[PATCH v2 5/9] mm/page_alloc: introduce init_reserved_pageblock()

[Doug Berger <opendmb@gmail.com>]

Most of the implementation of init_cma_reserved_pageblock() is
common to the initialization of any reserved pageblock for use
by the page allocator.

This commit breaks that functionality out into the new common
function init_reserved_pageblock() for use by code other than
CMA. The CMA specific code is relocated from page_alloc to the
point where init_cma_reserved_pageblock() was invoked and the
new function is used there instead. The error path is also
updated to use the function to operate on pageblocks rather
than pages.

Signed-off-by: Doug Berger <opendmb@gmail.com>
---
 include/linux/gfp.h |  5 +----
 mm/cma.c            | 15 +++++++++++----
 mm/page_alloc.c     |  8 ++------
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index f314be58fa77..71ed687be406 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -367,9 +367,6 @@ extern struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
 #endif
 void free_contig_range(unsigned long pfn, unsigned long nr_pages);
 
-#ifdef CONFIG_CMA
-/* CMA stuff */
-extern void init_cma_reserved_pageblock(struct page *page);
-#endif
+extern void init_reserved_pageblock(struct page *page);
 
 #endif /* __LINUX_GFP_H */
diff --git a/mm/cma.c b/mm/cma.c
index 4a978e09547a..6208a3e1cd9d 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -31,6 +31,7 @@
 #include <linux/highmem.h>
 #include <linux/io.h>
 #include <linux/kmemleak.h>
+#include <linux/page-isolation.h>
 #include <trace/events/cma.h>
 
 #include "cma.h"
@@ -116,8 +117,13 @@ static void __init cma_activate_area(struct cma *cma)
 	}
 
 	for (pfn = base_pfn; pfn < base_pfn + cma->count;
-	     pfn += pageblock_nr_pages)
-		init_cma_reserved_pageblock(pfn_to_page(pfn));
+	     pfn += pageblock_nr_pages) {
+		struct page *page = pfn_to_page(pfn);
+
+		set_pageblock_migratetype(page, MIGRATE_CMA);
+		init_reserved_pageblock(page);
+		page_zone(page)->cma_pages += pageblock_nr_pages;
+	}
 
 	spin_lock_init(&cma->lock);
 
@@ -133,8 +139,9 @@ static void __init cma_activate_area(struct cma *cma)
 out_error:
 	/* Expose all pages to the buddy, they are useless for CMA. */
 	if (!cma->reserve_pages_on_error) {
-		for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++)
-			free_reserved_page(pfn_to_page(pfn));
+		for (pfn = base_pfn; pfn < base_pfn + cma->count;
+		     pfn += pageblock_nr_pages)
+			init_reserved_pageblock(pfn_to_page(pfn));
 	}
 	totalcma_pages -= cma->count;
 	cma->count = 0;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 81f97c5ed080..6d4470b0daba 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2302,9 +2302,8 @@ void __init page_alloc_init_late(void)
 		set_zone_contiguous(zone);
 }
 
-#ifdef CONFIG_CMA
-/* Free whole pageblock and set its migration type to MIGRATE_CMA. */
-void __init init_cma_reserved_pageblock(struct page *page)
+/* Free whole pageblock */
+void __init init_reserved_pageblock(struct page *page)
 {
 	unsigned i = pageblock_nr_pages;
 	struct page *p = page;
@@ -2314,14 +2313,11 @@ void __init init_cma_reserved_pageblock(struct page *page)
 		set_page_count(p, 0);
 	} while (++p, --i);
 
-	set_pageblock_migratetype(page, MIGRATE_CMA);
 	set_page_refcounted(page);
 	__free_pages(page, pageblock_order);
 
 	adjust_managed_page_count(page, pageblock_nr_pages);
-	page_zone(page)->cma_pages += pageblock_nr_pages;
 }
-#endif
 
 /*
  * The order of subdivision here is critical for the IO subsystem.
-- 
2.25.1