[U-Boot] [PATCH] x86: make the LAPIC / IOAPIC construct switchable with Kconfig

[Bin Meng]

On Tue, Oct 23, 2018 at 3:03 AM Hannes Schmelzer <oe5hpm at oevsv.at> wrote:
>
> There are still systems running which do not have any LAPIC or even
> IOAPIC, furthermore the MSRs for that aren't existing and the systems

nits: furthermore -> Furthermore. aren't existing -> don't exist

> are crashing on trying setup LAPIC.
>
> So this commit makes the APIC stuff able to switch off for those boards
> which dont' have a LAPIC / IOAPIC.
>
> Signed-off-by: Hannes Schmelzer <oe5hpm at oevsv.at>
> ---
>
>  arch/x86/Kconfig              | 9 +++++++++
>  arch/x86/cpu/Makefile         | 2 +-
>  arch/x86/cpu/i386/interrupt.c | 3 ++-
>  3 files changed, 12 insertions(+), 2 deletions(-)
>

Reviewed-by: Bin Meng <bmeng.cn at gmail.com>

and please see comments below.

> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index a1c18d2..00b69c6 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -736,6 +736,15 @@ config I8259_PIC
>           slave) interrupt controllers. Include this to have U-Boot set up
>           the interrupt correctly.
>
> +config APIC
> +       bool
> +       default y
> +       help
> +         The (A)dvanced (P)rogrammable (I)nterrupt (C)ontroller is responsible
> +         for catching interrupts and distributing them to one one more CPU

one one? I think you wanted to say: one more ...

> +         cores. In most cases there is some LAPIC (local) for each core and one
> +         I/O APIC. This conjunction is found on most modern x86 systems.
> +
>  config PINCTRL_ICH6
>         bool
>         help
> diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
> index f862d8c..54668aa 100644
> --- a/arch/x86/cpu/Makefile
> +++ b/arch/x86/cpu/Makefile
> @@ -35,7 +35,7 @@ obj-$(CONFIG_NORTHBRIDGE_INTEL_IVYBRIDGE) += ivybridge/
>  obj-$(CONFIG_INTEL_QUARK) += quark/
>  obj-$(CONFIG_INTEL_QUEENSBAY) += queensbay/
>  obj-$(CONFIG_INTEL_TANGIER) += tangier/
> -obj-y += lapic.o ioapic.o
> +obj-$(CONFIG_APIC) += lapic.o ioapic.o
>  obj-y += irq.o
>  ifndef CONFIG_$(SPL_)X86_64
>  obj-$(CONFIG_SMP) += mp_init.o
> diff --git a/arch/x86/cpu/i386/interrupt.c b/arch/x86/cpu/i386/interrupt.c
> index ed8423e..2744e2e 100644
> --- a/arch/x86/cpu/i386/interrupt.c
> +++ b/arch/x86/cpu/i386/interrupt.c
> @@ -264,8 +264,9 @@ int interrupt_init(void)
>         i8259_init();
>  #endif
>
> +#ifdef CONFIG_APIC
>         lapic_setup();
> -
> +#endif

Please keep the blank line here and only add the #ifdefs

>         /* Initialize core interrupt and exception functionality of CPU */
>         cpu_init_interrupts();
>

Regards,
Bin