Merge branch 'Broadcom-tags-support-for-531x5-539x-families'

Florian Fainelli says:

====================
Broadcom tags support for 531x5/539x families

This patch series finally allows us to enable Broadcom tags on the
BCM531x5/BCM539x switch series which are very often cascaded onto
another on-chip Broadcom switch. Because of that we need to be able to
detect that Broadcom tags are already enabled on our DSA master which
happens to be a DSA slave in that case since they are not part of the
same DSA switch tree, the protocol does not support that.

Due to the way DSA works, get_tag_protocol() is called prior to
ds->ops->setup and we do not have all data structures set-up (in
particular dsa_port::cpu_dp is not filed yet) so doing this at the time
get_tag_protocol() is called and without exporting a helper function is
desirable to limit our footprint into the framework.

Having the core (net/dsa/dsa2.c) return and enforce DSA_TAG_PROTO_NONE
was considered and done initially but this leaves the driver outside of
the decision to force/fallback to a particular protocol, instead of
letting it in control. Also there is no reason to suspect that all
tagging protocols are problematic, e.g.: "inner" Marvell EDSA with
"outer" Broadcom tag may work just fine, and vice versa.

This was tested on:

- Lamobo R1 which now has working Broadcom tags for its external BCM53125 switch
- BCM7445 which has a BCM53125 hanging off one of its internal switch
  port, the BCM53125 still works with DSA_TAG_PROTO_NONE
- BCM7278 which has a peculiar dual CPU port set-up (so dual IMP mode
  needs to be enabled)
- Northstar Plus with DSA_TAG_PROTO_BRCM_PREPEND and no external
  switches hanging off the internal switch
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/b53/b53_common.c

@@ -371,8 +371,6 @@ static void b53_enable_vlan(struct b53_device *dev, bool enable,
 		b53_read8(dev, B53_VLAN_PAGE, B53_VLAN_CTRL5, &vc5);
 	}
 
-	mgmt &= ~SM_SW_FWD_MODE;
-
 	if (enable) {
 		vc0 |= VC0_VLAN_EN | VC0_VID_CHK_EN | VC0_VID_HASH_VID;
 		vc1 |= VC1_RX_MCST_UNTAG_EN | VC1_RX_MCST_FWD_EN;
@@ -573,9 +571,8 @@ EXPORT_SYMBOL(b53_disable_port);
 
 void b53_brcm_hdr_setup(struct dsa_switch *ds, int port)
 {
-	bool tag_en = !(ds->ops->get_tag_protocol(ds, port) ==
-			 DSA_TAG_PROTO_NONE);
 	struct b53_device *dev = ds->priv;
+	bool tag_en = !(dev->tag_protocol == DSA_TAG_PROTO_NONE);
 	u8 hdr_ctl, val;
 	u16 reg;
 
@@ -595,6 +592,22 @@ void b53_brcm_hdr_setup(struct dsa_switch *ds, int port)
 		break;
 	}
 
+	/* Enable management mode if tagging is requested */
+	b53_read8(dev, B53_CTRL_PAGE, B53_SWITCH_MODE, &hdr_ctl);
+	if (tag_en)
+		hdr_ctl |= SM_SW_FWD_MODE;
+	else
+		hdr_ctl &= ~SM_SW_FWD_MODE;
+	b53_write8(dev, B53_CTRL_PAGE, B53_SWITCH_MODE, hdr_ctl);
+
+	/* Configure the appropriate IMP port */
+	b53_read8(dev, B53_MGMT_PAGE, B53_GLOBAL_CONFIG, &hdr_ctl);
+	if (port == 8)
+		hdr_ctl |= GC_FRM_MGMT_PORT_MII;
+	else if (port == 5)
+		hdr_ctl |= GC_FRM_MGMT_PORT_M;
+	b53_write8(dev, B53_MGMT_PAGE, B53_GLOBAL_CONFIG, hdr_ctl);
+
 	/* Enable Broadcom tags for IMP port */
 	b53_read8(dev, B53_MGMT_PAGE, B53_BRCM_HDR, &hdr_ctl);
 	if (tag_en)
@@ -1866,36 +1879,57 @@ static bool b53_possible_cpu_port(struct dsa_switch *ds, int port)
 	return false;
 }
 
-static bool b53_can_enable_brcm_tags(struct dsa_switch *ds, int port)
+static bool b53_can_enable_brcm_tags(struct dsa_switch *ds, int port,
+				     enum dsa_tag_protocol tag_protocol)
 {
 	bool ret = b53_possible_cpu_port(ds, port);
 
