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,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D2A47C432BE for ; Tue, 10 Aug 2021 15:21:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B555C60E52 for ; Tue, 10 Aug 2021 15:21:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242918AbhHJPVm (ORCPT ); Tue, 10 Aug 2021 11:21:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242927AbhHJPVl (ORCPT ); Tue, 10 Aug 2021 11:21:41 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2A44C0613C1 for ; Tue, 10 Aug 2021 08:21:19 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id b7so1712232plh.7 for ; Tue, 10 Aug 2021 08:21:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=kTeuieYFo8ENaGwfkNtTCgQpsZjGUZAe4ytDOG3HS6Q=; b=YG9cF3SxMxGuZxmRz5+wU4aeeqigOSE3soVInU2XySjoVqNvPM6aCLbEoa+273dSsR xstlnXOnJgflyQMjvWh5RmOpWzOm+wppgilWvyrsrB6g+gKPNGQauC6ocrMD1q8fTzo7 C3E1Jcp4xcIAEXzcka1jNb2uixsI30YzbEMJBqHQ69CyS/D3Qu2LhcozwKkZJ9dxkTjz 7kXg81beN++3XQ/GQo3H0bPrwMirC93zNGEtCobCnKzJ/Xwr/L6P4CY0Wb3PAfHsNLO/ beXhmR2VR7ZB1KN56t6xYSc3p77ls9mPT/d5oeg5tsI/GLLmRxZTp8FpH0viTf9W/YdR 8VGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=kTeuieYFo8ENaGwfkNtTCgQpsZjGUZAe4ytDOG3HS6Q=; b=haGgaaR6wSNapooK0QjvQFogdfJOst5Tlzk+gTW80cvwc0Us8tU2Qwzg8Wkb4VHu/c EGaq3KLRI2WfgY24gDwr7YQBsBNJ44832HRjpE9BrCtJiRYhwtJrS8kAWLJLtjGE6wKr sM55xvdmLefM71uhowqm4FZ8Za/pTEviqBckEBNDEI/vQdDmZLmzb/kVyJjxLoYH5kAo msUtJBs6NbfQUSNur9QJ3BfYs4dV0o3ehsm9oXm7yNk3O3CJFJWOgNht7NoqaxDgY/Ti eMwxd8R+qm/Tlo/ndBzXqsp4xHxtnA86JC0DkJwJaQDzoEjH4cD8dmU/2gefN6W53p36 UFIw== X-Gm-Message-State: AOAM531fBmmIG3PCC7YuMyXaK66936gYV61f1Iz6ryxD52c3b5IepwTq /+PJZDixImwrNA45T5CXPAltTar/v7+9zJfI0PVggQ== X-Google-Smtp-Source: ABdhPJxNyBPxdejAYbv4NgfllrXKzGTDydYq6kDn/YU0qOEMlBo2sldIuizFv39iDX5nEMjMNFWG3JJ/WFym27JtJ/Q= X-Received: by 2002:a63:311:: with SMTP id 17mr842399pgd.450.1628608879272; Tue, 10 Aug 2021 08:21:19 -0700 (PDT) MIME-Version: 1.0 References: <20210811001850.GA39621@montage-desktop> In-Reply-To: <20210811001850.GA39621@montage-desktop> From: Dan Williams Date: Tue, 10 Aug 2021 08:21:08 -0700 Message-ID: Subject: Re: CXL 1.1 Support Plan To: johnny Cc: linux-cxl@vger.kernel.org, Jonathan Cameron , Ben Widawsky Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Tue, Aug 10, 2021 at 5:24 AM johnny wrote: > > Hello, > > Current CXL patches [1] focus on CXL 2.0 support. While in the real world, > CXL 1.1 capable host and EP are the first CXL components end user can use. May I > ask community plan on CXL 1.1 support The expectation is that CXL 1.1 is BIOS / platform-firmware supported. Just like the OS does not have a driver for DDR and relies on the BIOS to describe DDR resources via generic ACPI tables, the same expectation holds for CXL 1.1. CXL 2.0 explicitly adds features that exceed what platform-firmware can support with static ACPI tables. Something is broken if the OS requires a driver for CXL 1.1 device operation, at least for the generic memory expander use case. Ben did have some improvements to lspci to dump the range registers of a CXL 1.1 device: https://github.com/pciutils/pciutils/pull/59 ...but it does not seem the pciutils project has accepted that work.