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, int sectors,
52		   sector_t *first_bad, int *bad_sectors);
53int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
54			int acknowledged);
55int badblocks_clear(struct badblocks *bb, sector_t s, int 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