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[96.255.20.138]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8c530be5446sm204964985a.54.2026.01.14.10.26.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Jan 2026 10:26:26 -0800 (PST) Date: Wed, 14 Jan 2026 13:25:53 -0500 From: Gregory Price To: Jonathan Cameron Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, dave@stgolabs.net, dave.jiang@intel.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, dan.j.williams@intel.com Subject: Re: [PATCH 1/6] drivers/cxl: add cxl_memctrl_mode and region->memctrl Message-ID: References: <20260112163514.2551809-1-gourry@gourry.net> <20260112163514.2551809-2-gourry@gourry.net> <20260114171808.000067e2@huawei.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260114171808.000067e2@huawei.com> On Wed, Jan 14, 2026 at 05:18:08PM +0000, Jonathan Cameron wrote: > On Mon, 12 Jan 2026 11:35:09 -0500 > Gregory Price wrote: > > > The CXL driver presently hands policy management over to DAX subsystem > > for sysram regions, which makes building policy around the entire region > > clunky and at time difficult (e.g. multiple actions to offline and > > hot-unplug memory reliably). > > > > To support multiple backend controllers for memory regions (for example > > dax vs direct hotplug), implement a memctrl field in cxl_region allows > > switching uncomitted regions between different "memory controllers". > > > > CXL_CONTROL_NONE: No selected controller, probe will fail. > > CXL_CONTROL_AUTO: If memory is already online as SysRAM, no controller > > otherwise register a dax_region > > CXL_CONTROL_DAX : register a dax_region > > > > Auto regions will either be static sysram (BIOS-onlined) and has no > > region controller associated with it - or if the SP bit was set a > > DAX device will be created. > > > > Rather than default all regions to the auto-controller, only default > > auto-regions to the auto controller. > > > > Non-auto regions will be defaulted to CXL_CONTROL_NONE, which will cause > > a failure to probe unless a controller is selected. > > > > Signed-off-by: Gregory Price > Trivial comments whilst I try to get my head around the series. > > ... > Recommend piviting to v2 which simplifies and addresses some of your notes here already: https://lore.kernel.org/linux-cxl/aWfe-r7uEV-ajfhX@gourry-fedora-PF4VCD3F/T/#m791301178876f9b1ab55ed4091c674d4f4ceb07c Still need to add some docs. ~Gregory