-	if (!ret)
+	if (!ret) {
 		dev_warn(ds->dev, "Port %d is not Broadcom tag capable\n",
 			 port);
 		return ret;
+	}
+
+	switch (tag_protocol) {
+	case DSA_TAG_PROTO_BRCM:
+	case DSA_TAG_PROTO_BRCM_PREPEND:
+		dev_warn(ds->dev,
+			 "Port %d is stacked to Broadcom tag switch\n", port);
+		ret = false;
+		break;
+	default:
+		ret = true;
+		break;
+	}
+
+	return ret;
 }
 
-enum dsa_tag_protocol b53_get_tag_protocol(struct dsa_switch *ds, int port)
+enum dsa_tag_protocol b53_get_tag_protocol(struct dsa_switch *ds, int port,
+					   enum dsa_tag_protocol mprot)
 {
 	struct b53_device *dev = ds->priv;
 
 	/* Older models (5325, 5365) support a different tag format that we do
-	 * not support in net/dsa/tag_brcm.c yet. 539x and 531x5 require managed
-	 * mode to be turned on which means we need to specifically manage ARL
-	 * misses on multicast addresses (TBD).
+	 * not support in net/dsa/tag_brcm.c yet.
 	 */
-	if (is5325(dev) || is5365(dev) || is539x(dev) || is531x5(dev) ||
-	    !b53_can_enable_brcm_tags(ds, port))
-		return DSA_TAG_PROTO_NONE;
+	if (is5325(dev) || is5365(dev) ||
+	    !b53_can_enable_brcm_tags(ds, port, mprot)) {
+		dev->tag_protocol = DSA_TAG_PROTO_NONE;
+		goto out;
+	}
 
 	/* Broadcom BCM58xx chips have a flow accelerator on Port 8
 	 * which requires us to use the prepended Broadcom tag type
 	 */
-	if (dev->chip_id == BCM58XX_DEVICE_ID && port == B53_CPU_PORT)
-		return DSA_TAG_PROTO_BRCM_PREPEND;
+	if (dev->chip_id == BCM58XX_DEVICE_ID && port == B53_CPU_PORT) {
+		dev->tag_protocol = DSA_TAG_PROTO_BRCM_PREPEND;
+		goto out;
+	}
 
-	return DSA_TAG_PROTO_BRCM;
+	dev->tag_protocol = DSA_TAG_PROTO_BRCM;
+out:
+	return dev->tag_protocol;
 }
 EXPORT_SYMBOL(b53_get_tag_protocol);
 

drivers/net/dsa/b53/b53_priv.h

@@ -118,6 +118,7 @@ struct b53_device {
 	u8 jumbo_size_reg;
 	int reset_gpio;
 	u8 num_arl_entries;
+	enum dsa_tag_protocol tag_protocol;
 
 	/* used ports mask */
 	u16 enabled_ports;
@@ -359,7 +360,8 @@ int b53_mdb_del(struct dsa_switch *ds, int port,
 		const struct switchdev_obj_port_mdb *mdb);
 int b53_mirror_add(struct dsa_switch *ds, int port,
 		   struct dsa_mall_mirror_tc_entry *mirror, bool ingress);
-enum dsa_tag_protocol b53_get_tag_protocol(struct dsa_switch *ds, int port);
+enum dsa_tag_protocol b53_get_tag_protocol(struct dsa_switch *ds, int port,
+					   enum dsa_tag_protocol mprot);
 void b53_mirror_del(struct dsa_switch *ds, int port,
 		    struct dsa_mall_mirror_tc_entry *mirror);
 int b53_enable_port(struct dsa_switch *ds, int port, struct phy_device *phy);

drivers/net/dsa/dsa_loop.c

@@ -61,7 +61,8 @@ struct dsa_loop_priv {
 static struct phy_device *phydevs[PHY_MAX_ADDR];
 
 static enum dsa_tag_protocol dsa_loop_get_protocol(struct dsa_switch *ds,
-						   int port)
+						   int port,
+						   enum dsa_tag_protocol mp)
 {
 	dev_dbg(ds->dev, "%s: port: %d\n", __func__, port);
 

drivers/net/dsa/lan9303-core.c

@@ -883,7 +883,8 @@ static int lan9303_check_device(struct lan9303 *chip)
 /* ---------------------------- DSA -----------------------------------*/
 
 static enum dsa_tag_protocol lan9303_get_tag_protocol(struct dsa_switch *ds,
-						      int port)
+						      int port,
+						      enum dsa_tag_protocol mp)
 {
 	return DSA_TAG_PROTO_LAN9303;
 }

drivers/net/dsa/lantiq_gswip.c

@@ -841,7 +841,8 @@ static int gswip_setup(struct dsa_switch *ds)
 }
 
 static enum dsa_tag_protocol gswip_get_tag_protocol(struct dsa_switch *ds,
-						    int port)
+						    int port,
+						    enum dsa_tag_protocol mp)
 {
 	return DSA_TAG_PROTO_GSWIP;
 }

