-----Original Message-----
From: gregkh@linuxfoundation.org [mailto:gregkh@linuxfoundation.org]
Sent: Thursday, September 26, 2019 10:13 PM
To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>
Cc: Kirsher, Jeffrey T <redacted>; jgg@mellanox.com;
netdev@vger.kernel.org; linux-rdma@vger.kernel.org; dledford@redhat.com;
Ertman, David M [off-list ref]
Subject: Re: [RFC 01/20] ice: Initialize and register multi-function device to
provide RDMA

On Thu, Sep 26, 2019 at 11:39:22PM +0000, Nguyen, Anthony L wrote:

quoted

On Thu, 2019-09-26 at 20:05 +0200, Greg KH wrote:

quoted

On Thu, Sep 26, 2019 at 09:45:00AM -0700, Jeff Kirsher wrote:

quoted

From: Tony Nguyen <anthony.l.nguyen@intel.com>

The RDMA block does not advertise on the PCI bus or any other bus.

Huh?  How do you "know" where it is then?  Isn't is usually assigned
to a PCI device?

The RDMA block does not have its own PCI function so it must register
and interact with the ice driver.

So the "ice driver" is the real thing controlling the pci device?  How does it
"know" about the RDMA block?

thanks,

greg k-h

The ICE driver loads and registers to control the PCI device.  It then
creates an MFD device with the name 'ice_rdma'. The device data provided to
the MFD subsystem by the ICE driver is the struct iidc_peer_dev which
contains all of the relevant information that the IRDMA peer will need
to access this PF's IIDC API callbacks

The IRDMA driver loads as a software only driver, and then registers a MFD
function driver that takes ownership of MFD devices named 'ice_rdma'.
This causes the platform bus to perform a matching between ICE's MFD device
and IRDMA's driver.  Then the patform bus will call the IRDMA's IIDC probe
function.  This probe provides the device data to IRDMA.

Dave E