From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Fri, 7 May 2021 14:55:27 +0000 (-0400)
Subject: mm: Add folio_pfn()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=bf6bd276b374d44f6e7146d52aa6097eb91384a3;p=linux.git

mm: Add folio_pfn()

This is the folio equivalent of page_to_pfn().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
---

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 04e41d4d85ea9..47143f3e7f0a4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1624,6 +1624,20 @@ static inline unsigned long page_to_section(const struct page *page)
 }
 #endif
 
+/**
+ * folio_pfn - Return the Page Frame Number of a folio.
+ * @folio: The folio.
+ *
+ * A folio may contain multiple pages.  The pages have consecutive
+ * Page Frame Numbers.
+ *
+ * Return: The Page Frame Number of the first page in the folio.
+ */
+static inline unsigned long folio_pfn(struct folio *folio)
+{
+	return page_to_pfn(&folio->page);
+}
+
 /* MIGRATE_CMA and ZONE_MOVABLE do not allow pin pages */
 #ifdef CONFIG_MIGRATION
 static inline bool is_pinnable_page(struct page *page)