Dave Jiang wrote:
>
>
> On 2/5/23 6:02 PM, Dan Williams wrote:
> > Expand the region creation infrastructure to enable 'ram'
> > (volatile-memory) regions. The internals of create_pmem_region_store()
> > and create_pmem_region_show() are factored out into helpers
> > __create_region() and __create_region_show() for the 'ram' case to
> > reuse.
> >
> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
>
> Minor comment below, otherwise:
> Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
>
[..]
> > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> > index 4c4e1cbb1169..3acf2f17a73f 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-cxl
> > +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> > @@ -285,20 +285,20 @@ Description:
> > interleave_granularity).
> >
> >
> > -What: /sys/bus/cxl/devices/decoderX.Y/create_pmem_region
> > -Date: May, 2022
> > -KernelVersion: v6.0
> > +What: /sys/bus/cxl/devices/decoderX.Y/create_{pmem,ram}_region
> > +Date: May, 2022, January, 2023
> > +KernelVersion: v6.0 (pmem), v6.3 (ram)
> > Contact: linux-cxl@xxxxxxxxxxxxxxx
> > Description:
> > (RW) Write a string in the form 'regionZ' to start the process
> > - of defining a new persistent memory region (interleave-set)
> > - within the decode range bounded by root decoder 'decoderX.Y'.
> > - The value written must match the current value returned from
> > - reading this attribute. An atomic compare exchange operation is
> > - done on write to assign the requested id to a region and
> > - allocate the region-id for the next creation attempt. EBUSY is
> > - returned if the region name written does not match the current
> > - cached value.
> > + of defining a new persistent, or volatile memory region
> > + (interleave-set) within the decode range bounded by root decoder
> > + 'decoderX.Y'. The value written must match the current value
> > + returned from reading this attribute. An atomic compare exchange
> > + operation is done on write to assign the requested id to a
> > + region and allocate the region-id for the next creation attempt.
> > + EBUSY is returned if the region name written does not match the
>
> -EBUSY?
Userspace errno values are positive. So "$?" after "echo $region >
create_pmem_region" will be 16 not -16 in the busy case.
