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+		mt7530_hw_vlan_entry_init(&new_entry, port, untagged);
+		mt7530_hw_vlan_update(priv, vid, &new_entry,
+				      mt7530_hw_vlan_add);
+	}
+
+	if (pvid) {
+		mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK,
+			   G0_PORT_VID(vlan->vid_end));
+		priv->ports[port].pvid = vlan->vid_end;
+	}
+
+	mutex_unlock(&priv->reg_mutex);
+}
+
+static int
+mt7530_port_vlan_del(struct dsa_switch *ds, int port,
+		     const struct switchdev_obj_port_vlan *vlan)
+{
+	struct mt7530_hw_vlan_entry target_entry;
+	struct mt7530_priv *priv = ds->priv;
+	u16 vid, pvid;
+
+	/* The port is kept as VLAN-unaware if bridge with vlan_filtering not
+	 * being set.
+	 */
+	if (!priv->ports[port].vlan_filtering)
+		return 0;
+
+	mutex_lock(&priv->reg_mutex);
+
+	pvid = priv->ports[port].pvid;
+	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+		mt7530_hw_vlan_entry_init(&target_entry, port, 0);
+		mt7530_hw_vlan_update(priv, vid, &target_entry,
+				      mt7530_hw_vlan_del);
+
+		/* PVID is being restored to the default whenever the PVID port
+		 * is being removed from the VLAN.
+		 */
+		if (pvid == vid)
+			pvid = G0_PORT_VID_DEF;
+	}
+
+	mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK, pvid);
+	priv->ports[port].pvid = pvid;
+
+	mutex_unlock(&priv->reg_mutex);
+
+	return 0;
+}
+
 static enum dsa_tag_protocol
 mtk_get_tag_protocol(struct dsa_switch *ds, int port)
 {
@@ -1035,6 +1317,10 @@ static const struct dsa_switch_ops mt7530_switch_ops = {
 	.port_fdb_add		= mt7530_port_fdb_add,
 	.port_fdb_del		= mt7530_port_fdb_del,
 	.port_fdb_dump		= mt7530_port_fdb_dump,
+	.port_vlan_filtering	= mt7530_port_vlan_filtering,
+	.port_vlan_prepare	= mt7530_port_vlan_prepare,
+	.port_vlan_add		= mt7530_port_vlan_add,
+	.port_vlan_del		= mt7530_port_vlan_del,
 };
 
 static int
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 74db9822eb40..d9b407a22a58 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -17,6 +17,7 @@
 #define MT7530_NUM_PORTS		7
 #define MT7530_CPU_PORT			6
 #define MT7530_NUM_FDB_RECORDS		2048
+#define MT7530_ALL_MEMBERS		0xff
 
 #define	NUM_TRGMII_CTRL			5
 
@@ -88,21 +89,42 @@ enum mt7530_fdb_cmd {
 /* Register for vlan table control */
 #define MT7530_VTCR			0x90
 #define  VTCR_BUSY			BIT(31)
-#define  VTCR_FUNC			(((x) & 0xf) << 12)
-#define  VTCR_FUNC_RD_VID		0x1
-#define  VTCR_FUNC_WR_VID		0x2
-#define  VTCR_FUNC_INV_VID		0x3
-#define  VTCR_FUNC_VAL_VID		0x4
+#define  VTCR_INVALID			BIT(16)
+#define  VTCR_FUNC(x)			(((x) & 0xf) << 12)
 #define  VTCR_VID			((x) & 0xfff)
 
