include/linux/pagevec.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * include/linux/pagevec.h
   4  *
   5  * In many places it is efficient to batch an operation up against multiple
   6  * pages.  A pagevec is a multipage container which is used for that.
   7  */
   8
   9 #ifndef _LINUX_PAGEVEC_H
  10 #define _LINUX_PAGEVEC_H
  11
  12 /* 14 pointers + two long's align the pagevec structure to a power of two */
  13 #define PAGEVEC_SIZE    14
  14
  15 struct page;
  16 struct address_space;
  17
  18 struct pagevec {
  19         unsigned long nr;
  20         unsigned long cold;
  21         struct page *pages[PAGEVEC_SIZE];
  22 };
  23
  24 void __pagevec_release(struct pagevec *pvec);
  25 void __pagevec_lru_add(struct pagevec *pvec);
  26 unsigned pagevec_lookup_entries(struct pagevec *pvec,
  27                                 struct address_space *mapping,
  28                                 pgoff_t start, unsigned nr_entries,
  29                                 pgoff_t *indices);
  30 void pagevec_remove_exceptionals(struct pagevec *pvec);
  31 unsigned pagevec_lookup_range(struct pagevec *pvec,
  32                               struct address_space *mapping,
  33                               pgoff_t *start, pgoff_t end);
  34 static inline unsigned pagevec_lookup(struct pagevec *pvec,
  35                                       struct address_space *mapping,
  36                                       pgoff_t *start)
  37 {
  38         return pagevec_lookup_range(pvec, mapping, start, (pgoff_t)-1);
  39 }
  40
  41 unsigned pagevec_lookup_tag(struct pagevec *pvec,
  42                 struct address_space *mapping, pgoff_t *index, int tag,
  43                 unsigned nr_pages);
  44
  45 static inline void pagevec_init(struct pagevec *pvec, int cold)
  46 {
  47         pvec->nr = 0;
  48         pvec->cold = cold;
  49 }
  50
  51 static inline void pagevec_reinit(struct pagevec *pvec)
  52 {
  53         pvec->nr = 0;
  54 }
  55
  56 static inline unsigned pagevec_count(struct pagevec *pvec)
  57 {
  58         return pvec->nr;
  59 }
  60
  61 static inline unsigned pagevec_space(struct pagevec *pvec)
  62 {
  63         return PAGEVEC_SIZE - pvec->nr;
  64 }
  65
  66 /*
  67  * Add a page to a pagevec.  Returns the number of slots still available.
  68  */
  69 static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
  70 {
  71         pvec->pages[pvec->nr++] = page;
  72         return pagevec_space(pvec);
  73 }
  74
  75 static inline void pagevec_release(struct pagevec *pvec)
  76 {
  77         if (pagevec_count(pvec))
  78                 __pagevec_release(pvec);
  79 }
  80
  81 #endif /* _LINUX_PAGEVEC_H */