Re: [PATCH V3 1/4] x86: acpi: define uncached page flag

Ingo Molnar
2015-06-12T07:52:51Z

* Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org> wrote:

> From: "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org>
>
> This definition is used in APEI code when needing to map pages as
> uncached.
>
> Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
> ---
> arch/x86/include/asm/acpi.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
> index 3a45668f6dc3..6afb27682b00 100644
> --- a/arch/x86/include/asm/acpi.h
> +++ b/arch/x86/include/asm/acpi.h
> @@ -138,6 +138,10 @@ static inline void disable_acpi(void) { }
>
> #endif /* !CONFIG_ACPI */
>
> +#ifdef CONFIG_ACPI_APEI
> +#define ARCH_APEI_PAGE_KERNEL_UC (PAGE_KERNEL_NOCACHE)
> +#endif /*CONFIG_ACPI_APEI */

- Why the tab?

- Why the parentheses?

- Why the closing comment block for a oneliner define? It's not like we forget
what it's about.

- When the missing space in the closing comment?

That's 4 uglies in 3 lines of code, wow ...

Thanks,

Ingo