Re: [PATCH v2 2/4] mm: Add file_operations.get_mapping_order()

[Jason Gunthorpe]

On Tue, Dec 16, 2025 at 02:44:29PM -0500, Peter Xu wrote:
> > > Or maybe I misunderstood what you're suggesting to document?  If so, please
> > > let me know; some example would be greatly helpful.
> > 
> > Just document the 'VA % order = pgoff % order' equation in the kdoc
> > for the new op.
> 
> When it's "related to PTEs", it's talking about (2) above, so that's really
> what I want to avoid mentioning.

You can't avoid it. Drivers must ensure that

  pgoff % order == physical % order

And that is something only drivers can do by knowing about this
requirement.

Jason