net: hsr: add offloading support

Add support for offloading of HSR/PRP (IEC 62439-3) tag insertion
tag removal, duplicate generation and forwarding.

For HSR, insertion involves the switch adding a 6 byte HSR header after
the 14 byte Ethernet header. For PRP it adds a 6 byte trailer.

Tag removal involves automatically stripping the HSR/PRP header/trailer
in the switch. This is possible when the switch also performs auto
deduplication using the HSR/PRP header/trailer (making it no longer
required).

Forwarding involves automatically forwarding between redundant ports in
an HSR. This is crucial because delay is accumulated as a frame passes
through each node in the ring.

Duplication involves the switch automatically sending a single frame
from the CPU port to both redundant ports. This is required because the
inserted HSR/PRP header/trailer must contain the same sequence number
on the frames sent out both redundant ports.

Export is_hsr_master so DSA can tell them apart from other devices in
dsa_slave_changeupper.

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>

9 files changed, 52 insertions, 26 deletions

diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 835b9bba3e7e..c6a383dfd6c2 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -69,6 +69,10 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
 	[NETIF_F_GRO_FRAGLIST_BIT] =	 "rx-gro-list",
 	[NETIF_F_HW_MACSEC_BIT] =	 "macsec-hw-offload",
 	[NETIF_F_GRO_UDP_FWD_BIT] =	 "rx-udp-gro-forwarding",
+	[NETIF_F_HW_HSR_TAG_INS_BIT] =	 "hsr-tag-ins-offload",
+	[NETIF_F_HW_HSR_TAG_RM_BIT] =	 "hsr-tag-rm-offload",
+	[NETIF_F_HW_HSR_FWD_BIT] =	 "hsr-fwd-offload",
+	[NETIF_F_HW_HSR_DUP_BIT] =	 "hsr-dup-offload",
 };
 
 const char
diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
index ec6a68b403d5..7444ec6e298e 100644
--- a/net/hsr/hsr_device.c
+++ b/net/hsr/hsr_device.c
@@ -417,6 +417,7 @@ static struct hsr_proto_ops hsr_ops = {
 	.send_sv_frame = send_hsr_supervision_frame,
 	.create_tagged_frame = hsr_create_tagged_frame,
 	.get_untagged_frame = hsr_get_untagged_frame,
+	.drop_frame = hsr_drop_frame,
 	.fill_frame_info = hsr_fill_frame_info,
 	.invalid_dan_ingress_frame = hsr_invalid_dan_ingress_frame,
 };
@@ -464,10 +465,11 @@ void hsr_dev_setup(struct net_device *dev)
 
 /* Return true if dev is a HSR master; return false otherwise.
  */
-inline bool is_hsr_master(struct net_device *dev)
+bool is_hsr_master(struct net_device *dev)
 {
 	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
 }
+EXPORT_SYMBOL(is_hsr_master);
 
 /* Default multicast address for HSR Supervision frames */
 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
@@ -520,16 +522,6 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 
 	hsr->prot_version = protocol_version;
 
-	/* FIXME: should I modify the value of these?
-	 *
-	 * - hsr_dev->flags - i.e.
-	 *			IFF_MASTER/SLAVE?
-	 * - hsr_dev->priv_flags - i.e.
-	 *			IFF_EBRIDGE?
-	 *			IFF_TX_SKB_SHARING?
-	 *			IFF_HSR_MASTER/SLAVE?
-	 */
-
 	/* Make sure the 1st call to netif_carrier_on() gets through */
 	netif_carrier_off(hsr_dev);
 
diff --git a/net/hsr/hsr_device.h b/net/hsr/hsr_device.h
index 868373822ee4..9060c92168f9 100644
--- a/net/hsr/hsr_device.h
+++ b/net/hsr/hsr_device.h
@@ -19,6 +19,5 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 		     unsigned char multicast_spec, u8 protocol_version,
 		     struct netlink_ext_ack *extack);
 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr);
-bool is_hsr_master(struct net_device *dev);
 int hsr_get_max_mtu(struct hsr_priv *hsr);
 #endif /* __HSR_DEVICE_H */
diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
index d32cd87d5c5b..ed82a470b6e1 100644
--- a/net/hsr/hsr_forward.c
+++ b/net/hsr/hsr_forward.c
@@ -249,6 +249,8 @@ struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
 		/* set the lane id properly */
 		hsr_set_path_id(hsr_ethhdr, port);
 		return skb_clone(frame->skb_hsr, GFP_ATOMIC);
+	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
+		return skb_clone(frame->skb_std, GFP_ATOMIC);
 	}
 
 	/* Create the new skb with enough headroom to fit the HSR tag */
@@ -291,6 +293,8 @@ struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
 			return NULL;
 		}
 		return skb_clone(frame->skb_prp, GFP_ATOMIC);
+	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
+		return skb_clone(frame->skb_std, GFP_ATOMIC);
 	}
 
 	skb = skb_copy_expand(frame->skb_std, 0,
@@ -343,6 +347,14 @@ bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
 		 port->type ==  HSR_PT_SLAVE_A));
 }
 
+bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
+{
+	if (port->dev->features & NETIF_F_HW_HSR_FWD)
+		return prp_drop_frame(frame, port);
+
+	return false;
+}
+
 /* Forward the frame through all devices except:
  * - Back through the receiving device
  * - If it's a HSR frame: through a device where it has passed before
@@ -359,6 +371,7 @@ static void hsr_forward_do(struct hsr_frame_info *frame)
 {
 	struct hsr_port *port;
 	struct sk_buff *skb;
+	bool sent = false;
 
 	hsr_for_each_port(frame->port_rcv->hsr, port) {
 		struct hsr_priv *hsr = port->hsr;
@@ -374,6 +387,12 @@ static void hsr_forward_do(struct hsr_frame_info *frame)
 		if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
 			continue;
 
+		/* If hardware duplicate generation is enabled, only send out
+		 * one port.
+		 */
+		if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent)
+			continue;
+
 		/* Don't send frame over port where it has been sent before.
 		 * Also fro SAN, this shouldn't be done.
 		 */
@@ -405,10 +424,12 @@ static void hsr_forward_do(struct hsr_frame_info *frame)
 		}
 
 		skb->dev = port->dev;
-		if (port->type == HSR_PT_MASTER)
+		if (port->type == HSR_PT_MASTER) {
 			hsr_deliver_master(skb, port->dev, frame->node_src);
-		else
-			hsr_xmit(skb, port, frame);
+		} else {
+			if (!hsr_xmit(skb, port, frame))
+				sent = true;
+		}
 	}
 }
 
diff --git a/net/hsr/hsr_forward.h b/net/hsr/hsr_forward.h
index 618140d484ad..b6acaafa83fc 100644
--- a/net/hsr/hsr_forward.h
+++ b/net/hsr/hsr_forward.h
@@ -23,6 +23,7 @@ struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame,
 struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame,
 				       struct hsr_port *port);
 bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port);
+bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port);
 void prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
 			 struct hsr_frame_info *frame);
 void hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c
index 5c97de459905..f9a8cc82ae2e 100644
--- a/net/hsr/hsr_framereg.c
+++ b/net/hsr/hsr_framereg.c
@@ -277,6 +277,8 @@ void hsr_handle_sup_frame(struct hsr_frame_info *frame)
 		skb = frame->skb_hsr;
 	else if (frame->skb_prp)
 		skb = frame->skb_prp;
+	else if (frame->skb_std)
+		skb = frame->skb_std;
 	if (!skb)
 		return;
 
diff --git a/net/hsr/hsr_main.c b/net/hsr/hsr_main.c
index 2fd1976e5b1c..f7e284f23b1f 100644
--- a/net/hsr/hsr_main.c
+++ b/net/hsr/hsr_main.c
@@ -131,6 +131,17 @@ struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt)
 	return NULL;
 }
 
+int hsr_get_version(struct net_device *dev, enum hsr_version *ver)
+{
+	struct hsr_priv *hsr;
+
+	hsr = netdev_priv(dev);
+	*ver = hsr->prot_version;
+
+	return 0;
+}
+EXPORT_SYMBOL(hsr_get_version);
+
 static struct notifier_block hsr_nb = {
 	.notifier_call = hsr_netdev_notify,	/* Slave event notifications */
 };
diff --git a/net/hsr/hsr_main.h b/net/hsr/hsr_main.h
index a9c30a608e35..a169808ee78a 100644
--- a/net/hsr/hsr_main.h
+++ b/net/hsr/hsr_main.h
@@ -13,6 +13,7 @@
 #include <linux/netdevice.h>
 #include <linux/list.h>
 #include <linux/if_vlan.h>
+#include <linux/if_hsr.h>
 
 /* Time constants as specified in the HSR specification (IEC-62439-3 2010)
  * Table 8.
@@ -171,13 +172,6 @@ struct hsr_port {
 	enum hsr_port_type	type;
 };
 
-/* used by driver internally to differentiate various protocols */
-enum hsr_version {
-	HSR_V0 = 0,
-	HSR_V1,
-	PRP_V1,
-};
-
 struct hsr_frame_info;
 struct hsr_node;
 
diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c
index 36d5fcf09c61..c5227d42faf5 100644
--- a/net/hsr/hsr_slave.c
+++ b/net/hsr/hsr_slave.c
@@ -48,12 +48,14 @@ static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
 		goto finish_consume;
 	}
 
-	/* For HSR, only tagged frames are expected, but for PRP
-	 * there could be non tagged frames as well from Single
-	 * attached nodes (SANs).
+	/* For HSR, only tagged frames are expected (unless the device offloads
+	 * HSR tag removal), but for PRP there could be non tagged frames as
+	 * well from Single attached nodes (SANs).
 	 */
 	protocol = eth_hdr(skb)->h_proto;
-	if (hsr->proto_ops->invalid_dan_ingress_frame &&
+
+	if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
+	    hsr->proto_ops->invalid_dan_ingress_frame &&
 	    hsr->proto_ops->invalid_dan_ingress_frame(protocol))
 		goto finish_pass;