Re: [net-next PATCH 0/8] configuration support for switch headers & phy

On Tue, Mar 23, 2021 at 06:13:28PM +0000, Hariprasad Kelam wrote:

Hi Andrew ,

Please see inline,

No need to say that. That is the correct way to right emails.

quoted

Hi Hariprasad

Private flags sound very wrong here. I would expect to see some integration
between the switchdev/DSA driver and the MAC driver.
Please show how this works in combination with drivers/net/dsa/mv88e6xxx
or drivers/net/ethernet/marvell/prestera.

	Octeontx2 silicon supports NPC (network parser and cam) unit , through which packet parsing and packet classification is achieved.
              Packet parsing extracting different fields from each layer.
				  DMAC + SMAC  --> LA
		                               VLAN ID --> LB
		                               SIP + DIP --> LC
                                                            TCP SPORT + DPORT --> LD
    And packet classification is achieved through  flow identification in key extraction and mcam search key . User can install mcam rules
    With action as  
		forward packet to PF and to receive  queue 0
		forward packet to VF and  with as RSS ( Receive side scaling)
		drop the packet 
		etc..

   Now with switch header ( EDSA /FDSA) and HIGIG2 appended to regular packet , NPC can not parse these
   Ingress packets as these headers does not have fixed headers. To achieve this Special PKIND( port kind) is allocated in hardware
   which will help NPC to parse the packets.

 For example incase of EDSA 8 byte header which is placed right after SMAC , special PKIND reserved for EDSA helps NPC to 
 Identify the  input packet is EDSA . Such that NPC can extract fields in this header and forward to 
 Parse rest of the headers.

 Same is the case with higig2 header where 16 bytes header is placed at start of the packet.

In this case private flags helps user to configure interface in EDSA/FDSA or HIGIG2. Such that special
PKIND reserved for that header are assigned to the interface.  The scope of the patch series is how
User can configure interface mode as switch header(HIGIG2/EDSA etc) .In our case no DSA logical
Ports are created as these headers can be stripped by NPC.

So you completely skipped how this works with mv88e6xxx or
prestera. If you need this private flag for some out of mainline
Marvell SDK, it is very unlikely to be accepted.

	Andrew