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 */
ubi_calc_data_len(const struct ubi_device * ubi,const void * buf,int length)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 */
ubi_check_volume(struct ubi_device * ubi,int vol_id)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 */
ubi_update_reserved(struct ubi_device * ubi)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 */
ubi_calculate_reserved(struct ubi_device * ubi)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 */
ubi_check_pattern(const void * buf,uint8_t patt,int size)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 */
ubi_msg(const struct ubi_device * ubi,const char * fmt,...)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 */
ubi_warn(const struct ubi_device * ubi,const char * fmt,...)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 */
ubi_err(const struct ubi_device * ubi,const char * fmt,...)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 }
192