From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E351C636D4 for ; Fri, 10 Feb 2023 18:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232505AbjBJSjA (ORCPT ); Fri, 10 Feb 2023 13:39:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232807AbjBJSjA (ORCPT ); Fri, 10 Feb 2023 13:39:00 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED2942D16E; Fri, 10 Feb 2023 10:38:58 -0800 (PST) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4PD2TL3Ctvz6J67f; Sat, 11 Feb 2023 02:34:46 +0800 (CST) Received: from localhost (10.81.210.211) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.17; Fri, 10 Feb 2023 18:38:55 +0000 Date: Fri, 10 Feb 2023 18:38:54 +0000 From: Jonathan Cameron To: Dan Williams CC: , Fan Ni , , , , Subject: Re: [PATCH v2 20/20] cxl/dax: Create dax devices for CXL RAM regions Message-ID: <20230210183854.000022ee@Huawei.com> In-Reply-To: <167602003896.1924368.10335442077318970468.stgit@dwillia2-xfh.jf.intel.com> References: <167601992097.1924368.18291887895351917895.stgit@dwillia2-xfh.jf.intel.com> <167602003896.1924368.10335442077318970468.stgit@dwillia2-xfh.jf.intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.81.210.211] X-ClientProxiedBy: lhrpeml100004.china.huawei.com (7.191.162.219) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Fri, 10 Feb 2023 01:07:19 -0800 Dan Williams wrote: > While platform firmware takes some responsibility for mapping the RAM > capacity of CXL devices present at boot, the OS is responsible for > mapping the remainder and hot-added devices. Platform firmware is also > responsible for identifying the platform general purpose memory pool, > typically DDR attached DRAM, and arranging for the remainder to be 'Soft > Reserved'. That reservation allows the CXL subsystem to route the memory > to core-mm via memory-hotplug (dax_kmem), or leave it for dedicated > access (device-dax). > > The new 'struct cxl_dax_region' object allows for a CXL memory resource > (region) to be published, but also allow for udev and module policy to > act on that event. It also prevents cxl_core.ko from having a module > loading dependency on any drivers/dax/ modules. > > Tested-by: Fan Ni > Link: https://lore.kernel.org/r/167564545116.847146.4741351262959589920.stgit@dwillia2-xfh.jf.intel.com > Signed-off-by: Dan Williams I've not yet gotten around to testing this version yet but from a read through looks fine. Reviewed-by: Jonathan Cameron I've skipped a patch or two where I felt I didn't have the expertise to cover them adequately (and not enough time for now to get it...) in particular the policy patch. Hopefully that will get good review from others. Jonathan