[PATCH 5.4.y 1/4] mm: clarify a confusing comment for remap_pfn_range()

[Harshvardhan Jha <harshvardhan.j.jha@oracle.com>]

From: WANG Wenhu <wenhu.wang@vivo.com>

commit 86a76331d94c4cfa72fe1831dbe4b492f66fdb81 upstream

It really made me scratch my head.  Replace the comment with an accurate
and consistent description.

The parameter pfn actually refers to the page frame number which is
right-shifted by PAGE_SHIFT from the physical address.

Signed-off-by: WANG Wenhu <wenhu.wang@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200310073955.43415-1-wenhu.wang@vivo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 86a76331d94c4cfa72fe1831dbe4b492f66fdb81)
Signed-off-by: Harshvardhan Jha <harshvardhan.j.jha@oracle.com>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index f8d76c66311df..238064ef73ae8 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1921,7 +1921,7 @@ static inline int remap_p4d_range(struct mm_struct *mm, pgd_t *pgd,
  * remap_pfn_range - remap kernel memory to userspace
  * @vma: user vma to map to
  * @addr: target user address to start at
- * @pfn: physical address of kernel memory
+ * @pfn: page frame number of kernel physical memory address
  * @size: size of map area
  * @prot: page protection flags for this mapping
  *
-- 
2.46.0