diff options
Diffstat (limited to 'drivers/mtd/tests/mtd_nandbiterrs.c')
| -rw-r--r-- | drivers/mtd/tests/mtd_nandbiterrs.c | 461 |
1 files changed, 0 insertions, 461 deletions
diff --git a/drivers/mtd/tests/mtd_nandbiterrs.c b/drivers/mtd/tests/mtd_nandbiterrs.c deleted file mode 100644 index 207bf9a9972f..000000000000 --- a/drivers/mtd/tests/mtd_nandbiterrs.c +++ /dev/null @@ -1,461 +0,0 @@ -/* - * Copyright © 2012 NetCommWireless - * Iwo Mergler <Iwo.Mergler@netcommwireless.com.au> - * - * Test for multi-bit error recovery on a NAND page This mostly tests the - * ECC controller / driver. - * - * There are two test modes: - * - * 0 - artificially inserting bit errors until the ECC fails - * This is the default method and fairly quick. It should - * be independent of the quality of the FLASH. - * - * 1 - re-writing the same pattern repeatedly until the ECC fails. - * This method relies on the physics of NAND FLASH to eventually - * generate '0' bits if '1' has been written sufficient times. - * Depending on the NAND, the first bit errors will appear after - * 1000 or more writes and then will usually snowball, reaching the - * limits of the ECC quickly. - * - * The test stops after 10000 cycles, should your FLASH be - * exceptionally good and not generate bit errors before that. Try - * a different page in that case. - * - * Please note that neither of these tests will significantly 'use up' any - * FLASH endurance. Only a maximum of two erase operations will be performed. - * - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published by - * the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; see the file COPYING. If not, write to the Free Software - * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include <linux/init.h> -#include <linux/module.h> -#include <linux/moduleparam.h> -#include <linux/mtd/mtd.h> -#include <linux/err.h> -#include <linux/mtd/nand.h> -#include <linux/slab.h> - -static int dev; -module_param(dev, int, S_IRUGO); -MODULE_PARM_DESC(dev, "MTD device number to use"); - -static unsigned page_offset; -module_param(page_offset, uint, S_IRUGO); -MODULE_PARM_DESC(page_offset, "Page number relative to dev start"); - -static unsigned seed; -module_param(seed, uint, S_IRUGO); -MODULE_PARM_DESC(seed, "Random seed"); - -static int mode; -module_param(mode, int, S_IRUGO); -MODULE_PARM_DESC(mode, "0=incremental errors, 1=overwrite test"); - -static unsigned max_overwrite = 10000; - -static loff_t offset; /* Offset of the page we're using. */ -static unsigned eraseblock; /* Eraseblock number for our page. */ - -/* We assume that the ECC can correct up to a certain number - * of biterrors per subpage. */ -static unsigned subsize; /* Size of subpages */ -static unsigned subcount; /* Number of subpages per page */ - -static struct mtd_info *mtd; /* MTD device */ - -static uint8_t *wbuffer; /* One page write / compare buffer */ -static uint8_t *rbuffer; /* One page read buffer */ - -/* 'random' bytes from known offsets */ -static uint8_t hash(unsigned offset) -{ - unsigned v = offset; - unsigned char c; - v ^= 0x7f7edfd3; - v = v ^ (v >> 3); - v = v ^ (v >> 5); - v = v ^ (v >> 13); - c = v & 0xFF; - /* Reverse bits of result. */ - c = (c & 0x0F) << 4 | (c & 0xF0) >> 4; - c = (c & 0x33) << 2 | (c & 0xCC) >> 2; - c = (c & 0x55) << 1 | (c & 0xAA) >> 1; - return c; -} - -static int erase_block(void) -{ - int err; - struct erase_info ei; - loff_t addr = eraseblock * mtd->erasesize; - - pr_info("erase_block\n"); - - memset(&ei, 0, sizeof(struct erase_info)); - ei.mtd = mtd; - ei.addr = addr; - ei.len = mtd->erasesize; - - err = mtd_erase(mtd, &ei); - if (err || ei.state == MTD_ERASE_FAILED) { - pr_err("error %d while