[PATCH v2 3/3] cmd: mtd: add nandtest command support

Mikhail Kshevetskiy mikhail.kshevetskiy at iopsys.eu
Wed Jul 31 06:25:52 CEST 2024


This patch implements readonly test of nand flashes.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
---
 cmd/Kconfig |   6 ++
 cmd/mtd.c   | 203 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 209 insertions(+)

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 698e0e697f2..db5113e016b 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1445,6 +1445,12 @@ config CMD_MTD_TORTURE
 	help
 	  MTD torture command support.
 
+config CMD_MTD_NANDTEST
+	bool "mtd nandtest"
+	depends on CMD_MTD
+	help
+	  MTD nandtest command support.
+
 config CMD_MUX
 	bool "mux"
 	depends on MULTIPLEXER
diff --git a/cmd/mtd.c b/cmd/mtd.c
index 69ddfe1d9c6..4a380dcaf83 100644
--- a/cmd/mtd.c
+++ b/cmd/mtd.c
@@ -931,6 +931,202 @@ out_put_mtd:
 }
 #endif
 
+#ifdef CONFIG_CMD_MTD_NANDTEST
+enum nandtest_status {
+	NANDTEST_STATUS_UNKNOWN = 0,
+	NANDTEST_STATUS_NONECC_READ_FAIL,
+	NANDTEST_STATUS_ECC_READ_FAIL,
+	NANDTEST_STATUS_BAD_BLOCK,
+	NANDTEST_STATUS_BITFLIP_ABOVE_MAX,
+	NANDTEST_STATUS_BITFLIP_MISMATCH,
+	NANDTEST_STATUS_BITFLIP_MAX,
+	NANDTEST_STATUS_OK,
+};
+
+static enum nandtest_status nandtest_block_check(struct mtd_info *mtd,
+						 loff_t off, size_t blocksize)
+{
+	struct mtd_oob_ops	ops = {};
+	u_char			*buf;
+	int			i, d, ret, len, pos, cnt, max;
+
+	if (blocksize % mtd->writesize != 0) {
+		printf("\r  block at %llx: bad block size\n", off);
+		return NANDTEST_STATUS_UNKNOWN;
+	}
+
+	buf = malloc_cache_aligned(2 * blocksize);
+	if (buf == NULL) {
+		printf("\r  block at %llx: can't allocate memory\n", off);
+		return NANDTEST_STATUS_UNKNOWN;
+	}
+
+	ops.mode = MTD_OPS_RAW;
+	ops.len = blocksize;
+	ops.datbuf = buf;
+	ops.ooblen = 0;
+	ops.oobbuf = NULL;
+
+	if (mtd->_read_oob)
+		ret = mtd->_read_oob(mtd, off, &ops);
+	else
+		ret = mtd->_read(mtd, off, ops.len, &ops.retlen, ops.datbuf);
+
+	if (ret != 0) {
+		free(buf);
+		printf("\r  block at %llx: non-ecc reading error %d\n",
+		       off, ret);
+		return NANDTEST_STATUS_NONECC_READ_FAIL;
+	}
+
+	ops.mode = MTD_OPS_AUTO_OOB;
+	ops.datbuf = buf + blocksize;
+
+	if (mtd->_read_oob)
+		ret = mtd->_read_oob(mtd, off, &ops);
+	else
+		ret = mtd->_read(mtd, off, ops.len, &ops.retlen, ops.datbuf);
+
+	if (ret == -EBADMSG) {
+		free(buf);
+		printf("\r  block at %llx: bad block\n", off);
+		return NANDTEST_STATUS_BAD_BLOCK;
+	}
+
+	if (ret < 0) {
+		free(buf);
+		printf("\r  block at %llx: ecc reading error %d\n", off, ret);
+		return NANDTEST_STATUS_ECC_READ_FAIL;
+	}
+
+	if (mtd->ecc_strength == 0) {
+		free(buf);
+		return NANDTEST_STATUS_OK;
+	}
+
+	if (ret > mtd->ecc_strength) {
+		free(buf);
+		printf("\r  block at %llx: returned bit-flips value %d "
+		       "is above maximum value %d\n",
+		       off, ret, mtd->ecc_strength);
+		return NANDTEST_STATUS_BITFLIP_ABOVE_MAX;
+	}
+
+	max = 0;
+	pos = 0;
+	len = blocksize;
+	while (len > 0) {
+		cnt = 0;
+		for (i = 0; i < mtd->ecc_step_size; i++) {
+			d = buf[pos + i] ^ buf[blocksize + pos + i];
+			if (d == 0)
+				continue;
+
+			while (d > 0) {
+				d &= (d - 1);
+				cnt++;
+			}
+		}
+		if (cnt > max)
+			max = cnt;
+
+		len -= mtd->ecc_step_size;
+		pos += mtd->ecc_step_size;
+	}
+
+	free(buf);
+
+	if (max > ret) {
+		printf("\r  block at %llx: bitflip mismatch, "
