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8#ifndef DM_VERITY_FEC_H
9#define DM_VERITY_FEC_H
10
11#include "dm-verity.h"
12#include <linux/rslib.h>
13
14
15#define DM_VERITY_FEC_RSM 255
16#define DM_VERITY_FEC_MAX_RSN 253
17#define DM_VERITY_FEC_MIN_RSN 231
18
19
20#define DM_VERITY_FEC_BUF_PREALLOC 1
21#define DM_VERITY_FEC_BUF_RS_BITS 4
22
23#define DM_VERITY_FEC_BUF_MAX \
24 (1 << (PAGE_SHIFT - DM_VERITY_FEC_BUF_RS_BITS))
25
26
27#define DM_VERITY_FEC_MAX_RECURSION 4
28
29#define DM_VERITY_OPT_FEC_DEV "use_fec_from_device"
30#define DM_VERITY_OPT_FEC_BLOCKS "fec_blocks"
31#define DM_VERITY_OPT_FEC_START "fec_start"
32#define DM_VERITY_OPT_FEC_ROOTS "fec_roots"
33
34
35struct dm_verity_fec {
36 struct dm_dev *dev;
37 struct dm_bufio_client *data_bufio;
38 struct dm_bufio_client *bufio;
39 size_t io_size;
40 sector_t start;
41 sector_t blocks;
42 sector_t rounds;
43 sector_t hash_blocks;
44 unsigned char roots;
45 unsigned char rsn;
46 mempool_t rs_pool;
47 mempool_t prealloc_pool;
48 mempool_t extra_pool;
49 mempool_t output_pool;
50 struct kmem_cache *cache;
51};
52
53
54struct dm_verity_fec_io {
55 struct rs_control *rs;
56 int erasures[DM_VERITY_FEC_MAX_RSN];
57 u8 *bufs[DM_VERITY_FEC_BUF_MAX];
58 unsigned nbufs;
59 u8 *output;
60 size_t output_pos;
61 unsigned level;
62};
63
64#ifdef CONFIG_DM_VERITY_FEC
65
66
67#define DM_VERITY_OPTS_FEC 8
68
69extern bool verity_fec_is_enabled(struct dm_verity *v);
70
71extern int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io,
72 enum verity_block_type type, sector_t block,
73 u8 *dest, struct bvec_iter *iter);
74
75extern unsigned verity_fec_status_table(struct dm_verity *v, unsigned sz,
76 char *result, unsigned maxlen);
77
78extern void verity_fec_finish_io(struct dm_verity_io *io);
79extern void verity_fec_init_io(struct dm_verity_io *io);
80
81extern bool verity_is_fec_opt_arg(const char *arg_name);
82extern int verity_fec_parse_opt_args(struct dm_arg_set *as,
83 struct dm_verity *v, unsigned *argc,
84 const char *arg_name);
85
86extern void verity_fec_dtr(struct dm_verity *v);
87
88extern int verity_fec_ctr_alloc(struct dm_verity *v);
89extern int verity_fec_ctr(struct dm_verity *v);
90
91#else
92
93#define DM_VERITY_OPTS_FEC 0
94
95static inline bool verity_fec_is_enabled(struct dm_verity *v)
96{
97 return false;
98}
99
100static inline int verity_fec_decode(struct dm_verity *v,
101 struct dm_verity_io *io,
102 enum verity_block_type type,
103 sector_t block, u8 *dest,
104 struct bvec_iter *iter)
105{
106 return -EOPNOTSUPP;
107}
108
109static inline unsigned verity_fec_status_table(struct dm_verity *v,
110 unsigned sz, char *result,
111 unsigned maxlen)
112{
113 return sz;
114}
115
116static inline void verity_fec_finish_io(struct dm_verity_io *io)
117{
118}
119
120static inline void verity_fec_init_io(struct dm_verity_io *io)
121{
122}
123
124static inline bool verity_is_fec_opt_arg(const char *arg_name)
125{
126 return false;
127}
128
129static inline int verity_fec_parse_opt_args(struct dm_arg_set *as,
130 struct dm_verity *v,
131 unsigned *argc,
132 const char *arg_name)
133{
134 return -EINVAL;
135}
136
137static inline void verity_fec_dtr(struct dm_verity *v)
138{
139}
140
141static inline int verity_fec_ctr_alloc(struct dm_verity *v)
142{
143 return 0;
144}
145
146static inline int verity_fec_ctr(struct dm_verity *v)
147{
148 return 0;
149}
150
151#endif
152
153#endif
154