[155/192] mm: constify get_pfnblock_flags_mask and get_pfnblock_migratetype

Commit Message

Andrew Morton June 29, 2021, 2:41 a.m. UTC

From: "Matthew Wilcox (Oracle)" <[e-mail]>
Subject: mm: constify get_pfnblock_flags_mask and get_pfnblock_migratetype

The struct page is not modified by these routines, so it can be marked
const.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Matthew Wilcox (Oracle) <[e-mail]>
Reviewed-by: Vlastimil Babka <[e-mail]>
Reviewed-by: Anshuman Khandual <[e-mail]>
Reviewed-by: William Kucharski <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 include/linux/pageblock-flags.h |    2 +-
 mm/page_alloc.c                 |   13 +++++++------
 2 files changed, 8 insertions(+), 7 deletions(-)

Patch

--- a/include/linux/pageblock-flags.h~mm-constify-get_pfnblock_flags_mask-and-get_pfnblock_migratetype
+++ a/include/linux/pageblock-flags.h
@@ -54,7 +54,7 @@  extern unsigned int pageblock_order;
 /* Forward declaration */
 struct page;
 
-unsigned long get_pfnblock_flags_mask(struct page *page,
+unsigned long get_pfnblock_flags_mask(const struct page *page,
 				unsigned long pfn,
 				unsigned long mask);
 
--- a/mm/page_alloc.c~mm-constify-get_pfnblock_flags_mask-and-get_pfnblock_migratetype
+++ a/mm/page_alloc.c
@@ -474,7 +474,7 @@  static inline bool defer_init(int nid, u
 #endif
 
 /* Return a pointer to the bitmap storing bits affecting a block of pages */
-static inline unsigned long *get_pageblock_bitmap(struct page *page,
+static inline unsigned long *get_pageblock_bitmap(const struct page *page,
 							unsigned long pfn)
 {
 #ifdef CONFIG_SPARSEMEM
@@ -484,7 +484,7 @@  static inline unsigned long *get_pageblo
 #endif /* CONFIG_SPARSEMEM */
 }
 
-static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
+static inline int pfn_to_bitidx(const struct page *page, unsigned long pfn)
 {
 #ifdef CONFIG_SPARSEMEM
 	pfn &= (PAGES_PER_SECTION-1);
@@ -495,7 +495,7 @@  static inline int pfn_to_bitidx(struct p
 }
 
 static __always_inline
-unsigned long __get_pfnblock_flags_mask(struct page *page,
+unsigned long __get_pfnblock_flags_mask(const struct page *page,
 					unsigned long pfn,
 					unsigned long mask)
 {
@@ -520,13 +520,14 @@  unsigned long __get_pfnblock_flags_mask(
  *
  * Return: pageblock_bits flags
  */
-unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
-					unsigned long mask)
+unsigned long get_pfnblock_flags_mask(const struct page *page,
+					unsigned long pfn, unsigned long mask)
 {
 	return __get_pfnblock_flags_mask(page, pfn, mask);
 }
 
-static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
+static __always_inline int get_pfnblock_migratetype(const struct page *page,
+					unsigned long pfn)
 {
 	return __get_pfnblock_flags_mask(page, pfn, MIGRATETYPE_MASK);
 }