drivers/mtd/ubi/misc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) International Business Machines Corp., 2006
   4  *
   5  * Author: Artem Bityutskiy (Битюцкий Артём)
   6  */
   7
   8 /* Here we keep miscellaneous functions which are used all over the UBI code */
   9
  10 #include "ubi.h"
  11
  12 /**
  13  * calc_data_len - calculate how much real data is stored in a buffer.
  14  * @ubi: UBI device description object
  15  * @buf: a buffer with the contents of the physical eraseblock
  16  * @length: the buffer length
  17  *
  18  * This function calculates how much "real data" is stored in @buf and returnes
  19  * the length. Continuous 0xFF bytes at the end of the buffer are not
  20  * considered as "real data".
  21  */
  22 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
  23                       int length)
  24 {
  25         int i;
  26
  27         ubi_assert(!(length & (ubi->min_io_size - 1)));
  28
  29         for (i = length - 1; i >= 0; i--)
  30                 if (((const uint8_t *)buf)[i] != 0xFF)
  31                         break;
  32
  33         /* The resulting length must be aligned to the minimum flash I/O size */
  34         length = ALIGN(i + 1, ubi->min_io_size);
  35         return length;
  36 }
  37
  38 /**
  39  * ubi_check_volume - check the contents of a static volume.
  40  * @ubi: UBI device description object
  41  * @vol_id: ID of the volume to check
  42  *
  43  * This function checks if static volume @vol_id is corrupted by fully reading
  44  * it and checking data CRC. This function returns %0 if the volume is not
  45  * corrupted, %1 if it is corrupted and a negative error code in case of
  46  * failure. Dynamic volumes are not checked and zero is returned immediately.
  47  */
  48 int ubi_check_volume(struct ubi_device *ubi, int vol_id)
  49 {
  50         void *buf;
  51         int err = 0, i;
  52         struct ubi_volume *vol = ubi->volumes[vol_id];
  53
  54         if (vol->vol_type != UBI_STATIC_VOLUME)
  55                 return 0;
  56
  57         buf = vmalloc(vol->usable_leb_size);
  58         if (!buf)
  59                 return -ENOMEM;
  60
  61         for (i = 0; i < vol->used_ebs; i++) {
  62                 int size;
  63
  64                 cond_resched();
  65
  66                 if (i == vol->used_ebs - 1)
  67                         size = vol->last_eb_bytes;
  68                 else
  69                         size = vol->usable_leb_size;
  70
  71                 err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
  72                 if (err) {
  73                         if (mtd_is_eccerr(err))
  74                                 err = 1;
  75                         break;
  76                 }
  77         }
  78
  79         vfree(buf);
  80         return err;
  81 }
  82
  83 /**
  84  * ubi_update_reserved - update bad eraseblock handling accounting data.
  85  * @ubi: UBI device description object
  86  *
  87  * This function calculates the gap between current number of PEBs reserved for
  88  * bad eraseblock handling and the required level of PEBs that must be
  89  * reserved, and if necessary, reserves more PEBs to fill that gap, according
  90  * to availability. Should be called with ubi->volumes_lock held.
  91  */
  92 void ubi_update_reserved(struct ubi_device *ubi)
  93 {
  94         int need = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
  95
  96         if (need <= 0 || ubi->avail_pebs == 0)
  97                 return;
  98
  99         need = min_t(int, need, ubi->avail_pebs);
 100         ubi->avail_pebs -= need;
 101         ubi->rsvd_pebs += need;
 102         ubi->beb_rsvd_pebs += need;
 103         ubi_msg(ubi, "reserved more %d PEBs for bad PEB handling", need);
 104 }
 105
 106 /**
 107  * ubi_calculate_reserved - calculate how many PEBs must be reserved for bad
 108  * eraseblock handling.
 109  * @ubi: UBI device description object
 110  */
 111 void ubi_calculate_reserved(struct ubi_device *ubi)
 112 {
 113         /*
 114          * Calculate the actual number of PEBs currently needed to be reserved
 115          * for future bad eraseblock handling.
 116          */
 117         ubi->beb_rsvd_level = ubi->bad_peb_limit - ubi->bad_peb_count;
 118         if (ubi->beb_rsvd_level < 0) {
 119                 ubi->beb_rsvd_level = 0;
 120                 ubi_warn(ubi, "number of bad PEBs (%d) is above the expected limit (%d), not reserving any PEBs for bad PEB handling, will use available PEBs (if any)",
 121                          ubi->bad_peb_count, ubi->bad_peb_limit);
 122         }
 123 }
 124
 125 /**
 126  * ubi_check_pattern - check if buffer contains only a certain byte pattern.
 127  * @buf: buffer to check
 128  * @patt: the pattern to check
 129  * @size: buffer size in bytes
 130  *
 131  * This function returns %1 in there are only @patt bytes in @buf, and %0 if
 132  * something else was also found.
 133  */
 134 int ubi_check_pattern(const void *buf, uint8_t patt, int size)
 135 {
 136         int i;
 137
 138         for (i = 0; i < size; i++)
 139                 if (((const uint8_t *)buf)[i] != patt)
 140                         return 0;
 141         return 1;
 142 }
 143
 144 /* Normal UBI messages */
 145 void ubi_msg(const struct ubi_device *ubi, const char *fmt, ...)
 146 {
 147         struct va_format vaf;
 148         va_list args;
 149
 150         va_start(args, fmt);
 151
 152         vaf.fmt = fmt;
 153         vaf.va = &args;
 154
 155         pr_notice(UBI_NAME_STR "%d: %pV\n", ubi->ubi_num, &vaf);
 156
 157         va_end(args);
 158 }
 159
 160 /* UBI warning messages */
 161 void ubi_warn(const struct ubi_device *ubi, const char *fmt, ...)
 162 {
 163         struct va_format vaf;
 164         va_list args;
 165
 166         va_start(args, fmt);
 167
 168         vaf.fmt = fmt;
 169         vaf.va = &args;
 170
 171         pr_warn(UBI_NAME_STR "%d warning: %ps: %pV\n",
 172                 ubi->ubi_num, __builtin_return_address(0), &vaf);
 173
 174         va_end(args);
 175 }
 176
 177 /* UBI error messages */
 178 void ubi_err(const struct ubi_device *ubi, const char *fmt, ...)
 179 {
 180         struct va_format vaf;
 181         va_list args;
 182
 183         va_start(args, fmt);
 184
 185         vaf.fmt = fmt;
 186         vaf.va = &args;
 187
 188         pr_err(UBI_NAME_STR "%d error: %ps: %pV\n",
 189                ubi->ubi_num, __builtin_return_address(0), &vaf);
 190         va_end(args);
 191 }