net: dsa: xrs700x: add HSR offloading support

Add offloading for HSR/PRP (IEC 62439-3) tag insertion, tag removal
forwarding and duplication supported by the xrs7000 series switches.

Only HSR v1 and PRP v1 are supported by the xrs7000 series switches (HSR
v0 is not).
Signed-off-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/xrs700x/xrs700x.c

@@ -7,11 +7,17 @@
 #include <net/dsa.h>
 #include <linux/if_bridge.h>
 #include <linux/of_device.h>
+#include <linux/netdev_features.h>
+#include <linux/if_hsr.h>
 #include "xrs700x.h"
 #include "xrs700x_reg.h"
 
 #define XRS700X_MIB_INTERVAL msecs_to_jiffies(3000)
 
+#define XRS7000X_SUPPORTED_HSR_FEATURES \
+	(NETIF_F_HW_HSR_TAG_INS | NETIF_F_HW_HSR_TAG_RM | \
+	 NETIF_F_HW_HSR_FWD | NETIF_F_HW_HSR_DUP)
+
 #define XRS7003E_ID	0x100
 #define XRS7003F_ID	0x101
 #define XRS7004E_ID	0x200
@@ -496,6 +502,119 @@ static void xrs700x_bridge_leave(struct dsa_switch *ds, int port,
 	xrs700x_bridge_common(ds, port, bridge, false);
 }
 
+static int xrs700x_hsr_join(struct dsa_switch *ds, int port,
+			    struct net_device *hsr)
+{
+	unsigned int val = XRS_HSR_CFG_HSR_PRP;
+	struct dsa_port *partner = NULL, *dp;
+	struct xrs700x *priv = ds->priv;
+	struct net_device *slave;
+	int ret, i, hsr_pair[2];
+	enum hsr_version ver;
+
+	ret = hsr_get_version(hsr, &ver);
+	if (ret)
+		return ret;
+
+	/* Only ports 1 and 2 can be HSR/PRP redundant ports. */
+	if (port != 1 && port != 2)
+		return -EOPNOTSUPP;
+
+	if (ver == HSR_V1)
+		val |= XRS_HSR_CFG_HSR;
+	else if (ver == PRP_V1)
+		val |= XRS_HSR_CFG_PRP;
+	else
+		return -EOPNOTSUPP;
+
+	dsa_hsr_foreach_port(dp, ds, hsr) {
+		partner = dp;
+	}
+
+	/* We can't enable redundancy on the switch until both
+	 * redundant ports have signed up.
+	 */
+	if (!partner)
+		return 0;
+
+	regmap_fields_write(priv->ps_forward, partner->index,
+			    XRS_PORT_DISABLED);
+	regmap_fields_write(priv->ps_forward, port, XRS_PORT_DISABLED);
+
+	regmap_write(priv->regmap, XRS_HSR_CFG(partner->index),
+		     val | XRS_HSR_CFG_LANID_A);
+	regmap_write(priv->regmap, XRS_HSR_CFG(port),
+		     val | XRS_HSR_CFG_LANID_B);
+
+	/* Clear bits for both redundant ports (HSR only) and the CPU port to
+	 * enable forwarding.
+	 */
+	val = GENMASK(ds->num_ports - 1, 0);
+	if (ver == HSR_V1) {
+		val &= ~BIT(partner->index);
+		val &= ~BIT(port);
+	}
+	val &= ~BIT(dsa_upstream_port(ds, port));
+	regmap_write(priv->regmap, XRS_PORT_FWD_MASK(partner->index), val);
+	regmap_write(priv->regmap, XRS_PORT_FWD_MASK(port), val);
+
+	regmap_fields_write(priv->ps_forward, partner->index,
+			    XRS_PORT_FORWARDING);
+	regmap_fields_write(priv->ps_forward, port, XRS_PORT_FORWARDING);
+
+	hsr_pair[0] = port;
+	hsr_pair[1] = partner->index;
+	for (i = 0; i < ARRAY_SIZE(hsr_pair); i++) {
+		slave = dsa_to_port(ds, hsr_pair[i])->slave;
+		slave->features |= XRS7000X_SUPPORTED_HSR_FEATURES;
+	}
+
+	return 0;
+}
+
+static int xrs700x_hsr_leave(struct dsa_switch *ds, int port,
+			     struct net_device *hsr)
+{
+	struct dsa_port *partner = NULL, *dp;
+	struct xrs700x *priv = ds->priv;
+	struct net_device *slave;
+	int i, hsr_pair[2];
+	unsigned int val;
+
+	dsa_hsr_foreach_port(dp, ds, hsr) {
+		partner = dp;
+	}
+
+	if (!partner)
+		return 0;
+
+	regmap_fields_write(priv->ps_forward, partner->index,
+			    XRS_PORT_DISABLED);
+	regmap_fields_write(priv->ps_forward, port, XRS_PORT_DISABLED);
+
+	regmap_write(priv->regmap, XRS_HSR_CFG(partner->index), 0);
+	regmap_write(priv->regmap, XRS_HSR_CFG(port), 0);
+
+	/* Clear bit for the CPU port to enable forwarding. */
+	val = GENMASK(ds->num_ports - 1, 0);
+	val &= ~BIT(dsa_upstream_port(ds, port));
+	regmap_write(priv->regmap, XRS_PORT_FWD_MASK(partner->index), val);
+	regmap_write(priv->regmap, XRS_PORT_FWD_MASK(port), val);
+
+	regmap_fields_write(priv->ps_forward, partner->index,
+			    XRS_PORT_FORWARDING);
+	regmap_fields_write(priv->ps_forward, port, XRS_PORT_FORWARDING);
+
+	hsr_pair[0] = port;
+	hsr_pair[1] = partner->index;
+	for (i = 0; i < ARRAY_SIZE(hsr_pair); i++) {
+		slave = dsa_to_port(ds, hsr_pair[i])->slave;
+		slave->features &= ~XRS7000X_SUPPORTED_HSR_FEATURES;
+	}
+
+	return 0;
+}
+
 static const struct dsa_switch_ops xrs700x_ops = {
 	.get_tag_protocol	= xrs700x_get_tag_protocol,
 	.setup			= xrs700x_setup,
@@ -509,6 +628,8 @@ static const struct dsa_switch_ops xrs700x_ops = {
 	.get_stats64		= xrs700x_get_stats64,
 	.port_bridge_join	= xrs700x_bridge_join,
 	.port_bridge_leave	= xrs700x_bridge_leave,
+	.port_hsr_join		= xrs700x_hsr_join,
+	.port_hsr_leave		= xrs700x_hsr_leave,
 };
 
