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_HELO_NONE,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 0AEC5C31E46 for ; Wed, 12 Jun 2019 13:27:35 +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 D9B28208CA for ; Wed, 12 Jun 2019 13:27:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AYwMZfOH"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ucR0cDZm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9B28208CA 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=802jFxJ/TMp+q0HrGMAz+PAYp6Mcoq//tD1xRJCedO4=; b=AYwMZfOHvQZXM/ v9xMEZmkm7/F4Evld2FVlZXVG31xR20VJ6UQeB8Yowr6VLxCFVFQyxseBrJoKVejE9+KVv6kLr3tT PXtiuhfIqyxs62YhQESOhbyX6QZbCs9wgcRaqHCEZlkhyTBu1MwarwZgluoOMa/36L8CnfbrZG/E/ FC/m0KdRhIdqKqCAvZEsosa+8z9AJbNvJNtFXylMT7v+a2iu1uaVPXbEV5CaHwVKXhdfGsxU6T1su 0PIWnCpjs3Vr+JCNW0OeGiJoUBDMxqgpLrCtNXnVjzt9kmukp/adr2yI0ymn9oNJcdFl1zdzLgBPA RZnszMJVM/gyFCVYjV0A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hb3Hq-0004mX-Hw; Wed, 12 Jun 2019 13:27:34 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hb3Ho-0004m8-4b for linux-arm-kernel@lists.infradead.org; Wed, 12 Jun 2019 13:27:33 +0000 Received: from localhost (173-25-83-245.client.mchsi.com [173.25.83.245]) (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 9B30D20866; Wed, 12 Jun 2019 13:27:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560346051; bh=fCiEkHOn4IM9qMiFXhbfh3OOyEoB+GLRdm6K+ZhmpQQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ucR0cDZmFIAHAdxv2kahFhIRw1/m7K1Irbr3F1WGoYg1wU8GwY+GO3X8PGXOr9MfO 27guwNNyMJRbXvYoPvcn2+SOMPfBEAIolvLJ1NJBgjuCA2nqD3gs+VATaw4iJSpvae 0+8MmKtLZitZu83Igh7zA0p4Wi1UecnRG/psFaa0= Date: Wed, 12 Jun 2019 08:27:30 -0500 From: Bjorn Helgaas To: Benjamin Herrenschmidt Subject: Re: [PATCH/RESEND] arm64: acpi/pci: invoke _DSM whether to preserve firmware PCI setup Message-ID: <20190612132730.GB13533@google.com> References: <56715377f941f1953be43b488c2203ec090079a1.camel@kernel.crashing.org> <20190604014945.GE189360@google.com> <960c94eb151ba1d066090774621cf6ca6566d135.camel@kernel.crashing.org> <20190604124959.GF189360@google.com> <20190611233908.GA13533@google.com> <97fd2516fdde7f9f01688af426c103806f68dd2c.camel@kernel.crashing.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <97fd2516fdde7f9f01688af426c103806f68dd2c.camel@kernel.crashing.org> 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-20190612_062732_194326_FA9955D8 X-CRM114-Status: GOOD ( 14.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lorenzo Pieralisi , Ard Biesheuvel , linux-pci@vger.kernel.org, Sinan Kaya , "Zilberman, Zeev" , "Saidi, Ali" , 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 Wed, Jun 12, 2019 at 10:06:06AM +1000, Benjamin Herrenschmidt wrote: > On Tue, 2019-06-11 at 18:39 -0500, Bjorn Helgaas wrote: > > This is fine, but can we make a tiny step toward doing this in generic > > code instead of adding more arch-specific stuff? > > > > E.g., evaluate the _DSM in the generic acpi_pci_root_add(), set a > > "preserve_config" bit in the struct acpi_pci_root, and test the bit > > here? > > I'd rather have the flag in the host bridge no ? Oh, of course, that would make more sense. > Talking of which, look at the ongoing discussion I have with Lorenzo > when it comes to pci_bus_claim_resources vs. what x86 does, I'd love > for you to chime in. I'd like to try to consolidate things further > accross architectures but there might be reasons I don't see as to why > things are different in that area, so ... I don't know any reasons why things are different per arch. In most cases I suspect FUD. Speaking of which, *this* patch looks like FUD because it essentially says "Linux shouldn't change the PCI configuration on this system" but it offers no explanation of *why* the config needs to be preserved. I would really like some note like "run-time firmware depends on the addresses of device X". Bjorn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel