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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/mtd/ubi/misc.c
2 * Copyright (c) International Business Machines Corp., 2006
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.
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.
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
18 * Author: Artem Bityutskiy (Битюцкий Артём)
21 /* Here we keep miscellaneous functions which are used all over the UBI code */
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
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".
35 int ubi_calc_data_len ( const struct ubi_device
* ubi
, const void * buf
,
40 ubi_assert (!( length
& ( ubi
-> min_io_size
- 1 )));
42 for ( i
= length
- 1 ; i
>= 0 ; i
--)
43 if ((( const uint8_t *) buf
)[ i
] != 0xFF )
46 /* The resulting length must be aligned to the minimum flash I/O size */
47 length
= ALIGN ( i
+ 1 , ubi
-> min_io_size
);
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
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.
61 int ubi_check_volume ( struct ubi_device
* ubi
, int vol_id
)
65 struct ubi_volume
* vol
= ubi
-> volumes
[ vol_id
];
67 if ( vol
-> vol_type
!= UBI_STATIC_VOLUME
)
70 buf
= vmalloc ( vol
-> usable_leb_size
);
74 for ( i
= 0 ; i
< vol
-> used_ebs
; i
++) {
79 if ( i
== vol
-> used_ebs
- 1 )
80 size
= vol
-> last_eb_bytes
;
82 size
= vol
-> usable_leb_size
;
84 err
= ubi_eba_read_leb ( ubi
, vol
, i
, buf
, 0 , size
, 1 );
86 if ( mtd_is_eccerr ( err
))
97 * ubi_update_reserved - update bad eraseblock handling accounting data.
98 * @ubi: UBI device description object
100 * This function calculates the gap between current number of PEBs reserved for
101 * bad eraseblock handling and the required level of PEBs that must be
102 * reserved, and if necessary, reserves more PEBs to fill that gap, according
103 * to availability. Should be called with ubi->volumes_lock held.
105 void ubi_update_reserved ( struct ubi_device
* ubi
)
107 int need
= ubi
-> beb_rsvd_level
- ubi
-> beb_rsvd_pebs
;
109 if ( need
<= 0 || ubi
-> avail_pebs
== 0 )
112 need
= min_t ( int , need
, ubi
-> avail_pebs
);
113 ubi
-> avail_pebs
-= need
;
114 ubi
-> rsvd_pebs
+= need
;
115 ubi
-> beb_rsvd_pebs
+= need
;
116 ubi_msg ( ubi
, "reserved more %d PEBs for bad PEB handling" , need
);
120 * ubi_calculate_reserved - calculate how many PEBs must be reserved for bad
121 * eraseblock handling.
122 * @ubi: UBI device description object
124 void ubi_calculate_reserved ( struct ubi_device
* ubi
)
127 * Calculate the actual number of PEBs currently needed to be reserved
128 * for future bad eraseblock handling.
130 ubi
-> beb_rsvd_level
= ubi
-> bad_peb_limit
- ubi
-> bad_peb_count
;
131 if ( ubi
-> beb_rsvd_level
< 0 ) {
132 ubi
-> beb_rsvd_level
= 0 ;
133 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)" ,
134 ubi
-> bad_peb_count
, ubi
-> bad_peb_limit
);
139 * ubi_check_pattern - check if buffer contains only a certain byte pattern.
140 * @buf: buffer to check
141 * @patt: the pattern to check
142 * @size: buffer size in bytes
144 * This function returns %1 in there are only @patt bytes in @buf, and %0 if
145 * something else was also found.
147 int ubi_check_pattern ( const void * buf
, uint8_t patt
, int size
)
151 for ( i
= 0 ; i
< size
; i
++)
152 if ((( const uint8_t *) buf
)[ i
] != patt
)