Re: [PATCH v3 4/4] x86/APIC: make connections between seemingly arbitrary numbers

["Roger Pau Monné" <roger.pau@citrix.com>]

On Mon, Feb 14, 2022 at 10:25:57AM +0100, Jan Beulich wrote:
> Making adjustments to arbitrarily chosen values shouldn't require
> auditing the code for possible derived numbers - such a change should
> be doable in a single place, having an effect on all code depending on
> that choice.
> 
> For one make the TDCR write actually use APIC_DIVISOR. With the
> necessary mask constant introduced, also use that in vLAPIC code. While
> introducing the constant, drop APIC_TDR_DIV_TMBASE: The bit has been
> undefined in halfway recent SDM and PM versions.
> 
> And then introduce a constant tying together the scale used when
> converting nanoseconds to bus clocks.
> 
> No functional change intended.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

> ---
> I thought we have a generic "glue" macro, but I couldn't find one. Hence
> I'm (ab)using _AC().

I would be fine if you want to introduce something right in this
commit to cover those needs, using _AC is not overly nice (or
clear) IMO.

Thanks, Roger.