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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 8435AC47082 for ; Wed, 26 May 2021 15:38:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57965613D2 for ; Wed, 26 May 2021 15:38:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233940AbhEZPjc (ORCPT ); Wed, 26 May 2021 11:39:32 -0400 Received: from mail-oi1-f182.google.com ([209.85.167.182]:38484 "EHLO mail-oi1-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232762AbhEZPjb (ORCPT ); Wed, 26 May 2021 11:39:31 -0400 Received: by mail-oi1-f182.google.com with SMTP id z3so1898916oib.5; Wed, 26 May 2021 08:37:59 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=3V7OvaoqMXmN2vukgJxl15xdT6MPuq7Vv/XnykugDl0=; b=Ixl+rrbCuOqaBM/3ynm/e8404PMSqnGZPUM3/9XiKimW01tF6mPqS9Lt4KEYgmvAmG mQVh2RMkOhUYBKWhBrXojHkdtPTRO1VX0G3KjOiYYwPOZsXHjFD2vRY4HA9qRoMFRpC2 kv2CuEDJSRCnTS6itUxPlf7ScoqI7JmaSREqWWTcdeDMekUkIICAaC0d7Gy963qoUVS1 4lYuKCxzBEQ9rjwXBi9gFxH3ZjyoDypfUnnlSOgplPz7lUkurcRksILpBtzzE3mGyEr7 rBrCZYl+M8ByM1/IfwRYHsGbdDhI1azZvvtcty+ygn62baxwvW1JX5z0DidAJPQRajgb 9k/Q== X-Gm-Message-State: AOAM530UCdVbTEWOf0vl/KwqhVW7S53kB2UiYR2jI4KLafPaq65PBw99 LLQ46DpZjjwwNsg/IlehEQ== X-Google-Smtp-Source: ABdhPJw5rSamTwsWLcCBwAFrbj+IDR+9OhxFmsTMbUkCQ/CBncqAjYplNK5RkYmAlpnRkyX+oQljRA== X-Received: by 2002:aca:a9c6:: with SMTP id s189mr2414457oie.92.1622043479017; Wed, 26 May 2021 08:37:59 -0700 (PDT) Received: from robh.at.kernel.org (24-155-109-49.dyn.grandenetworks.net. [24.155.109.49]) by smtp.gmail.com with ESMTPSA id n11sm3881657oom.1.2021.05.26.08.37.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 May 2021 08:37:58 -0700 (PDT) Received: (nullmailer pid 2611152 invoked by uid 1000); Wed, 26 May 2021 15:37:57 -0000 Date: Wed, 26 May 2021 10:37:57 -0500 From: Rob Herring To: Ard Biesheuvel Cc: Punit Agrawal , Robin Murphy , Alexandru Elisei , Linux Kernel Mailing List , linux-rockchip@lists.infradead.org, arm-mail-list , Heiko Stuebner , leobras.c@gmail.com, PCI Subject: Re: [BUG] rockpro64: PCI BAR reassignment broken by commit 9d57e61bf723 ("of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses") Message-ID: <20210526153757.GA2467427@robh.at.kernel.org> References: <7a1e2ebc-f7d8-8431-d844-41a9c36a8911@arm.com> <01efd004-1c50-25ca-05e4-7e4ef96232e2@arm.com> <87eedxbtkn.fsf@stealth> <877djnaq11.fsf@stealth> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, May 25, 2021 at 03:54:30PM +0200, Ard Biesheuvel wrote: > On Tue, 25 May 2021 at 15:42, Punit Agrawal wrote: > > > > Hi Ard, > > > > Ard Biesheuvel writes: > > > > > On Sun, 23 May 2021 at 13:06, Punit Agrawal wrote: > > >> > > >> Robin Murphy writes: > > >> > > >> > [ +linux-pci for visibility ] > > >> > > > >> > On 2021-05-18 10:09, Alexandru Elisei wrote: > > >> >> After doing a git bisect I was able to trace the following error when booting my > > >> >> rockpro64 v2 (rk3399 SoC) with a PCIE NVME expansion card: > > >> >> [..] > > >> >> [ 0.305183] rockchip-pcie f8000000.pcie: host bridge /pcie@f8000000 ranges: > > >> >> [ 0.305248] rockchip-pcie f8000000.pcie: MEM 0x00fa000000..0x00fbdfffff -> > > >> >> 0x00fa000000 > > >> >> [ 0.305285] rockchip-pcie f8000000.pcie: IO 0x00fbe00000..0x00fbefffff -> > > >> >> 0x00fbe00000 > > >> >> [ 0.306201] rockchip-pcie f8000000.pcie: supply vpcie1v8 not found, using dummy > > >> >> regulator > > >> >> [ 0.306334] rockchip-pcie f8000000.pcie: supply vpcie0v9 not found, using dummy > > >> >> regulator > > >> >> [ 0.373705] rockchip-pcie f8000000.pcie: PCI host bridge to