[PATCH 02/45] mm: Add {pmd,pud}_huge_lock helper

[Oscar Salvador <osalvador@suse.de>]

Deep down hugetlb and thp use the same lock for pud and pmd.
Create two helpers that can be directly used by both of them,
as they will be used in the generic pagewalkers.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 include/linux/mm_inline.h | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index f4fe593c1400..93e3eb86ef4e 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -9,6 +9,7 @@
 #include <linux/string.h>
 #include <linux/userfaultfd_k.h>
 #include <linux/swapops.h>
+#include <linux/hugetlb.h>
 
 /**
  * folio_is_file_lru - Should the folio be on a file LRU or anon LRU?
@@ -590,4 +591,30 @@ static inline bool vma_has_recency(struct vm_area_struct *vma)
 	return true;
 }
 
+static inline spinlock_t *pmd_huge_lock(pmd_t *pmd, struct vm_area_struct *vma)
+{
+	spinlock_t *ptl;
+
+	if (pmd_leaf(*pmd)) {
+		ptl = pmd_lock(vma->vm_mm, pmd);
+		if (pmd_leaf(*pmd))
+			return ptl;
+		spin_unlock(ptl);
+	}
+	return NULL;
+}
+
+static inline spinlock_t *pud_huge_lock(pud_t *pud, struct vm_area_struct *vma)
+{
+	spinlock_t *ptl = pud_lock(vma->vm_mm, pud);
+
+	if (pud_leaf(*pud)) {
+		ptl = pud_lock(vma->vm_mm, pud);
+		if (pud_leaf(*pud))
+			return ptl;
+		spin_unlock(ptl);
+	}
+	return NULL;
+}
+
 #endif
-- 
2.26.2