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
28struct 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
45struct badblocks_context {
46 sector_t start;
47 sector_t len;
48 int ack;
49};
50
51int badblocks_check(struct badblocks *bb, sector_t s, sector_t sectors,
52 sector_t *first_bad, sector_t *bad_sectors);
53bool badblocks_set(struct badblocks *bb, sector_t s, sector_t sectors,
54 int acknowledged);
55bool badblocks_clear(struct badblocks *bb, sector_t s, sector_t sectors);
56void ack_all_badblocks(struct badblocks *bb);
57ssize_t badblocks_show(struct badblocks *bb, char *page, int unack);
58ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len,
59 int unack);
60int badblocks_init(struct badblocks *bb, int enable);
61void badblocks_exit(struct badblocks *bb);
62struct device;
63int devm_init_badblocks(struct device *dev, struct badblocks *bb);
64static 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
74static inline int badblocks_full(struct badblocks *bb)
75{
76 return (bb->count >= MAX_BADBLOCKS);
77}
78
79static inline int badblocks_empty(struct badblocks *bb)
80{
81 return (bb->count == 0);
82}
83
84static inline void set_changed(struct badblocks *bb)
85{
86 if (bb->changed != 1)
87 bb->changed = 1;
88}
89
90static inline void clear_changed(struct badblocks *bb)
91{
92 if (bb->changed != 0)
93 bb->changed = 0;
94}
95
96#endif
97