| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * include/linux/pagevec.h |
| * |
| * In many places it is efficient to batch an operation up against multiple |
| * pages. A pagevec is a multipage container which is used for that. |
| */ |
| |
| #ifndef _LINUX_PAGEVEC_H |
| #define _LINUX_PAGEVEC_H |
| |
| #include <linux/xarray.h> |
| |
| /* 15 pointers + header align the pagevec structure to a power of two */ |
| #define PAGEVEC_SIZE 15 |
| |
| struct page; |
| struct folio; |
| struct address_space; |
| |
| /* Layout must match folio_batch */ |
| struct pagevec { |
| unsigned char nr; |
| bool percpu_pvec_drained; |
| struct page *pages[PAGEVEC_SIZE]; |
| }; |
| |
| void __pagevec_release(struct pagevec *pvec); |
| unsigned pagevec_lookup_range_tag(struct pagevec *pvec, |
| struct address_space *mapping, pgoff_t *index, pgoff_t end, |
| xa_mark_t tag); |
| static inline unsigned pagevec_lookup_tag(struct pagevec *pvec, |
| struct address_space *mapping, pgoff_t *index, xa_mark_t tag) |
| { |
| return pagevec_lookup_range_tag(pvec, mapping, index, (pgoff_t)-1, tag); |
| } |
| |
| static inline void pagevec_init(struct pagevec *pvec) |
| { |
| pvec->nr = 0; |
| pvec->percpu_pvec_drained = false; |
| } |
| |
| static inline void pagevec_reinit(struct pagevec *pvec) |
| { |
| pvec->nr = 0; |
| } |
| |
| static inline unsigned pagevec_count(struct pagevec *pvec) |
| { |
| return pvec->nr; |
| } |
| |
| static inline unsigned pagevec_space(struct pagevec *pvec) |
| { |
| return PAGEVEC_SIZE - pvec->nr; |
| } |
| |
| /* |
| * Add a page to a pagevec. Returns the number of slots still available. |
| */ |
| static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page) |
| { |
| pvec->pages[pvec->nr++] = page; |
| return pagevec_space(pvec); |
| } |
| |
| static inline void pagevec_release(struct pagevec *pvec) |
| { |
| if (pagevec_count(pvec)) |
| __pagevec_release(pvec); |
| } |
| |
| /** |
| * struct folio_batch - A collection of folios. |
| * |
| * The folio_batch is used to amortise the cost of retrieving and |
| * operating on a set of folios. The order of folios in the batch may be |
| * significant (eg delete_from_page_cache_batch()). Some users of the |
| * folio_batch store "exceptional" entries in it which can be removed |
| * by calling folio_batch_remove_exceptionals(). |
| */ |
| struct folio_batch { |
| unsigned char nr; |
| bool percpu_pvec_drained; |
| struct folio *folios[PAGEVEC_SIZE]; |
| }; |
| |
| /* Layout must match pagevec */ |
| static_assert(sizeof(struct pagevec) == sizeof(struct folio_batch)); |
| static_assert(offsetof(struct pagevec, pages) == |
| offsetof(struct folio_batch, folios)); |
| |
| /** |
| * folio_batch_init() - Initialise a batch of folios |
| * @fbatch: The folio batch. |
| * |
| * A freshly initialised folio_batch contains zero folios. |
| */ |
| static inline void folio_batch_init(struct folio_batch *fbatch) |
| { |
| fbatch->nr = 0; |
| fbatch->percpu_pvec_drained = false; |
| } |
| |
| static inline unsigned int folio_batch_count(struct folio_batch *fbatch) |
| { |
| return fbatch->nr; |
| } |
| |
| static inline unsigned int fbatch_space(struct folio_batch *fbatch) |
| { |
| return PAGEVEC_SIZE - fbatch->nr; |
| } |
| |
| /** |
| * folio_batch_add() - Add a folio to a batch. |
| * @fbatch: The folio batch. |
| * @folio: The folio to add. |
| * |
| * The folio is added to the end of the batch. |
| * The batch must have previously been initialised using folio_batch_init(). |
| * |
| * Return: The number of slots still available. |
| */ |
| static inline unsigned folio_batch_add(struct folio_batch *fbatch, |
| struct folio *folio) |
| { |
| fbatch->folios[fbatch->nr++] = folio; |
| return fbatch_space(fbatch); |
| } |
| |
| static inline void folio_batch_release(struct folio_batch *fbatch) |
| { |
| pagevec_release((struct pagevec *)fbatch); |
| } |
| |
| void folio_batch_remove_exceptionals(struct folio_batch *fbatch); |
| #endif /* _LINUX_PAGEVEC_H */ |