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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D5BEC05027 for ; Fri, 10 Feb 2023 18:39:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CEEBA280012; Fri, 10 Feb 2023 13:39:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C9EB3280003; Fri, 10 Feb 2023 13:39:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B8D9D280012; Fri, 10 Feb 2023 13:39:04 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id A7E48280003 for ; Fri, 10 Feb 2023 13:39:04 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 689631C60F5 for ; Fri, 10 Feb 2023 18:39:04 +0000 (UTC) X-FDA: 80452244208.23.0FACEFF Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by imf29.hostedemail.com (Postfix) with ESMTP id 0AC9D120011 for ; Fri, 10 Feb 2023 18:39:00 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf29.hostedemail.com: domain of jonathan.cameron@huawei.com designates 185.176.79.56 as permitted sender) smtp.mailfrom=jonathan.cameron@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1676054342; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Z7XPrvvOTl/WupDsL8yQfl1eKjJ4ASynXDcRwWxfOJw=; b=c6E0Gl3JVqPKyI9lfwl3JVHOr/GW+AeoGYiCHARHLxkuytjOg7qXv8nIdmTFliAuk0Wusc hXL9c96ob0+V2OwzSiJLMGk8+hleeNXvNa5zIUvk7QMFb2rEzxNELcj6nzsqVktoQL1fXM ezJPBPeRpnyoIehz1yBcoIvEIB/ebXs= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf29.hostedemail.com: domain of jonathan.cameron@huawei.com designates 185.176.79.56 as permitted sender) smtp.mailfrom=jonathan.cameron@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1676054342; a=rsa-sha256; cv=none; b=q65Q9IcItxiWM8HxVOx9A4w4YB4y3+Jin7uIEmvUWN3btP9ZQqx43TjfMLFl0lgRqJA7z+ KLZsJUwpTEU3+zqHyhjL3JwAoPM7lg682a2gP26eQusPLA/546hRhn3wpPFJm+3DLcoPwR lUhbAeKpa96EmTYoo1vJD3KxaWCOXlE= 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 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 0AC9D120011 X-Stat-Signature: hagcwgykisgmnn7qsczt81rrij8j5pzj X-Rspam-User: X-HE-Tag: 1676054340-756632 X-HE-Meta: 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 kLL82oXw IdkQNztNdeQZDmYBMDjPwKqYBBLhTVKQJxUqxAI262UW0tPX2dgr4WvjdddFF5dwUXurYBzJJrZzNTc/CNh8G84iLIh0WfqN2EqSaG+KCmSrx3F2Xn6cwaRAU4FQQcJx8Rn19j7izd50HLBvuCLzSpy0IPjRjaNi/IiIc9twqCto2gkmETij5v8E09FkrRlmMh6q0Jcv8bvMwUyBJn+hvqpIEIXSYEmfz69RetP0Sv4SJhWEaL0KXR7jlCt1a39HqJms5OCz9+R15P7pT/XpDv//KlA328mOZ3zjzkPRKcAs3T8PIpHBdlrfGTEoqwquw7lfO3a1Px+wCa+Gm8bWRTvcckLVWbHTZqErB X-Bogosity: Ham, tests=bogofilter, spamicity=0.000050, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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