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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 79CDEC47088 for ; Wed, 26 May 2021 18:01:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BDD9611C2 for ; Wed, 26 May 2021 18:01:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235440AbhEZSDX (ORCPT ); Wed, 26 May 2021 14:03:23 -0400 Received: from mga11.intel.com ([192.55.52.93]:49288 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235429AbhEZSDR (ORCPT ); Wed, 26 May 2021 14:03:17 -0400 IronPort-SDR: /6piuKlZGOLbY7SdAafAlokXk7usvTkHkmWLh3f565c8vD3ARWlC2yok3ZyCAA96NPjSX+vrfh bIJSkPpviEpA== X-IronPort-AV: E=McAfee;i="6200,9189,9996"; a="199480477" X-IronPort-AV: E=Sophos;i="5.82,331,1613462400"; d="scan'208";a="199480477" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 May 2021 11:01:44 -0700 IronPort-SDR: JpJxsRdfmOk+ZdneFKfO7/jMyGD8yv7JcsXHuVeeN5Sltr4+/Y0gapOYvV9tPuAgym+uXhGjbL +p8+KGAwKXVA== X-IronPort-AV: E=Sophos;i="5.82,331,1613462400"; d="scan'208";a="477057592" Received: from kkomeyli-mobl4.amr.corp.intel.com (HELO intel.com) ([10.252.135.245]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 May 2021 11:01:44 -0700 Date: Wed, 26 May 2021 11:01:43 -0700 From: Ben Widawsky To: linux-cxl@vger.kernel.org, Dan Williams Cc: Jonathan Cameron , Alison Schofield , Ira Weiny , Vishal Verma Subject: Re: [PATCH v3] cxl: Rename mem to pci Message-ID: <20210526180143.ndu4rs5lnxgfeg6c@intel.com> References: <20210526174413.802913-1-ben.widawsky@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210526174413.802913-1-ben.widawsky@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On 21-05-26 10:44:13, Ben Widawsky wrote: > As the driver has undergone development, it's become clear that the > majority [entirety?] of the current functionality in mem.c is actually a > layer encapsulating functionality exposed through PCI based > interactions. This layer can be used either in isolation or to provide > functionality for higher level functionality. > > CXL capabilities exist in a parallel domain to PCIe. CXL devices are > enumerable and controllable via "legacy" PCIe mechanisms; however, their > CXL capabilities are a superset of PCIe. For example, a CXL device may > be connected to a non-CXL capable PCIe root port, and therefore will not > be able to participate in CXL.mem or CXL.cache operations, but can still > be accessed through PCIe mechanisms for CXL.io operations. > > To properly represent the PCI nature of this driver, and in preparation for > introducing a new driver for the CXL.mem / HDM decoder (Host-managed Device > Memory) capabilities of a CXL memory expander, rename mem.c to pci.c so that > mem.c is available for this new driver. > > The result of the change is that there is a clear layering distinction > in the driver, and a systems administrator may load only the cxl_pci > module and gain access to such operations as, firmware update, offline > provisioning of devices, and error collection. In addition to freeing up > the file name for another purpose, there are two primary reasons this is > useful, > 1. Acting upon devices which don't have full CXL capabilities. This > may happen for instance if the CXL device is connected in a CXL > unaware part of the platform topology. > 2. Userspace-first provisioning for devices without kernel driver > interference. This may be useful when provisioning a new device > in a specific manner that might otherwise be blocked or prevented > by the real CXL mem driver. > > Reviewed-by: Dan Williams > Signed-off-by: Ben Widawsky [snip] I forgot to put the reasoning for v3... I accidentally left acpi.o in the Makefile. The only diff from v2 is acpi.o is dropped. Ben