[RFC][PATCH] mtd-utils: Add read disturb test utility
David Oberhollenzer
david.oberhollenzer at sigma-star.at
Wed Nov 25 07:41:19 EST 2015
- Read disturb test mode repeatedly reads range of blocks
and counts bit flips. The page with the highest number is
reported for each block.
- Implements functionallity of proposed in-kernel read
disturb test.
- MLC test mode counts and compares bit flips before and after
writing to a paired page.
- Still looking for a better name for the utility.
Signed-off-by: David Oberhollenzer <david.oberhollenzer at sigma-star.at>
---
.gitignore | 1 +
Makefile | 2 +-
nand-utils/readdisturbtest.c | 397 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 399 insertions(+), 1 deletion(-)
create mode 100644 nand-utils/readdisturbtest.c
diff --git a/.gitignore b/.gitignore
index 2aac52c..7fa8468 100644
--- a/.gitignore
+++ b/.gitignore
@@ -35,6 +35,7 @@
/jffsX-utils/mkfs.jffs2
/misc-utils/mtd_debug
/misc-utils/mtdpart
+/nand-utils/readdisturbtest
/nand-utils/nanddump
/nand-utils/nandtest
/nand-utils/nandwrite
diff --git a/Makefile b/Makefile
index bd9504a..1bcc0af 100644
--- a/Makefile
+++ b/Makefile
@@ -29,7 +29,7 @@ UBIFS_BINS = \
JFFSX_BINS = \
mkfs.jffs2 sumtool jffs2reader jffs2dump
NAND_BINS = \
- nanddump nandwrite nandtest nftldump nftl_format
+ nanddump nandwrite nandtest nftldump nftl_format readdisturbtest
NOR_BINS = \
rfddump rfdformat
diff --git a/nand-utils/readdisturbtest.c b/nand-utils/readdisturbtest.c
new file mode 100644
index 0000000..86ea1c4
--- /dev/null
+++ b/nand-utils/readdisturbtest.c
@@ -0,0 +1,397 @@
+#define PROGRAM_NAME "readdisturbtest"
+
+#include <mtd/mtd-user.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <libmtd.h>
+#include <stdio.h>
+#include <fcntl.h>
+
+#include "common.h"
+
+#define KEEP_CONTENTS 0x01
+#define RUN_READTEST 0x02
+#define RUN_MLCTEST 0x04
+#define READ_MULTI 0x08
+
+static int peb=-1, pair1=-1, pair2=-1, reads=-1, blocks=-1, skip=-1, log=-1;
+static struct mtd_dev_info mtd;
+static const char *mtddev;
+static libmtd_t mtd_desc;
+static int mtdfd, flags;
+
+static void usage(int status)
+{
+ fputs(
+ "Usage: "PROGRAM_NAME" [OPTIONS] <device>\n\n"
+ "Common options:\n"
+ " -h, --help Display this help output\n"
+ " -b, --peb <num> Start from this physical erase block\n"
+ " -c, --blocks <num> Number of erase blocks to read\n"
+ " -s, --skip <num> Number of erase blocks to skip\n"
+ " -k, --keep Restore existing contents after test\n\n"
+ "Options for MLC test:\n"
+ " -p, --pair <first> <second> Assume the given pages are paired\n\n"
+ "Options for read disturb test:\n"
+ " -r, --reads <num> Number of iterations\n"
+ " -l, --log <num> If set, only log statistics after\n"
+ " the Nth iteration.\n",
+ status==EXIT_SUCCESS ? stdout : stderr);
