soc/intel/meteorlake: Enable `DEFAULT_X2APIC_LATE_WORKAROUND`

This patch ensures Intel Meteor Lake can enable the X2APIC feature.

While debugging Intel Meteor Lake (MTL) based platforms it seems like
enabling `DEFAULT_X2APIC` runs into a hang while coreboot tries to
bring the application processors (APs) from reset using X2APIC mode.

[INFO ] LAPIC 0x10 switched to X2APIC mode.
...
[DEBUG] Attempting to start 3 APs
[DEBUG] Waiting for 10ms after sending INIT.
[DEBUG] Waiting for SIPI to complete...
[DEBUG] done.
[DEBUG] Waiting for SIPI to complete...
[DEBUG] done.
[ERROR] Not all APs checked in: 0/3.
[DEBUG] 0/3 eventually checked in?
[ERROR] MP initialization failure.
[ERROR] MP initialization failure.

Note: The AP bring up flow between XAPIC and X2APIC are the same
except the way to access those LAPIC registers. X2APIC expects to
access all LAPIC registers using MSR (base with 0x800).

The correct flow to enable X2APIC on MTL would be as follows:
1. Let BSP bring all APs in XAPIC mode.

[INFO ]  LAPIC 0x10 in XAPIC mode.
...
[DEBUG]  Attempting to start 3 APs
[DEBUG]  Waiting for 10ms after sending INIT.
[DEBUG]  Waiting for SIPI to complete...
[DEBUG]  done.
[DEBUG]  Waiting for SIPI to complete...
[DEBUG]  done.
[INFO ]  LAPIC 0x11 in XAPIC mode.
[INFO ]  LAPIC 0x0 in XAPIC mode.
[INFO ]  LAPIC 0x80 in XAPIC mode.

2. Call enable_x2apic() function on all CPUs (BSP and APs)

And at the end of #2 above, all cores will now switch to X2APIC
from XAPIC.

[INFO ]  Initializing CPU #0
[DEBUG]  CPU: vendor Intel device a06a0
[DEBUG]  Clearing out pending MCEs
[INFO ]  LAPIC 0x10 switched to X2APIC mode.
...
[INFO ]  CPU #0 initialized
[INFO ]  Initializing CPU #1
[DEBUG]  CPU: vendor Intel device a06a0
[DEBUG]  Clearing out pending MCEs
[INFO ]  LAPIC 0x11 switched to X2APIC mode.

Note: Intel MTL FSP also follow the same steps for x2APIC enablement
while coreboot selects USE_INTEL_FSP_MP_INIT config instead
MP_SERVICES_PPI_V2.

BUG=b:219061518, b:219053812
TEST=Able to perform coreboot doing AP init with
DEFAULT_X2APIC_LATE_WORKAROUND config enabled without running into
any hang issue.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: Ie9c8fad6c46b15b5b08c9cc4ef53f2a6872bd0ea
Reviewed-on: https://review.coreboot.org/c/coreboot/+/65741
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2 files changed
tree: 3b0c4130f4a7f043e6e973fb08abd0b4d62e70e1
  1. 3rdparty/
  2. configs/
  3. Documentation/
  4. LICENSES/
  5. payloads/
  6. spd/
  7. src/
  8. tests/
  9. util/
  10. .checkpatch.conf
  11. .clang-format
  12. .editorconfig
  13. .gitignore
  14. .gitmodules
  15. .gitreview
  16. .mailmap
  17. AUTHORS
  18. COPYING
  19. gnat.adc
  20. MAINTAINERS
  21. Makefile
  22. Makefile.inc
  23. README.md
  24. toolchain.inc
README.md

coreboot README

coreboot is a Free Software project aimed at replacing the proprietary BIOS (firmware) found in most computers. coreboot performs a little bit of hardware initialization and then executes additional boot logic, called a payload.

With the separation of hardware initialization and later boot logic, coreboot can scale from specialized applications that run directly firmware, run operating systems in flash, load custom bootloaders, or implement firmware standards, like PC BIOS services or UEFI. This allows for systems to only include the features necessary in the target application, reducing the amount of code and flash space required.

coreboot was formerly known as LinuxBIOS.

Payloads

After the basic initialization of the hardware has been performed, any desired "payload" can be started by coreboot.

See https://www.coreboot.org/Payloads for a list of supported payloads.

Supported Hardware

coreboot supports a wide range of chipsets, devices, and mainboards.

For details please consult:

Build Requirements

  • make
  • gcc / g++ Because Linux distribution compilers tend to use lots of patches. coreboot does lots of "unusual" things in its build system, some of which break due to those patches, sometimes by gcc aborting, sometimes - and that's worse - by generating broken object code. Two options: use our toolchain (eg. make crosstools-i386) or enable the ANY_TOOLCHAIN Kconfig option if you're feeling lucky (no support in this case).
  • iasl (for targets with ACPI support)
  • pkg-config
  • libssl-dev (openssl)

Optional:

  • gdb (for better debugging facilities on some targets)
  • ncurses (for make menuconfig and make nconfig)
  • flex and bison (for regenerating parsers)

Building coreboot

Please consult https://www.coreboot.org/Build_HOWTO for details.

Testing coreboot Without Modifying Your Hardware

If you want to test coreboot without any risks before you really decide to use it on your hardware, you can use the QEMU system emulator to run coreboot virtually in QEMU.

Please see https://www.coreboot.org/QEMU for details.

Website and Mailing List

Further details on the project, a FAQ, many HOWTOs, news, development guidelines and more can be found on the coreboot website:

https://www.coreboot.org

You can contact us directly on the coreboot mailing list:

https://www.coreboot.org/Mailinglist

Copyright and License

The copyright on coreboot is owned by quite a large number of individual developers and companies. Please check the individual source files for details.

coreboot is licensed under the terms of the GNU General Public License (GPL). Some files are licensed under the "GPL (version 2, or any later version)", and some files are licensed under the "GPL, version 2". For some parts, which were derived from other projects, other (GPL-compatible) licenses may apply. Please check the individual source files for details.

This makes the resulting coreboot images licensed under the GPL, version 2.