From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:44138)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <mst@redhat.com>) id 1ZoHq8-00042M-B4
	for qemu-devel@nongnu.org; Mon, 19 Oct 2015 17:19:33 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <mst@redhat.com>) id 1ZoHq3-0002Bx-H3
	for qemu-devel@nongnu.org; Mon, 19 Oct 2015 17:19:32 -0400
Received: from mx1.redhat.com ([209.132.183.28]:40282)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <mst@redhat.com>) id 1ZoHq3-0002Bb-CX
	for qemu-devel@nongnu.org; Mon, 19 Oct 2015 17:19:27 -0400
Date: Tue, 20 Oct 2015 00:19:22 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
Message-ID: <20151020001411-mutt-send-email-mst@redhat.com>
References: <1445216059-88521-1-git-send-email-guangrong.xiao@linux.intel.com>
	<1445216059-88521-28-git-send-email-guangrong.xiao@linux.intel.com>
	<20151018201620-mutt-send-email-mst@redhat.com>
	<56246BE0.2040901@linux.intel.com>
	<20151019100724-mutt-send-email-mst@redhat.com>
	<CAPcyv4h4Vw03u8gmeK3ux1xkUMWpw4fWDGRG2W9kOvR0m_wYXA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAPcyv4h4Vw03u8gmeK3ux1xkUMWpw4fWDGRG2W9kOvR0m_wYXA@mail.gmail.com>
Subject: Re: [Qemu-devel] [PATCH v4 27/33] nvdimm acpi: save arg3 for NVDIMM
 device _DSM method
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>, ehabkost@redhat.com, KVM list <kvm@vger.kernel.org>, Gleb Natapov <gleb@kernel.org>, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, imammedo@redhat.com, Paolo Bonzini <pbonzini@redhat.com>, rth@twiddle.net

On Mon, Oct 19, 2015 at 10:29:50AM -0700, Dan Williams wrote:
> On Mon, Oct 19, 2015 at 12:09 AM, Michael S. Tsirkin <mst@redhat.com> 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

So it seems to say "3.1.1.1.1 Input (Arg3)".
Is that right? So

Aml *input = aml_arg(3); /* Input (Arg3) */
or even
Aml *input_arg3 =  aml_arg(3); /* Input (Arg3) */

My point is we are not writing ASL. There is no reason
to use cryptic names.