Re: [PATCH v5 05/21] libnvdimm: control (ioctl) messages for libnvdimm bus and dimm devices

On Mon, Jun 08, 2015 at 11:57:42PM -0700, Dan Williams wrote:

Data payload size for one, these commands transfer more than a page
worth of data at a time.

Even if we killed the ioctl interface to userspace we still need all
the ugly data marshaling code in the kernel to craft properly
formatted ACPI _DSM messages.  I try to share as much common
infrastructure from the ACPI _DSM implementation to the ioctl
interface (nd_cmd_dimm_desc() + nd_cmd_bus_desc()).

Ok.  Not a fan of these dual interfaces but in this case they might be
justified.