drivers/net/dsa/microchip/ksz8795.c

@@ -645,7 +645,8 @@ static void ksz8795_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)
 }
 
 static enum dsa_tag_protocol ksz8795_get_tag_protocol(struct dsa_switch *ds,
-						      int port)
+						      int port,
+						      enum dsa_tag_protocol mp)
 {
 	return DSA_TAG_PROTO_KSZ8795;
 }

drivers/net/dsa/microchip/ksz9477.c

@@ -295,7 +295,8 @@ static void ksz9477_port_init_cnt(struct ksz_device *dev, int port)
 }
 
 static enum dsa_tag_protocol ksz9477_get_tag_protocol(struct dsa_switch *ds,
-						      int port)
+						      int port,
+						      enum dsa_tag_protocol mp)
 {
 	enum dsa_tag_protocol proto = DSA_TAG_PROTO_KSZ9477;
 	struct ksz_device *dev = ds->priv;

drivers/net/dsa/mt7530.c

@@ -1223,7 +1223,8 @@ mt7530_port_vlan_del(struct dsa_switch *ds, int port,
 }
 
 static enum dsa_tag_protocol
-mtk_get_tag_protocol(struct dsa_switch *ds, int port)
+mtk_get_tag_protocol(struct dsa_switch *ds, int port,
+		     enum dsa_tag_protocol mp)
 {
 	struct mt7530_priv *priv = ds->priv;
 

drivers/net/dsa/mv88e6060.c

@@ -43,7 +43,8 @@ static const char *mv88e6060_get_name(struct mii_bus *bus, int sw_addr)
 }
 
 static enum dsa_tag_protocol mv88e6060_get_tag_protocol(struct dsa_switch *ds,
-							int port)
+							int port,
+							enum dsa_tag_protocol m)
 {
 	return DSA_TAG_PROTO_TRAILER;
 }

drivers/net/dsa/mv88e6xxx/chip.c

@@ -5217,7 +5217,8 @@ static struct mv88e6xxx_chip *mv88e6xxx_alloc_chip(struct device *dev)
 }
 
 static enum dsa_tag_protocol mv88e6xxx_get_tag_protocol(struct dsa_switch *ds,
-							int port)
+							int port,
+							enum dsa_tag_protocol m)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 

drivers/net/dsa/ocelot/felix.c

@@ -16,7 +16,8 @@
 #include "felix.h"
 
 static enum dsa_tag_protocol felix_get_tag_protocol(struct dsa_switch *ds,
-						    int port)
+						    int port,
+						    enum dsa_tag_protocol mp)
 {
 	return DSA_TAG_PROTO_OCELOT;
 }

drivers/net/dsa/qca/ar9331.c

@@ -347,7 +347,8 @@ static void ar9331_sw_port_disable(struct dsa_switch *ds, int port)
 }
 
 static enum dsa_tag_protocol ar9331_sw_get_tag_protocol(struct dsa_switch *ds,
-							int port)
+							int port,
+							enum dsa_tag_protocol m)
 {
 	return DSA_TAG_PROTO_AR9331;
 }

drivers/net/dsa/qca8k.c

@@ -1017,7 +1017,8 @@ qca8k_port_fdb_dump(struct dsa_switch *ds, int port,
 }
 
 static enum dsa_tag_protocol
-qca8k_get_tag_protocol(struct dsa_switch *ds, int port)
+qca8k_get_tag_protocol(struct dsa_switch *ds, int port,
+		       enum dsa_tag_protocol mp)
 {
 	return DSA_TAG_PROTO_QCA;
 }

drivers/net/dsa/rtl8366rb.c

@@ -964,7 +964,8 @@ static int rtl8366rb_setup(struct dsa_switch *ds)
 }
 
 static enum dsa_tag_protocol rtl8366_get_tag_protocol(struct dsa_switch *ds,
-						      int port)
+						      int port,
+						      enum dsa_tag_protocol mp)
 {
 	/* For now, the RTL switches are handled without any custom tags.
 	 *

drivers/net/dsa/sja1105/sja1105_main.c

@@ -1534,7 +1534,8 @@ static int sja1105_setup_8021q_tagging(struct dsa_switch *ds, bool enabled)
 }
 
 static enum dsa_tag_protocol
-sja1105_get_tag_protocol(struct dsa_switch *ds, int port)
+sja1105_get_tag_protocol(struct dsa_switch *ds, int port,
+			 enum dsa_tag_protocol mp)
 {
 	return DSA_TAG_PROTO_SJA1105;
 }