+enum mt7530_vlan_cmd {
+	/* Read/Write the specified VID entry from VAWD register based
+	 * on VID.
+	 */
+	MT7530_VTCR_RD_VID = 0,
+	MT7530_VTCR_WR_VID = 1,
+};
+
 /* Register for setup vlan and acl write data */
 #define MT7530_VAWD1			0x94
 #define  PORT_STAG			BIT(31)
+/* Independent VLAN Learning */
 #define  IVL_MAC			BIT(30)
+/* Per VLAN Egress Tag Control */
+#define  VTAG_EN			BIT(28)
+/* VLAN Member Control */
 #define  PORT_MEM(x)			(((x) & 0xff) << 16)
-#define  VALID				BIT(1)
+/* VLAN Entry Valid */
+#define  VLAN_VALID			BIT(0)
+#define  PORT_MEM_SHFT			16
+#define  PORT_MEM_MASK			0xff
 
 #define MT7530_VAWD2			0x98
+/* Egress Tag Control */
+#define  ETAG_CTRL_P(p, x)		(((x) & 0x3) << ((p) << 1))
+#define  ETAG_CTRL_P_MASK(p)		ETAG_CTRL_P(p, 3)
+
+enum mt7530_vlan_egress_attr {
+	MT7530_VLAN_EGRESS_UNTAG = 0,
+	MT7530_VLAN_EGRESS_TAG = 2,
+	MT7530_VLAN_EGRESS_STACK = 3,
+};
 
 /* Register for port STP state control */
 #define MT7530_SSP_P(x)			(0x2000 + ((x) * 0x100))
@@ -120,11 +142,23 @@ enum mt7530_stp_state {
 /* Register for port control */
 #define MT7530_PCR_P(x)			(0x2004 + ((x) * 0x100))
 #define  PORT_VLAN(x)			((x) & 0x3)
+
+enum mt7530_port_mode {
+	/* Port Matrix Mode: Frames are forwarded by the PCR_MATRIX members. */
+	MT7530_PORT_MATRIX_MODE = PORT_VLAN(0),
+
+	/* Security Mode: Discard any frame due to ingress membership
+	 * violation or VID missed on the VLAN table.
+	 */
+	MT7530_PORT_SECURITY_MODE = PORT_VLAN(3),
+};
+
 #define  PCR_MATRIX(x)			(((x) & 0xff) << 16)
 #define  PORT_PRI(x)			(((x) & 0x7) << 24)
 #define  EG_TAG(x)			(((x) & 0x3) << 28)
 #define  PCR_MATRIX_MASK		PCR_MATRIX(0xff)
 #define  PCR_MATRIX_CLR			PCR_MATRIX(0)
+#define  PCR_PORT_VLAN_MASK		PORT_VLAN(3)
 
 /* Register for port security control */
 #define MT7530_PSC_P(x)			(0x200c + ((x) * 0x100))
@@ -134,10 +168,20 @@ enum mt7530_stp_state {
 #define MT7530_PVC_P(x)			(0x2010 + ((x) * 0x100))
 #define  PORT_SPEC_TAG			BIT(5)
 #define  VLAN_ATTR(x)			(((x) & 0x3) << 6)
+#define  VLAN_ATTR_MASK			VLAN_ATTR(3)
+
+enum mt7530_vlan_port_attr {
+	MT7530_VLAN_USER = 0,
+	MT7530_VLAN_TRANSPARENT = 3,
+};
+
 #define  STAG_VPID			(((x) & 0xffff) << 16)
 
 /* Register for port port-and-protocol based vlan 1 control */
 #define MT7530_PPBV1_P(x)		(0x2014 + ((x) * 0x100))
+#define  G0_PORT_VID(x)			(((x) & 0xfff) << 0)
+#define  G0_PORT_VID_MASK		G0_PORT_VID(0xfff)
+#define  G0_PORT_VID_DEF		G0_PORT_VID(1)
 
 /* Register for port MAC control register */
 #define MT7530_PMCR_P(x)		(0x3000 + ((x) * 0x100))
@@ -345,9 +389,20 @@ struct mt7530_fdb {
 	bool noarp;
 };
 
