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-rw-r--r--fs/bcachefs/fifo.h125
1 files changed, 125 insertions, 0 deletions
diff --git a/fs/bcachefs/fifo.h b/fs/bcachefs/fifo.h
new file mode 100644
index 000000000000..bd1534ecadb6
--- /dev/null
+++ b/fs/bcachefs/fifo.h
@@ -0,0 +1,125 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_FIFO_H
+#define _BCACHEFS_FIFO_H
+
+#include "util.h"
+
+#define FIFO(type) \
+struct { \
+ size_t front, back, size, mask; \
+ type *data; \
+}
+
+#define DECLARE_FIFO(type, name) FIFO(type) name
+
+#define fifo_buf_size(fifo) \
+ (roundup_pow_of_two((fifo)->size) * sizeof((fifo)->data[0]))
+
+#define init_fifo(fifo, _size, _gfp) \
+({ \
+ (fifo)->front = (fifo)->back = 0; \
+ (fifo)->size = (_size); \
+ (fifo)->mask = (fifo)->size \
+ ? roundup_pow_of_two((fifo)->size) - 1 \
+ : 0; \
+ (fifo)->data = kvpmalloc(fifo_buf_size(fifo), (_gfp)); \
+})
+
+#define free_fifo(fifo) \
+do { \
+ kvpfree((fifo)->data, fifo_buf_size(fifo)); \
+ (fifo)->data = NULL; \
+} while (0)
+
+#define fifo_swap(l, r) \
+do { \
+ swap((l)->front, (r)->front); \
+ swap((l)->back, (r)->back); \
+ swap((l)->size, (r)->size); \
+ swap((l)->mask, (r)->mask); \
+ swap((l)->data, (r)->data); \
+} while (0)
+
+#define fifo_move(dest, src) \
+do { \
+ typeof(*((dest)->data)) _t; \
+ while (!fifo_full(dest) && \
+ fifo_pop(src, _t)) \
+ fifo_push(dest, _t); \
+} while (0)
+
+#define fifo_used(fifo) (((fifo)->back - (fifo)->front))
+#define fifo_free(fifo) ((fifo)->size - fifo_used(fifo))
+
+#define fifo_empty(fifo) ((fifo)->front == (fifo)->back)
+#define fifo_full(fifo) (fifo_used(fifo) == (fifo)->size)
+
+#define fifo_peek_front(fifo) ((fifo)->data[(fifo)->front & (fifo)->mask])
+#define fifo_peek_back(fifo) ((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
+
+#define fifo_entry_idx_abs(fifo, p) \
+ ((((p) >= &fifo_peek_front(fifo) \
+ ? (fifo)->front : (fifo)->back) & ~(fifo)->mask) + \
+ (((p) - (fifo)->data)))
+
+#define fifo_entry_idx(fifo, p) (((p) - &fifo_peek_front(fifo)) & (fifo)->mask)
+#define fifo_idx_entry(fifo, i) (fifo)->data[((fifo)->front + (i)) & (fifo)->mask]
+
+#define fifo_push_back_ref(f) \
+ (fifo_full((f)) ? NULL : &(f)->data[(f)->back++ & (f)->mask])
+
+#define fifo_push_front_ref(f) \
+ (fifo_full((f)) ? NULL : &(f)->data[--(f)->front & (f)->mask])
+
+#define fifo_push_back(fifo, new) \
+({ \
+ typeof((fifo)->data) _r = fifo_push_back_ref(fifo); \
+ if (_r) \
+ *_r = (new); \
+ _r != NULL; \
+})
+
+#define fifo_push_front(fifo, new) \
+({ \
+ typeof((fifo)->data) _r = fifo_push_front_ref(fifo); \
+ if (_r) \
+ *_r = (new); \
+ _r != NULL; \
+})
+
+#define fifo_pop_front(fifo, i) \
+({ \
+ bool _r = !fifo_empty((fifo)); \
+ if (_r) \
+ (i) = (fifo)->data[(fifo)->front++ & (fifo)->mask]; \
+ _r; \
+})
+
+#define fifo_pop_back(fifo, i) \
+({ \
+ bool _r = !fifo_empty((fifo)); \
+ if (_r) \
+ (i) = (fifo)->data[--(fifo)->back & (fifo)->mask] \
+ _r; \
+})
+
+#define fifo_push_ref(fifo) fifo_push_back_ref(fifo)
+#define fifo_push(fifo, i) fifo_push_back(fifo, (i))
+#define fifo_pop(fifo, i) fifo_pop_front(fifo, (i))
+#define fifo_peek(fifo) fifo_peek_front(fifo)
+
+#define fifo_for_each_entry(_entry, _fifo, _iter) \
+ for (((void) (&(_iter) == &(_fifo)->front)), \
+ _iter = (_fifo)->front; \
+ ((_iter != (_fifo)->back) && \
+ (_entry = (_fifo)->data[(_iter) & (_fifo)->mask], true)); \
+ _iter++)
+
+#define fifo_for_each_entry_ptr(_ptr, _fifo, _iter) \
+ for (((void) (&(_iter) == &(_fifo)->front)), \
+ _iter = (_fifo)->front; \
+ ((_iter != (_fifo)->back) && \
+ (_ptr = &(_fifo)->data[(_iter) & (_fifo)->mask], true)); \
+ _iter++)
+
+#endif /* _BCACHEFS_FIFO_H */