#include <linux/module.h>
#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
return nand_set_features_op(chip, addr, subfeature_param);
}
-/**
- * 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
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 */
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);
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