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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2#ifndef _PCACHE_CACHE_DEV_H
3#define _PCACHE_CACHE_DEV_H
4
5#include <linux/device.h>
6#include <linux/device-mapper.h>
7
8#include "pcache_internal.h"
9
10#define PCACHE_MAGIC 0x65B05EFA96C596EFULL
11
12#define PCACHE_SB_OFF (4 * PCACHE_KB)
13#define PCACHE_SB_SIZE (4 * PCACHE_KB)
14
15#define PCACHE_CACHE_INFO_OFF (PCACHE_SB_OFF + PCACHE_SB_SIZE)
16#define PCACHE_CACHE_INFO_SIZE (4 * PCACHE_KB)
17
18#define PCACHE_CACHE_CTRL_OFF (PCACHE_CACHE_INFO_OFF + (PCACHE_CACHE_INFO_SIZE * PCACHE_META_INDEX_MAX))
19#define PCACHE_CACHE_CTRL_SIZE (4 * PCACHE_KB)
20
21#define PCACHE_SEGMENTS_OFF (PCACHE_CACHE_CTRL_OFF + PCACHE_CACHE_CTRL_SIZE)
22#define PCACHE_SEG_INFO_SIZE (4 * PCACHE_KB)
23
24#define PCACHE_CACHE_DEV_SIZE_MIN (512 * PCACHE_MB) /* 512 MB */
25#define PCACHE_SEG_SIZE (16 * PCACHE_MB) /* Size of each PCACHE segment (16 MB) */
26
27#define CACHE_DEV_SB(cache_dev) ((struct pcache_sb *)(cache_dev->mapping + PCACHE_SB_OFF))
28#define CACHE_DEV_CACHE_INFO(cache_dev) ((void *)cache_dev->mapping + PCACHE_CACHE_INFO_OFF)
29#define CACHE_DEV_CACHE_CTRL(cache_dev) ((void *)cache_dev->mapping + PCACHE_CACHE_CTRL_OFF)
30#define CACHE_DEV_SEGMENTS(cache_dev) ((void *)cache_dev->mapping + PCACHE_SEGMENTS_OFF)
31#define CACHE_DEV_SEGMENT(cache_dev, id) ((void *)CACHE_DEV_SEGMENTS(cache_dev) + (u64)id * PCACHE_SEG_SIZE)
32
33/*
34 * PCACHE SB flags configured during formatting
35 *
36 * The PCACHE_SB_F_xxx flags define registration requirements based on cache_dev
37 * formatting. For a machine to register a cache_dev:
38 * - PCACHE_SB_F_BIGENDIAN: Requires a big-endian machine.
39 */
40#define PCACHE_SB_F_BIGENDIAN BIT(0)
41
42struct pcache_sb {
43 __le32 crc;
44 __le32 flags;
45 __le64 magic;
46
47 __le32 seg_num;
48};
49
50struct pcache_cache_dev {
51 u32 sb_flags;
52 u32 seg_num;
53 void *mapping;
54 bool use_vmap;
55
56 struct dm_dev *dm_dev;
57
58 struct mutex seg_lock;
59 unsigned long *seg_bitmap;
60};
61
62struct dm_pcache;
63int cache_dev_start(struct dm_pcache *pcache);
64void cache_dev_stop(struct dm_pcache *pcache);
65
66void cache_dev_zero_range(struct pcache_cache_dev *cache_dev, void *pos, u32 size);
67
68int cache_dev_get_empty_segment_id(struct pcache_cache_dev *cache_dev, u32 *seg_id);
69
70#endif /* _PCACHE_CACHE_DEV_H */