+ exit(status);
+}
+
+static long read_num(int idx, int argidx, int argc, char **argv)
+{
+ char *end;
+ long num;
+
+ if (argidx >= argc) {
+ fprintf(stderr, "%s: missing argument\n", argv[idx]);
+ exit(EXIT_FAILURE);
+ }
+
+ num = strtol(argv[argidx], &end, 0);
+
+ if (!end || *end!='\0') {
+ fprintf(stderr, "%s: expected integer argument\n", argv[idx]);
+ exit(EXIT_FAILURE);
+ }
+ return num;
+}
+
+static void process_options(int argc, char **argv)
+{
+ int i;
+
+ for (i=1; i<argc; ++i) {
+ if (!strcmp(argv[i], "--help") || !strcmp(argv[i], "-h")) {
+ usage(EXIT_SUCCESS);
+ } else if (!strcmp(argv[i], "--keep") || !strcmp(argv[i], "-k")) {
+ if (flags & KEEP_CONTENTS)
+ goto failmulti;
+ flags |= KEEP_CONTENTS;
+ } else if (!strcmp(argv[i], "--peb") || !strcmp(argv[i], "-b")) {
+ if (peb >= 0)
+ goto failmulti;
+ peb = read_num(i, i+1, argc, argv);
+ if (peb < 0)
+ goto failarg;
+ ++i;
+ } else if (!strcmp(argv[i], "--pair") || !strcmp(argv[i], "-p")) {
+ if (flags & RUN_MLCTEST)
+ goto failmulti;
+ pair1 = read_num(i, i+1, argc, argv);
+ pair2 = read_num(i, i+2, argc, argv);
+ if (pair1<0 || pair2<0 || pair1==pair2)
+ goto failarg;
+ i += 2;
+ flags |= RUN_MLCTEST;
+ } else if (!strcmp(argv[i], "--reads") || !strcmp(argv[i], "-r")) {
+ if (flags & RUN_READTEST)
+ goto failmulti;
+ reads = read_num(i, i+1, argc, argv);
+ if (reads <= 0)
+ goto failarg;
+ ++i;
+ flags |= RUN_READTEST;
+ } else if (!strcmp(argv[i], "--blocks") || !strcmp(argv[i], "-c")) {
+ if (blocks > 0)
+ goto failmulti;
+ blocks = read_num(i, i+1, argc, argv);
+ if (blocks <= 0)
+ goto failarg;
+ ++i;
+ flags |= READ_MULTI;
+ } else if (!strcmp(argv[i], "--skip") || !strcmp(argv[i], "-s")) {
+ if (skip >= 0)
+ goto failmulti;
+ skip = read_num(i, i+1, argc, argv);
+ if (skip < 0)
+ goto failarg;
+ ++i;
+ flags |= READ_MULTI;
+ } else if (!strcmp(argv[i], "--log") || !strcmp(argv[i], "-l")) {
+ if (log>0)
+ goto failmulti;
+ log = read_num(i, i+1, argc, argv);
+ if (log <= 0)
+ goto failarg;
+ ++i;
+ } else {
+ if (mtddev)
+ usage(EXIT_FAILURE);
+ mtddev = argv[i];
+ }
+ }
+
+ if ((flags & READ_MULTI) && blocks <= 0)
+ errmsg_die("Block skip specified, but no block count!\n");
+
+ if (!(flags & (RUN_READTEST|RUN_MLCTEST)))
+ errmsg_die("Neither page pair nor read test iterations specified!\n");
+
+ if (!mtddev)
+ errmsg_die("No device specified!\n");
+
+ if (log < 0)
+ log = 1;
+ if (peb < 0)
+ peb = 0;
+ if (skip < 0)
+ skip = 0;
+ if (blocks < 0)
+ blocks = 1;
+ return;
+failmulti:
+ fprintf(stderr, "'%s' specified more than once!\n", argv[i]);
+ exit(EXIT_FAILURE);
+failarg:
+ fprintf(stderr, "Invalid argument for '%s'!\n", argv[i]);
+ exit(EXIT_FAILURE);
+}
+
+static size_t count_bitflips(unsigned char* a, unsigned char* b, size_t size)
