[dm-devel] [PATCH 1/5] dax, pmem: Add a dax operation zero_page_range

[Christoph Hellwig]

On Wed, Feb 05, 2020 at 04:40:44PM -0800, Dan Williams wrote:
> > I don't have any reason not to pass phys_addr_t. If that sounds better,
> > will make changes.
> 
> The problem is device-mapper. That wants to use offset to route
> through the map to the leaf device. If it weren't for the firmware
> communication requirement you could do:
> 
> dax_direct_access(...)
> generic_dax_zero_page_range(...)
> 
> ...but as long as the firmware error clearing path is required I think
> we need to do pass the pgoff through the interface and do the pgoff to
> virt / phys translation inside the ops handler.

Maybe phys_addr_t was the wrong type - but why do we split the offset
into the block device argument into a pgoff and offset into page instead
of a single 64-bit value?