bus 0000:00 > > >> >> [ 0.373730] pci_bus 0000:00: root bus resource [bus 00-1f] > > >> >> [ 0.373751] pci_bus 0000:00: root bus resource [mem 0xfa000000-0xfbdfffff 64bit] > > >> >> [ 0.373777] pci_bus 0000:00: root bus resource [io 0x0000-0xfffff] (bus > > >> >> address [0xfbe00000-0xfbefffff]) > > >> >> [ 0.373839] pci 0000:00:00.0: [1d87:0100] type 01 class 0x060400 > > >> >> [ 0.373973] pci 0000:00:00.0: supports D1 > > >> >> [ 0.373992] pci 0000:00:00.0: PME# supported from D0 D1 D3hot > > >> >> [ 0.378518] pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), > > >> >> reconfiguring > > >> >> [ 0.378765] pci 0000:01:00.0: [144d:a808] type 00 class 0x010802 > > >> >> [ 0.378869] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x00003fff 64bit] > > >> >> [ 0.379051] pci 0000:01:00.0: Max Payload Size set to 256 (was 128, max 256) > > >> >> [ 0.379661] pci 0000:01:00.0: 8.000 Gb/s available PCIe bandwidth, limited by > > >> >> 2.5 GT/s PCIe x4 link at 0000:00:00.0 (capable of 31.504 Gb/s with 8.0 GT/s PCIe > > >> >> x4 link) > > >> >> [ 0.393269] pci_bus 0000:01: busn_res: [bus 01-1f] end is updated to 01 > > >> >> [ 0.393311] pci 0000:00:00.0: BAR 14: no space for [mem size 0x00100000] > > >> >> [ 0.393333] pci 0000:00:00.0: BAR 14: failed to assign [mem size 0x00100000] > > >> >> [ 0.393356] pci 0000:01:00.0: BAR 0: no space for [mem size 0x00004000 64bit] > > >> >> [ 0.393375] pci 0000:01:00.0: BAR 0: failed to assign [mem size 0x00004000 64bit] > > >> >> [ 0.393397] pci 0000:00:00.0: PCI bridge to [bus 01] > > >> >> [ 0.393839] pcieport 0000:00:00.0: PME: Signaling with IRQ 78 > > >> >> [ 0.394165] pcieport 0000:00:00.0: AER: enabled with IRQ 78 > > >> >> [..] > > >> >> to the commit 9d57e61bf723 ("of/pci: Add IORESOURCE_MEM_64 to > > >> >> resource flags for > > >> >> 64-bit memory addresses"). > > >> > > > >> > FWFW, my hunch is that the host bridge advertising no 32-bit memory > > >> > resource, only only a single 64-bit non-prefetchable one (even though > > >> > it's entirely below 4GB) might be a bit weird and tripping something > > >> > up in the resource assignment code. It certainly seems like the thing > > >> > most directly related to the offending commit. > > >> > > > >> > I'd be tempted to try fiddling with that in the DT (i.e. changing > > >> > 0x83000000 to 0x82000000 in the PCIe node's "ranges" property) to see > > >> > if it makes any difference. Note that even if it helps, though, I > > >> > don't know whether that's the correct fix or just a bodge around a > > >> > corner-case bug somewhere in the resource code. > > >> > > >> From digging into this further the failure seems to be due to a mismatch > > >> of flags when allocating resources in pci_bus_alloc_from_region() - > > >> > > >> if ((res->flags ^ r->flags) & type_mask) > > >> continue; > > >> > > >> Though I am also not sure why the failure is only being reported on > > >> RK3399 - does a single 64-bit window have anything to do with it? > > >> > > > > > > The NVMe in the example exposes a single 64-bit non-prefetchable BAR. > > > Such BARs can not be allocated in a prefetchable host bridge window > > > (unlike the converse, i.e., allocating a prefetchable BAR in a > > > non-prefetchable host bridge window is fine) > > > > > > 64-bit non-prefetchable host bridge windows cannot be forwarded by PCI > > > to PCI bridges, they simply lack the BAR registers to describe them. > > > Therefore, non-prefetchable endpoint BARs (even 64-bit ones) need to > > > be carved out of a host bridge's