 static int xrs700x_detect(struct xrs700x *priv)

drivers/net/dsa/xrs700x/xrs700x_reg.h

@@ -49,6 +49,11 @@
 
 /* Port Configuration Registers - HSR/PRP */
 #define XRS_HSR_CFG(x)			(XRS_PORT_HSR_BASE(x) + 0x0)
+#define XRS_HSR_CFG_HSR_PRP		BIT(0)
+#define XRS_HSR_CFG_HSR			0
+#define XRS_HSR_CFG_PRP			BIT(8)
+#define XRS_HSR_CFG_LANID_A		0
+#define XRS_HSR_CFG_LANID_B		BIT(10)
 
 /* Port Configuration Registers - PTP */
 #define XRS_PTP_RX_SYNC_DELAY_NS_LO(x)	(XRS_PORT_PTP_BASE(x) + 0x2)

net/dsa/tag_xrs700x.c

@@ -11,12 +11,17 @@
 
 static struct sk_buff *xrs700x_xmit(struct sk_buff *skb, struct net_device *dev)
 {
-	struct dsa_port *dp = dsa_slave_to_port(dev);
+	struct dsa_port *partner, *dp = dsa_slave_to_port(dev);
 	u8 *trailer;
 
 	trailer = skb_put(skb, 1);
 	trailer[0] = BIT(dp->index);
 
+	if (dp->hsr_dev)
+		dsa_hsr_foreach_port(partner, dp->ds, dp->hsr_dev)
+			if (partner != dp)
+				trailer[0] |= BIT(partner->index);
+
 	return skb;
 }