From 843e1be108b9130e5ec5a78a14f77dc237c83e1e Mon Sep 17 00:00:00 2001
From: Miaohe Lin <linmiaohe@huawei.com>
Date: Tue, 4 May 2021 18:37:13 -0700
Subject: [PATCH] mm/migrate.c: use helper migrate_vma_collect_skip() in
 migrate_vma_collect_hole()

It's more recommended to use helper function migrate_vma_collect_skip() to
skip the unexpected case and it also helps remove some duplicated codes.
Move migrate_vma_collect_skip() above migrate_vma_collect_hole() to avoid
compiler warning.

Link: https://lkml.kernel.org/r/20210325131524.48181-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/migrate.c | 50 ++++++++++++++++++++++----------------------------
 1 file changed, 22 insertions(+), 28 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index c40075d48ef9..6876696ab302 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2290,34 +2290,6 @@ out:
 #endif /* CONFIG_NUMA */
 
 #ifdef CONFIG_DEVICE_PRIVATE
-static int migrate_vma_collect_hole(unsigned long start,
-				    unsigned long end,
-				    __always_unused int depth,
-				    struct mm_walk *walk)
-{
-	struct migrate_vma *migrate = walk->private;
-	unsigned long addr;
-
-	/* Only allow populating anonymous memory. */
-	if (!vma_is_anonymous(walk->vma)) {
-		for (addr = start; addr < end; addr += PAGE_SIZE) {
-			migrate->src[migrate->npages] = 0;
-			migrate->dst[migrate->npages] = 0;
-			migrate->npages++;
-		}
-		return 0;
-	}
-
-	for (addr = start; addr < end; addr += PAGE_SIZE) {
-		migrate->src[migrate->npages] = MIGRATE_PFN_MIGRATE;
-		migrate->dst[migrate->npages] = 0;
-		migrate->npages++;
-		migrate->cpages++;
-	}
-
-	return 0;
-}
-
 static int migrate_vma_collect_skip(unsigned long start,
 				    unsigned long end,
 				    struct mm_walk *walk)
@@ -2333,6 +2305,28 @@ static int migrate_vma_collect_skip(unsigned long start,
 	return 0;
 }
 
+static int migrate_vma_collect_hole(unsigned long start,
+				    unsigned long end,
+				    __always_unused int depth,
+				    struct mm_walk *walk)
+{
+	struct migrate_vma *migrate = walk->private;
+	unsigned long addr;
+
+	/* Only allow populating anonymous memory. */
+	if (!vma_is_anonymous(walk->vma))
+		return migrate_vma_collect_skip(start, end, walk);
+
+	for (addr = start; addr < end; addr += PAGE_SIZE) {
+		migrate->src[migrate->npages] = MIGRATE_PFN_MIGRATE;
+		migrate->dst[migrate->npages] = 0;
+		migrate->npages++;
+		migrate->cpages++;
+	}
+
+	return 0;
+}
+
 static int migrate_vma_collect_pmd(pmd_t *pmdp,
 				   unsigned long start,
 				   unsigned long end,