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

From: Ingo Molnar <mingo@kernel.org>
To: "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, Matt Fleming <matt.fleming@intel.com>,
	fu.wei@linaro.org, al.stone@linaro.org, bp@alien8.de,
	tony.luck@gmail.com, ying.huang@intel.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3 1/4] x86: acpi: define uncached page flag
Date: Fri, 12 Jun 2015 09:52:44 +0200	[thread overview]
Message-ID: <20150612075244.GB8759@gmail.com> (raw)
In-Reply-To: <1434047160-23358-2-git-send-email-zjzhang@codeaurora.org>

* 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