On 03/03/2016 05:32 PM, Murali Karicheri wrote: > 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 >> > > Andrew,
>From the high level, it looks like netcp switch meets the specifications of a DSA hardware. Can you point me to a specific implementation that I can use as an example to implement this for netcp? -- Murali Karicheri Linux Kernel, Keystone
