~funderscore blog cgit wiki get in touch
aboutsummaryrefslogtreecommitdiff
blob: 81275deaeb77ecd65fd3c15dc6fb76f957116c97 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) International Business Machines Corp., 2006
 *
 * Author: Artem Bityutskiy (Битюцкий Артём)
 */

/* Here we keep miscellaneous functions which are used all over the UBI code */

#include <log.h>
#include <malloc.h>
#include <ubi_uboot.h>
#include "ubi.h"

/**
 * calc_data_len - calculate how much real data is stored in a buffer.
 * @ubi: UBI device description object
 * @buf: a buffer with the contents of the physical eraseblock
 * @length: the buffer length
 *
 * This function calculates how much "real data" is stored in @buf and returnes
 * the length. Continuous 0xFF bytes at the end of the buffer are not
 * considered as "real data".
 */
int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
		      int length)
{
	int i;

	ubi_assert(!(length & (ubi->min_io_size - 1)));

	for (i = length - 1; i >= 0; i--)
		if (((const uint8_t *)buf)[i] != 0xFF)
			break;

	/* The resulting length must be aligned to the minimum flash I/O size */
	length = ALIGN(i + 1, ubi->min_io_size);
	return length;
}

/**
 * ubi_check_volume - check the contents of a static volume.
 * @ubi: UBI device description object
 * @vol_id: ID of the volume to check
 *
 * This function checks if static volume @vol_id is corrupted by fully reading
 * it and checking data CRC. This function returns %0 if the volume is not
 * corrupted, %1 if it is corrupted and a negative error code in case of
 * failure. Dynamic volumes are not checked and zero is returned immediately.
 */
int ubi_check_volume(struct ubi_device *ubi, int vol_id)
{
	void *buf;
	int err = 0, i;
	struct ubi_volume *vol = ubi->volumes[vol_id];

	if (vol->vol_type != UBI_STATIC_VOLUME)
		return 0;

	buf = vmalloc(vol->usable_leb_size);
	if (!buf)
		return -ENOMEM;

	for (i = 0; i < vol->used_ebs; i++) {
		int size;

		cond_resched();

		if (i == vol->used_ebs - 1)
			size = vol->last_eb_bytes;
		else
			size = vol->usable_leb_size;

		err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
		if (err) {
			if (mtd_is_eccerr(err))
				err = 1;
			break;
		}
	}

	vfree(buf);
	return err;
}

/**
 * ubi_update_reserved - update bad eraseblock handling accounting data.
 * @ubi: UBI device description object
 *
 * This function calculates the gap between current number of PEBs reserved for
 * bad eraseblock handling and the required level of PEBs that must be
 * reserved, and if necessary, reserves more PEBs to fill that gap, according
 * to availability. Should be called with ubi->volumes_lock held.
 */
void ubi_update_reserved(struct ubi_device *ubi)
{
	int need = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;

	if (need <= 0 || ubi->avail_pebs == 0)
		return;

	need = min_t(int, need, ubi->avail_pebs);
	ubi->avail_pebs -= need;
	ubi->rsvd_pebs += need;
	ubi->beb_rsvd_pebs += need;
	ubi_msg(ubi, "reserved more %d PEBs for bad PEB handling", need);
}

/**
 * ubi_calculate_reserved - calculate how many PEBs must be reserved for bad
 * eraseblock handling.
 * @ubi: UBI device description object
 */
void ubi_calculate_reserved(struct ubi_device *ubi)
{
	/*
	 * Calculate the actual number of PEBs currently needed to be reserved
	 * for future bad eraseblock handling.
	 */
	ubi->beb_rsvd_level = ubi->bad_peb_limit - ubi->bad_peb_count;
	if (ubi->beb_rsvd_level < 0) {
		ubi->beb_rsvd_level = 0;
		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)",
			 ubi->bad_peb_count, ubi->bad_peb_limit);
	}
}

/**
 * ubi_check_pattern - check if buffer contains only a certain byte pattern.
 * @buf: buffer to check
 * @patt: the pattern to check
 * @size: buffer size in bytes
 *
 * This function returns %1 in there are only @patt bytes in @buf, and %0 if
 * something else was also found.
 */
int ubi_check_pattern(const void *buf, uint8_t patt, int size)
{
	int i;

	for (i = 0; i < size; i++)
		if (((const uint8_t *)buf)[i] != patt)
			return 0;
	return 1;
}