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=-14.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 DFA60C47089 for ; Thu, 27 May 2021 18:08:11 +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 98B28613BE for ; Thu, 27 May 2021 18:08:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 98B28613BE 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+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.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=psSwgPNfGRs1HV0QInSZNaOg5KJPg9auhHuJAvabpO8=; b=zxz8cbtSbPtSxe YK/4K+YMooQWJsc2+EONc3xcKZN0J4eWEiC4co8zJSSCy4wJ0kb4YFhIpc91gQSd7dAtyrDUPYWIl t1dQsV6Ro94b3HDArADwzwh3oINXNtrVIeYViC+RAUZ320/QR7Ye0GfXSzjGpSKw/l/mA9GUGInUz GkD7Tu+n1Fvs3Ypw4fwQU1uSUdwXBMNKJOQydIXMOzOc83fUeepkWYtwALVW6Y8sCYOPl/+gbsFv9 D2bHgyXhLRamW7Nsh+o585bs4q41VyaVHCPHKB8VegCUk4ohjnhGG9dKpjflf70KeYmevlnIqh1PM EIWz2pMy2Izyq/Jhgw1A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lmKOc-008L7Z-Ct; Thu, 27 May 2021 18:06:15 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lmIyE-007fU1-G7 for linux-arm-kernel@lists.infradead.org; Thu, 27 May 2021 16:34:56 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 82F8A61077; Thu, 27 May 2021 16:34:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622133293; bh=IsdX7aBRh7T+5Cs2YQCUr1eculVqE7cgTlmKcUzghtw=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=pW8dEcGvcslftdvA+7SeEV3shWhIBt1vMtAdU2jrFJ0oB5h3Fvh5hmWpF8MoKf70L 7xEivnA7j+jZ0t57MfE3t7gn5fRR/95frbZ61OqucjNanqwlFuEU9xh/Ru3gq2PXpp jb6jcIRF325vcvmXuRiawNXjQ8UUqHrNY5cmMC4k8HWEBvN1PsQFCmf8cLkjqRvzJ0 bDY5FQQqOJn/te1373BWCf4GrJd29C9XwbGWZ+4JC9K8E+8zcvWkag2ipyw717PfrW 6s9nyyZi9JTX09x4j+ngJX1f3aJY/RdG/gre9KEfPDBPHW1LJroW4FzPNLwNYvjpPE IEmcX21+d414A== Date: Thu, 27 May 2021 11:34:52 -0500 From: Bjorn Helgaas To: Lorenzo Pieralisi Cc: Will Deacon , Bjorn Helgaas , Maximilian Luz , "Rafael J. Wysocki" , Len Brown , Catalin Marinas , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] Revert "arm64: PCI: Exclude ACPI "consumer" resources from host bridge windows" Message-ID: <20210527163452.GA1402454@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210527093200.GA16444@lpieralisi> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210527_093454_623966_042E8618 X-CRM114-Status: GOOD ( 33.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, May 27, 2021 at 10:32:00AM +0100, Lorenzo Pieralisi wrote: > On Wed, May 26, 2021 at 09:58:36PM +0100, Will Deacon wrote: > > On Tue, May 11, 2021 at 01:40:20AM +0200, Maximilian Luz wrote: > > > The Microsoft Surface Pro X has host bridges defined as > > > > > > Name (_HID, EisaId ("PNP0A08") /* PCI Express Bus */) // _HID: Hardware ID > > > Name (_CID, EisaId ("PNP0A03") /* PCI Bus */) // _CID: Compatible ID > > > > > > Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings > > > { > > > Name (RBUF, ResourceTemplate () > > > { > > > Memory32Fixed (ReadWrite, > > > 0x60200000, // Address Base > > > 0x01DF0000, // Address Length > > > ) > > > WordBusNumber (ResourceProducer, MinFixed, MaxFixed, PosDecode, > > > 0x0000, // Granularity > > > 0x0000, // Range Minimum > > > 0x0001, // Range Maximum > > > 0x0000, // Translation Offset > > > 0x0002, // Length > > > ,, ) > > > }) > > > Return (RBUF) /* \_SB_.PCI0._CRS.RBUF */ > > > } > > > > > > meaning that the memory resources aren't (explicitly) defined as > > > "producers", i.e. host bridge windows. > > > > > > Commit 8fd4391ee717 ("arm64: PCI: Exclude ACPI "consumer" resources from > > > host bridge windows") introduced a check that removes such resources, > > > causing BAR allocation failures later on: > > > > > > [ 0.150731] pci 0002:00:00.0: BAR 14: no space for [mem size 0x00100000] > > > [ 0.150744] pci 0002:00:00.0: BAR 14: failed to assign [mem size 0x00100000] > > > [ 0.150758] pci 0002:01:00.0: BAR 0: no space for [mem size 0x00004000 64bit] > > > [ 0.150769] pci 0002:01:00.0: BAR 0: failed to assign [mem size 0x00004000 64bit] > > > > > > This eventually prevents the PCIe NVME drive from being accessible. > > > > > > On x86 we already skip the check for producer/window due to some history > > > with negligent firmware. It seems that Microsoft is intent on continuing > > > that history on their ARM devices, so let's drop that check here too. > > > > > > Signed-off-by: Maximilian Luz > > > --- > > > > > > Please note: I am not sure if this is the right way to fix that, e.g. I > > > don't know if any additional checks like on IA64 or x86 might be > > > required instead, or if this might break things on other devices. So > > > please consider this more as a bug report rather than a fix. > > > > > > Apologies for the re-send, I seem to have unintentionally added a blank > > > line before the subject. > > > > > > --- > > > arch/arm64/kernel/pci.c | 14 -------------- > > > 1 file changed, 14 deletions(-) > > > > Adding Lorenzo to cc, as he'll have a much better idea about this than me. > > > > This is: > > > > https://lore.kernel.org/r/20210510234020.1330087-1-luzmaximilian@gmail.com > > Sigh. We can't apply this patch since it would trigger regressions on > other platforms (IIUC the root complex registers would end up in the > host bridge memory windows). > > I am not keen on reverting commit 8fd4391ee717 because it does the > right thing. > > I think this requires a quirk and immediate reporting to Microsoft. > > Bjorn, what are your thoughts on this ? In retrospect, I think 8fd4391ee717 (which I wrote), was probably a mistake. Sure, it's a nice idea to have PNP0A03 _CRS methods that work nicely as designed, by describing host bridge registers as "consumer" resources and host bridge windows as "producer" registers, instead of having the bridge registers in _CRS of an unrelated PNP0C02 device. But realistically, the PNP0A03/PNP0C02 issue is a solved problem, even though it's ugly, and I'm not sure why I thought Microsoft would see value in doing this differently on arm64 than on x86 and ia64. What would break if we reverted 8fd4391ee717? I guess any arm64 platforms that described host bridge register space in PNP0A03 _CRS "consumer" resources? And Windows probably doesn't work or isn't supported on those platforms? Bjorn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel