Messages in this thread | | | Date | Tue, 10 Jan 2023 15:38:27 -0500 | Subject | Re: [PATCH 0/2] PCI: Fix extended config space regression | From | "Liang, Kan" <> |
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On 2023-01-10 1:02 p.m., Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelgaas@google.com> > > 07eab0901ede ("efi/x86: Remove EfiMemoryMappedIO from E820 map") appeared > in v6.2-rc1 and broke extended config space on several machines. > > This broke drivers that use things in extended config space, e.g., perf, > VSEC telemetry, EDAC, QAT, etc. > > This happened because mmconfig-shared.c checks to see that ECAM space is > reserved in E820 or ACPI motherboard resources. If it's not, it assumes > ECAM doesn't work. 07eab0901ede removed some E820 entries, so it looked > like ECAM was no longer reserved, so we stopped using it. > > The machines where this broke don't reserve the ECAM in ACPI PNP0C02 > devices (which seems to be what the PCI Firmware spec requires), but they > do mention it in the EFI memory map as EfiMemoryMappedIO. > > Bjorn Helgaas (2): > x86/pci: Simplify is_mmconf_reserved() messages > x86/pci: Treat EfiMemoryMappedIO as reservation of ECAM space >
This patch series fixes the issue on my machine.
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Thanks, Kan
> arch/x86/pci/mmconfig-shared.c | 44 +++++++++++++++++++++++++++++----- > 1 file changed, 38 insertions(+), 6 deletions(-) >
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