diff options
-rw-r--r-- | drivers/mtd/nand/core.c | 131 | ||||
-rw-r--r-- | drivers/mtd/nand/raw/nand_base.c | 131 | ||||
-rw-r--r-- | include/linux/mtd/nand.h | 5 | ||||
-rw-r--r-- | include/linux/mtd/rawnand.h | 5 |
4 files changed, 136 insertions, 136 deletions
diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c index 7737b1a4a177..3e76d127715f 100644 --- a/drivers/mtd/nand/core.c +++ b/drivers/mtd/nand/core.c @@ -13,6 +13,137 @@ #include <linux/mtd/nand.h> /** + * nand_check_erased_buf - check if a buffer contains (almost) only 0xff data + * @buf: buffer to test + * @len: buffer length + * @bitflips_threshold: maximum number of bitflips + * + * Check if a buffer contains only 0xff, which means the underlying region + * has been erased and is ready to be programmed. + * The bitflips_threshold specify the maximum number of bitflips before + * considering the region is not erased. + * Note: The logic of this function has been extracted from the memweight + * implementation, except that nand_check_erased_buf function exit before + * testing the whole buffer if the number of bitflips exceed the + * bitflips_threshold value. + * + * Returns a positive number of bitflips less than or equal to + * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the + * threshold. + */ +static int nand_check_erased_buf(void *buf, int len, int bitflips_threshold) +{ + const unsigned char *bitmap = buf; + int bitflips = 0; + int weight; + + for (; len && ((uintptr_t)bitmap) % sizeof(long); + len--, bitmap++) { + weight = hweight8(*bitmap); + bitflips += BITS_PER_BYTE - weight; + if (unlikely(bitflips > bitflips_threshold)) + return -EBADMSG; + } + + for (; len >= sizeof(long); + len -= sizeof(long), bitmap += sizeof(long)) { + unsigned long d = *((unsigned long *)bitmap); + if (d == ~0UL) + continue; + weight = hweight_long(d); + bitflips += BITS_PER_LONG - weight; + if (unlikely(bitflips > bitflips_threshold)) + return -EBADMSG; + } + + for (; len > 0; len--, bitmap++) { + weight = hweight8(*bitmap); + bitflips += BITS_PER_BYTE - weight; + if (unlikely(bitflips > bitflips_threshold)) + return -EBADMSG; + } + + return bitflips; +} + +/** + * nand_check_erased_ecc_chunk - check if an ECC chunk contains (almost) only + * 0xff data + * @data: data buffer to test + * @datalen: data length + * @ecc: ECC buffer + * @ecclen: ECC length + * @extraoob: extra OOB buffer + * @extraooblen: extra OOB length + * @bitflips_threshold: maximum number of bitflips + * + * Check if a data buffer and its associated ECC and OOB data contains only + * 0xff pattern, which means the underlying region has been erased and is + * ready to be programmed. + * The bitflips_threshold specify the maximum number of bitflips before + * considering the region as not erased. + * + * Note: + * 1/ ECC algorithms are working on pre-defined block sizes which are usually + * different from the NAND page size. When fixing bitflips, ECC engines will + * report the number of errors per chunk, and the NAND core infrastructure + * expect you to return the maximum number of bitflips for the whole page. + * This is why you should always use this function on a single chunk and + * not on the whole page. After checking each chunk you should update your + * max_bitflips value accordingly. + * 2/ When checking for bitflips in erased pages you should not only check + * the payload data but also their associated ECC data, because a user might + * have programmed almost all bits to 1 but a few. In this case, we + * shouldn't consider the chunk as erased, and checking ECC bytes prevent + * this case. + * 3/ The extraoob argument is optional, and should be used if some of your OOB + * data are protected by the ECC engine. + * It could also be used if you support subpages and want to attach some + * extra OOB data to an ECC chunk. + * + * Returns a positive number of bitflips less than or equal to + * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the + * threshold. In case of success, the passed buffers are filled with 0xff. + */ +int nand_check_erased_ecc_chunk(void *data, int datalen, + void *ecc, int ecclen, + void *extraoob, int extraooblen, + int bitflips_threshold) +{ + int data_bitflips = 0, ecc_bitflips = 0, extraoob_bitflips = 0; + + data_bitflips = nand_check_erased_buf(data, datalen, + bitflips_threshold); + if (data_bitflips < 0) + return data_bitflips; + + bitflips_threshold -= data_bitflips; + + ecc_bitflips = nand_check_erased_buf(ecc, ecclen, bitflips_threshold); + if (ecc_bitflips < 0) + return ecc_bitflips; + + bitflips_threshold -= ecc_bitflips; + + extraoob_bitflips = nand_check_erased_buf(extraoob, extraooblen, + bitflips_threshold); + if (extraoob_bitflips < 0) + return extraoob_bitflips; + + if (data_bitflips) + memset(data, 0xff, datalen); + + if (ecc_bitflips) + memset(ecc, 0xff, ecclen); + + if (extraoob_bitflips) + memset(extraoob, 0xff, extraooblen); + + return data_bitflips + ecc_bitflips + extraoob_bitflips; +} +EXPORT_SYMBOL(nand_check_erased_ecc_chunk); + +/** * nanddev_isbad() - Check if a block is bad * @nand: NAND device * @pos: position pointing to the block we want to check diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index 13e4060bd1b6..c7d9501f646b 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -2784,137 +2784,6 @@ int nand_set_features(struct nand_chip *chip, int addr, } /** - * nand_check_erased_buf - check if a buffer contains (almost) only 0xff data - * @buf: buffer to test - * @len: buffer length - * @bitflips_threshold: maximum number of bitflips - * - * Check if a buffer contains only 0xff, which