mm/vma: remove duplicative vma_pgoff_offset() helper

This is doing what linear_page_index() does, so eliminate it and replace it
with linear_page_index().

Update the VMA userland tests to reflect this change.

No functional change intended.

Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-20-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Ackerley Tng <ackerleytng@google.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Kai Huang <kai.huang@intel.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: SJ Park <sj@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 17 insertions, 8 deletions

diff --git a/mm/vma.h b/mm/vma.h
index 527716c8739d..2342516ce00e 100644
--- a/mm/vma.h
+++ b/mm/vma.h
@@ -247,13 +247,6 @@ static inline pgoff_t vmg_end_pgoff(const struct vma_merge_struct *vmg)
 	return vmg_start_pgoff(vmg) + vmg_pages(vmg);
 }
 
-/* Assumes addr >= vma->vm_start. */
-static inline pgoff_t vma_pgoff_offset(struct vm_area_struct *vma,
-				       unsigned long addr)
-{
-	return vma->vm_pgoff + PHYS_PFN(addr - vma->vm_start);
-}
-
 #define VMG_STATE(name, mm_, vmi_, start_, end_, vma_flags_, pgoff_)	\
 	struct vma_merge_struct name = {				\
 		.mm = mm_,						\
@@ -275,7 +268,7 @@ static inline pgoff_t vma_pgoff_offset(struct vm_area_struct *vma,
 		.start = start_,				\
 		.end = end_,					\
 		.vm_flags = vma_->vm_flags,			\
-		.pgoff = vma_pgoff_offset(vma_, start_),	\
+		.pgoff = linear_page_index(vma_, start_),	\
 		.file = vma_->vm_file,				\
 		.anon_vma = vma_->anon_vma,			\
 		.policy = vma_policy(vma_),			\
diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h
index 535747d7fee4..7ed165c8d9bc 100644
--- a/tools/testing/vma/include/dup.h
+++ b/tools/testing/vma/include/dup.h
@@ -1548,3 +1548,19 @@ static inline pgprot_t vma_get_page_prot(vma_flags_t vma_flags)
 
 	return vm_get_page_prot(vm_flags);
 }
+
+static inline pgoff_t linear_page_delta(const struct vm_area_struct *vma,
+					const unsigned long address)
+{
+	return (address - vma->vm_start) >> PAGE_SHIFT;
+}
+
+static inline pgoff_t linear_page_index(const struct vm_area_struct *vma,
+					const unsigned long address)
+{
+	pgoff_t pgoff;
+
+	pgoff = linear_page_delta(vma, address);
+	pgoff += vma_start_pgoff(vma);
+	return pgoff;
+}