include/linux/badblocks.h

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