drivers/md/dm-pcache/segment.h

Source file repositories/reference/linux-study-clean/drivers/md/dm-pcache/segment.h

File Facts

System
Linux kernel
Corpus path
drivers/md/dm-pcache/segment.h
Extension
.h
Size
1977 bytes
Lines
75
Domain
Driver Families
Bucket
drivers/md
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct pcache_segment_info {
	struct pcache_meta_header	header;
	__u32			flags;
	__u32			next_seg;
};

#define PCACHE_SEG_INFO_FLAGS_HAS_NEXT		BIT(0)

#define PCACHE_SEG_INFO_FLAGS_TYPE_MASK         GENMASK(4, 1)
#define PCACHE_SEGMENT_TYPE_CACHE_DATA		1

static inline bool segment_info_has_next(struct pcache_segment_info *seg_info)
{
	return (seg_info->flags & PCACHE_SEG_INFO_FLAGS_HAS_NEXT);
}

static inline void segment_info_set_type(struct pcache_segment_info *seg_info, u8 type)
{
	seg_info->flags &= ~PCACHE_SEG_INFO_FLAGS_TYPE_MASK;
	seg_info->flags |= FIELD_PREP(PCACHE_SEG_INFO_FLAGS_TYPE_MASK, type);
}

static inline u8 segment_info_get_type(struct pcache_segment_info *seg_info)
{
	return FIELD_GET(PCACHE_SEG_INFO_FLAGS_TYPE_MASK, seg_info->flags);
}

struct pcache_segment_pos {
	struct pcache_segment	*segment;	/* Segment associated with the position */
	u32			off;		/* Offset within the segment */
};

struct pcache_segment_init_options {
	u8			type;
	u32			seg_id;
	u32			data_off;

	struct pcache_segment_info	*seg_info;
};

struct pcache_segment {
	struct pcache_cache_dev	*cache_dev;

	void			*data;
	u32			data_size;
	u32			seg_id;

	struct pcache_segment_info	*seg_info;
};

int segment_copy_to_bio(struct pcache_segment *segment,
		      u32 data_off, u32 data_len, struct bio *bio, u32 bio_off);
int segment_copy_from_bio(struct pcache_segment *segment,
			u32 data_off, u32 data_len, struct bio *bio, u32 bio_off);

static inline void segment_pos_advance(struct pcache_segment_pos *seg_pos, u32 len)
{
	BUG_ON(seg_pos->off + len > seg_pos->segment->data_size);

	seg_pos->off += len;
}

void pcache_segment_init(struct pcache_cache_dev *cache_dev, struct pcache_segment *segment,
		      struct pcache_segment_init_options *options);
#endif /* _PCACHE_SEGMENT_H */

Annotation

Implementation Notes