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From:   Dan Williams <dan.j.williams@intel.com>
Date:   Tue, 13 Apr 2021 17:42:37 -0700
Message-ID: <CAPcyv4iueMDPxcEuLg=NKydkRL+xmEn-udHjKYB493iTQShaAg@mail.gmail.com>
Subject: Re: [PATCH v2 1/8] cxl/mem: Move some definitions to mem.h
To:     Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc:     linux-cxl@vger.kernel.org, Linux PCI <linux-pci@vger.kernel.org>,
        Linux ACPI <linux-acpi@vger.kernel.org>,
        "Weiny, Ira" <ira.weiny@intel.com>,
        Vishal L Verma <vishal.l.verma@intel.com>,
        "Schofield, Alison" <alison.schofield@intel.com>,
        Ben Widawsky <ben.widawsky@intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Tue, Apr 13, 2021 at 5:18 PM Dan Williams <dan.j.williams@intel.com> wrote:
>
> On Tue, Apr 6, 2021 at 10:47 AM Jonathan Cameron
> <Jonathan.Cameron@huawei.com> wrote:
> >
> > On Thu, 1 Apr 2021 07:30:47 -0700
> > Dan Williams <dan.j.williams@intel.com> wrote:
> >
> > > In preparation for sharing cxl.h with other generic CXL consumers,
> > > move / consolidate some of the memory device specifics to mem.h.
> > >
> > > Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
> > > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> >
> > Hi Dan,
> >
> > Would be good to see something in this patch description saying
> > why you chose to have mem.h rather than push the defines down
> > into mem.c (which from the current code + patch set looks like
> > the more logical thing to do).
>
> The main motivation was least privilege access to memory-device
> details, so they had to move out of cxl.h. As to why move them in to a
> new mem.h instead of piling more into mem.c that's just a personal
> organizational style choice to aid review. I tend to go to headers
> first and read data structure definitions before reading the
> implementation, and having that all in one place is cleaner than
> interspersed with implementation details in the C code. It's all still
> private to drivers/cxl/ so I don't see any "least privilege" concerns
> with moving it there.
>
> Does that satisfy your concern?
>
> If yes, I'll add the above to v3.

Oh, another thing it helps is the information content of diffstats to
distinguish definition changes from implementation development.