[PATCH 3/5] mm: Rename __thp_get_unmapped_area to mm_get_unmapped_area_aligned

[Peter Xu <peterx@redhat.com>]

This function is pretty handy for any type of VMA to provide a size-aligned
VMA address when mmap().  Rename the function and export it.

About the rename:

  - Dropping "THP" because it doesn't really have much to do with THP
    internally.

  - The suffix "_aligned" imply it is a helper to generate aligned virtual
    address based on what is specified (which can be not PMD_SIZE).

Cc: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Barry Song <baohua@kernel.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 include/linux/huge_mm.h | 14 +++++++++++++-
 mm/huge_memory.c        |  6 ++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 2f190c90192d..706488d92bb6 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -339,7 +339,10 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
 unsigned long thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags,
 		vm_flags_t vm_flags);
-
+unsigned long mm_get_unmapped_area_aligned(struct file *filp,
+		unsigned long addr, unsigned long len,
+		loff_t off, unsigned long flags, unsigned long size,
+		vm_flags_t vm_flags);
 bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins);
 int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
 		unsigned int new_order);
@@ -543,6 +546,15 @@ thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
 	return 0;
 }
 
+static inline unsigned long
+mm_get_unmapped_area_aligned(struct file *filp,
+			     unsigned long addr, unsigned long len,
+			     loff_t off, unsigned long flags, unsigned long size,
+			     vm_flags_t vm_flags)
+{
+	return 0;
+}
+
 static inline bool
 can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
 {
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 4734de1dc0ae..52f13a70562f 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1088,7 +1088,7 @@ static inline bool is_transparent_hugepage(const struct folio *folio)
 		folio_test_large_rmappable(folio);
 }
 
-static unsigned long __thp_get_unmapped_area(struct file *filp,
+unsigned long mm_get_unmapped_area_aligned(struct file *filp,
 		unsigned long addr, unsigned long len,
 		loff_t off, unsigned long flags, unsigned long size,
 		vm_flags_t vm_flags)
@@ -1132,6 +1132,7 @@ static unsigned long __thp_get_unmapped_area(struct file *filp,
 	ret += off_sub;
 	return ret;
 }
+EXPORT_SYMBOL_GPL(mm_get_unmapped_area_aligned);
 
 unsigned long thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags,
@@ -1140,7 +1141,8 @@ unsigned long thp_get_unmapped_area_vmflags(struct file *filp, unsigned long add
 	unsigned long ret;
 	loff_t off = (loff_t)pgoff << PAGE_SHIFT;
 
-	ret = __thp_get_unmapped_area(filp, addr, len, off, flags, PMD_SIZE, vm_flags);
+	ret = mm_get_unmapped_area_aligned(filp, addr, len, off, flags,
+					   PMD_SIZE, vm_flags);
 	if (ret)
 		return ret;
 
-- 
2.49.0