[PATCH 0/2] RFC: Move efi bgrt code out of arch/x86

[Ard Biesheuvel]

On 16 February 2017 at 04:34, Bhupesh Sharma <bhsharma at redhat.com> wrote:
> Hi Ard, Rafael
>
> On Thu, Feb 16, 2017 at 5:14 AM, Rafael J. Wysocki <rjw at rjwysocki.net> wrote:
>> On Wednesday, February 15, 2017 05:44:28 PM Ard Biesheuvel wrote:
>>> Hello Bhupesh,
>>>
>>> On 15 February 2017 at 13:04, Bhupesh Sharma <bhsharma at redhat.com> wrote:
>>> > This patchset presents a RFC approach to move the ACPI BGRT table
>>> > handling related code out of 'arch/x86' and place it inside
>>> > 'drivers/firmware/efi' so that it can be used to support
>>> > ACPI BGRT table and BGRT logo across x86 and AARCH64 ARCHs.
>>> >
>>> > Note that this patchset is primarily tested on Qemu VMs for x86_64
>>> > and AARCH64 environments, while I try to get my hands on a real
>>> > AARCH64 hardware which supports a graphic card and whose boot firmware
>>> > I can modify to support the ACPI BGRT table to be passed to the kernel.
>>> >
>>> > Here are some details/outputs about/from the test environment:
>>> >
>>> > AARCH64:
>>> > ========
>>> > 1. I used the latest Qemu (master branch) and compiled it for aarch64 with softmmu support.
>>> >    Here is the command line I use to launch the same:
>>> >
>>> > # qemu-system-aarch64 -cpu cortex-a57 -M virt -m 2048 -bios QEMU_EFI.fd -kernel Image -initrd rootfs.cpio -serial stdio --append "acpi=force" -device virtio-gpu-pci
>>> >
>>> > where, QEMU_EFI.fd is the DEBUG build of EDK2 ArmVirtQemu.dsc (master branch)
>>> >        rootfs.cpio is the AARCH64 build of Buildroot (Little Endian AARCH64)
>>> >        -device virtio-gpu-pci provides the Graphical support required to have BGRT logo.
>>> >
>>> >
>>> > 2. Here are some test results once Linux boots up, which show a valid BGRT table/logo being
>>> >    seen by the kernel:
>>> >
>>> > # acpidump
>>> > ...
>>> >
>>> > BGRT @ 0x0000000000000000
>>> >   0000: 42 47 52 54 38 00 00 00 01 B4 49 4E 54 45 4C 20  BGRT8.....INTEL
>>> >   0010: 45 44 4B 32 20 20 20 20 02 00 00 00 20 20 20 20  EDK2    ....
>>> >   0020: 13 00 00 01 01 00 01 00 00 80 B0 BA 00 00 00 00  ................
>>> >   0030: 2F 01 00 00 0F 01 00 00                          /.......
>>> >
>>> > # dmesg | grep -i BGRT
>>> > [    0.000000] ACPI: BGRT 0x00000000B8640000 000038 (v01 INTEL  EDK2     00000002      01000013)
>>> >
>>> >
>>> > # ls -lah /sys/firmware/acpi/bgrt/image
>>> > -r--r--r--    1 root     root       32.9K Feb 15 11:27 /sys/firmware/acpi/bgrt/image
>>> >
>>> > x86:
>>> > ====
>>> > 1. I used the latest Qemu (master branch) and compiled it for x86.
>>> >    Here is the command line I use to launch the same:
>>> >
>>> > # qemu-system-x86_64 -enable-kvm -sdl -m 2048 -vga std -boot c -cpu host -bios OVMF_CODE.fd -kernel bzImage -initrd rootfs.cpio -serial stdio
>>> >
>>> > where, OVMF_CODE.fd is the RELEASE build of EDK2 OvmfPkg (master branch)
>>> >        rootfs.cpio is the x86_64 build of Buildroot
>>> >
>>> > 2. Similar test results are seen as noted for the AARCH64 case above, which show a valid BGRT table/logo being
>>> >    seen by the kernel.
>>> >
>>> > Cc: Ard Biesheuvel <ard.biesheuvel at linaro.org>
>>> > Cc: Ingo Molnar <mingo at kernel.org>
>>> > Cc: Matt Fleming <matt at codeblueprint.co.uk>
>>> > Cc: Dan Williams <dan.j.williams at intel.com>
>>> > Cc: Dave Young <dyoung at redhat.com>
>>> > Cc: Thomas Gleixner <tglx at linutronix.de>
>>> > Cc: Mark Rutland <mark.rutland at arm.com>
>>> > Cc: Will Deacon <will.deacon at arm.com>
>>> >
>>> > Bhupesh Sharma (2):
>>> >   x86/efi-bgrt: Move efi-bgrt handling out of arch/x86
>>> >   bgrt: Make ACPI BGRT parsing code common for ARCHs
>>> >
>>> >  arch/arm64/kernel/acpi.c                               | 3 +++
>>> >  arch/x86/kernel/acpi/boot.c                            | 6 ------
>>> >  arch/x86/platform/efi/Makefile                         | 1 -
>>> >  drivers/acpi/Kconfig                                   | 2 +-
>>> >  drivers/acpi/bgrt.c                                    | 6 ++++++
>>> >  drivers/firmware/efi/Makefile                          | 1 +
>>> >  {arch/x86/platform => drivers/firmware}/efi/efi-bgrt.c | 0
>>> >  include/linux/efi-bgrt.h                               | 2 ++
>>> >  8 files changed, 13 insertions(+), 8 deletions(-)
>>> >  rename {arch/x86/platform => drivers/firmware}/efi/efi-bgrt.c (100%)
>>> >
>>>
>>> These patches look fine to me, and I think we should be able to merge
>>> them without any changes.
>>>
>>> Reviewed-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
>>>
>>> You only failed to cc the ACPI maintainers, please add Len and Rafael next time.
>
> Oops. Will take care in future.
>
>> No worries.
>>
>> The changes are fine by me.
>>
>

Thanks Rafael

I will queue these for v4.12 in efi/next

-- 
Ard.