Re: [PATCH -v2 4/6] x86, RAS: Add function enabling direct writesto MCE MSRs

From: Joe Perches
Date: Tue Oct 16 2012 - 13:59:00 EST

On Tue, 2012-10-16 at 16:52 +0200, Borislav Petkov wrote:
> From: Borislav Petkov <borislav.petkov@xxxxxxx>
> Normally, writing to MCE MSRs causes a #GP. Add a function to enable
> direct accesses to those MSRs.
> diff --git a/arch/x86/ras/amd/mce-inject.c b/arch/x86/ras/amd/mce-inject.c

> @@ -55,6 +55,30 @@ DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n");
> +static int toggle_hw_mce_inject(unsigned int cpu, bool enable)
> + enable ? (l |= BIT(18)) : (l &= ~BIT(18));

This is very unusual style.
I found just one like it in the kernel tree.
(unnecessary parens here too btw)

This style is much more common:
if (enable)
l |= BIT(18);
l &= ~BIT(18);

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