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

From: Rafael J. Wysocki
Date: Wed Feb 15 2017 - 18:50:10 EST


On Wednesday, February 15, 2017 05:44:28 PM Ard Biesheuvel wrote:
> Hello Bhupesh,
>
> On 15 February 2017 at 13:04, Bhupesh Sharma <bhsharma@xxxxxxxxxx> 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@xxxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> > Cc: Dave Young <dyoung@xxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: Mark Rutland <mark.rutland@xxxxxxx>
> > Cc: Will Deacon <will.deacon@xxxxxxx>
> >
> > 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@xxxxxxxxxx>
>
> You only failed to cc the ACPI maintainers, please add Len and Rafael next time.

No worries.

The changes are fine by me.

Thanks,
Rafael