Merge remote-tracking branch 'lsk/v3.10/topic/earlycon' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / mm / util.c

diff --git a/mm/util.c b/mm/util.c
index 3704bf1bef9409ee1b48c8ae8867b1383b6a41f2..ab1424dbe2e6c9396ee66ab4446f1bc1cd557382 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -5,6 +5,8 @@
 #include <linux/err.h>
 #include <linux/sched.h>
 #include <linux/security.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
 #include <asm/uaccess.h>
 
 #include "internal.h"
@@ -382,6 +384,24 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
 }
 EXPORT_SYMBOL(vm_mmap);
 
+struct address_space *page_mapping(struct page *page)
+{
+       struct address_space *mapping = page->mapping;
+
+       VM_BUG_ON(PageSlab(page));
+#ifdef CONFIG_SWAP
+       if (unlikely(PageSwapCache(page))) {
+               swp_entry_t entry;
+
+               entry.val = page_private(page);
+               mapping = swap_address_space(entry);
+       } else
+#endif
+       if ((unsigned long)mapping & PAGE_MAPPING_ANON)
+               mapping = NULL;
+       return mapping;
+}
+
 /* Tracepoints definitions. */
 EXPORT_TRACEPOINT_SYMBOL(kmalloc);
 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);