From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Ben Widawsky <ben.widawsky@intel.com>
Cc: <linux-cxl@vger.kernel.org>,
Alison Schofield <alison.schofield@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
"Ira Weiny" <ira.weiny@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>
Subject: Re: [RFC PATCH 4/4] cxl/region: Introduce concept of region configuration
Date: Mon, 14 Jun 2021 17:20:55 +0100 [thread overview]
Message-ID: <20210614172055.00007ae3@Huawei.com> (raw)
In-Reply-To: <20210614161851.iipfwo5dvxkht7yw@intel.com>
On Mon, 14 Jun 2021 09:18:51 -0700
Ben Widawsky <ben.widawsky@intel.com> wrote:
> On 21-06-11 14:52:06, Jonathan Cameron wrote:
> > On Thu, 10 Jun 2021 11:57:25 -0700
> > Ben Widawsky <ben.widawsky@intel.com> wrote:
> >
> > > The region creation APIs leave a region unconfigured. Configuring the
> > > region will work in the same way as similar subsystems such as devdax.
> > > Sysfs attrs will be provided to allow userspace to configure the region.
> > > Finally once all configuration is complete, userspace may "commit" the
> > > config. What the kernel decides to do after a config is committed is out
> > > of scope at this point.
> > >
> > > Introduced here are the most basic attributes needed to configure a
> > > region.
> > >
> > > A x1 interleave example is provided below:
> > >
> > > decoder1.0
> > > ├── create_region
> > > ├── delete_region
> > > ├── devtype
> > > ├── locked
> > > ├── region1.0:0
> > > │ ├── offset
> > > │ ├── size
> > > │ ├── subsystem -> ../../../../../../../bus/cxl
> > > │ ├── target0
> > > │ ├── uevent
> > > │ ├── uuid
> > > │ └── verify
> > > ├── size
> > > ├── start
> > > ├── subsystem -> ../../../../../../bus/cxl
> > > ├── target_list
> > > ├── target_type
> > > └── uevent
> > >
> > > Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
> > > ---
> > > Documentation/ABI/testing/sysfs-bus-cxl | 27 +++
> > > drivers/cxl/mem.h | 2 +
> > > drivers/cxl/region.c | 227 +++++++++++++++++++++++-
> > > 3 files changed, 255 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> > > index 699c8514fd7b..d7174a84f70d 100644
> > > --- a/Documentation/ABI/testing/sysfs-bus-cxl
> > > +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> > > @@ -159,3 +159,30 @@ Description:
> > > integer is returned describing the first error found in the
> > > configuration. A verified region can still fail binding due to
> > > lack of resources.
> > > +
> > > +What: /sys/bus/cxl/devices/decoderX.Y/regionX.Y:Z/{offset,size}
> >
> > I missed this before, but why do we need X.Y in the region naming given it's
> > always inside decoderX.Y. Seems like RegionZ would work.
> >
>
> Yes. There are two options, either we do X.Y:Z, or Z where Z is globally unique
> across all decoders. The reason for this is the devices are symlinked into sysfs
> and so you can't have the same Z for multiple regions in different decoders.
>
> My preference is to have regionX.y:[0-n] for each decoder, rather than the globally
> unique. I'll entertain an argument the other way though.
I'm happy with either approach.
Thanks,
Jonathan
next prev parent reply other threads:[~2021-06-14 16:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 18:57 [RFC PATCH 0/4] Region Creation Ben Widawsky
2021-06-10 18:57 ` [RFC PATCH 1/4] cxl/region: Add region creation ABI Ben Widawsky
2021-06-11 13:31 ` Jonathan Cameron
2021-06-16 17:38 ` Ben Widawsky
2021-06-10 18:57 ` [RFC PATCH 2/4] cxl/region: Create attribute structure / verify Ben Widawsky
2021-06-11 13:37 ` Jonathan Cameron
2021-06-12 0:59 ` Dan Williams
2021-06-14 16:12 ` Ben Widawsky
2021-06-10 18:57 ` [RFC PATCH 3/4] cxl: Move cxl_memdev conversion helper to mem.h Ben Widawsky
2021-06-10 18:57 ` [RFC PATCH 4/4] cxl/region: Introduce concept of region configuration Ben Widawsky
2021-06-11 13:52 ` Jonathan Cameron
2021-06-14 16:18 ` Ben Widawsky
2021-06-14 16:20 ` Jonathan Cameron [this message]
2021-06-11 13:11 ` [RFC PATCH 0/4] Region Creation Jonathan Cameron
2021-06-11 13:53 ` Jonathan Cameron
2021-06-11 16:12 ` Ben Widawsky
2021-06-12 0:44 ` Dan Williams
2021-06-14 8:20 ` Jonathan Cameron
2021-06-14 16:12 ` Ben Widawsky
2021-06-14 21:04 ` Dan Williams
2021-06-14 21:54 ` Ben Widawsky
2021-06-14 22:21 ` Dan Williams
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