From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Wed, 29 Oct 2025 16:37:21 +0000 (-0400)
Subject: mm/userfaultfd: Create page_shift uffd_ops
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ffb79ebf2ca995d6ffd229ba313d1aac69f1d90d;p=users%2Fjedix%2Flinux-maple.git

mm/userfaultfd: Create page_shift uffd_ops

Page shift differs for hugetlb, so modularize the caller.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 6f919008bdde..dbf5f7072899 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -116,6 +116,7 @@ struct uffd_info {
 }
 
 /* VMA userfaultfd operations */
+unsigned int uffd_page_shift(struct vm_area_struct *vma);
 int uffd_writeprotect(struct uffd_info *info);
 ssize_t uffd_failed_do_unlock(struct userfaultfd_ctx *ctx,
 		struct vm_area_struct *dst, struct folio *folio,
@@ -134,6 +135,7 @@ struct vm_uffd_ops {
 	ssize_t (*failed_do_unlock)(struct userfaultfd_ctx *ctx,
 			struct vm_area_struct *dst, struct folio *folio,
 			unsigned long src_addr);
+	unsigned int (*page_shift)(struct vm_area_struct *src_vma);
 };
 
 #define MFILL_ATOMIC_MODE_BITS (const_ilog2(NR_MFILL_ATOMIC_MODES - 1) + 1)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 0cf9c6907468..a725d6ba554e 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5529,6 +5529,11 @@ static ssize_t hugetlb_failed_do_unlock(struct userfaultfd_ctx *ctx,
 	return copy_folio_from_user(folio,(const void __user *)src_addr, true);
 }
 
+static inline unsigned int hugetlb_page_shift(struct vm_area_struct *vma)
+{
+	return huge_page_shift(hstate_vma(vma));
+}
+
 static int hugetlb_mfill_pte_poison(struct uffd_info *info);
 static int hugetlb_mfill_pte_continue(struct uffd_info *info);
 static int hugetlb_mfill_atomic_pte_copy(struct uffd_info *info);
@@ -5543,6 +5548,7 @@ static const struct vm_uffd_ops hugetlb_uffd_ops = {
 	.is_dst_valid		=	hugetlb_is_dst_valid,
 	.increment		=	hugetlb_mfill_size,
 	.failed_do_unlock	=	hugetlb_failed_do_unlock,
+	.page_shift		=	hugetlb_page_shift,
 };
 #endif
 
diff --git a/mm/shmem.c b/mm/shmem.c
index 3ddf7f42e1fa..55d2bb73f8c6 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -5277,6 +5277,7 @@ static const struct vm_uffd_ops shmem_uffd_ops = {
 	.is_dst_valid		=	shmem_is_dst_valid,
 	.increment		=	mfill_size,
 	.failed_do_unlock	=	uffd_failed_do_unlock,
+	.page_shift		=	uffd_page_shift,
 };
 #endif
 
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 2b77fe81f122..7614fe039887 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -479,8 +479,14 @@ static const struct vm_uffd_ops default_uffd_ops = {
 	.is_dst_valid		= uffd_def_is_dst_valid,
 	.increment		= mfill_size,
 	.failed_do_unlock	= uffd_failed_do_unlock,
+	.page_shift		= uffd_page_shift,
 };
 
+unsigned int uffd_page_shift(struct vm_area_struct *vma)
+{
+	return PAGE_SHIFT;
+}
+
 static inline const struct vm_uffd_ops *vma_get_uffd_ops(struct vm_area_struct *vma)
 {
 	if (vma->vm_ops && vma->vm_ops->userfaultfd_ops)
@@ -998,8 +1004,13 @@ static long move_present_ptes(struct mm_struct *mm,
 	}
 
 	arch_leave_lazy_mmu_mode();
-	if (src_addr > src_start)
-		flush_tlb_range(src_vma, src_start, src_addr);
+	if (src_addr > src_start) {
+		unsigned int shift;
+		const struct vm_uffd_ops *uffd_ops = vma_get_uffd_ops(src_vma);
+
+		shift = uffd_ops->page_shift(src_vma);
+		flush_tlb_mm_range(mm, src_start, src_addr, shift, true);
+	}
 
 	if (src_folio)
 		folio_unlock(src_folio);