git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/fifo.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _BCACHEFS_FIFO_H
   3 #define _BCACHEFS_FIFO_H
   4
   5 #include "util.h"
   6
   7 #define FIFO(type)                                                      \
   8 struct {                                                                \
   9         size_t front, back, size, mask;                                 \
  10         type *data;                                                     \
  11 }
  12
  13 #define DECLARE_FIFO(type, name)        FIFO(type) name
  14
  15 #define fifo_buf_size(fifo)                                             \
  16         ((fifo)->size                                                   \
  17          ? roundup_pow_of_two((fifo)->size) * sizeof((fifo)->data[0])   \
  18          : 0)
  19
  20 #define init_fifo(fifo, _size, _gfp)                                    \
  21 ({                                                                      \
  22         (fifo)->front   = (fifo)->back = 0;                             \
  23         (fifo)->size    = (_size);                                      \
  24         (fifo)->mask    = (fifo)->size                                  \
  25                 ? roundup_pow_of_two((fifo)->size) - 1                  \
  26                 : 0;                                                    \
  27         (fifo)->data    = kvpmalloc(fifo_buf_size(fifo), (_gfp));       \
  28 })
  29
  30 #define free_fifo(fifo)                                                 \
  31 do {                                                                    \
  32         kvpfree((fifo)->data, fifo_buf_size(fifo));                     \
  33         (fifo)->data = NULL;                                            \
  34 } while (0)
  35
  36 #define fifo_swap(l, r)                                                 \
  37 do {                                                                    \
  38         swap((l)->front, (r)->front);                                   \
  39         swap((l)->back, (r)->back);                                     \
  40         swap((l)->size, (r)->size);                                     \
  41         swap((l)->mask, (r)->mask);                                     \
  42         swap((l)->data, (r)->data);                                     \
  43 } while (0)
  44
  45 #define fifo_move(dest, src)                                            \
  46 do {                                                                    \
  47         typeof(*((dest)->data)) _t;                                     \
  48         while (!fifo_full(dest) &&                                      \
  49                fifo_pop(src, _t))                                       \
  50                 fifo_push(dest, _t);                                    \
  51 } while (0)
  52
  53 #define fifo_used(fifo)         (((fifo)->back - (fifo)->front))
  54 #define fifo_free(fifo)         ((fifo)->size - fifo_used(fifo))
  55
  56 #define fifo_empty(fifo)        ((fifo)->front == (fifo)->back)
  57 #define fifo_full(fifo)         (fifo_used(fifo) == (fifo)->size)
  58
  59 #define fifo_peek_front(fifo)   ((fifo)->data[(fifo)->front & (fifo)->mask])
  60 #define fifo_peek_back(fifo)    ((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
  61
  62 #define fifo_entry_idx_abs(fifo, p)                                     \
  63         ((((p) >= &fifo_peek_front(fifo)                                \
  64            ? (fifo)->front : (fifo)->back) & ~(fifo)->mask) +           \
  65            (((p) - (fifo)->data)))
  66
  67 #define fifo_entry_idx(fifo, p) (((p) - &fifo_peek_front(fifo)) & (fifo)->mask)
  68 #define fifo_idx_entry(fifo, i) ((fifo)->data[((fifo)->front + (i)) & (fifo)->mask])
  69
  70 #define fifo_push_back_ref(f)                                           \
  71         (fifo_full((f)) ? NULL : &(f)->data[(f)->back++ & (f)->mask])
  72
  73 #define fifo_push_front_ref(f)                                          \
  74         (fifo_full((f)) ? NULL : &(f)->data[--(f)->front & (f)->mask])
  75
  76 #define fifo_push_back(fifo, new)                                       \
  77 ({                                                                      \
  78         typeof((fifo)->data) _r = fifo_push_back_ref(fifo);             \
  79         if (_r)                                                         \
  80                 *_r = (new);                                            \
  81         _r != NULL;                                                     \
  82 })
  83
  84 #define fifo_push_front(fifo, new)                                      \
  85 ({                                                                      \
  86         typeof((fifo)->data) _r = fifo_push_front_ref(fifo);            \
  87         if (_r)                                                         \
  88                 *_r = (new);                                            \
  89         _r != NULL;                                                     \
  90 })
  91
  92 #define fifo_pop_front(fifo, i)                                         \
  93 ({                                                                      \
  94         bool _r = !fifo_empty((fifo));                                  \
  95         if (_r)                                                         \
  96                 (i) = (fifo)->data[(fifo)->front++ & (fifo)->mask];     \
  97         _r;                                                             \
  98 })
  99
 100 #define fifo_pop_back(fifo, i)                                          \
 101 ({                                                                      \
 102         bool _r = !fifo_empty((fifo));                                  \
 103         if (_r)                                                         \
 104                 (i) = (fifo)->data[--(fifo)->back & (fifo)->mask];      \
 105         _r;                                                             \
 106 })
 107
 108 #define fifo_push_ref(fifo)     fifo_push_back_ref(fifo)
 109 #define fifo_push(fifo, i)      fifo_push_back(fifo, (i))
 110 #define fifo_pop(fifo, i)       fifo_pop_front(fifo, (i))
 111 #define fifo_peek(fifo)         fifo_peek_front(fifo)
 112
 113 #define fifo_for_each_entry(_entry, _fifo, _iter)                       \
 114         for (typecheck(typeof((_fifo)->front), _iter),                  \
 115              (_iter) = (_fifo)->front;                                  \
 116              ((_iter != (_fifo)->back) &&                               \
 117               (_entry = (_fifo)->data[(_iter) & (_fifo)->mask], true)); \
 118              (_iter)++)
 119
 120 #define fifo_for_each_entry_ptr(_ptr, _fifo, _iter)                     \
 121         for (typecheck(typeof((_fifo)->front), _iter),                  \
 122              (_iter) = (_fifo)->front;                                  \
 123              ((_iter != (_fifo)->back) &&                               \
 124               (_ptr = &(_fifo)->data[(_iter) & (_fifo)->mask], true));  \
 125              (_iter)++)
 126
 127 #endif /* _BCACHEFS_FIFO_H */