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 */ 128