Re: [PATCH v2 1/5] iommu/amd: Simplify build_inv_address()

[Jason Gunthorpe <jgg@nvidia.com>]

On Mon, Apr 06, 2026 at 09:18:19PM +0800, Wei Wang wrote:

> > -	msb_diff = fls64(end ^ address) - 1;
> > +	if (unlikely(sz_lg2 > 52))
> > +		return (CMD_INV_IOMMU_ALL_PAGES_ADDRESS & PAGE_MASK) |
> > +		       CMD_INV_IOMMU_PAGES_SIZE_MASK;

I was looking at Ankit's series and thinking this is slightly better as:

+	if (unlikely(sz_lg2 > min(52, BITS_PER_LONG - 1)))

So a ULONG_MAX gather will trigger full invalidation on 32 bit as
well, though it shouldn't be necessary it seems a tish cleaner and
matches how vt-d ended up

It is probably too late for this cycle, I'll repost it after the merge
window.

Thanks,
Jason