[PATCH v2 07/17] mm/sparse-vmemmap: move vmemmap_get_tail() before PTE population

[Muchun Song]

A follow-up change will call vmemmap_get_tail() from
vmemmap_pte_populate(). Move it before the PTE population helpers to
avoid adding a forward declaration.

Move vmemmap_alloc_block_zero() with it because vmemmap_get_tail()
depends on that helper. No functional change is intended.

Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
 mm/sparse-vmemmap.c | 78 +++++++++++++++++++++++----------------------
 1 file changed, 40 insertions(+), 38 deletions(-)

diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index b7abc5494bb9..b770fe2428fd 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -148,6 +148,46 @@ void __meminit vmemmap_verify(pte_t *pte, int node,
 			start, end - 1);
 }
 
+static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node)
+{
+	void *p = vmemmap_alloc_block(size, node);
+
+	if (!p)
+		return NULL;
+	memset(p, 0, size);
+
+	return p;
+}
+
+#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
+static __meminit struct page *vmemmap_get_tail(unsigned int order, struct zone *zone)
+{
+	struct page *p, *tail;
+	unsigned int idx;
+	int node = zone_to_nid(zone);
+
+	if (WARN_ON_ONCE(order < VMEMMAP_OPTIMIZATION_MIN_ORDER))
+		return NULL;
+	if (WARN_ON_ONCE(order > MAX_FOLIO_ORDER))
+		return NULL;
+
+	idx = order - VMEMMAP_OPTIMIZATION_MIN_ORDER;
+	tail = zone->vmemmap_tails[idx];
+	if (tail)
+		return tail;
+	p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
+	if (!p)
+		return NULL;
+	for (int i = 0; i < PAGE_SIZE / sizeof(struct page); i++)
+		init_compound_tail(p + i, NULL, order, zone);
+
+	tail = virt_to_page(p);
+	zone->vmemmap_tails[idx] = tail;
+
+	return tail;
+}
+#endif
+
 static pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
 				       struct vmem_altmap *altmap,
 				       unsigned long ptpfn, unsigned long flags)
@@ -181,17 +221,6 @@ static pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, in
 	return pte;
 }
 
-static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node)
-{
-	void *p = vmemmap_alloc_block(size, node);
-
-	if (!p)
-		return NULL;
-	memset(p, 0, size);
-
-	return p;
-}
-
 static pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
 {
 	pmd_t *pmd = pmd_offset(pud, addr);
@@ -323,33 +352,6 @@ void vmemmap_wrprotect_hvo(unsigned long addr, unsigned long end,
 }
 
 #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
-static __meminit struct page *vmemmap_get_tail(unsigned int order, struct zone *zone)
-{
-	struct page *p, *tail;
-	unsigned int idx;
-	int node = zone_to_nid(zone);
-
-	if (WARN_ON_ONCE(order < VMEMMAP_OPTIMIZATION_MIN_ORDER))
-		return NULL;
-	if (WARN_ON_ONCE(order > MAX_FOLIO_ORDER))
-		return NULL;
-
-	idx = order - VMEMMAP_OPTIMIZATION_MIN_ORDER;
-	tail = zone->vmemmap_tails[idx];
-	if (tail)
-		return tail;
-	p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
-	if (!p)
-		return NULL;
-	for (int i = 0; i < PAGE_SIZE / sizeof(struct page); i++)
-		init_compound_tail(p + i, NULL, order, zone);
-
-	tail = virt_to_page(p);
-	zone->vmemmap_tails[idx] = tail;
-
-	return tail;
-}
-
 int __meminit vmemmap_populate_hvo(unsigned long addr, unsigned long end,
 				       unsigned int order, struct zone *zone,
 				       unsigned long headsize)
-- 
2.54.0