+{
+ size_t i, count=0;
+ unsigned char x;
+
+ for (i=0; i < size; ++i) {
+ x = *(a++) ^ *(b++);
+ count += __builtin_popcount(x);
+ }
+
+ return count;
+}
+
+static int mlc_test(void)
+{
+ void *page1=NULL, *page2=NULL, *scratch=NULL;
+ int err = -1, i, block;
+ size_t count1, count2;
+
+ puts("================= MLC test ================");
+
+ page1 = malloc(mtd.subpage_size);
+ if (!page1)
+ goto failalloc;
+ page2 = malloc(mtd.subpage_size);
+ if (!page2)
+ goto failalloc;
+ scratch = malloc(mtd.subpage_size);
+ if (!scratch)
+ goto failalloc;
+
+ memset(page1, 0xAA, mtd.subpage_size);
+ memset(page2, 0x55, mtd.subpage_size);
+
+ for (i=0; i < blocks; ++i) {
+ block = peb + i*(skip+1);
+
+ if (mtd_erase(mtd_desc, &mtd, mtdfd, block)) {
+ perror("mtd_erase");
+ goto out;
+ }
+
+ mtd_write(mtd_desc, &mtd, mtdfd, block, mtd.subpage_size*pair1,
+ page1, mtd.subpage_size, NULL, 0, 0);
+ mtd_read(&mtd, mtdfd, block, mtd.subpage_size*pair1,
+ scratch, mtd.subpage_size);
+
+ count1 = count_bitflips(page1, scratch, mtd.subpage_size);
+ printf("Detected %zu bit flips in block %d, page %zu\n",
+ count1,block,pair1);
+
+ mtd_write(mtd_desc, &mtd, mtdfd, block, mtd.subpage_size*pair2,
+ page2, mtd.subpage_size, NULL, 0, 0);
+ mtd_read(&mtd, mtdfd, block, mtd.subpage_size*pair1,
+ scratch, mtd.subpage_size);
+
+ count2 = count_bitflips(page1, scratch, mtd.subpage_size);
+ printf("Detected %zu bit flips in block %d, page %zu\n",
+ count2,block,pair1);
+
+ if (count2 > count1)
+ printf("Number of bitflips increased by %zu\n", count2-count1);
+ else if(count2 < count1)
+ printf("At least %zu previously flipped bits flipped back\n",
+ count1-count2);
+ }
+ err = 0;
+out:
+ free(page1);
+ free(page2);
+ free(scratch);
+ return err;
+failalloc:
+ fputs("Out of memory", stderr);
+ goto out;
+}
+
+static int read_test(void)
+{
+ size_t i, count, worst, worstpage;
+ void *pattern=NULL, *scratch=NULL;
+ int j, k, err=-1;
+
+ puts("============ read disturb test ============");
+
+ pattern = malloc(mtd.eb_size);
+ if (!pattern)
+ goto failalloc;
+
+ scratch = malloc(mtd.eb_size);
+ if (!scratch)
+ goto failalloc;
+
+ for (i=0; i < mtd.eb_size; i += mtd.subpage_size)
+ memset(pattern + i, i & 0x01 ? 0xAA : 0x55, mtd.subpage_size);
+
+ for (i=0; i < blocks; ++i) {
+ if (mtd_erase(mtd_desc, &mtd, mtdfd, peb+i*(skip+1))) {
+ perror("mtd_erase");
+ goto out;
+ }
+
+ mtd_write(mtd_desc, &mtd, mtdfd, peb+i*(skip+1), 0,
+ pattern, mtd.eb_size, NULL, 0, 0);
+ }
+
+ for (j=0; j < reads; ++j) {
+ for (k=0; k < blocks; ++k) {
+ mtd_read(&mtd, mtdfd, peb+k*(skip+1), 0, scratch, mtd.eb_size);
+ worstpage = 0;
+ worst = 0;
+
+ for (i=0; i < mtd.eb_size; i += mtd.subpage_size) {
+ count = count_bitflips(pattern + i, scratch + i,
