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From:   WANG Wenhu <wenhu.wang@vivo.com>
To:     Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Cc:     wenhu.pku@gmail.com, WANG Wenhu <wenhu.wang@vivo.com>
Subject: [PATCH] mm: clarify a confusing comment of remap_pfn_range
Date:   Tue, 10 Mar 2020 00:39:54 -0700
Message-Id: <20200310073955.43415-1-wenhu.wang@vivo.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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

The parameter pfn actually referes 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>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index e8bfdf0d9d1d..583f84519870 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1939,7 +1939,7 @@ 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
  *
-- 
2.17.1