RE: [patch 08/20] genirq/msi: Make MSI descriptor iterators device domain aware

Thomas Gleixner
2022-11-18T12:17:25Z

On Fri, Nov 18 2022 at 07:57, Kevin Tian wrote:
>> From: Thomas Gleixner <tglx@linutronix.de>
>> Sent: Friday, November 11, 2022 9:57 PM
>>
>> +/* Invalid XA index which is outside of any searchable range */
>> +#define MSI_XA_MAX_INDEX (ULONG_MAX - 1)
>> +#define MSI_XA_DOMAIN_SIZE (MSI_MAX_INDEX + 1)
>> +
>
> Out of curiosity. Other places treat MSI_MAX_INDEX - 1 as the upper
> bound of a valid range. This size definition here implies that the last ID
> is wasted for every domain. Is it intended?

Bah. MSI_MAX_INDEX is inclusive so the size must be + 1. I obviously
missed that in the other places which use it as upper bound.

Not that it matters, but yes. Let me fix that.