From: <dan.j.williams@intel.com>
To: Alejandro Lucero Palau <alucerop@amd.com>,
<dan.j.williams@intel.com>,
"Koralahalli Channabasappa, Smita" <skoralah@amd.com>,
Jonathan Cameron <jonathan.cameron@huawei.com>,
Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Cc: <linux-cxl@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<nvdimm@lists.linux.dev>, <linux-fsdevel@vger.kernel.org>,
<linux-pm@vger.kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
"Alison Schofield" <alison.schofield@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
Yazen Ghannam <yazen.ghannam@amd.com>,
Dave Jiang <dave.jiang@intel.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@kernel.org>,
Li Ming <ming.li@zohomail.com>,
Jeff Johnson <jeff.johnson@oss.qualcomm.com>,
"Ying Huang" <huang.ying.caritas@gmail.com>,
Yao Xingtao <yaoxt.fnst@fujitsu.com>,
Peter Zijlstra <peterz@infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Nathan Fontenot <nathan.fontenot@amd.com>,
Terry Bowman <terry.bowman@amd.com>,
Robert Richter <rrichter@amd.com>,
Benjamin Cheatham <benjamin.cheatham@amd.com>,
Zhijian Li <lizhijian@fujitsu.com>,
Borislav Petkov <bp@alien8.de>,
Tomasz Wolski <tomasz.wolski@fujitsu.com>
Subject: Re: [PATCH v5 3/7] cxl/region: Skip decoder reset on detach for autodiscovered regions
Date: Wed, 28 Jan 2026 13:24:26 -0800 [thread overview]
Message-ID: <697a7e8a815b_3095100e9@dwillia2-mobl4.notmuch> (raw)
In-Reply-To: <04e92860-e616-4e74-a349-1397b3a0db81@amd.com>
Alejandro Lucero Palau wrote:
[..]
> I have been trying to figure out how to preserve the decoders for Type2
> auto discover regions since, I think, this was demanded after v22 sent
> upstream. This patch/change is what I was looking for, and although I
> did implement it in another way requiring "consensus", this one seems
> good enough and already discussed and approved, so all good.
>
>
> However, I think it would be also interesting to give the Type2 driver
> the option of resetting decoders as well, what I have been using for v22
> and successfully tested. But this change will preclude that other
> possibility, so, what about an option for clearing CXL_REGION_F_AUTO by
> Type2 drivers? If you want this only to be done by admin/root, I guess a
> module param would do it.
The expecation is that as long as "Fixed Device Configuration" is not
set then reconfiguration is possible. The best case is BIOS does not
create the ambiguity and leaves accelerators alone. The hard part is
that HPA space going back into a general CXL pool for other regions when
it is really earmarked for a singular use case.
So yes, a future helper for accelerator drivers to reclaim decoder
ownership from the platform seems reasonable, but the first hope is to
just have a BIOS switch / change to stop mapping accelerators and let
the OS handle it.
next prev parent reply other threads:[~2026-01-28 21:24 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-22 4:55 [PATCH v5 0/7] dax/hmem, cxl: Coordinate Soft Reserved handling with CXL and HMEM Smita Koralahalli
2026-01-22 4:55 ` [PATCH v5 1/7] dax/hmem: Request cxl_acpi and cxl_pci before walking Soft Reserved ranges Smita Koralahalli
2026-01-22 16:16 ` Jonathan Cameron
2026-01-22 4:55 ` [PATCH v5 2/7] dax/hmem: Gate Soft Reserved deferral on DEV_DAX_CXL Smita Koralahalli
2026-01-22 4:55 ` [PATCH v5 3/7] cxl/region: Skip decoder reset on detach for autodiscovered regions Smita Koralahalli
2026-01-22 16:18 ` Jonathan Cameron
