Re: [PATCH 2/2] cxl: Document missing sysfs files

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Sun, 12 Jan 2025 18:52:40 -0800
Davidlohr Bueso <dave@stgolabs.net> wrote:

> Add to the ABI documentation the payload_max and label_storage_size
> read-only files, which have been there since the early days.
> 
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
> ---
>  Documentation/ABI/testing/sysfs-bus-cxl | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index 7bdf0eb79d7c..96c7fffa5442 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -18,6 +18,24 @@ Description:
>  		specification.
>  
>  
> +What:		/sys/bus/cxl/devices/memX/payload_max
> +Date:		December, 2020
> +KernelVersion:	v5.12
> +Contact:	linux-cxl@vger.kernel.org
> +Description:
> +		(RO) Maximum size (in bytes) of the mailbox command payload
> +		registers. Linux caps this at 1Mb if the device reports a
> +		larger size.

Spec currently caps it to 1MiB as well so a device reporting larger is buggy
but I guess we don't need to mention that :)
Units wise probably MB or MiB if we are being fusy. I think Mb is mega bit?

MB is slightly more common in ABI docs.  Oddly neither MiB or MB shows
up much. Mb not there at all.

> +
> +
> +What:		/sys/bus/cxl/devices/memX/label_storage_size
> +Date:		May, 2021
> +KernelVersion:	v5.13
> +Contact:	linux-cxl@vger.kernel.org
> +Description:
> +		(RO) Size (in bytes) of the Label Storage Area (LSA).
> +
> +
>  What:		/sys/bus/cxl/devices/memX/ram/size
>  Date:		December, 2020
>  KernelVersion:	v5.12