1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) International Business Machines Corp., 2006
4 *
5 * Author: Artem Bityutskiy (���������������� ����������)
6 */
7
8/* Here we keep miscellaneous functions which are used all over the UBI code */
9
10#include "ubi.h"
11
12/**
13 * ubi_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 */
22int 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 */
48int 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 */
92void 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 */
111void 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 */
134int 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 */
145void 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 */
161void 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 */
178void 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