2026-01-26 21:37 ` Koralahalli Channabasappa, Smita
2026-01-27 23:37 ` dan.j.williams
2026-01-28 15:39 ` Alejandro Lucero Palau
2026-01-28 21:24 ` dan.j.williams [this message]
2026-01-23 10:42 ` Alejandro Lucero Palau
2026-01-23 21:58 ` Dave Jiang
2026-01-22 4:55 ` [PATCH v5 4/7] cxl/region: Add helper to check Soft Reserved containment by CXL regions Smita Koralahalli
2026-01-22 16:25 ` Jonathan Cameron
2026-01-27 21:47 ` Koralahalli Channabasappa, Smita
2026-01-23 22:19 ` Dave Jiang
2026-01-25 3:30 ` Koralahalli Channabasappa, Smita
2026-01-27 21:59 ` dan.j.williams
2026-01-28 21:07 ` Koralahalli Channabasappa, Smita
2026-01-28 21:33 ` dan.j.williams
2026-01-22 4:55 ` [PATCH v5 5/7] dax: Introduce dax_cxl_mode for CXL coordination Smita Koralahalli
2026-01-22 16:33 ` Jonathan Cameron
2026-01-23 22:30 ` Dave Jiang
2026-01-27 20:03 ` Alison Schofield
2026-01-22 4:55 ` [PATCH v5 6/7] dax/hmem, cxl: Defer and resolve ownership of Soft Reserved memory ranges Smita Koralahalli
2026-01-22 13:40 ` kernel test robot
2026-01-23 5:30 ` kernel test robot
2026-01-23 6:35 ` Alison Schofield
2026-01-26 21:05 ` Koralahalli Channabasappa, Smita
2026-01-26 22:33 ` Alison Schofield
2026-01-27 21:45 ` Koralahalli Channabasappa, Smita
2026-01-29 0:45 ` dan.j.williams
2026-01-23 11:59 ` Alejandro Lucero Palau
2026-01-25 3:17 ` Koralahalli Channabasappa, Smita
2026-01-26 12:20 ` Alejandro Lucero Palau
2026-01-26 14:26 ` Alejandro Lucero Palau
2026-01-26 23:53 ` dan.j.williams
2026-01-27 12:16 ` Alejandro Lucero Palau
2025-10-01 17:15 ` Tomasz Wolski
2026-01-27 16:52 ` Alejandro Lucero Palau
2026-01-27 23:41 ` dan.j.williams
2026-01-28 16:19 ` Alejandro Lucero Palau
2026-01-27 21:29 ` Koralahalli Channabasappa, Smita
2026-01-23 22:55 ` Dave Jiang
2026-01-27 1:38 ` Alison Schofield
2026-01-28 21:14 ` Koralahalli Channabasappa, Smita
2026-01-28 21:47 ` Alison Schofield
2026-01-27 20:11 ` Alison Schofield
2026-01-28 23:35 ` dan.j.williams
2026-01-29 3:09 ` dan.j.williams
2026-01-29 21:20 ` Koralahalli Channabasappa, Smita
2026-01-29 22:01 ` dan.j.williams
2026-02-04 23:27 ` Tomasz Wolski
2026-01-22 4:55 ` [PATCH v5 7/7] dax/hmem: Reintroduce Soft Reserved ranges back into the iomem tree Smita Koralahalli
2026-01-22 16:39 ` Jonathan Cameron
2026-01-28 22:07 ` Koralahalli Channabasappa, Smita
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=697a7e8a815b_3095100e9@dwillia2-mobl4.notmuch \
--to=dan.j.williams@intel.com \
--cc=Smita.KoralahalliChannabasappa@amd.com \
--cc=alison.schofield@intel.com \
--cc=alucerop@amd.com \
--cc=ardb@kernel.org \
--cc=benjamin.cheatham@amd.com \
--cc=bp@alien8.de \
--cc=dave.jiang@intel.com \
--cc=dave@stgolabs.net \
--cc=gregkh@linuxfoundation.org \
--cc=huang.ying.caritas@gmail.com \
--cc=ira.weiny@intel.com \
--cc=jack@suse.cz \
--cc=jeff.johnson@oss.qualcomm.com \
--cc=jonathan.cameron@huawei.com \
--cc=len.brown@intel.com \
--cc=linux-cxl@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=lizhijian@fujitsu.com \
--cc=ming.li@zohomail.com \
--cc=nathan.fontenot@amd.com \
--cc=nvdimm@lists.linux.dev \
--cc=pavel@kernel.org \
--cc=peterz@infradead.org \
--cc=rafael@kernel.org \
--cc=rrichter@amd.com \
--cc=skoralah@amd.com \
--cc=terry.bowman@amd.com \
--cc=tomasz.wolski@fujitsu.com \
--cc=vishal.l.verma@intel.com \
--cc=willy@infradead.org \
--cc=yaoxt.fnst@fujitsu.com \
--cc=yazen.ghannam@amd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox