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_uboot.h> 24 #include "ubi.h" 25 26 /** 27 * calc_data_len - calculate how much real data is stored in a buffer. 28 * @ubi: UBI device description object 29 * @buf: a buffer with the contents of the physical eraseblock 30 * @length: the buffer length 31 * 32 * This function calculates how much "real data" is stored in @buf and returnes 33 * the length. Continuous 0xFF bytes at the end of the buffer are not 34 * considered as "real data". 35 */ 36 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, 37 int length) 38 { 39 int i; 40 41 ubi_assert(!(length & (ubi->min_io_size - 1))); 42 43 for (i = length - 1; i >= 0; i--) 44 if (((const uint8_t *)buf)[i] != 0xFF) 45 break; 46 47 /* The resulting length must be aligned to the minimum flash I/O size */ 48 length = ALIGN(i + 1, ubi->min_io_size); 49 return length; 50 } 51 52 /** 53 * ubi_check_volume - check the contents of a static volume. 54 * @ubi: UBI device description object 55 * @vol_id: ID of the volume to check 56 * 57 * This function checks if static volume @vol_id is corrupted by fully reading 58 * it and checking data CRC. This function returns %0 if the volume is not 59 * corrupted, %1 if it is corrupted and a negative error code in case of 60 * failure. Dynamic volumes are not checked and zero is returned immediately. 61 */ 62 int ubi_check_volume(struct ubi_device *ubi, int vol_id) 63 { 64 void *buf; 65 int err = 0, i; 66 struct ubi_volume *vol = ubi->volumes[vol_id]; 67 68 if (vol->vol_type != UBI_STATIC_VOLUME) 69 return 0; 70 71 buf = vmalloc(vol->usable_leb_size); 72 if (!buf) 73 return -ENOMEM; 74 75 for (i = 0; i < vol->used_ebs; i++) { 76 int size; 77 78 if (i == vol->used_ebs - 1) 79 size = vol->last_eb_bytes; 80 else 81 size = vol->usable_leb_size; 82 83 err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1); 84 if (err) { 85 if (err == -EBADMSG) 86 err = 1; 87 break; 88 } 89 } 90 91 vfree(buf); 92 return err; 93 } 94 95 /** 96 * ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad 97 * eraseblock handling. 98 * @ubi: UBI device description object 99 */ 100 void ubi_calculate_reserved(struct ubi_device *ubi) 101 { 102 ubi->beb_rsvd_level = ubi->good_peb_count/100; 103 ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE; 104 if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS) 105 ubi->beb_rsvd_level = MIN_RESEVED_PEBS; 106 } 107