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 X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06B25C433E0 for ; Wed, 17 Feb 2021 12:24:07 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4D0E564E0F for ; Wed, 17 Feb 2021 12:24:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D0E564E0F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=Huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 10382100EAAE6; Wed, 17 Feb 2021 04:24:06 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=185.176.79.56; helo=frasgout.his.huawei.com; envelope-from=jonathan.cameron@huawei.com; receiver= Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 9BCEA100EBB68 for ; Wed, 17 Feb 2021 04:24:03 -0800 (PST) Received: from fraeml709-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4DgcMF4f0Yz67q1Q; Wed, 17 Feb 2021 20:18:49 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml709-chm.china.huawei.com (10.206.15.37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Wed, 17 Feb 2021 13:24:00 +0100 Received: from localhost (10.47.29.73) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2106.2; Wed, 17 Feb 2021 12:23:59 +0000 Date: Wed, 17 Feb 2021 12:22:53 +0000 From: Jonathan Cameron To: Ben Widawsky Subject: Re: [PATCH v5 2/9] cxl/mem: Find device capabilities Message-ID: <20210217122253.00007bc2@Huawei.com> In-Reply-To: <20210217040958.1354670-3-ben.widawsky@intel.com> References: <20210217040958.1354670-1-ben.widawsky@intel.com> <20210217040958.1354670-3-ben.widawsky@intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 X-Originating-IP: [10.47.29.73] X-ClientProxiedBy: lhreml704-chm.china.huawei.com (10.201.108.53) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Message-ID-Hash: DPRL54RACY4YK2PHAB2DJSXUKW7XYGS3 X-Message-ID-Hash: DPRL54RACY4YK2PHAB2DJSXUKW7XYGS3 X-MailFrom: jonathan.cameron@huawei.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: linux-cxl@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, Bjorn Helgaas , "Chris Browy , Christoph Hellwig , Dan Williams , David Hildenbrand , David Rientjes" , "Jon Masters , Rafael Wysocki , Randy Dunlap" , "John Groves (jgroves)" , "Kelley, Sean V" , Colin Ian King , Dan Carpenter X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Tue, 16 Feb 2021 20:09:51 -0800 Ben Widawsky wrote: > Provide enough functionality to utilize the mailbox of a memory device. > The mailbox is used to interact with the firmware running on the memory > device. The flow is proven with one implemented command, "identify". > Because the class code has already told the driver this is a memory > device and the identify command is mandatory. > > CXL devices contain an array of capabilities that describe the > interactions software can have with the device or firmware running on > the device. A CXL compliant device must implement the device status and > the mailbox capability. Additionally, a CXL compliant memory device must > implement the memory device capability. Each of the capabilities can > [will] provide an offset within the MMIO region for interacting with the > CXL device. > > The capabilities tell the driver how to find and map the register space > for CXL Memory Devices. The registers are required to utilize the CXL > spec defined mailbox interface. The spec outlines two mailboxes, primary > and secondary. The secondary mailbox is earmarked for system firmware, > and not handled in this driver. > > Primary mailboxes are capable of generating an interrupt when submitting > a background command. That implementation is saved for a later time. > > Reported-by: Colin Ian King (coverity) > Reported-by: Dan Carpenter (smatch) > Link: https://www.computeexpresslink.org/download-the-specification > Signed-off-by: Ben Widawsky > Reviewed-by: Dan Williams (v2) Looks good to me. Reviewed-by: Jonathan Cameron _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org