From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> 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/20210416231531.2521383-6-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/pageblock-flags.h | 2 +- mm/page_alloc.c | 13 +++++++------ 2 files changed, 8 insertions(+), 7 deletions(-) --- 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); } _
