Re: [PATCH] powerpc/mm: Use pte_advance_pfn() in set_huge_pte_at()
From: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Date: 2025-12-18 18:30:17
Hi Andrew, Le 18/12/2025 à 17:21, Andrew Donnellan a écrit :
quoted hunk ↗ jump to hunk
In set_huge_pte_at(), replace the existing open coded pte value calculation with the new helper pte_advance_pfn(). Signed-off-by: Andrew Donnellan <redacted> --- arch/powerpc/mm/pgtable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index 56d7e8960e77d877390d6bcbf0d8a305cc222101..9073e373e1e8a88f904cae592e1e8c34707545e6 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c@@ -365,7 +365,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, for (i = 0; i < sz / pdsize; i++, ptep++, addr += pdsize) { __set_pte_at(mm, addr, ptep, pte, 0); - pte = __pte(pte_val(pte) + ((unsigned long long)pdsize / PAGE_SIZE << PFN_PTE_SHIFT)); + pte = pte_advance_pfn(pte, pdsize / PAGE_SIZE);
How can this work ? pdsize is 4M, PAGE_SIZE is 4k so pdsize/PAGE_SIZE is 0x400. PFN_PTE_SHIFT is 24. 0x400 << 24 is more than what an unsigned long can contain in pte_advance_pfn() Christophe
} } #endif --- base-commit: ea1013c1539270e372fc99854bc6e4d94eaeff66 change-id: 20251219-set_huge_pte_at_pte_advance_pfn-0ae18078fcca -- Andrew Donnellan OzLabs, ADL Canberra ajd@linux.ibm.com IBM Australia Limited