Re: [patch net-next RFC 03/12] net: introduce generic switch devices support

Sun, Aug 24, 2014 at 01:46:05PM CEST, tgraf-G/eBtMaohhA@public.gmane.org wrote:

On 08/21/14 at 06:18pm, Jiri Pirko wrote:

quoted

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 39294b9..8b5d14c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h

@@ -49,6 +49,8 @@
 
 #include <linux/netdev_features.h>
 #include <linux/neighbour.h>
+#include <linux/sw_flow.h>
+
 #include <uapi/linux/netdevice.h>
 
 struct netpoll_info;

@@ -997,6 +999,24 @@ typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
+ * int (*ndo_swdev_flow_insert)(struct net_device *dev,
+ *				const struct sw_flow *flow);
+ *	Called to insert a flow into switch device. If driver does
+ *	not implement this, it is assumed that the hw does not have
+ *	a capability to work with flows.

I asume you are planning to add an additional expandable struct
paramter to handle insertion parameters when the first is introduced
to avoid requiring to touch every driver every time.

Sure. That is the way to go.

quoted

+/**
+ *	swdev_flow_insert - Insert a flow into switch
+ *	@dev: port device
+ *	@flow: flow descriptor
+ *
+ *	Insert a flow into switch this port is part of.
+ */
+int swdev_flow_insert(struct net_device *dev, const struct sw_flow *flow)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	print_flow(flow, dev, "insert");
+	if (!ops->ndo_swdev_flow_insert)
+		return -EOPNOTSUPP;
+	WARN_ON(!ops->ndo_swdev_get_id);
+	BUG_ON(!flow->actions);
+	return ops->ndo_swdev_flow_insert(dev, flow);
+}
+EXPORT_SYMBOL(swdev_flow_insert);

Splitting the flow specific API into a separate file (maybe
swdev_flow.c?) might help resolve some of the concerns around the
focus on flows. It would make it clear that it's one of multiple
models to be supported.

I understand your point. But the file is tiny as it is. I would keep all
in one file for now.