On 02/29/2016 05:29 PM, Andrew Lunn wrote: > On Mon, Feb 29, 2016 at 04:43:16PM -0500, Murali Karicheri wrote: > > Hi Murali > > Please can you get your email client to wrap lines at ~ 75 characters. Hi Andrew,
Thanks for responding. I have tried the instruction below and it doesn't seem to work for me. Do you know what will I have to set in thunderbird to do this? http://arapulido.com/2009/12/01/enabling-line-wrapping-in-thunderbird/ >> TI Keystone netcp h/w has a switch. It has n slave ports and 1 host >> port. Currently the netcp driver disables the switch functionality >> which makes them appear as n nic ports. However we have requirement >> to add switch support in the driver. I have reviewed the >> experimental driver documentation >> Documentation/networking/switchdev.txt and would like to understand >> it better so that I can add this support to keystone netcp driver. > >> NetCP h/w has a 1 (host port) x n (slave port) switch. It can do >> layer 2 forwarding between ports. In the switch mode, host driver >> provides the frame to the switch and switch uses the filter data >> base (AKA ALE table, Address Learning Engine table) to forward the >> packet. There is a piece of information available per frame (meta >> data) to decide if frame to be forwarded to a particular port or use >> the fdb for forward decisions. > > This makes is sound like a good fit for DSA. > > Documentation/networking/dsa/dsa.txt. Let me check and get back to you on this and below after reading the above. Murali > > You probably need to implement a new tagging protocol in > net/dsa/tag_*.c and a driver in drivers/net/dsa/ > >> 1. How does port netdev differ from regular netdev that carries data >> when registering netdev? Any example you can point to? > > They don't differ at all. You consider each port of the switch to be a > normal Linux interface. > >> 2. I assume port netdev will appear as an interface in ifconfig -a >> command and it is not assigned an IP address. Correct? > > The user can assign an address, if they want. It is a normal Linux > interface. They can also create a bridge, and add the interface to the > bridge. An advanced DSA driver will keep track of which interfaces are > in which bridge, and if possible, offload the bridge to the hardware. > >> 3. with 1xn switch, so we have n + 1 netdev registered with net >> core? I assume, only 1 netdev is for data plane and the rest are >> control plane. Is this correct? > > No. You only have netdev devices for the external ports of the > switch. The other port is known as the cpu port, and does not have a > netdev. > >> 4. We have bunch of port specific configuration that we would like >> to control or configure from use space using standard tools. For >> example, switch port state, flow control etc. Is that possible to >> add using this framework? ethtool update needed for this? > > The whole idea here is that the switch ports are normal Linux > interface. You use normal linux APIs to configure them. You probably > don't need to add any new features. > > One key things to get your head around. The switch is a hardware > accelerator for the Linux stack. You have to think how you can make > your switch accelerate the Linux stack. It takes people a while to get > this. > > Andrew > -- Murali Karicheri Linux Kernel, Keystone
