[RFC PATCH 2/8] arch/s390: Teach arch_get_unmapped_area{_topdown} to handle hugetlb mappings

[Oscar Salvador <osalvador@suse.de>]

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.
s390 specific hugetlb function does not set info.align_offset, so do
the same here for compatibility.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 arch/s390/mm/mmap.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index 206756946589..e98c00df586f 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -73,6 +73,8 @@ static inline unsigned long mmap_base(unsigned long rnd,
 
 static int get_align_mask(struct file *filp, unsigned long flags)
 {
+	if (filp && is_file_hugepages(filp))
+		return huge_page_mask_align(filp);
 	if (!(current->flags & PF_RANDOMIZE))
 		return 0;
 	if (filp || (flags & MAP_SHARED))
@@ -106,7 +108,8 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 	info.low_limit = mm->mmap_base;
 	info.high_limit = TASK_SIZE;
 	info.align_mask = get_align_mask(filp, flags);
-	info.align_offset = pgoff << PAGE_SHIFT;
+	if (!(file && is_file_hugepages(filp))
+		info.align_offset = pgoff << PAGE_SHIFT;
 	addr = vm_unmapped_area(&info);
 	if (offset_in_page(addr))
 		return addr;
@@ -144,7 +147,8 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long ad
 	info.low_limit = PAGE_SIZE;
 	info.high_limit = mm->mmap_base;
 	info.align_mask = get_align_mask(filp, flags);
-	info.align_offset = pgoff << PAGE_SHIFT;
+	if (!(file && is_file_hugepages(filp))
+		info.align_offset = pgoff << PAGE_SHIFT;
 	addr = vm_unmapped_area(&info);
 
 	/*
-- 
2.45.2