+		       "read %d but actual %d\n", off, ret, max);
+		return NANDTEST_STATUS_BITFLIP_MISMATCH;
+	}
+
+	if (ret == mtd->ecc_strength) {
+		printf("\r  block at %llx: max bitflip reached, "
+		       "block is unreliable\n", off);
+		return NANDTEST_STATUS_BITFLIP_MAX;
+	}
+
+	return NANDTEST_STATUS_OK;
+}
+
+static int do_mtd_nandtest(struct cmd_tbl *cmdtp, int flag, int argc,
+			   char *const argv[])
+{
+	struct mtd_info		*mtd;
+	loff_t			off, len;
+	int			stat[NANDTEST_STATUS_OK + 1];
+	enum nandtest_status	ret;
+	size_t			block_size;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	mtd = get_mtd_by_name(argv[1]);
+	if (IS_ERR_OR_NULL(mtd))
+		return CMD_RET_FAILURE;
+
+	if (!mtd_can_have_bb(mtd)) {
+		printf("Only NAND-based devices can be checked\n");
+		goto out_put_mtd;
+	}
+
+	off = 0;
+	len = mtd->size;
+	block_size = mtd->erasesize;
+
+	printf("ECC strength:     %d\n",   mtd->ecc_strength);
+	printf("ECC step size:    %d\n",   mtd->ecc_step_size);
+	printf("Erase block size: 0x%x\n", mtd->erasesize);
+	printf("Total blocks:     %d\n",   (u32)len / mtd->erasesize);
+
+	memset(stat, 0, sizeof(stat));
+	while (len > 0) {
+		if (mtd_is_aligned_with_block_size(mtd, off))
+			printf("\r  block at %llx ", off);
+
+		ret = nandtest_block_check(mtd, off, block_size);
+		stat[ret]++;
+
+		switch (ret) {
+		case NANDTEST_STATUS_BAD_BLOCK:
+		case NANDTEST_STATUS_BITFLIP_MAX:
+			if (!mtd_block_isbad(mtd, off))
+				printf("\r  block at %llx: should be marked "
+				       "as BAD\n", off);
+			break;
+
+		case NANDTEST_STATUS_OK:
+			if (mtd_block_isbad(mtd, off))
+				printf("\r  block at %llx: marked as BAD, but "
+				       "probably is GOOD\n", off);
+			break;
+
+		default:
+			break;
+		}
+
+		off += block_size;
+		len -= block_size;
+	}
+
+out_put_mtd:
+	put_mtd_device(mtd);
+	printf("\n");
+	printf("results:\n");
+	printf("  Good blocks:            %d\n", stat[NANDTEST_STATUS_OK]);
+	printf("  Physically bad blocks:  %d\n", stat[NANDTEST_STATUS_BAD_BLOCK]);
+	printf("  Unreliable blocks:      %d\n", stat[NANDTEST_STATUS_BITFLIP_MAX]);
+	printf("  Non checked blocks:     %d\n", stat[NANDTEST_STATUS_UNKNOWN]);
+	printf("  Failed to check blocks: %d\n", stat[NANDTEST_STATUS_NONECC_READ_FAIL] +
+						 stat[NANDTEST_STATUS_ECC_READ_FAIL]);
+	printf("  Suspictious blocks:     %d\n", stat[NANDTEST_STATUS_BITFLIP_ABOVE_MAX] +
+						 stat[NANDTEST_STATUS_BITFLIP_MISMATCH]);
+	return CMD_RET_SUCCESS;
+}
+#endif
+
 static int do_mtd_bad(struct cmd_tbl *cmdtp, int flag, int argc,
 		      char *const argv[])
 {
@@ -1019,6 +1215,9 @@ U_BOOT_LONGHELP(mtd,
 #endif
 #ifdef CONFIG_CMD_MTD_TORTURE
 	"mtd torture                           <name>        [<off> [<size>]]\n"
+#endif
+#ifdef CONFIG_CMD_MTD_NANDTEST
+	"mtd nandtest                          <name>\n"
 #endif
 	"\n"
 	"With:\n"
@@ -1060,6 +1259,10 @@ U_BOOT_CMD_WITH_SUBCMDS(mtd, "MTD utils", mtd_help_text,
 #ifdef CONFIG_CMD_MTD_TORTURE
 		U_BOOT_SUBCMD_MKENT_COMPLETE(torture, 4, 0, do_mtd_torture,
 					     mtd_name_complete),
+#endif
+#ifdef CONFIG_CMD_MTD_NANDTEST
+		U_BOOT_SUBCMD_MKENT_COMPLETE(nandtest, 2, 0, do_mtd_nandtest,
+					     mtd_name_complete),
 #endif
 		U_BOOT_SUBCMD_MKENT_COMPLETE(bad, 2, 1, do_mtd_bad,
 					     mtd_name_complete));
-- 
2.39.2



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