+/* struct mt7530_port -	This is the main data structure for holding the state
+ *			of the port.
+ * @enable:	The status used for show port is enabled or not.
+ * @pm:		The matrix used to show all connections with the port.
+ * @pvid:	The VLAN specified is to be considered a PVID at ingress.  Any
+ *		untagged frames will be assigned to the related VLAN.
+ * @vlan_filtering: The flags indicating whether the port that can recognize
+ *		    VLAN-tagged frames.
+ */
 struct mt7530_port {
 	bool enable;
 	u32 pm;
+	u16 pvid;
+	bool vlan_filtering;
 };
 
 /* struct mt7530_priv -	This is the main data structure for holding the state
@@ -382,6 +437,22 @@ struct mt7530_priv {
 	struct mutex reg_mutex;
 };
 
+struct mt7530_hw_vlan_entry {
+	int port;
+	u8  old_members;
+	bool untagged;
+};
+
+static inline void mt7530_hw_vlan_entry_init(struct mt7530_hw_vlan_entry *e,
+					     int port, bool untagged)
+{
+	e->port = port;
+	e->untagged = untagged;
+}
+
+typedef void (*mt7530_vlan_op)(struct mt7530_priv *,
+			       struct mt7530_hw_vlan_entry *);
+
 struct mt7530_hw_stats {
 	const char	*string;
 	u16		reg;
diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c
index 8475434af7d5..11535bc70743 100644
--- a/net/dsa/tag_mtk.c
+++ b/net/dsa/tag_mtk.c
@@ -13,10 +13,13 @@
  */
 
 #include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
 
 #include "dsa_priv.h"
 
 #define MTK_HDR_LEN		4
+#define MTK_HDR_XMIT_UNTAGGED		0
+#define MTK_HDR_XMIT_TAGGED_TPID_8100	1
 #define MTK_HDR_RECV_SOURCE_PORT_MASK	GENMASK(2, 0)
 #define MTK_HDR_XMIT_DP_BIT_MASK	GENMASK(5, 0)
 
@@ -25,20 +28,37 @@ static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb,
 {
 	struct dsa_port *dp = dsa_slave_to_port(dev);
 	u8 *mtk_tag;
+	bool is_vlan_skb = true;
 
-	if (skb_cow_head(skb, MTK_HDR_LEN) < 0)
-		return NULL;
-
-	skb_push(skb, MTK_HDR_LEN);
+	/* Build the special tag after the MAC Source Address. If VLAN header
+	 * is present, it's required that VLAN header and special tag is
+	 * being combined. Only in this way we can allow the switch can parse
+	 * the both special and VLAN tag at the same time and then look up VLAN
+	 * table with VID.
+	 */
+	if (!skb_vlan_tagged(skb)) {
+		if (skb_cow_head(skb, MTK_HDR_LEN) < 0)
+			return NULL;
 
-	memmove(skb->data, skb->data + MTK_HDR_LEN, 2 * ETH_ALEN);
+		skb_push(skb, MTK_HDR_LEN);
+		memmove(skb->data, skb->data + MTK_HDR_LEN, 2 * ETH_ALEN);
+		is_vlan_skb = false;
+	}
 
-	/* Build the tag after the MAC Source Address */
 	mtk_tag = skb->data + 2 * ETH_ALEN;
-	mtk_tag[0] = 0;
+
+	/* Mark tag attribute on special tag insertion to notify hardware
+	 * whether that's a combined special tag with 802.1Q header.
+	 */
+	mtk_tag[0] = is_vlan_skb ? MTK_HDR_XMIT_TAGGED_TPID_8100 :
+		     MTK_HDR_XMIT_UNTAGGED;
 	mtk_tag[1] = (1 << dp->index) & MTK_HDR_XMIT_DP_BIT_MASK;
-	mtk_tag[2] = 0;
-	mtk_tag[3] = 0;
+
+	/* Tag control information is kept for 802.1Q */
+	if (!is_vlan_skb) {
+		mtk_tag[2] = 0;
+		mtk_tag[3] = 0;
+	}
 
 	return skb;
 }