erasing\n", err); - if (!err) - err = -EIO; - return err; - } - - return 0; -} - -/* Writes wbuffer to page */ -static int write_page(int log) -{ - int err = 0; - size_t written; - - if (log) - pr_info("write_page\n"); - - err = mtd_write(mtd, offset, mtd->writesize, &written, wbuffer); - if (err || written != mtd->writesize) { - pr_err("error: write failed at %#llx\n", (long long)offset); - if (!err) - err = -EIO; - } - - return err; -} - -/* Re-writes the data area while leaving the OOB alone. */ -static int rewrite_page(int log) -{ - int err = 0; - struct mtd_oob_ops ops; - - if (log) - pr_info("rewrite page\n"); - - ops.mode = MTD_OPS_RAW; /* No ECC */ - ops.len = mtd->writesize; - ops.retlen = 0; - ops.ooblen = 0; - ops.oobretlen = 0; - ops.ooboffs = 0; - ops.datbuf = wbuffer; - ops.oobbuf = NULL; - - err = mtd_write_oob(mtd, offset, &ops); - if (err || ops.retlen != mtd->writesize) { - pr_err("error: write_oob failed (%d)\n", err); - if (!err) - err = -EIO; - } - - return err; -} - -/* Reads page into rbuffer. Returns number of corrected bit errors (>=0) - * or error (<0) */ -static int read_page(int log) -{ - int err = 0; - size_t read; - struct mtd_ecc_stats oldstats; - - if (log) - pr_info("read_page\n"); - - /* Saving last mtd stats */ - memcpy(&oldstats, &mtd->ecc_stats, sizeof(oldstats)); - - err = mtd_read(mtd, offset, mtd->writesize, &read, rbuffer); - if (err == -EUCLEAN) - err = mtd->ecc_stats.corrected - oldstats.corrected; - - if (err < 0 || read != mtd->writesize) { - pr_err("error: read failed at %#llx\n", (long long)offset); - if (err >= 0) - err = -EIO; - } - - return err; -} - -/* Verifies rbuffer against random sequence */ -static int verify_page(int log) -{ - unsigned i, errs = 0; - - if (log) - pr_info("verify_page\n"); - - for (i = 0; i < mtd->writesize; i++) { - if (rbuffer[i] != hash(i+seed)) { - pr_err("Error: page offset %u, expected %02x, got %02x\n", - i, hash(i+seed), rbuffer[i]); - errs++; - } - } - - if (errs) - return -EIO; - else - return 0; -} - -#define CBIT(v, n) ((v) & (1 << (n))) -#define BCLR(v, n) ((v) = (v) & ~(1 << (n))) - -/* Finds the first '1' bit in wbuffer starting at offset 'byte' - * and sets it to '0'. */ -static int insert_biterror(unsigned byte) -{ - int bit; - - while (byte < mtd->writesize) { - for (bit = 7; bit >= 0; bit--) { - if (CBIT(wbuffer[byte], bit)) { - BCLR(wbuffer[byte], bit); - pr_info("Inserted biterror @ %u/%u\n", byte, bit); - return 0; - } - } - byte++; - } - pr_err("biterror: Failed to find a '1' bit\n"); - return -EIO; -} - -/* Writes 'random' data to page and then introduces deliberate bit - * errors into the page, while verifying each step. */ -static int incremental_errors_test(void) -{ - int err = 0; - unsigned i; - unsigned errs_per_subpage = 0; - - pr_info("incremental biterrors test\n"); - - for (i = 0; i < mtd->writesize; i++) - wbuffer[i] = hash(i+seed); - - err = write_page(1); - if (err) - goto exit; - - while (1) { - - err = rewrite_page(1); - if (err) - goto exit; - - err = read_page(1); - if (err > 0) - pr_info("Read reported %d corrected bit errors\n", err); - if (err < 0) { - pr_err("After %d biterrors per subpage, read reported error %d\n", - errs_per_subpage, err); - err = 0; - goto exit; - } - - err = verify_page(1); - if (err) { - pr_err("ECC failure, read data is incorrect despite read success\n"); - goto exit; - } - - pr_info("Successfully corrected %d bit errors per subpage\n", - errs_per_subpage); - - for (i = 0; i < subcount; i++) { - err = insert_biterror(i * subsize); - if (err < 0) - goto exit; - } - errs_per_subpage++; - } - -exit: - return err; -} - - -/* Writes 'random' data to page and then re-writes that same data