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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 C9234C282C2 for ; Thu, 7 Feb 2019 19:52:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 94A932147C for ; Thu, 7 Feb 2019 19:52:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="jZxmf/gF"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="e+hYjJZd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94A932147C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=b9y2Gu0KyxppE8LrghvZDEj9CPi8RvjDld0HFM1KNMs=; b=jZxmf/gFhnAPPc mOuUa5qnRj/hBvLZXit5nV19Obs6S+bDVxVOBfZSqhZZzwagWcccsKXXZwfKoHOtjXEeRefVDHKSN GTlMLkVQI1ekN7GiPMwBWQK0hdnnkEmh2K4pJXTU35AMpA4wU903ABPkeAEvAYeKz71Zk5Oy/tNok f3W6jv9QvUhDx/n/epjP47ATZ88mK23W/FxTn2lgC+pUDy7gS6PknXUcLaytdCOwPHBmTOd/Ji7ZF gQm60+z/WbzArozC79+PWZ+Hu55rUbO2XRJ1L9i9G2SBhM2LQT5F2UkFTzbKbUqdSHL1ck2H7FdSQ Ezl0KzuPhay1JOvlytGA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1grpiw-0007yv-6a; Thu, 07 Feb 2019 19:52:38 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1grpis-0007yZ-QY; Thu, 07 Feb 2019 19:52:36 +0000 Received: from localhost (unknown [69.71.4.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0E9A32147C; Thu, 7 Feb 2019 19:52:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549569154; bh=yNiMpTVg55DaX5Wf82kFMN/MvA5KnKfjzih2bD2G7iI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=e+hYjJZdsYNknAZCPGXeN2oMMyEhTpy+RSXu9dl/HyycUAcl8E7nH471ma+Mmeymp GG9RLlISCngYJDib5cVcO824lVsGIaNNBSIr0N3AOYzxbkXHR5YLdzkFeHyoHSi6mw 3UdqSqt4aB8x6fqygxfHjFJ0g5T6nEfy9CoaxMxs= Date: Thu, 7 Feb 2019 13:52:30 -0600 From: Bjorn Helgaas To: honghui.zhang@mediatek.com Subject: Re: [RFC PATCH] PCI/portdrv: Support for subtractive decode bridge Message-ID: <20190207195230.GJ7268@google.com> References: <1544758829-10327-1-git-send-email-honghui.zhang@mediatek.com> <20190207151816.GI7268@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190207151816.GI7268@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190207_115234_872227_FBB96334 X-CRM114-Status: GOOD ( 13.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: youlin.pei@mediatek.com, lorenzo.pieralisi@arm.com, poza@codeaurora.org, fred@fredlawl.com, linux-pci@vger.kernel.org, rafael.j.wysocki@intel.com, linux-kernel@vger.kernel.org, jianjun.wang@mediatek.com, ryder.lee@mediatek.com, linux-mediatek@lists.infradead.org, matthias.bgg@gmail.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Feb 07, 2019 at 09:18:16AM -0600, Bjorn Helgaas wrote: > On Fri, Dec 14, 2018 at 11:40:29AM +0800, honghui.zhang@mediatek.com wrote: > > From: Honghui Zhang > > > > The Class Code for subtractive decode PCI-to-PCI bridge is 060401h, > > change the class_mask values to make portdrv support this type bridge. > > I assume you have a Root Port or Switch Port that supports subtractive > decode? I'm trying to understand how such a device would work. > > Out of curiosity, can you show the "lspci -vv" output for the device > and the downstream devices of interest? Actually, since subtractive decode has to do with how the bridge interacts with its *peers*, what would be interesting is the host bridge window information from ACPI _CRS or DT and the lspci info for everything under that host bridge. Assuming we're talking about a Root Port, I guess that would mean anything inside the host bridge windows but outside the positive decode windows (the normal PCI-PCI bridge apertures in the Root Ports) would be claimed by the subtractive decode Root Port? I guess you would want this because this path ultimately leads to an ISA or similar bus where you don't know what resources the device actually consumes? Bjorn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel