Re: [PATCH v1 01/11] arm/pgtable: define PFN_PTE_SHIFT on arm and arm64

David Hildenbrand
2024-01-23T11:33:28Z

>>
>>> 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.
>>
>>>
>>> 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);
}
}

--
Cheers,

David / dhildenb