quoted

quoted

quoted

If high bits are used for
something else, then we might produce a garbage PTE on overflow, but that
shouldn't really matter I concluded for folio_pte_batch() purposes, we'd not
detect "belongs to this folio batch" either way.

Exactly.

quoted

Maybe it's likely cleaner to also have a custom pte_next_pfn() on ppc, I just
hope that we don't lose any other arbitrary PTE bits by doing the pte_pgprot().

I don't see the need for ppc to implement pte_next_pfn().

Agreed.

So likely we should then do on top for powerpc (whitespace damage):

diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index a04ae4449a025..549a440ed7f65 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c

@@ -220,10 +220,7 @@ void set_ptes(struct mm_struct *mm, unsigned long addr,

pte_t *ptep,
                        break;
                ptep++;
                addr += PAGE_SIZE;
-               /*
-                * increment the pfn.
-                */
-               pte = pfn_pte(pte_pfn(pte) + 1, pte_pgprot((pte)));
+               pte = pte_next_pfn(pte);
        }
 }