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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2249FC433F5 for ; Thu, 27 Jan 2022 12:27:54 +0000 (UTC) Received: from localhost ([::1]:56578 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nD3sX-0003w2-T6 for qemu-devel@archiver.kernel.org; Thu, 27 Jan 2022 07:27:53 -0500 Received: from eggs.gnu.org ([209.51.188.92]:50928) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nD3WZ-0000no-0C for qemu-devel@nongnu.org; Thu, 27 Jan 2022 07:05:11 -0500 Received: from [2a00:1450:4864:20::42a] (port=36750 helo=mail-wr1-x42a.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nD3WW-0005xF-J9 for qemu-devel@nongnu.org; Thu, 27 Jan 2022 07:05:10 -0500 Received: by mail-wr1-x42a.google.com with SMTP id u15so4375804wrt.3 for ; Thu, 27 Jan 2022 04:05:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=references:user-agent:from:to:cc:subject:date:in-reply-to :message-id:mime-version:content-transfer-encoding; bh=wC5AJAToOzdyWv76wjRLKppn9pQtgWR38O4l4EJP0E0=; b=ALLf2LsuxHIZC5I1LP7FulLCCIxU9f7vI6+K2R/gzZkj5/+onZppJOefECeXSY5TrN qfE0Tw+kNTqRoQzmTpkJsfEcs9ah0CQ4Lr08Z4Ki1K/OOb/DV4vCRew/pPogpnQyWbZY yuM1wIvgcoB4hOVVp4lSNk32C+AyxljiXpYBxUhHxFIKdIPWdTG+WE+NeojAQNIAgCkd iaurGRPCzB0VJgWZY77QmHtqVxva4iOlhOnkiK8sX3ecPGqb0m/D351FIfFJLJG/3Y8V zwDy3i/Jv9pz+AAoqOtOX5rji6UFVpSLOyayJ9PN7YaBoQszUEX44KlLczB9cb/e4ORq /9Lw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:references:user-agent:from:to:cc:subject:date :in-reply-to:message-id:mime-version:content-transfer-encoding; bh=wC5AJAToOzdyWv76wjRLKppn9pQtgWR38O4l4EJP0E0=; b=PMnbWbfoN+V7RAfgZXkJ7M3uy0YpWsdxVeHXCD5lQ2RfH8Y1ClQ5dqKPwmR3Njz1AM CKnw8UugbSTdrmsQvQ7HzKgN7FMiVGZrGOGS7LmOVl6CDRjEgTuUKefAR7l8oVKwZayM QNnWKklbjZH2GowpbVvHOzuGpmfsHHrpjI6WY2B1FIpP+gMPK/O6fEVdMH0eL6AubJID NeRzpRDL0F9wYYyGkcuTQcbn5EV5ooL4QpMa2PvGicL4muI1ws4gaYGNH4Gr521PkO4+ 6tuohqLEYfV6e73HM8mLwq7i+dXVgEKN+HEyBK6xvlCG6MPj7C1nUm/+DbSd/fuUo7kF Z3DA== X-Gm-Message-State: AOAM531oPG5zHXqBVK7bGGTZ41caMI07lSf2wUmMsm4Z8Qbb4HjjehFf I+aSB5J0R7Nd2+GV++pgxiZIWg== X-Google-Smtp-Source: ABdhPJwlXJ9yWjlrcjJcAF/GSPCFnEUgq6J5oh9ztAq8cJhZb6ef5bBQX0jf0nF6m4LJNiA/tlkiqw== X-Received: by 2002:a05:6000:1292:: with SMTP id f18mr2836522wrx.133.1643285107124; Thu, 27 Jan 2022 04:05:07 -0800 (PST) Received: from zen.linaroharston ([51.148.130.216]) by smtp.gmail.com with ESMTPSA id k37sm10803669wms.0.2022.01.27.04.05.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Jan 2022 04:05:05 -0800 (PST) Received: from zen (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 11FA21FFB7; Thu, 27 Jan 2022 12:05:05 +0000 (GMT) References: <20220124171705.10432-1-Jonathan.Cameron@huawei.com> <20220124171705.10432-13-Jonathan.Cameron@huawei.com> User-agent: mu4e 1.7.6; emacs 28.0.91 From: Alex =?utf-8?Q?Benn=C3=A9e?= To: Jonathan Cameron Subject: Re: [PATCH v4 12/42] hw/pci/cxl: Create a CXL bus type Date: Thu, 27 Jan 2022 12:05:00 +0000 In-reply-to: <20220124171705.10432-13-Jonathan.Cameron@huawei.com> Message-ID: <87r18t9yfi.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::42a (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::42a; envelope-from=alex.bennee@linaro.org; helo=mail-wr1-x42a.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, PDS_HP_HELO_NORDNS=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Ben Widawsky , "Michael S . Tsirkin" , Samarth Saxena , Chris Browy , qemu-devel@nongnu.org, linux-cxl@vger.kernel.org, linuxarm@huawei.com, Shreyas Shah , Saransh Gupta1 , Shameerali Kolothum Thodi , Marcel Apfelbaum , Igor Mammedov , Dan Williams , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Jonathan Cameron writes: > From: Ben Widawsky > > The easiest way to differentiate a CXL bus, and a PCIE bus is using a > flag. A CXL bus, in hardware, is backward compatible with PCIE, and > therefore the code tries pretty hard to keep them in sync as much as > possible. > > The other way to implement this would be to try to cast the bus to the > correct type. This is less code and useful for debugging via simply > looking at the flags. > > Signed-off-by: Ben Widawsky > Signed-off-by: Jonathan Cameron Reviewed-by: Alex Benn=C3=A9e --=20 Alex Benn=C3=A9e