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Message-ID: <20231109184405.GA488882@bhelgaas>
Date: Thu, 9 Nov 2023 12:44:05 -0600
From: Bjorn Helgaas <helgaas@...nel.org>
To: Tomasz Pala <gotar@...anet.pl>
Cc: linux-pci@...r.kernel.org,
Dan J Williams <dan.j.williams@...el.com>,
Kan Liang <kan.liang@...ux.intel.com>,
Tony Luck <tony.luck@...el.com>,
David E Box <david.e.box@...el.com>,
Yunying Sun <yunying.sun@...el.com>,
Dave Jiang <dave.jiang@...el.com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
Giovanni Cabiddu <giovanni.cabiddu@...el.com>,
Herbert Xu <herbert@...dor.apana.org.au>,
Hans de Goede <hdegoede@...hat.com>,
Florent DELAHAYE <linuxkernelml@...ead.fr>,
Konrad J Hambrick <kjhambrick@...il.com>,
Matt Hansen <2lprbe78@...k.com>,
Nicholas Johnson <nicholas.johnson-opensource@...look.com.au>,
Benoit Grégoire <benoitg@...us.ca>,
Werner Sembach <wse@...edocomputers.com>,
mumblingdrunkard@...tonmail.com, linux-kernel@...r.kernel.org,
Bjorn Helgaas <bhelgaas@...gle.com>,
Sebastian Manciulea <manciuleas@...tonmail.com>
Subject: Re: [PATCH 2/2] x86/pci: Treat EfiMemoryMappedIO as reservation of
ECAM space
[+cc Sebastian]
On Fri, Nov 03, 2023 at 02:18:58PM -0500, Bjorn Helgaas wrote:
> On Thu, Oct 26, 2023 at 03:53:19PM -0500, Bjorn Helgaas wrote:
> > On Thu, Oct 12, 2023 at 05:33:47PM +0200, Tomasz Pala wrote:
> > > On Tue, Jan 10, 2023 at 12:02:43 -0600, Bjorn Helgaas wrote:
> > > > Normally we reject ECAM space unless it is reported as
> > > > reserved in the E820 table or via a PNP0C02 _CRS method (PCI
> > > > Firmware, r3.3, sec 4.1.2). This means PCI extended config
> > > > space (offsets 0x100-0xfff) may not be accessible.
> > > >
> > > > Some firmware doesn't report ECAM space via PNP0C02 _CRS
> > > > methods, but does mention it as an EfiMemoryMappedIO region
> > > > via EFI GetMemoryMap(), which is normally converted to an E820
> > > > entry by a bootloader or EFI stub.
> > > >
> > > > 07eab0901ede ("efi/x86: Remove EfiMemoryMappedIO from E820
> > > > map"), removes E820 entries that correspond to
> > > > EfiMemoryMappedIO regions because some other firmware uses
> > > > EfiMemoryMappedIO for PCI host bridge windows, and the E820
> > > > entries prevent Linux from allocating BAR space for hot-added
> > > > devices.
> > > >
> > > > Allow use of ECAM for extended config space when the region is
> > > > covered by an EfiMemoryMappedIO region, even if it's not
> > > > included in E820 or PNP0C02 _CRS.
> > >
> > > I'm still having a problem initializing ixgbe NICs with pristine
> > > 6.5.7 kernel.
> >
> > Thanks very much for the report, and sorry for the inconvenience and
> > my delay in looking at it.
> >
> > > efi: Remove mem63: MMIO range=[0x80000000-0x8fffffff] (256MB) from e820 map
> > > [mem 0x7f800000-0xfed1bfff] available for PCI devices
> > > PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000)
> > > [Firmware Info]: PCI: MMCONFIG at [mem 0x80000000-0x8fffffff] not reserved in ACPI motherboard resources
> > > PCI: MMCONFIG at [mem 0x80000000-0x8fffffff] reserved as EfiMemoryMappedIO
> > > ixgbe 0000:02:00.0: enabling device (0140 -> 0142)
> > > ixgbe 0000:02:00.0: BAR 0: can't reserve [mem 0x80000000-0x8007ffff 64bit]
> > > ixgbe 0000:02:00.0: pci_request_selected_regions failed 0xfffffff0
> > > ixgbe: probe of 0000:02:00.0 failed with error -16
> >
> > Something is wrong with our allocation scheme. Both the MMCONFIG
> > region and the ixgbe BAR 0 are at 0x80000000, which obviously cannot
> > work. Maybe the full dmesg log will have a clue about why we didn't
> > move ixgbe out of the way.
> >
> > > After disabling the code causing this (using always-false condition:
> > > if (size >= 256*1024 && 0) {
> > > ) in the chunk:
> > >
> > > https://lore.kernel.org/lkml/20221208190341.1560157-2-helgaas@kernel.org/
> > >
> > > the BAR starts at 0x90000000 (not 0x80000000):
> > >
> > > efi: Not removing mem63: MMIO range=[0x80000000-0x8fffffff] (262144KB) from e820 map
> > > [...]
> > > [mem 0x90000000-0xfed1bfff] available for PCI devices
> > > [...]
> > > PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000)
> > > PCI: MMCONFIG at [mem 0x80000000-0x8fffffff] reserved as E820 entry
> > >
> > > and everything seems to work again.
> > >
> > >
> > > I've got full system bootup logs from the upstream and worked around,
> > > but I'm not sure if this is OK to attach them (the CC list is long).
> >
> > Would you mind opening a new report at https://bugzilla.kernel.org,
> > attaching those logs, and responding here with the URL?
>
> Thanks for the report and the logs, which are attached at
> https://bugzilla.kernel.org/show_bug.cgi?id=218050
>
> I think the problem is that the MMCONFIG region is at
> [mem 0x80000000-0x8fffffff], and that is *also* included in one of the
> host bridge windows reported via _CRS:
>
> PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000)
> pci_bus 0000:00: root bus resource [mem 0x80000000-0xfbffffff window]
>
> I'll try to figure out how to deal with that. In the meantime, would
> you mind attaching the contents of /proc/iomem to the bugzilla? I
> think you have to cat it as root to get the actual values included.
I attached a debug patch to both bugzilla entries. If you could
attach the "acpidump" output and (if practical) boot a kernel with the
debug patch and attach the dmesg logs, that would be great.
Bjorn
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