drivers/net/dsa/vitesse-vsc73xx-core.c

@@ -542,7 +542,8 @@ static int vsc73xx_phy_write(struct dsa_switch *ds, int phy, int regnum,
 }
 
 static enum dsa_tag_protocol vsc73xx_get_tag_protocol(struct dsa_switch *ds,
-						      int port)
+						      int port,
+						      enum dsa_tag_protocol mp)
 {
 	/* The switch internally uses a 8 byte header with length,
 	 * source port, tag, LPA and priority. This is supposedly

include/net/dsa.h

@@ -380,7 +380,8 @@ typedef int dsa_fdb_dump_cb_t(const unsigned char *addr, u16 vid,
 			      bool is_static, void *data);
 struct dsa_switch_ops {
 	enum dsa_tag_protocol (*get_tag_protocol)(struct dsa_switch *ds,
-						  int port);
+						  int port,
+						  enum dsa_tag_protocol mprot);
 
 	int	(*setup)(struct dsa_switch *ds);
 	void	(*teardown)(struct dsa_switch *ds);

net/dsa/dsa2.c

@@ -614,6 +614,32 @@ static int dsa_port_parse_dsa(struct dsa_port *dp)
 	return 0;
 }
 
+static enum dsa_tag_protocol dsa_get_tag_protocol(struct dsa_port *dp,
+						  struct net_device *master)
+{
+	enum dsa_tag_protocol tag_protocol = DSA_TAG_PROTO_NONE;
+	struct dsa_switch *mds, *ds = dp->ds;
+	unsigned int mdp_upstream;
+	struct dsa_port *mdp;
+
+	/* It is possible to stack DSA switches onto one another when that
+	 * happens the switch driver may want to know if its tagging protocol
+	 * is going to work in such a configuration.
+	 */
+	if (dsa_slave_dev_check(master)) {
+		mdp = dsa_slave_to_port(master);
+		mds = mdp->ds;
+		mdp_upstream = dsa_upstream_port(mds, mdp->index);
+		tag_protocol = mds->ops->get_tag_protocol(mds, mdp_upstream,
+							  DSA_TAG_PROTO_NONE);
+	}
+
+	/* If the master device is not itself a DSA slave in a disjoint DSA
+	 * tree, then return immediately.
+	 */
+	return ds->ops->get_tag_protocol(ds, dp->index, tag_protocol);
+}
+
 static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
 {
 	struct dsa_switch *ds = dp->ds;
@@ -621,20 +647,21 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
 	const struct dsa_device_ops *tag_ops;
 	enum dsa_tag_protocol tag_protocol;
 
-	tag_protocol = ds->ops->get_tag_protocol(ds, dp->index);
+	tag_protocol = dsa_get_tag_protocol(dp, master);
 	tag_ops = dsa_tag_driver_get(tag_protocol);
 	if (IS_ERR(tag_ops)) {
 		if (PTR_ERR(tag_ops) == -ENOPROTOOPT)
 			return -EPROBE_DEFER;
 		dev_warn(ds->dev, "No tagger for this switch\n");
+		dp->master = NULL;
 		return PTR_ERR(tag_ops);
 	}
 
+	dp->master = master;
 	dp->type = DSA_PORT_TYPE_CPU;
 	dp->filter = tag_ops->filter;
 	dp->rcv = tag_ops->rcv;
 	dp->tag_ops = tag_ops;
-	dp->master = master;
 	dp->dst = dst;
 
 	return 0;

net/dsa/dsa_priv.h

@@ -157,6 +157,7 @@ extern const struct dsa_device_ops notag_netdev_ops;
 void dsa_slave_mii_bus_init(struct dsa_switch *ds);
 int dsa_slave_create(struct dsa_port *dp);
 void dsa_slave_destroy(struct net_device *slave_dev);
+bool dsa_slave_dev_check(const struct net_device *dev);
 int dsa_slave_suspend(struct net_device *slave_dev);
 int dsa_slave_resume(struct net_device *slave_dev);
 int dsa_slave_register_notifier(void);

net/dsa/slave.c

@@ -22,8 +22,6 @@
 
 #include "dsa_priv.h"
 
-static bool dsa_slave_dev_check(const struct net_device *dev);
-
 /* slave mii_bus handling ***************************************************/
 static int dsa_slave_phy_read(struct mii_bus *bus, int addr, int reg)
 {
@@ -1473,7 +1471,7 @@ void dsa_slave_destroy(struct net_device *slave_dev)
 	free_netdev(slave_dev);
 }
 
-static bool dsa_slave_dev_check(const struct net_device *dev)
+bool dsa_slave_dev_check(const struct net_device *dev)
 {
 	return dev->netdev_ops == &dsa_slave_netdev_ops;
 }