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_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
19 
20 /* Bad block numbers are stored sorted in a single page.
21  * 64bits is used for each block or extent.
22  * 54 bits are sector number, 9 bits are extent size,
23  * 1 bit is an 'acknowledged' flag.
24  */
25 #define MAX_BADBLOCKS	(PAGE_SIZE/8)
26 
27 struct badblocks {
28 	struct device *dev;	/* set by devm_init_badblocks */
29 	int count;		/* count of bad blocks */
30 	int unacked_exist;	/* there probably are unacknowledged
31 				 * bad blocks.  This is only cleared
32 				 * when a read discovers none
33 				 */
34 	int shift;		/* shift from sectors to block size
35 				 * a -ve shift means badblocks are
36 				 * disabled.*/
37 	u64 *page;		/* badblock list */
38 	int changed;
39 	seqlock_t lock;
40 	sector_t sector;
41 	sector_t size;		/* in sectors */
42 };
43 
44 int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
45 		   sector_t *first_bad, int *bad_sectors);
46 int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
47 			int acknowledged);
48 int badblocks_clear(struct badblocks *bb, sector_t s, int sectors);
49 void ack_all_badblocks(struct badblocks *bb);
50 ssize_t badblocks_show(struct badblocks *bb, char *page, int unack);
51 ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len,
52 			int unack);
53 int badblocks_init(struct badblocks *bb, int enable);
54 void badblocks_exit(struct badblocks *bb);
55 struct device;
56 int devm_init_badblocks(struct device *dev, struct badblocks *bb);
devm_exit_badblocks(struct device * dev,struct badblocks * bb)57 static inline void devm_exit_badblocks(struct device *dev, struct badblocks *bb)
58 {
59 	if (bb->dev != dev) {
60 		dev_WARN_ONCE(dev, 1, "%s: badblocks instance not associated\n",
61 				__func__);
62 		return;
63 	}
64 	badblocks_exit(bb);
65 }
66 #endif
67