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=-8.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 7F805C55ABD for ; Wed, 11 Nov 2020 06:17:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23ABE207BB for ; Wed, 11 Nov 2020 06:17:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="GBtVWmiI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725894AbgKKGRU (ORCPT ); Wed, 11 Nov 2020 01:17:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725468AbgKKGRU (ORCPT ); Wed, 11 Nov 2020 01:17:20 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D993CC0613D1; Tue, 10 Nov 2020 22:17:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description; bh=kGYmI/Q6Qz0/0VlGhaOnBJBqjqnYbQCh0GWbtl2e1Es=; b=GBtVWmiIT0NgrhKoxSVkVZpC24 /97KAT4o4d0fOpB5PtVxfzOA8gEh1zZ7+3aezyHPpss6hSbIZ1Bs06njo7p+UBCviitngnjTX3m2M AG65JPtruyeK8QU3HaPqIn0EgALUkx4Eqc3oj/oELOVNnBzOhm2ZRJGE68jWRCi0FrRUs1na9ushh pAeU7QWFHb+/ig3ToybGI8CpcKJHTpyYJD3ZS1Y+usjF7QC+JUAD/iRmuyB/IL4ahTtVjYoirc19B mRU6QzBhE991shqiXe9xYDAxJfPE4vnuf5vGhUaNTgjS1n38eXK05NjBnspS4lJsY3/0rTJWnOY7t Sk9vuFbg==; Received: from [2601:1c0:6280:3f0::662d] by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kcjRS-00080D-6G; Wed, 11 Nov 2020 06:17:14 +0000 Subject: Re: [RFC PATCH 3/9] cxl/mem: Add a driver for the type-3 mailbox To: Ben Widawsky , linux-cxl@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, Dan Williams , Ira Weiny , Vishal Verma , "Kelley, Sean V" , Bjorn Helgaas , "Rafael J . Wysocki" References: <20201111054356.793390-1-ben.widawsky@intel.com> <20201111054356.793390-4-ben.widawsky@intel.com> From: Randy Dunlap Message-ID: <1dbfc3a3-5f81-90b2-5b0b-5dcb99e2eecd@infradead.org> Date: Tue, 10 Nov 2020 22:17:08 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20201111054356.793390-4-ben.widawsky@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Hi, On 11/10/20 9:43 PM, Ben Widawsky wrote: > --- > drivers/cxl/Kconfig | 20 +++++++++++ > drivers/cxl/Makefile | 2 ++ > drivers/cxl/mem.c | 82 ++++++++++++++++++++++++++++++++++++++++++++ > drivers/cxl/pci.h | 15 ++++++++ > 4 files changed, 119 insertions(+) > diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig > index dd724bd364df..15548f5c77ff 100644 > --- a/drivers/cxl/Kconfig > +++ b/drivers/cxl/Kconfig > @@ -27,4 +27,24 @@ config CXL_ACPI > resources described by the CEDT (CXL Early Discovery Table) > > Say 'y' to enable CXL (Compute Express Link) drivers. > + > +config CXL_MEM > + tristate "CXL.mem Device Support" > + depends on PCI && CXL_BUS_PROVIDER != n > + default m if CXL_BUS_PROVIDER The "if CXL_BUS_PROVIDER" should be redundant due to the "depends on" clause. However, having any default or 'm' or 'y' needs to be justified. > + help > + The CXL.mem protocol allows a device to act as a provider of > + "System RAM" and/or "Persistent Memory" that is fully coherent > + as if the memory was attached to the typical CPU memory > + controller. > + > + Say 'y/m' to enable a driver named "cxl_mem.ko" that will attach The builtin driver will not be named cxl-mem.ko. > + to CXL.mem devices for configuration, provisioning, and health > + monitoring, the so called "type-3 mailbox". Note, this driver > + is required for dynamic provisioning of CXL.mem attached > + memory, a pre-requisite for persistent memory support, but prerequisite > + devices that provide volatile memory may be fully described by > + existing platform firmware memory enumeration. > + > + If unsure say 'n'. > endif -- ~Randy