Re: [PATCH] x86: coco: mark cc_mask as __maybe_unused

Arnd Bergmann
2025-03-10T13:50:41Z

On Wed, Mar 5, 2025, at 11:44, Ingo Molnar wrote:
> * Arnd Bergmann <arnd@kernel.org> wrote:
>
>> @@ -25,7 +25,7 @@ u64 cc_mkdec(u64 val);
>> void cc_random_init(void);
>> #else
>> #define cc_vendor (CC_VENDOR_NONE)
>> -static const u64 cc_mask = 0;
>> +static const __maybe_unused u64 cc_mask = 0;
>
> So I detest __maybe_unused with a vengeance: the 'maybe' unnecessarily
> inserts uncertainty & probability language into the text, while there's
> nothing uncertain about this interface or the code. Why cannot the
> compiler figure it out?

Right, I'm also trying to remove a lot of the __maybe_unused
annotations in places like power management and device_id tables
where we now have better solutions in place.

> Anyway, I'd suggest we change direct usage of cc_mask to a
> get_cc_mask() inline function instead, this will resolve the warning,
> plus it avoids some messy looking variable shadowing in tdx.c AFAICS:
>
> arch/x86/coco/tdx/tdx.c:static void tdx_setup(u64 *cc_mask)

I've sent a v2 now.

Arnd