repeatedly. - This eventually develops bit errors (bits written as '1' will slowly become - '0'), which are corrected as far as the ECC is capable of. */ -static int overwrite_test(void) -{ - int err = 0; - unsigned i; - unsigned max_corrected = 0; - unsigned opno = 0; - /* We don't expect more than this many correctable bit errors per - * page. */ - #define MAXBITS 512 - static unsigned bitstats[MAXBITS]; /* bit error histogram. */ - - memset(bitstats, 0, sizeof(bitstats)); - - pr_info("overwrite biterrors test\n"); - - for (i = 0; i < mtd->writesize; i++) - wbuffer[i] = hash(i+seed); - - err = write_page(1); - if (err) - goto exit; - - while (opno < max_overwrite) { - - err = rewrite_page(0); - if (err) - break; - - err = read_page(0); - if (err >= 0) { - if (err >= MAXBITS) { - pr_info("Implausible number of bit errors corrected\n"); - err = -EIO; - break; - } - bitstats[err]++; - if (err > max_corrected) { - max_corrected = err; - pr_info("Read reported %d corrected bit errors\n", - err); - } - } else { /* err < 0 */ - pr_info("Read reported error %d\n", err); - err = 0; - break; - } - - err = verify_page(0); - if (err) { - bitstats[max_corrected] = opno; - pr_info("ECC failure, read data is incorrect despite read success\n"); - break; - } - - opno++; - } - - /* At this point bitstats[0] contains the number of ops with no bit - * errors, bitstats[1] the number of ops with 1 bit error, etc. */ - pr_info("Bit error histogram (%d operations total):\n", opno); - for (i = 0; i < max_corrected; i++) - pr_info("Page reads with %3d corrected bit errors: %d\n", - i, bitstats[i]); - -exit: - return err; -} - -static int __init mtd_nandbiterrs_init(void) -{ - int err = 0; - - printk("\n"); - printk(KERN_INFO "==================================================\n"); - pr_info("MTD device: %d\n", dev); - - mtd = get_mtd_device(NULL, dev); - if (IS_ERR(mtd)) { - err = PTR_ERR(mtd); - pr_err("error: cannot get MTD device\n"); - goto exit_mtddev; - } - - if (mtd->type != MTD_NANDFLASH) { - pr_info("this test requires NAND flash\n"); - err = -ENODEV; - goto exit_nand; - } - - pr_info("MTD device size %llu, eraseblock=%u, page=%u, oob=%u\n", - (unsigned long long)mtd->size, mtd->erasesize, - mtd->writesize, mtd->oobsize); - - subsize = mtd->writesize >> mtd->subpage_sft; - subcount = mtd->writesize / subsize; - - pr_info("Device uses %d subpages of %d bytes\n", subcount, subsize); - - offset = page_offset * mtd->writesize; - eraseblock = mtd_div_by_eb(offset, mtd); - - pr_info("Using page=%u, offset=%llu, eraseblock=%u\n", - page_offset, offset, eraseblock); - - wbuffer = kmalloc(mtd->writesize, GFP_KERNEL); - if (!wbuffer) { - err = -ENOMEM; - goto exit_wbuffer; - } - - rbuffer = kmalloc(mtd->writesize, GFP_KERNEL); - if (!rbuffer) { - err = -ENOMEM; - goto exit_rbuffer; - } - - err = erase_block(); - if (err) - goto exit_error; - - if (mode == 0) - err = incremental_errors_test(); - else - err = overwrite_test(); - - if (err) - goto exit_error; - - /* We leave the block un-erased in case of test failure. */ - err = erase_block(); - if (err) - goto exit_error; - - err = -EIO; - pr_info("finished successfully.\n"); - printk(KERN_INFO "==================================================\n"); - -exit_error: - kfree(rbuffer); -exit_rbuffer: - kfree(wbuffer); -exit_wbuffer: - /* Nothing */ -exit_nand: - put_mtd_device(mtd); -exit_mtddev: - return err; -} - -static void __exit mtd_nandbiterrs_exit(void) -{ - return; -} - -module_init(mtd_nandbiterrs_init); -module_exit(mtd_nandbiterrs_exit); - -MODULE_DESCRIPTION("NAND bit error recovery test"); -MODULE_AUTHOR("Iwo Mergler"); -MODULE_LICENSE("GPL"); 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