[PATCH RFC 11/19] mm: rejig pageblock mask definitions

[Brendan Jackman <jackmanb@google.com>]

A later patch will complicate the definition of these masks, this is a
preparatory patch to make that patch easier to review.

- More masks will be needed, so add a PAGEBLOCK_ prefix to the names
  to avoid polluting the "global namespace" too much.

- This makes MIGRATETYPE_AND_ISO_MASK start to look pretty long. Well,
  that global mask only exists for quite a specific purpose so just drop
  it and take advantage of the newly-defined PAGEBLOCK_ISO_MASK.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
---
 include/linux/pageblock-flags.h |  6 +++---
 mm/page_alloc.c                 | 12 ++++++------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h
index e046278a01fa8..9a6c3ea17684d 100644
--- a/include/linux/pageblock-flags.h
+++ b/include/linux/pageblock-flags.h
@@ -36,12 +36,12 @@ enum pageblock_bits {
 
 #define NR_PAGEBLOCK_BITS (roundup_pow_of_two(__NR_PAGEBLOCK_BITS))
 
-#define MIGRATETYPE_MASK (BIT(PB_migrate_0)|BIT(PB_migrate_1)|BIT(PB_migrate_2))
+#define PAGEBLOCK_MIGRATETYPE_MASK (BIT(PB_migrate_0)|BIT(PB_migrate_1)|BIT(PB_migrate_2))
 
 #ifdef CONFIG_MEMORY_ISOLATION
-#define MIGRATETYPE_AND_ISO_MASK (MIGRATETYPE_MASK | BIT(PB_migrate_isolate))
+#define PAGEBLOCK_ISO_MASK	BIT(PB_migrate_isolate)
 #else
-#define MIGRATETYPE_AND_ISO_MASK MIGRATETYPE_MASK
+#define PAGEBLOCK_ISO_MASK	0
 #endif
 
 #if defined(CONFIG_HUGETLB_PAGE)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 66d4843da8512..9635433c7d711 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -397,7 +397,7 @@ get_pfnblock_bitmap_bitidx(const struct page *page, unsigned long pfn,
 #else
 	BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
 #endif
-	BUILD_BUG_ON(__MIGRATE_TYPE_END > MIGRATETYPE_MASK);
+	BUILD_BUG_ON(__MIGRATE_TYPE_END > PAGEBLOCK_MIGRATETYPE_MASK);
 	VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
 
 	bitmap = get_pageblock_bitmap(page, pfn);
@@ -501,7 +501,7 @@ get_pfnblock_freetype(const struct page *page, unsigned long pfn)
 __always_inline enum migratetype
 get_pfnblock_migratetype(const struct page *page, unsigned long pfn)
 {
-	unsigned long mask = MIGRATETYPE_AND_ISO_MASK;
+	unsigned long mask = PAGEBLOCK_MIGRATETYPE_MASK | PAGEBLOCK_ISO_MASK;
 	unsigned long flags;
 
 	flags = __get_pfnblock_flags_mask(page, pfn, mask);
@@ -510,7 +510,7 @@ get_pfnblock_migratetype(const struct page *page, unsigned long pfn)
 	if (flags & BIT(PB_migrate_isolate))
 		return MIGRATE_ISOLATE;
 #endif
-	return flags & MIGRATETYPE_MASK;
+	return flags & PAGEBLOCK_MIGRATETYPE_MASK;
 }
 
 /**
@@ -598,11 +598,11 @@ static void set_pageblock_migratetype(struct page *page,
 	}
 	VM_WARN_ONCE(get_pageblock_isolate(page),
 		     "Use clear_pageblock_isolate() to unisolate pageblock");
-	/* MIGRATETYPE_AND_ISO_MASK clears PB_migrate_isolate if it is set */
+	/* PAGEBLOCK_ISO_MASK clears PB_migrate_isolate if it is set */
 #endif
 	__set_pfnblock_flags_mask(page, page_to_pfn(page),
 				  (unsigned long)migratetype,
-				  MIGRATETYPE_AND_ISO_MASK);
+				  PAGEBLOCK_MIGRATETYPE_MASK | PAGEBLOCK_ISO_MASK);
 }
 
 void __meminit init_pageblock_migratetype(struct page *page,
@@ -628,7 +628,7 @@ void __meminit init_pageblock_migratetype(struct page *page,
 		flags |= BIT(PB_migrate_isolate);
 #endif
 	__set_pfnblock_flags_mask(page, page_to_pfn(page), flags,
-				  MIGRATETYPE_AND_ISO_MASK);
+				  PAGEBLOCK_MIGRATETYPE_MASK | PAGEBLOCK_ISO_MASK);
 }
 
 #ifdef CONFIG_DEBUG_VM

-- 
2.51.2