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>

1 files changed, 24 insertions, 3 deletions

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;
+		}
 	}
 }