Re: [PATCH V9 6/9] cxl/port: Read CDAT table

[Jonathan Cameron]

On Thu, 2 Jun 2022 15:47:37 -0700
Ira Weiny <ira.weiny@xxxxxxxxx> wrote:

> On Thu, Jun 02, 2022 at 11:31:56AM -0700, Ira wrote:
> > On Wed, Jun 01, 2022 at 05:31:13PM +0100, Jonathan Cameron wrote:  
> > > On Wed, 1 Jun 2022 16:35:40 +0100
> > > Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote:
> > >   
> > > > On Tue, 31 May 2022 08:26:29 -0700
> > > > ira.weiny@xxxxxxxxx wrote:
> > > >   
> > > > > From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> > > > > 
> > > > > The OS will need CDAT data from CXL devices to properly set up
> > > > > interleave sets.  Currently this is supported through a DOE mailbox
> > > > > which supports CDAT.
> > > > > 
> > > > > Cache the CDAT data for later parsing.  Provide a sysfs binary attribute
> > > > > to allow dumping of the CDAT.
> > > > > 
> > > > > Binary dumping is modeled on /sys/firmware/ACPI/tables/
> > > > > 
> > > > > The ability to dump this table will be very useful for emulation of real
> > > > > devices once they become available as QEMU CXL type 3 device emulation will
> > > > > be able to load this file in.
> > > > > 
> > > > > This does not support table updates at runtime. It will always provide
> > > > > whatever was there when first cached. Handling of table updates can be
> > > > > implemented later.
> > > > > 
> > > > > Finally create a complete list of DOE defines within cdat.h for code
> > > > > wishing to decode the CDAT table.
> > > > > 
> > > > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> > > > > Co-developed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> > > > > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> > > > >     
> > > > 
> > > > Fun question of ownership inline...  
> > > 
> > > And a follow up due to triggering a bug that predated this series...
> > > 
> > > I'd send a fix, but I'm off on a long weekend shortly :)  
> > 
> > NP I discussed with Dan and the use of dev_groups should allow me to move this
> > to port probe where it belongs.  I put it here for the sysfs stuff.  
> 
> Not to make a habit of replying to my own mails but this works.
> 
> So I'm going to go forward with spinning this again.

It's the right solution - cleaner than moving the ownership.

Jonathan

> 
> Ira