means the underlying region - * has been erased and is ready to be programmed. - * The bitflips_threshold specify the maximum number of bitflips before - * considering the region is not erased. - * Note: The logic of this function has been extracted from the memweight - * implementation, except that nand_check_erased_buf function exit before - * testing the whole buffer if the number of bitflips exceed the - * bitflips_threshold value. - * - * Returns a positive number of bitflips less than or equal to - * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the - * threshold. - */ -static int nand_check_erased_buf(void *buf, int len, int bitflips_threshold) -{ - const unsigned char *bitmap = buf; - int bitflips = 0; - int weight; - - for (; len && ((uintptr_t)bitmap) % sizeof(long); - len--, bitmap++) { - weight = hweight8(*bitmap); - bitflips += BITS_PER_BYTE - weight; - if (unlikely(bitflips > bitflips_threshold)) - return -EBADMSG; - } - - for (; len >= sizeof(long); - len -= sizeof(long), bitmap += sizeof(long)) { - unsigned long d = *((unsigned long *)bitmap); - if (d == ~0UL) - continue; - weight = hweight_long(d); - bitflips += BITS_PER_LONG - weight; - if (unlikely(bitflips > bitflips_threshold)) - return -EBADMSG; - } - - for (; len > 0; len--, bitmap++) { - weight = hweight8(*bitmap); - bitflips += BITS_PER_BYTE - weight; - if (unlikely(bitflips > bitflips_threshold)) - return -EBADMSG; - } - - return bitflips; -} - -/** - * nand_check_erased_ecc_chunk - check if an ECC chunk contains (almost) only - * 0xff data - * @data: data buffer to test - * @datalen: data length - * @ecc: ECC buffer - * @ecclen: ECC length - * @extraoob: extra OOB buffer - * @extraooblen: extra OOB length - * @bitflips_threshold: maximum number of bitflips - * - * Check if a data buffer and its associated ECC and OOB data contains only - * 0xff pattern, which means the underlying region has been erased and is - * ready to be programmed. - * The bitflips_threshold specify the maximum number of bitflips before - * considering the region as not erased. - * - * Note: - * 1/ ECC algorithms are working on pre-defined block sizes which are usually - * different from the NAND page size. When fixing bitflips, ECC engines will - * report the number of errors per chunk, and the NAND core infrastructure - * expect you to return the maximum number of bitflips for the whole page. - * This is why you should always use this function on a single chunk and - * not on the whole page. After checking each chunk you should update your - * max_bitflips value accordingly. - * 2/ When checking for bitflips in erased pages you should not only check - * the payload data but also their associated ECC data, because a user might - * have programmed almost all bits to 1 but a few. In this case, we - * shouldn't consider the chunk as erased, and checking ECC bytes prevent - * this case. - * 3/ The extraoob argument is optional, and should be used if some of your OOB - * data are protected by the ECC engine. - * It could also be used if you support subpages and want to attach some - * extra OOB data to an ECC chunk. - * - * Returns a positive number of bitflips less than or equal to - * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the - * threshold. In case of success, the passed buffers are filled with 0xff. - */ -int nand_check_erased_ecc_chunk(void *data, int datalen, - void *ecc, int ecclen, - void *extraoob, int extraooblen, - int bitflips_threshold) -{ - int data_bitflips = 0, ecc_bitflips = 0, extraoob_bitflips = 0; - - data_bitflips = nand_check_erased_buf(data, datalen, - bitflips_threshold); - if (data_bitflips < 0) - return data_bitflips; - - bitflips_threshold -= data_bitflips; - - ecc_bitflips = nand_check_erased_buf(ecc, ecclen, bitflips_threshold); - if (ecc_bitflips < 0) - return ecc_bitflips; - - bitflips_threshold -= ecc_bitflips; - - extraoob_bitflips = nand_check_erased_buf(extraoob, extraooblen, - bitflips_threshold); - if (extraoob_bitflips < 0) - return extraoob_bitflips; - - if (data_bitflips) - memset(data, 0xff, datalen); - - if (ecc_bitflips) - memset(ecc, 0xff, ecclen); - - if (extraoob_bitflips) - memset(extraoob, 0xff, extraooblen); - - return data_bitflips + ecc_bitflips + extraoob_bitflips; -} -EXPORT_SYMBOL(nand_check_erased_ecc_chunk); - -/** * nand_read_page_raw_notsupp - dummy read raw page function * @chip: nand chip info structure * @buf: buffer to store read data diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 07486168d104..09c8c93e4dba 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -1136,4 +1136,9 @@ static inline bool nanddev_bbt_is_initialized(struct nand_device *nand) int nanddev_mtd_erase(struct mtd_info *mtd, struct erase_info *einfo); int nanddev_mtd_max_bad_blocks(struct mtd_info *mtd, loff_t offs, size_t len); +int nand_check_erased_ecc_chunk(void *data, int datalen, + void *ecc, int ecclen, + void *extraoob, int extraooblen, + int threshold); + #endif /* __LINUX_MTD_NAND_H */ diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h index e84522e31301..d30bdc3fcfd7 100644 --- a/include/linux/mtd/rawnand.h +++ b/include/linux/mtd/rawnand.h @@ -1519,11 +1519,6 @@ int rawnand_sw_bch_correct(struct nand_chip *chip, unsigned char *buf, unsigned char *read_ecc, unsigned char *calc_ecc); void rawnand_sw_bch_cleanup(struct nand_chip *chip); -int nand_check_erased_ecc_chunk(void *data, int datalen, - void *ecc, int ecclen, - void *extraoob, int extraooblen, - int threshold); - int nand_ecc_choose_conf(struct nand_chip *chip, const struct nand_ecc_caps *caps, int oobavail); |