Re: [Qemu-devel] [PATCH v4 27/33] nvdimm acpi: save arg3 for NVDIMM device _DSM method

[Dan Williams]

On Mon, Oct 19, 2015 at 12:09 AM, Michael S. Tsirkin <address@hidden> wrote:
> On Mon, Oct 19, 2015 at 12:04:48PM +0800, Xiao Guangrong wrote:
> I mean don't use ASL to comment C. It's not more readable.
> Describe why the code is the way it is. Use variables by preference,
> C does not have weird limitations like ASL so you don't need to call
> your variables "arg3". What does it hold?
>

What it holds is function number specific.  It's similar to
SYSCALL_DEFINEx where the ASL code is there to marshal arguments from
the OS through ACPI to a BIOS routine.  See the definition of the
example _DSM functions here and the usages of "Arg3":
http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf