diff options
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 906c46a..6581c21 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -568,18 +568,32 @@ int split_free_page(struct page *page); /* * Compound pages have a destructor function. Provide a * prototype for that function and accessor functions. - * These are _only_ valid on the head of a PG_compound page. + * These are _only_ valid on the head of a compound page. */ +typedef void compound_page_dtor(struct page *); + +/* Keep the enum in sync with compound_page_dtors array in mm/page_alloc.c */ +enum compound_dtor_id { + NULL_COMPOUND_DTOR, + COMPOUND_PAGE_DTOR, +#ifdef CONFIG_HUGETLB_PAGE + HUGETLB_PAGE_DTOR, +#endif + NR_COMPOUND_DTORS, +}; +extern compound_page_dtor * const compound_page_dtors[]; static inline void set_compound_page_dtor(struct page *page, - compound_page_dtor *dtor) + enum compound_dtor_id compound_dtor) { - page[1].compound_dtor = dtor; + VM_BUG_ON_PAGE(compound_dtor >= NR_COMPOUND_DTORS, page); + page[1].compound_dtor = compound_dtor; } static inline compound_page_dtor *get_compound_page_dtor(struct page *page) { - return page[1].compound_dtor; + VM_BUG_ON_PAGE(page[1].compound_dtor >= NR_COMPOUND_DTORS, page); + return compound_page_dtors[page[1].compound_dtor]; } static inline int compound_order(struct page *page) @@ -589,7 +603,7 @@ static inline int compound_order(struct page *page) return page[1].compound_order; } -static inline void set_compound_order(struct page *page, unsigned long order) +static inline void set_compound_order(struct page *page, unsigned int order) { page[1].compound_order = order; } |