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);
devm_exit_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  
badblocks_full(struct badblocks * bb)74  static inline int badblocks_full(struct badblocks *bb)
75  {
76  	return (bb->count >= MAX_BADBLOCKS);
77  }
78  
badblocks_empty(struct badblocks * bb)79  static inline int badblocks_empty(struct badblocks *bb)
80  {
81  	return (bb->count == 0);
82  }
83  
set_changed(struct badblocks * bb)84  static inline void set_changed(struct badblocks *bb)
85  {
86  	if (bb->changed != 1)
87  		bb->changed = 1;
88  }
89  
clear_changed(struct badblocks * bb)90  static inline void clear_changed(struct badblocks *bb)
91  {
92  	if (bb->changed != 0)
93  		bb->changed = 0;
94  }
95  
96  #endif
97