[PATCH] tmp

[David Hildenbrand (Arm)]

Signed-off-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
---
 include/linux/page_ext.h | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
index 61e876e255e8..468c074582e1 100644
--- a/include/linux/page_ext.h
+++ b/include/linux/page_ext.h
@@ -112,6 +112,7 @@ static inline struct page_ext *page_ext_next(struct page_ext *curr)
 
 struct page_ext_iter {
 	unsigned long index;
+	unsigned long pgcount;
 	unsigned long start_pfn;
 	struct page_ext *page_ext;
 };
@@ -120,15 +121,19 @@ struct page_ext_iter {
  * page_ext_iter_begin() - Prepare for iterating through page extensions.
  * @iter: page extension iterator.
  * @pfn: PFN of the page we're interested in.
+ * @pgcount: number of page_ext entries to iterate
  *
  * Must be called with RCU read lock taken.
  *
  * Return: NULL if no page_ext exists for this page.
  */
 static inline struct page_ext *page_ext_iter_begin(struct page_ext_iter *iter,
-						unsigned long pfn)
+		unsigned long pfn, unsigned long pgcount)
 {
+	VM_WARN_ON_ONCE(!pgcount);
+
 	iter->index = 0;
+	iter->pgcount = pgcount;
 	iter->start_pfn = pfn;
 	iter->page_ext = page_ext_lookup(pfn);
 
@@ -149,8 +154,9 @@ static inline struct page_ext *page_ext_iter_next(struct page_ext_iter *iter)
 
 	if (WARN_ON_ONCE(!iter->page_ext))
 		return NULL;
+	if (++iter->index >= iter->pgcount)
+		return NULL;
 
-	iter->index++;
 	pfn = iter->start_pfn + iter->index;
 
 	if (page_ext_iter_next_fast_possible(pfn))
@@ -183,9 +189,9 @@ static inline struct page_ext *page_ext_iter_get(const struct page_ext_iter *ite
  * IMPORTANT: must be called with RCU read lock taken.
  */
 #define for_each_page_ext(__page, __pgcount, __page_ext, __iter) \
-	for (__page_ext = page_ext_iter_begin(&__iter, page_to_pfn(__page));\
-		__page_ext && __iter.index < __pgcount;          \
-		__page_ext = page_ext_iter_next(&__iter))
+	for (__page_ext = page_ext_iter_begin(&__iter, page_to_pfn(__page), __pgcount);\
+	     __page_ext; \
+	     __page_ext = page_ext_iter_next(&__iter))
 
 #else /* !CONFIG_PAGE_EXTENSION */
 struct page_ext;
-- 
2.43.0


-- 
Cheers,

David