[openib-general] [PATCH][iWARP] IW CM Verbs

[Steve Wise]

> -----Original Message-----
> From: openib-general-bounces at openib.org 
> [mailto:openib-general-bounces at openib.org] On Behalf Of James Lentini
> Sent: Monday, August 29, 2005 8:42 AM
> To: Tom Tucker
> Cc: openib-general at openib.org
> Subject: Re: [openib-general] [PATCH][iWARP] IW CM Verbs
> 
> 
> 
> On Fri, 26 Aug 2005, Tom Tucker wrote:
> 
> > Index: ib_verbs.h
> > ===================================================================
> > --- ib_verbs.h	(revision 3120)
> > +++ ib_verbs.h	(working copy)
> > @@ -804,6 +806,7 @@
> >  	struct ib_gid_cache   **gid_cache;
> >  };
> >  
> > +struct iw_cm;
> >  struct ib_device {
> >  	struct device                *dma_device;
> >  
> > @@ -820,6 +823,8 @@
> >  
> >  	u32                           flags;
> >  
> > +	struct iw_cm                  *iwcm;
> > +
> >  	int		           (*query_device)(struct 
> ib_device *device,
> >  						   struct 
> ib_device_attr *device_attr);
> >  	int		           (*query_port)(struct 
> ib_device *device,
> 
> Why does the ib_device need a cm structure for iWARP but not IB?

Some RNIC devices fully establish the connection in hardware.  However,
_all_ openib IB devices export the MAD interface, which is used to send
low level connection setup primitives, thus allowing connection setup in
the host. 

> If 
> you used either Guy or Roland's generic RDMA connection API and did 
> the iWARP implementation, would you still need to add the iw_cm 
> structure?

Yes.

The struct iw_cm allows the RNIC device to export a set of high level
connection verbs, if that device supports it.

Hope this helps...

Steve.