On Sun, Jul 3, 2016 at 8:32 AM, Gavin Shan <gws...@linux.vnet.ibm.com> wrote:
> This series rebases on David's linux-net git repo ("master" branch). It's
> to support NCSI stack on net/farady/ftgmac100.c
>
> The following figure gives an example about how NCSI is deployed: The NCSI is
> specified by DSP0222, which can be downloaded from the following link here
> (http://www.dmtf.org/sites/default/files/standards/documents/DSP0222_1.0.0.pdf).
>
> * The NC-SI (aka NCSI) is defined as the interface between a (Base)
> Management
> Controller (BMC) and one or multiple Network Controlers (NC) on host
> side.
> The interface is responsible for providing external network connectivity
> for BMC.
> * Each BMC can connect to multiple packages, up to 8. Each package can have
> multiple channels, up to 32. Every package and channel are identified by
> 3-bits and 5-bits in NCSI packet. At one moment, one channel is active to
> provide service.
> * NCSI packet, encapsulated in ethernet frame, has 0x88F8 in the protocol
> field. The destination MAC address should be 0xFF's while the source MAC
> address can be arbitrary one.
> * NCSI packets are classified to command, response, AEN (Asynchronous Event
> Notification). Commands are sent from BMC to host for configuration and
> information retrival. Responses, corresponding to commands, are sent from
> host to BMC for confirmation and requested information. One command
> should
> have one and only one response. AEN is sent from host to BMC for
> notification
> (e.g. link down on active channel) so that BMC can take appropriate
> action.
>
> +------------------+
> +----------------------------------------------+
> | | | Host
> |
> | BMC | |
> |
> | | | +-------------------+ +-------------------+
> |
> | +---------+ | | | Package-A | | Package-B |
> |
> | | | | | +---------+---------+ +-------------------+
> |
> | | NIC | | | | Channel | Channel | | Channel | Channel |
> |
> +----+----+----+---+
> +-+---------+---------+--+---------+---------+-+
> | | |
> | | |
> +-----------------------------+----------------------+
>
> The design for the patchset is highlighted as below:
>
> * The NCSI interface is abstracted with "struct ncsi_dev". It's registered
> when net_device is created, started to work by calling ncsi_start_dev()
> when net_device is opened (ndo_open()). For the first time, NCSI packets
> are sent and received to/from the far end (host in above figure) to probe
> available NCSI packages and channels. After that, one channel is chosen
> as
> active one to provide service.
> * The NCSI stack is driven by workqueue and state machine internally.
> * AEN (Asychronous Event Notification) might be received from the far end
> (host). The currently active NCSI channel fails over to another available
> one if possible. Otherwise, the NCSI channel is out of service.
> * NCSI stack should be configurable through netlink or another mechanism,
> but it's not implemented in this patchset. It's something TBD.
> * The first NIC driver that is aware of NCSI:
> drivers/net/ethernet/faraday/ftgmac100.c
FWIW, talking to a colleague, he made a comment that some of the text
above is wrong:
AENs are sent from NIC to BMC. Not from Host to BMC.
The traffic between a BMC and a NIC is over RBT if it is formatted as
NC-SI packets. This is not over network traffic....
Or.
