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Bjorn Helgaas 199f968f14 x86/pci: Skip early E820 check for ECAM region 
Arul, Mateusz, Imcarneiro91, and Aman reported a regression caused by
07eab0901e ("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, 946f2ee5c7 ("[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 946f2ee5c7, 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: 07eab0901e ("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
History 2024-05-16 14:35:08 -05:00
arch x86/pci: Skip early E820 check for ECAM region 2024-05-16 14:35:08 -05:00
block vfs-6.9-rc1.fixes 2024-03-18 09:15:50 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
Documentation Documentation: PCI: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY 2024-04-25 12:53:29 -05:00
drivers PCI: Remove unused pci_enable_device_io() 2024-05-16 14:35:08 -05:00
fs A patch to minimize blockage when processing very large batches of 2024-03-22 11:15:45 -07:00
include PCI: Remove unused pci_enable_device_io() 2024-05-16 14:35:08 -05:00
init RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
io_uring io_uring/sqpoll: early exit thread if task_context wasn't allocated 2024-03-18 20:22:42 -06:00
ipc sysctl changes for v6.9-rc1 2024-03-18 14:59:13 -07:00
kernel dma-mapping fixes for Linux 6.9 2024-03-24 10:45:31 -07:00
lib hardening fixes for v6.9-rc1 2024-03-23 08:43:21 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
net Including fixes from CAN, netfilter, wireguard and IPsec. 2024-03-21 14:50:39 -07:00
rust Kbuild updates for v6.9 2024-03-21 14:41:00 -07:00
samples Tracing updates for 6.9: 2024-03-18 15:11:44 -07:00
scripts LoongArch changes for v6.9 2024-03-22 10:22:45 -07:00
security - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min 2024-03-14 18:03:09 -07:00
sound ASoC: Intel: avs: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY 2024-04-25 12:53:29 -05:00
tools RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM Xen and pfncache changes for 6.9: 2024-03-11 10:42:55 -04:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap Char/Misc and other driver subsystem updates for 6.9-rc1 2024-03-21 13:21:31 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Not a ton of stuff happening in the clk framework in this pull request. We got 2024-03-15 11:48:01 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
Makefile Linux 6.9-rc1 2024-03-24 14:10:05 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.