On Tue, Aug 19, 2025 at 09:45:02AM +0530, Upadhyay, Neeraj wrote:
> Maybe change it to below?
>
> /*
> * Valid APIC_IRR/SAVIC_ALLOWED_IRR registers are at 16 bytes strides
> * from their respective base offset.
> */
>
> if (WARN_ONCE(!(IS_ALIGNED(reg - APIC_IRR, 16) ||
> IS_ALIGNED(reg - SAVIC_ALLOWED_IRR, 16)),
> "Misaligned APIC_IRR/ALLOWED_IRR APIC register read offset
> 0x%x",
> reg))
Let's beef that up some more with a crystal-clear explanation what is going on
here so that readers don't have to stop and stare for 5 mins before they grok
what this is doing:
/*
* Valid APIC_IRR/SAVIC_ALLOWED_IRR registers are at 16 bytes strides from
* their respective base offset. APIC_IRRs are in the range
*
* (0x200, 0x210, ..., 0x270)
*
* while the SAVIC_ALLOWED_IRR range starts 4 bytes later, in the rangea
*
* (0x204, 0x214, ..., 0x274).
*
* Filter out everything else.
*/
if (WARN_ONCE(!(IS_ALIGNED(reg, 16) ||
IS_ALIGNED(reg - 4, 16)),
"Misaligned APIC_IRR/ALLOWED_IRR APIC register read offset 0x%x", reg));
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
