1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BADBLOCKS_H
3 #define _LINUX_BADBLOCKS_H
4
5 #include <linux/seqlock.h>
6 #include <linux/device.h>
7 #include <linux/kernel.h>
8 #include <linux/stddef.h>
9 #include <linux/types.h>
10
11 #define BB_LEN_MASK (0x00000000000001FFULL)
12 #define BB_OFFSET_MASK (0x7FFFFFFFFFFFFE00ULL)
13 #define BB_ACK_MASK (0x8000000000000000ULL)
14 #define BB_MAX_LEN 512
15 #define BB_OFFSET(x) (((x) & BB_OFFSET_MASK) >> 9)
16 #define BB_LEN(x) (((x) & BB_LEN_MASK) + 1)
17 #define BB_ACK(x) (!!((x) & BB_ACK_MASK))
18 #define BB_END(x) (BB_OFFSET(x) + BB_LEN(x))
19 #define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
20
21 /* Bad block numbers are stored sorted in a single page.
22 * 64bits is used for each block or extent.
23 * 54 bits are sector number, 9 bits are extent size,
24 * 1 bit is an 'acknowledged' flag.
25 */
26 #define MAX_BADBLOCKS (PAGE_SIZE/8)
27
28 struct badblocks {
29 struct device *dev; /* set by devm_init_badblocks */
30 int count; /* count of bad blocks */
31 int unacked_exist; /* there probably are unacknowledged
32 * bad blocks. This is only cleared
33 * when a read discovers none
34 */
35 int shift; /* shift from sectors to block size
36 * a -ve shift means badblocks are
37 * disabled.*/
38 u64 *page; /* badblock list */
39 int changed;
40 seqlock_t lock;
41 sector_t sector;
42 sector_t size; /* in sectors */
43 };
44
45 struct badblocks_context {
46 sector_t start;
47 sector_t len;
48 int ack;
49 };
50
51 int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
52 sector_t *first_bad, int *bad_sectors);
53 int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
54 int acknowledged);
55 int badblocks_clear(struct badblocks *bb, sector_t s, int sectors);
56 void ack_all_badblocks(struct badblocks *bb);
57 ssize_t badblocks_show(struct badblocks *bb, char *page, int unack);
58 ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len,
59 int unack);
60 int badblocks_init(struct badblocks *bb, int enable);
61 void badblocks_exit(struct badblocks *bb);
62 struct device;
63 int devm_init_badblocks(struct device *dev, struct badblocks *bb);
64 static inline void devm_exit_badblocks(struct device *dev, struct badblocks *bb)
65 {
66 if (bb->dev != dev) {
67 dev_WARN_ONCE(dev, 1, "%s: badblocks instance not associated\n",
68 __func__);
69 return;
70 }
71 badblocks_exit(bb);
72 }
73
74 static inline int badblocks_full(struct badblocks *bb)
75 {
76 return (bb->count >= MAX_BADBLOCKS);
77 }
78
79 static inline int badblocks_empty(struct badblocks *bb)
80 {
81 return (bb->count == 0);
82 }
83
84 static inline void set_changed(struct badblocks *bb)
85 {
86 if (bb->changed != 1)
87 bb->changed = 1;
88 }
89
90 static inline void clear_changed(struct badblocks *bb)
91 {
92 if (bb->changed != 0)
93 bb->changed = 0;
94 }
95
96 #endif
97
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