[PATCH 2/6] hugetlb: remove the hugetlb_linear_page_index() helper

[Jane Chu <jane.chu@oracle.com>]

hugetlb_linear_page_index() is just linear_page_index() converted from
base-page units to hugetlb page units.

Open-code that conversion at its remaining call site in
mfill_atomic_hugetlb() and drop the helper.

No functional change intended.

Signed-off-by: Jane Chu <jane.chu@oracle.com>
---
 include/linux/hugetlb.h | 17 -----------------
 mm/userfaultfd.c        |  3 ++-
 2 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index c64c6e5e50f5..71691a2b6855 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -792,23 +792,6 @@ static inline unsigned huge_page_shift(struct hstate *h)
 	return h->order + PAGE_SHIFT;
 }
 
-/**
- * hugetlb_linear_page_index() - linear_page_index() but in hugetlb
- *				 page size granularity.
- * @vma: the hugetlb VMA
- * @address: the virtual address within the VMA
- *
- * Return: the page offset within the mapping in huge page units.
- */
-static inline pgoff_t hugetlb_linear_page_index(struct vm_area_struct *vma,
-		unsigned long address)
-{
-	struct hstate *h = hstate_vma(vma);
-
-	return ((address - vma->vm_start) >> huge_page_shift(h)) +
-		(vma->vm_pgoff >> huge_page_order(h));
-}
-
 static inline bool order_is_gigantic(unsigned int order)
 {
 	return order > MAX_PAGE_ORDER;
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 2c565c7134b6..c053aa4389b6 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -573,7 +573,8 @@ static __always_inline ssize_t mfill_atomic_hugetlb(
 		 * in the case of shared pmds.  fault mutex prevents
 		 * races with other faulting threads.
 		 */
-		idx = hugetlb_linear_page_index(dst_vma, dst_addr);
+		idx = linear_page_index(dst_vma, dst_addr);
+		idx >>= huge_page_order(hstate_vma(dst_vma));
 		mapping = dst_vma->vm_file->f_mapping;
 		hash = hugetlb_fault_mutex_hash(mapping, idx);
 		mutex_lock(&hugetlb_fault_mutex_table[hash]);
-- 
2.43.5