+ mtd.subpage_size);
+
+ if (count > worst) {
+ worst = count;
+ worstpage = i / mtd.subpage_size;
+ }
+ }
+
+ if (((j+1) % log)==0) {
+ printf("Detected %zu bitflips in block %d, page %zu "
+ "after %d reads\n", worst, peb+k*(skip+1),
+ worstpage, j+1);
+ }
+ }
+ }
+
+ err = 0;
+out:
+ free(pattern);
+ free(scratch);
+ return err;
+failalloc:
+ fputs("Out of memory", stderr);
+ goto out;
+}
+
+int main(int argc, char **argv)
+{
+ int pagecount, err, status=EXIT_FAILURE, i;
+ void *old = NULL;
+
+ process_options(argc, argv);
+
+ mtd_desc = libmtd_open();
+ if (!mtd_desc)
+ return errmsg("can't initialize libmtd");
+
+ /* sanity check */
+ if (mtd_get_dev_info(mtd_desc, mtddev, &mtd) < 0)
+ return errmsg("mtd_get_dev_info failed");
+
+ if (mtd.type!=MTD_MLCNANDFLASH && mtd.type!=MTD_NANDFLASH)
+ return errmsg("%s is not a NAND flash!\n", mtddev);
+
+ pagecount = mtd.eb_size / mtd.subpage_size;
+
+ if (peb >= mtd.eb_cnt)
+ return errmsg("Physical erase block %d is out of range!\n", peb);
+ if (pair1 >= pagecount)
+ return errmsg("Page number %d is out of range!\n", pair1);
+ if (pair2 >= pagecount)
+ return errmsg("Page number %d is out of range!\n", pair2);
+
+ if ((peb + (blocks - 1)*(skip + 1)) >= mtd.eb_cnt) {
+ return errmsg("Given block range exceeds block count of %d!\n",
+ mtd.eb_cnt);
+ }
+
+ /* open device and set raw mode (no ECC) */
+ if ((mtdfd = open(mtddev, O_RDWR)) == -1) {
+ perror(mtddev);
+ return EXIT_FAILURE;
+ }
+
+ if (flags & KEEP_CONTENTS) {
+ old = malloc(mtd.eb_size * blocks);
+ if (!old) {
+ fputs("Not enough memory to backup old data!\n", stderr);
+ return EXIT_FAILURE;
+ }
+
+ for (i=0; i < blocks; ++i) {
+ err = mtd_read(&mtd, mtdfd, peb+i*(skip+1), 0,
+ old+i*mtd.eb_size, mtd.eb_size);
+
+ if (err) {
+ perror("mtd_read");
+ return EXIT_FAILURE;
+ }
+ }
+ }
+
+ if (ioctl(mtdfd, MTDFILEMODE, MTD_FILE_MODE_RAW)!=0) {
+ perror("MTDFILEMODE");
+ return EXIT_FAILURE;
+ }
+
+ /* run test */
+ if (flags & RUN_MLCTEST) {
+ if (mlc_test( ))
+ goto out;
+ }
+ if (flags & RUN_READTEST) {
+ if (read_test( ))
+ goto out;
+ }
+
+ status = EXIT_SUCCESS;
+
+ /* restore */
+out:
+ if (flags & KEEP_CONTENTS) {
+ if (ioctl(mtdfd, MTDFILEMODE, MTD_FILE_MODE_NORMAL)!=0) {
+ perror("MTDFILEMODE");
+ return EXIT_FAILURE;
+ }
+
+ for (i=0; i < blocks; ++i) {
+ if (mtd_erase(mtd_desc, &mtd, mtdfd, peb+i*(skip+1))) {
+ perror("mtd_erase");
+ status = EXIT_FAILURE;
+ }
+
+ err = mtd_write(mtd_desc, &mtd, mtdfd, peb+i*(skip+1), 0,
+ old+i*mtd.eb_size, mtd.eb_size,
+ NULL, 0, 0);
+
+ if (err) {
+ perror("mtd_write");
+ status = EXIT_FAILURE;
+ }
+ }
+ }
+
+ /* cleanup */
+ close(mtdfd);
+ free(old);
+ return status;
+}
--
2.6.2
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