On Tue, Jan 23, 2024 at 10:34:21AM +0000, Ryan Roberts wrote: > > +#define PFN_PTE_SHIFT PAGE_SHIFT > > I think this is buggy. And so is the arm64 implementation of set_ptes(). It > works fine for 48-bit output address, but for 52-bit OAs, the high bits are not > kept contigously, so if you happen to be setting a mapping for which the > physical memory block straddles bit 48, this won't work. I'd like to see the folio allocation that can straddle bit 48 ... agreed, it's not workable _in general_, but specifically for a memory allocation from a power-of-two allocator, you'd have to do a 49-bit allocation (half a petabyte) to care.
