6.6-stable review patch. If anyone has any objections, please let me know.
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From: Bjorn Helgaas bhelgaas@google.com
commit 199f968f1484a14024d0d467211ffc2faf193eb4 upstream.
Arul, Mateusz, Imcarneiro91, and Aman reported a regression caused by 07eab0901ede ("efi/x86: Remove EfiMemoryMappedIO from E820 map"). On the Lenovo Legion 9i laptop, that commit removes the ECAM area from E820, which means the early E820 validation fails, which means we don't enable ECAM in the "early MCFG" path.
The static MCFG table describes ECAM without depending on the ACPI interpreter. Many Legion 9i ACPI methods rely on that, so they fail when PCI config access isn't available, resulting in the embedded controller, PS/2, audio, trackpad, and battery devices not being detected. The _OSC method also fails, so Linux can't take control of the PCIe hotplug, PME, and AER features:
# pci_mmcfg_early_init()
PCI: ECAM [mem 0xc0000000-0xce0fffff] (base 0xc0000000) for domain 0000 [bus 00-e0] PCI: not using ECAM ([mem 0xc0000000-0xce0fffff] not reserved)
ACPI Error: AE_ERROR, Returned by Handler for [PCI_Config] (20230628/evregion-300) ACPI: Interpreter enabled ACPI: Ignoring error and continuing table load ACPI BIOS Error (bug): Could not resolve symbol [_SB.PC00.RP01._SB.PC00], AE_NOT_FOUND (20230628/dswload2-162) ACPI Error: AE_NOT_FOUND, During name lookup/catalog (20230628/psobject-220) ACPI: Skipping parse of AML opcode: OpcodeName unavailable (0x0010) ACPI BIOS Error (bug): Could not resolve symbol [_SB.PC00.RP01._SB.PC00], AE_NOT_FOUND (20230628/dswload2-162) ACPI Error: AE_NOT_FOUND, During name lookup/catalog (20230628/psobject-220) ... ACPI Error: Aborting method _SB.PC00._OSC due to previous error (AE_NOT_FOUND) (20230628/psparse-529) acpi PNP0A08:00: _OSC: platform retains control of PCIe features (AE_NOT_FOUND)
# pci_mmcfg_late_init()
PCI: ECAM [mem 0xc0000000-0xce0fffff] (base 0xc0000000) for domain 0000 [bus 00-e0] PCI: [Firmware Info]: ECAM [mem 0xc0000000-0xce0fffff] not reserved in ACPI motherboard resources PCI: ECAM [mem 0xc0000000-0xce0fffff] is EfiMemoryMappedIO; assuming valid PCI: ECAM [mem 0xc0000000-0xce0fffff] reserved to work around lack of ACPI motherboard _CRS
Per PCI Firmware r3.3, sec 4.1.2, ECAM space must be reserved by a PNP0C02 resource, but there's no requirement to mention it in E820, so we shouldn't look at E820 to validate the ECAM space described by MCFG.
In 2006, 946f2ee5c731 ("[PATCH] i386/x86-64: Check that MCFG points to an e820 reserved area") added a sanity check of E820 to work around buggy MCFG tables, but that over-aggressive validation causes failures like this one.
Keep the E820 validation check for machines older than 2016, an arbitrary ten years after 946f2ee5c731, so machines that depend on it don't break.
Skip the early E820 check for 2016 and newer BIOSes since there's no requirement to describe ECAM in E820.
Link: https://lore.kernel.org/r/20240417204012.215030-2-helgaas@kernel.org Fixes: 07eab0901ede ("efi/x86: Remove EfiMemoryMappedIO from E820 map") Reported-by: Mateusz Kaduk mateusz.kaduk@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218444 Signed-off-by: Bjorn Helgaas bhelgaas@google.com Tested-by: Mateusz Kaduk mateusz.kaduk@gmail.com Reviewed-by: Andy Shevchenko andy@kernel.org Reviewed-by: Hans de Goede hdegoede@redhat.com Reviewed-by: Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/pci/mmconfig-shared.c | 40 +++++++++++++++++++++++++++++----------- 1 file changed, 29 insertions(+), 11 deletions(-)
--- a/arch/x86/pci/mmconfig-shared.c +++ b/arch/x86/pci/mmconfig-shared.c @@ -527,7 +527,34 @@ pci_mmcfg_check_reserved(struct device * { struct resource *conflict;
- if (!early && !acpi_disabled) { + if (early) { + + /* + * Don't try to do this check unless configuration type 1 + * is available. How about type 2? + */ + + /* + * 946f2ee5c731 ("Check that MCFG points to an e820 + * reserved area") added this E820 check in 2006 to work + * around BIOS defects. + * + * Per PCI Firmware r3.3, sec 4.1.2, ECAM space must be + * reserved by a PNP0C02 resource, but it need not be + * mentioned in E820. Before the ACPI interpreter is + * available, we can't check for PNP0C02 resources, so + * there's no reliable way to verify the region in this + * early check. Keep it only for the old machines that + * motivated 946f2ee5c731. + */ + if (dmi_get_bios_year() < 2016 && raw_pci_ops) + return is_mmconf_reserved(e820__mapped_all, cfg, dev, + "E820 entry"); + + return true; + } + + if (!acpi_disabled) { if (is_mmconf_reserved(is_acpi_reserved, cfg, dev, "ACPI motherboard resource")) return true; @@ -563,16 +590,7 @@ pci_mmcfg_check_reserved(struct device * * For MCFG information constructed from hotpluggable host bridge's * _CBA method, just assume it's reserved. */ - if (pci_mmcfg_running_state) - return true; - - /* Don't try to do this check unless configuration - type 1 is available. how about type 2 ?*/ - if (raw_pci_ops) - return is_mmconf_reserved(e820__mapped_all, cfg, dev, - "E820 entry"); - - return false; + return pci_mmcfg_running_state; }
static void __init pci_mmcfg_reject_broken(int early)