non-prefetchable 32-bit window if > > > they need to pass through a bridge. > > > > Thank you for the explanation. I also looked at the PCI-to-PCI Bridge > > spec to understand where some of the limitations are coming from. > > > > > So the error seems to be here that the host bridge's 32-bit > > > non-prefetchable window has the 64-bit attribute set, even though it > > > resides below 4 GB entirely. I suppose that the resource allocation > > > could be made more forgiving (and it was in the past, before commit > > > 9d57e61bf723 was applied). However, I would strongly recommend not > > > deviating from common practice, and just describe the 32-bit > > > addressable non-prefetchable resource window as such. > > > > IIUC, the host bridge's configuration (64-bit on non-prefetchable > > window) is based on what the hardware advertises. > > > > What do you mean by 'what the hardware advertises'? The host bridge is > apparently configured to decode a 32-bit addressable window as MMIO, > and the question is why this window has the 64-bit attribute set in > the DT description. > > > Can you elaborate on what you have in mind to correct the > > non-prefetchable resource window? Are you thinking of adding a quirk > > somewhere to address this? > > > > No. Just fix the DT. We can't only fix the DT as we shouldn't require a DT update due to a kernel change. Especially for RK3399 which is pretty stable and widely used. Do I understand correctly that 64-bit non-prefetchable never correct? We recently gained a warning for this in commit fede8526cc48 ("PCI: of: Warn if non-prefetchable memory aperture size is > 32-bit"), but that only looks at addresses, not the 64-bit flag. Can't we just not set the 64-bit flag if non-prefetchable? BTW, the DT schema is checking ranges hi cell: - 0x01000000 - 0x02000000 - 0x03000000 - 0x42000000 - 0x43000000 - 0x81000000 - 0x82000000 - 0x83000000 - 0xc2000000 - 0xc3000000 I just went with what I found in dts files. Sounds like 03 and 83 should be removed. (Really, bit 31 or relocatable should probably not be set either.) There's a number of other cases: Documentation/devicetree/bindings/numa.txt: ranges = <0x03000000 0x8010 0x00000000 0x8010 0x00000000 0x70 0x00000000>; Documentation/devicetree/bindings/numa.txt: ranges = <0x03000000 0x9010 0x00000000 0x9010 0x00000000 0x70 0x00000000>; Documentation/devicetree/bindings/pci/mediatek-pcie.txt- 0x83000000 0 0x60000000 0 0x60000000 0 0x10000000>; /* memory space */ Documentation/devicetree/bindings/pci/microchip,pcie-host.yaml: ranges = <0x03000000 0x0 0x78000000 0x0 0x78000000 0x0 0x04000000>; Documentation/devicetree/bindings/pci/mobiveil-pcie.txt: ranges = < 0x83000000 0 0x00000000 0xa8000000 0 0x8000000>; Documentation/devicetree/bindings/pci/rockchip-pcie-host.txt: ranges = <0x83000000 0x0 0xfa000000 0x0 0xfa000000 0x0 0x600000 arch/arm/boot/dts/mt7623.dtsi- 0x83000000 0 0x60000000 0 0x60000000 0 0x10000000>; arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi: ranges = <0x83000000 0 0x00000000 0 0x00000000 0 0x20000000>; arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi: ranges = <0x83000000 0 0x00000000 0 0x30000000 0 0x20000000>; arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi: ranges = <0x83000000 0 0x00000000 0 0x60000000 0 0x00c00000>; arch/arm64/boot/dts/broadcom/stingray/stingray-pcie.dtsi: ranges = <0x83000000 0 0x10000000 0 0x10000000 0 0x20000000>; arch/arm64/boot/dts/rockchip/rk3399.dtsi: ranges = <0x83000000 0x0 0xfa000000 0x0 0xfa000000 0x0 0x1e00000>, Rob