segment.h

 1/* SPDX-License-Identifier: GPL-2.0-or-later */
 2#ifndef _PCACHE_SEGMENT_H
 3#define _PCACHE_SEGMENT_H
 4
 5#include <linux/bio.h>
 6#include <linux/bitfield.h>
 7
 8#include "pcache_internal.h"
 9
10struct pcache_segment_info {
11	struct pcache_meta_header	header;
12	__u32			flags;
13	__u32			next_seg;
14};
15
16#define PCACHE_SEG_INFO_FLAGS_HAS_NEXT		BIT(0)
17
18#define PCACHE_SEG_INFO_FLAGS_TYPE_MASK         GENMASK(4, 1)
19#define PCACHE_SEGMENT_TYPE_CACHE_DATA		1
20
21static inline bool segment_info_has_next(struct pcache_segment_info *seg_info)
22{
23	return (seg_info->flags & PCACHE_SEG_INFO_FLAGS_HAS_NEXT);
24}
25
26static inline void segment_info_set_type(struct pcache_segment_info *seg_info, u8 type)
27{
28	seg_info->flags &= ~PCACHE_SEG_INFO_FLAGS_TYPE_MASK;
29	seg_info->flags |= FIELD_PREP(PCACHE_SEG_INFO_FLAGS_TYPE_MASK, type);
30}
31
32static inline u8 segment_info_get_type(struct pcache_segment_info *seg_info)
33{
34	return FIELD_GET(PCACHE_SEG_INFO_FLAGS_TYPE_MASK, seg_info->flags);
35}
36
37struct pcache_segment_pos {
38	struct pcache_segment	*segment;	/* Segment associated with the position */
39	u32			off;		/* Offset within the segment */
40};
41
42struct pcache_segment_init_options {
43	u8			type;
44	u32			seg_id;
45	u32			data_off;
46
47	struct pcache_segment_info	*seg_info;
48};
49
50struct pcache_segment {
51	struct pcache_cache_dev	*cache_dev;
52
53	void			*data;
54	u32			data_size;
55	u32			seg_id;
56
57	struct pcache_segment_info	*seg_info;
58};
59
60int segment_copy_to_bio(struct pcache_segment *segment,
61		      u32 data_off, u32 data_len, struct bio *bio, u32 bio_off);
62int segment_copy_from_bio(struct pcache_segment *segment,
63			u32 data_off, u32 data_len, struct bio *bio, u32 bio_off);
64
65static inline void segment_pos_advance(struct pcache_segment_pos *seg_pos, u32 len)
66{
67	BUG_ON(seg_pos->off + len > seg_pos->segment->data_size);
68
69	seg_pos->off += len;
70}
71
72void pcache_segment_init(struct pcache_cache_dev *cache_dev, struct pcache_segment *segment,
73		      struct pcache_segment_init_options *options);
74#endif /* _PCACHE_SEGMENT_H */