From 4b1d3145c1045d4b0db4622cd2c224a247f25a20 Mon Sep 17 00:00:00 2001 From: Alistair Popple Date: Thu, 19 Jun 2025 18:57:56 +1000 Subject: mm: convert vmf_insert_mixed() from using pte_devmap to pte_special MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit DAX no longer requires device PTEs as it always has a ZONE_DEVICE page associated with the PTE that can be reference counted normally. Other users of pte_devmap are drivers that set PFN_DEV when calling vmf_insert_mixed() which ensures vm_normal_page() returns NULL for these entries. There is no reason to distinguish these pte_devmap users so in order to free up a PTE bit use pte_special instead for entries created with vmf_insert_mixed(). This will ensure vm_normal_page() will continue to return NULL for these pages. Architectures that don't support pte_special also don't support pte_devmap so those will continue to rely on pfn_valid() to determine if the page can be mapped. Link: https://lkml.kernel.org/r/93086bd446e7bf8e4c85345613ac18f706b01f60.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple Reviewed-by: Jason Gunthorpe Reviewed-by: Dan Williams Cc: Balbir Singh Cc: Björn Töpel Cc: Björn Töpel Cc: Christoph Hellwig Cc: Chunyan Zhang Cc: David Hildenbrand Cc: Deepak Gupta Cc: Gerald Schaefer Cc: Inki Dae Cc: John Groves Cc: John Hubbard Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Will Deacon Signed-off-by: Andrew Morton --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index 56d540b8a1d0..6698fadf5d04 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3425,7 +3425,7 @@ static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned if (!pte_present(pte) || is_zero_pfn(pfn)) return -1; - if (WARN_ON_ONCE(pte_devmap(pte) || pte_special(pte))) + if (WARN_ON_ONCE(pte_special(pte))) return -1; if (!pte_young(pte) && !mm_has_notifiers(vma->vm_mm)) -- cgit v1.2.3