Re: [PATCH v2 0/3] nvdimm: Add an IOCTL pass thru for DSM calls

[Jerry Hoemann <jerry.hoemann@hpe.com>]

On Mon, Nov 16, 2015 at 05:29:41PM -0800, Dan Williams wrote:
> On Mon, Nov 16, 2015 at 1:10 PM, Jerry Hoemann <jerry.hoemann@hpe.com> wrote:
> > On Mon, Nov 16, 2015 at 11:00:20AM -0800, Dan Williams wrote:
> >> On Mon, Nov 16, 2015 at 10:38 AM, Jerry Hoemann <jerry.hoemann@hpe.com> wrote:
> >> >
> >>

...

> >> Let's not do the _intel vs _passthru split.  I want to convert the
> >> existing commands over to this new interface and deprecate the old
> >> ioctl-command formats.  I.e. it isn't the case that this will be a
> >> always be a blind "passthru" mechanism, the kernel will need to crack
> >> open this payload in some circumstances.
> >
> >
> > I'm confused.
> >
> > In this version there is only 1 ioctl 'N'.  The pass thru is using
> > number 100.  This is what I thought you wanted from prior comments.
> 
> It is indeed, I like that change.
> 
> > The split are for internal functions that deal specifically w/
> > the argument marshaling code and copy-in/copy-out.  These mechanisms
> > are different.
> >
> > I understand that you want to switch over, but don't you (at least for
> > the time being) need to keep the old marshaling code for the current
> > use case?   I was assuming a sequence like:
> >         1. The pass thru code gets submitted.
> >         2. The current tools are converted over to using the pass thru,
> >         3. The marshaling code using nd_cmd_in_size etc., would then
> >                 be removed.
> >
> > Are you wanting to make one big change and not in separate steps?
> 
> I want to do it in separate steps, I'd just like to see cmd number 100
> added to the existing __nd_ioctl and acpi_nfit_ctl routines.  That

   Why?

> plus quibbling about the name "ND_CMD_PASSTHRU".  Given the plans to
> eventually replace the existing commands we can call it something like
> 'ND_DSM_GENERIC'.


  No problem.  I'll change the name for ndn_passthru_pkg in a similar fashion.


  Question:	Are you planning to add other CMDs to the IOCTL in the future?
		(eg. ones not directly related to calling _dsm?)

	 	Or, is the ultimate goal to have an IOCTL that supports
		only the generic DSM call?

-- 

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Jerry Hoemann            Software Engineer      Hewlett-Packard Enterprise
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