(Somehow I can't find the original in my inbox, so replying here). The correct helper to use is is_ioremap_addr, as in the generic iounmap implementation. This won't matter for x86 currently, but it clearly documents what the code is doing. More long term, but I really hate how x86 is not using more of the generic ioremap code. kmsan_iounmap_page_range should really move to generic_iounmap, as should memtype_free after adding a properly stubbed out API for it. With that x86 iounmap would just contain a hook for the magic ISA region, the mmio trace call and then call into generic_ioremap and we'd get rid of these open coded checks.
