ANDROID: dma-buf: heaps: export defer-free list size

For memory analysis, need to know all memory-consuming of dma-buf heaps.
But now, other modules can't get defer-free list size.

Export get_freelist_nr_pages to let other modules can get
defer-free list total size.

Bug: 192041645

Change-Id: Icaa1b98e9ab7e330141a92ad147a4e2150c2534b
Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com>

drivers/dma-buf/heaps/deferred-free-helper.c

@@ -62,7 +62,7 @@ static size_t free_one_item(enum df_reason reason)
 	return nr_pages;
 }
 
-static unsigned long get_freelist_nr_pages(void)
+unsigned long get_freelist_nr_pages(void)
 {
 	unsigned long nr_pages;
 	unsigned long flags;
@@ -72,6 +72,7 @@ static unsigned long get_freelist_nr_pages(void)
 	spin_unlock_irqrestore(&free_list_lock, flags);
 	return nr_pages;
 }
+EXPORT_SYMBOL_GPL(get_freelist_nr_pages);
 
 static unsigned long freelist_shrink_count(struct shrinker *shrinker,
 					   struct shrink_control *sc)

drivers/dma-buf/heaps/deferred-free-helper.h

@@ -52,4 +52,6 @@ void deferred_free(struct deferred_freelist_item *item,
 		   void (*free)(struct deferred_freelist_item *i,
 				enum df_reason reason),
 		   size_t nr_pages);
+
+unsigned long get_freelist_nr_pages(void);
 #endif