xref: /linux-6.15/include/linux/badblocks.h (revision 1f330c32)
1 #ifndef _LINUX_BADBLOCKS_H
2 #define _LINUX_BADBLOCKS_H
3 
4 #include <linux/seqlock.h>
5 #include <linux/device.h>
6 #include <linux/kernel.h>
7 #include <linux/stddef.h>
8 #include <linux/types.h>
9 
10 #define BB_LEN_MASK	(0x00000000000001FFULL)
11 #define BB_OFFSET_MASK	(0x7FFFFFFFFFFFFE00ULL)
12 #define BB_ACK_MASK	(0x8000000000000000ULL)
13 #define BB_MAX_LEN	512
14 #define BB_OFFSET(x)	(((x) & BB_OFFSET_MASK) >> 9)
15 #define BB_LEN(x)	(((x) & BB_LEN_MASK) + 1)
16 #define BB_ACK(x)	(!!((x) & BB_ACK_MASK))
17 #define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
18 
19 /* Bad block numbers are stored sorted in a single page.
20  * 64bits is used for each block or extent.
21  * 54 bits are sector number, 9 bits are extent size,
22  * 1 bit is an 'acknowledged' flag.
23  */
24 #define MAX_BADBLOCKS	(PAGE_SIZE/8)
25 
26 struct badblocks {
27 	struct device *dev;	/* set by devm_init_badblocks */
28 	int count;		/* count of bad blocks */
29 	int unacked_exist;	/* there probably are unacknowledged
30 				 * bad blocks.  This is only cleared
31 				 * when a read discovers none
32 				 */
33 	int shift;		/* shift from sectors to block size
34 				 * a -ve shift means badblocks are
35 				 * disabled.*/
36 	u64 *page;		/* badblock list */
37 	int changed;
38 	seqlock_t lock;
39 	sector_t sector;
40 	sector_t size;		/* in sectors */
41 };
42 
43 int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
44 		   sector_t *first_bad, int *bad_sectors);
45 int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
46 			int acknowledged);
47 int badblocks_clear(struct badblocks *bb, sector_t s, int sectors);
48 void ack_all_badblocks(struct badblocks *bb);
49 ssize_t badblocks_show(struct badblocks *bb, char *page, int unack);
50 ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len,
51 			int unack);
52 int badblocks_init(struct badblocks *bb, int enable);
53 void badblocks_exit(struct badblocks *bb);
54 struct device;
55 int devm_init_badblocks(struct device *dev, struct badblocks *bb);
56 static inline void devm_exit_badblocks(struct device *dev, struct badblocks *bb)
57 {
58 	if (bb->dev != dev) {
59 		dev_WARN_ONCE(dev, 1, "%s: badblocks instance not associated\n",
60 				__func__);
61 		return;
62 	}
63 	badblocks_exit(bb);
64 }
65 #endif
66