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1/*
2 * Copyright (c) International Business Machines Corp., 2006
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author: Artem Bityutskiy (Битюцкий Артём)
19 */
20
21/* Here we keep miscellaneous functions which are used all over the UBI code */
22
23#include "ubi.h"
24
25/**
26 * calc_data_len - calculate how much real data is stored in a buffer.
27 * @ubi: UBI device description object
28 * @buf: a buffer with the contents of the physical eraseblock
29 * @length: the buffer length
30 *
31 * This function calculates how much "real data" is stored in @buf and returnes
32 * the length. Continuous 0xFF bytes at the end of the buffer are not
33 * considered as "real data".
34 */
35int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
36 int length)
37{
38 int i;
39
40 ubi_assert(!(length & (ubi->min_io_size - 1)));
41
42 for (i = length - 1; i >= 0; i--)
43 if (((const uint8_t *)buf)[i] != 0xFF)
44 break;
45
46 /* The resulting length must be aligned to the minimum flash I/O size */
47 length = ALIGN(i + 1, ubi->min_io_size);
48 return length;
49}
50
51/**
52 * ubi_check_volume - check the contents of a static volume.
53 * @ubi: UBI device description object
54 * @vol_id: ID of the volume to check
55 *
56 * This function checks if static volume @vol_id is corrupted by fully reading
57 * it and checking data CRC. This function returns %0 if the volume is not
58 * corrupted, %1 if it is corrupted and a negative error code in case of
59 * failure. Dynamic volumes are not checked and zero is returned immediately.
60 */
61int ubi_check_volume(struct ubi_device *ubi, int vol_id)
62{
63 void *buf;
64 int err = 0, i;
65 struct ubi_volume *vol = ubi->volumes[vol_id];
66
67 if (vol->vol_type != UBI_STATIC_VOLUME)
68 return 0;
69
70 buf = vmalloc(vol->usable_leb_size);
71 if (!buf)
72 return -ENOMEM;
73
74 for (i = 0; i < vol->used_ebs; i++) {
75 int size;
76
77 if (i == vol->used_ebs - 1)
78 size = vol->last_eb_bytes;
79 else
80 size = vol->usable_leb_size;
81
82 err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
83 if (err) {
84 if (err == -EBADMSG)
85 err = 1;
86 break;
87 }
88 }
89
90 vfree(buf);
91 return err;
92}
93
94/**
95 * ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad
96 * eraseblock handling.
97 * @ubi: UBI device description object
98 */
99void ubi_calculate_reserved(struct ubi_device *ubi)
100{
101 ubi->beb_rsvd_level = ubi->good_peb_count/100;
102 ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE;
103 if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
104 ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
105}
106
107/**
108 * ubi_check_pattern - check if buffer contains only a certain byte pattern.
109 * @buf: buffer to check
110 * @patt: the pattern to check
111 * @size: buffer size in bytes
112 *
113 * This function returns %1 in there are only @patt bytes in @buf, and %0 if
114 * something else was also found.
115 */
116int ubi_check_pattern(const void *buf, uint8_t patt, int size)
117{
118 int i;
119
120 for (i = 0; i < size; i++)
121 if (((const uint8_t *)buf)[i] != patt)
122 return 0;
123 return 1;
124}
1/*
2 * Copyright (c) International Business Machines Corp., 2006
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author: Artem Bityutskiy (Битюцкий Артём)
19 */
20
21/* Here we keep miscellaneous functions which are used all over the UBI code */
22
23#include "ubi.h"
24
25/**
26 * calc_data_len - calculate how much real data is stored in a buffer.
27 * @ubi: UBI device description object
28 * @buf: a buffer with the contents of the physical eraseblock
29 * @length: the buffer length
30 *
31 * This function calculates how much "real data" is stored in @buf and returnes
32 * the length. Continuous 0xFF bytes at the end of the buffer are not
33 * considered as "real data".
34 */
35int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
36 int length)
37{
38 int i;
39
40 ubi_assert(!(length & (ubi->min_io_size - 1)));
41
42 for (i = length - 1; i >= 0; i--)
43 if (((const uint8_t *)buf)[i] != 0xFF)
44 break;
45
46 /* The resulting length must be aligned to the minimum flash I/O size */
47 length = ALIGN(i + 1, ubi->min_io_size);
48 return length;
49}
50
51/**
52 * ubi_check_volume - check the contents of a static volume.
53 * @ubi: UBI device description object
54 * @vol_id: ID of the volume to check
55 *
56 * This function checks if static volume @vol_id is corrupted by fully reading
57 * it and checking data CRC. This function returns %0 if the volume is not
58 * corrupted, %1 if it is corrupted and a negative error code in case of
59 * failure. Dynamic volumes are not checked and zero is returned immediately.
60 */
61int ubi_check_volume(struct ubi_device *ubi, int vol_id)
62{
63 void *buf;
64 int err = 0, i;
65 struct ubi_volume *vol = ubi->volumes[vol_id];
66
67 if (vol->vol_type != UBI_STATIC_VOLUME)
68 return 0;
69
70 buf = vmalloc(vol->usable_leb_size);
71 if (!buf)
72 return -ENOMEM;
73
74 for (i = 0; i < vol->used_ebs; i++) {
75 int size;
76
77 if (i == vol->used_ebs - 1)
78 size = vol->last_eb_bytes;
79 else
80 size = vol->usable_leb_size;
81
82 err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
83 if (err) {
84 if (mtd_is_eccerr(err))
85 err = 1;
86 break;
87 }
88 }
89
90 vfree(buf);
91 return err;
92}
93
94/**
95 * ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad
96 * eraseblock handling.
97 * @ubi: UBI device description object
98 */
99void ubi_calculate_reserved(struct ubi_device *ubi)
100{
101 ubi->beb_rsvd_level = ubi->good_peb_count/100;
102 ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE;
103 if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
104 ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
105}
106
107/**
108 * ubi_check_pattern - check if buffer contains only a certain byte pattern.
109 * @buf: buffer to check
110 * @patt: the pattern to check
111 * @size: buffer size in bytes
112 *
113 * This function returns %1 in there are only @patt bytes in @buf, and %0 if
114 * something else was also found.
115 */
116int ubi_check_pattern(const void *buf, uint8_t patt, int size)
117{
118 int i;
119
120 for (i = 0; i < size; i++)
121 if (((const uint8_t *)buf)[i] != patt)
122 return 0;
123 return 1;
124}