[RFC PATCH 5/8] arch/powerpc: Teach book3s64 arch_get_unmapped_area{_topdown} to handle hugetlb mappings

[Oscar Salvador <osalvador@xxxxxxx>]

We want to stop special casing hugetlb mappings and make them go
through generic channels, so teach arch_get_unmapped_area{_topdown}
to handle those.
Reshuffle file_to_psize() definition so arch_get_unmapped_area{_topdown}
can make use of it.

Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
---
 arch/powerpc/mm/book3s64/slice.c | 39 ++++++++++++++++++++++++--------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/slice.c b/arch/powerpc/mm/book3s64/slice.c
index ef3ce37f1bb3..6914b8de627c 100644
--- a/arch/powerpc/mm/book3s64/slice.c
+++ b/arch/powerpc/mm/book3s64/slice.c
@@ -633,17 +633,36 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 }
 EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
 
+#ifdef CONFIG_HUGETLB_PAGE
+static int file_to_psize(struct file *file)
+{
+	struct hstate *hstate = hstate_file(file);
+	return shift_to_mmu_psize(huge_page_shift(hstate));
+}
+#else
+static int file_to_psize(struct file *file)
+{
+	return 0;
+}
+#endif
+
 unsigned long arch_get_unmapped_area(struct file *filp,
 				     unsigned long addr,
 				     unsigned long len,
 				     unsigned long pgoff,
 				     unsigned long flags)
 {
+	unsigned int psize;
+
 	if (radix_enabled())
 		return generic_get_unmapped_area(filp, addr, len, pgoff, flags);
 
-	return slice_get_unmapped_area(addr, len, flags,
-				       mm_ctx_user_psize(&current->mm->context), 0);
+	if (filp && is_file_hugepages(filp))
+		psize = file_to_psize(filp);
+	else
+		psize = mm_ctx_user_psize(&current->mm->context);
+
+	return slice_get_unmapped_area(addr, len, flags, psize, 0);
 }
 
 unsigned long arch_get_unmapped_area_topdown(struct file *filp,
@@ -652,11 +671,17 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 					     const unsigned long pgoff,
 					     const unsigned long flags)
 {
+	unsigned int psize;
+
 	if (radix_enabled())
 		return generic_get_unmapped_area_topdown(filp, addr0, len, pgoff, flags);
 
-	return slice_get_unmapped_area(addr0, len, flags,
-				       mm_ctx_user_psize(&current->mm->context), 1);
+	if (filp && is_file_hugepages(filp))
+		psize = file_to_psize(filp);
+	else
+		psize = mm_ctx_user_psize(&current->mm->context);
+
+	return slice_get_unmapped_area(addr0, len, flags, psize, 1);
 }
 
 unsigned int notrace get_slice_psize(struct mm_struct *mm, unsigned long addr)
@@ -787,12 +812,6 @@ unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
 	return 1UL << mmu_psize_to_shift(get_slice_psize(vma->vm_mm, vma->vm_start));
 }
 
-static int file_to_psize(struct file *file)
-{
-	struct hstate *hstate = hstate_file(file);
-	return shift_to_mmu_psize(huge_page_shift(hstate));
-}
-
 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 					unsigned long len, unsigned long pgoff,
 					unsigned long flags)
-- 
2.45.2