From 2ed18d818d1f7492172f8dd5904344c7d367e8ed Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micha=C5=82=20K=C4=99pie=C5=84?= Date: Wed, 29 Jun 2022 14:57:36 +0200 Subject: [PATCH 3/4] mtd: add ECC error accounting for each read request MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Extend struct mtd_req_stats with two new fields holding the number of corrected bitflips and uncorrectable errors detected during a read operation. This is a prerequisite for ultimately passing those counters to user space, where they can be useful to applications for making better-informed choices about moving data around. Unlike 'max_bitflips' (which is set - in a common code path - to the return value of a function called while the MTD device's mutex is held), these counters have to be maintained in each MTD driver which defines the '_read_oob' callback because the statistics need to be calculated while the MTD device's mutex is held. Suggested-by: Boris Brezillon Signed-off-by: Michał Kępień Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220629125737.14418-4-kernel@kempniu.pl --- drivers/mtd/devices/docg3.c | 8 ++++++++ drivers/mtd/nand/onenand/onenand_base.c | 12 ++++++++++++ drivers/mtd/nand/raw/nand_base.c | 10 ++++++++++ drivers/mtd/nand/spi/core.c | 10 ++++++++++ include/linux/mtd/mtd.h | 2 ++ 5 files changed, 42 insertions(+) --- a/drivers/mtd/devices/docg3.c +++ b/drivers/mtd/devices/docg3.c @@ -871,6 +871,7 @@ static int doc_read_oob(struct mtd_info u8 *buf = ops->datbuf; size_t len, ooblen, nbdata, nboob; u8 hwecc[DOC_ECC_BCH_SIZE], eccconf1; + struct mtd_ecc_stats old_stats; int max_bitflips = 0; if (buf) @@ -895,6 +896,7 @@ static int doc_read_oob(struct mtd_info ret = 0; skip = from % DOC_LAYOUT_PAGE_SIZE; mutex_lock(&docg3->cascade->lock); + old_stats = mtd->ecc_stats; while (ret >= 0 && (len > 0 || ooblen > 0)) { calc_block_sector(from - skip, &block0, &block1, &page, &ofs, docg3->reliable); @@ -966,6 +968,12 @@ static int doc_read_oob(struct mtd_info } out: + if (ops->stats) { + ops->stats->uncorrectable_errors += + mtd->ecc_stats.failed - old_stats.failed; + ops->stats->corrected_bitflips += + mtd->ecc_stats.corrected - old_stats.corrected; + } mutex_unlock(&docg3->cascade->lock); return ret; err_in_read: --- a/drivers/mtd/nand/onenand/onenand_base.c +++ b/drivers/mtd/nand/onenand/onenand_base.c @@ -1440,6 +1440,7 @@ static int onenand_read_oob(struct mtd_i struct mtd_oob_ops *ops) { struct onenand_chip *this = mtd->priv; + struct mtd_ecc_stats old_stats; int ret; switch (ops->mode) { @@ -1453,12 +1454,23 @@ static int onenand_read_oob(struct mtd_i } onenand_get_device(mtd, FL_READING); + + old_stats = mtd->ecc_stats; + if (ops->datbuf) ret = ONENAND_IS_4KB_PAGE(this) ? onenand_mlc_read_ops_nolock(mtd, from, ops) : onenand_read_ops_nolock(mtd, from, ops); else ret = onenand_read_oob_nolock(mtd, from, ops); + + if (ops->stats) { + ops->stats->uncorrectable_errors += + mtd->ecc_stats.failed - old_stats.failed; + ops->stats->corrected_bitflips += + mtd->ecc_stats.corrected - old_stats.corrected; + } + onenand_release_device(mtd); return ret; --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -3815,6 +3815,7 @@ static int nand_read_oob(struct mtd_info struct mtd_oob_ops *ops) { struct nand_chip *chip = mtd_to_nand(mtd); + struct mtd_ecc_stats old_stats; int ret; ops->retlen = 0; @@ -3826,11 +3827,20 @@ static int nand_read_oob(struct mtd_info nand_get_device(chip); + old_stats = mtd->ecc_stats; + if (!ops->datbuf) ret = nand_do_read_oob(chip, from, ops); else ret = nand_do_read_ops(chip, from, ops); + if (ops->stats) { + ops->stats->uncorrectable_errors += + mtd->ecc_stats.failed - old_stats.failed; + ops->stats->corrected_bitflips += + mtd->ecc_stats.corrected - old_stats.corrected; + } + nand_release_device(chip); return ret; } --- a/drivers/mtd/nand/spi/core.c +++ b/drivers/mtd/nand/spi/core.c @@ -629,6 +629,7 @@ static int spinand_mtd_read(struct mtd_i { struct spinand_device *spinand = mtd_to_spinand(mtd); struct nand_device *nand = mtd_to_nanddev(mtd); + struct mtd_ecc_stats old_stats; unsigned int max_bitflips = 0; struct nand_io_iter iter; bool disable_ecc = false; @@ -640,6 +641,8 @@ static int spinand_mtd_read(struct mtd_i mutex_lock(&spinand->lock); + old_stats = mtd->ecc_stats; + nanddev_io_for_each_page(nand, NAND_PAGE_READ, from, ops, &iter) { if (disable_ecc) iter.req.mode = MTD_OPS_RAW; @@ -662,6 +665,13 @@ static int spinand_mtd_read(struct mtd_i ops->oobretlen += iter.req.ooblen; } + if (ops->stats) { + ops->stats->uncorrectable_errors += + mtd->ecc_stats.failed - old_stats.failed; + ops->stats->corrected_bitflips += + mtd->ecc_stats.corrected - old_stats.corrected; + } + mutex_unlock(&spinand->lock); if (ecc_failed && !ret) --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -41,6 +41,8 @@ struct mtd_erase_region_info { }; struct mtd_req_stats { + unsigned int uncorrectable_errors; + unsigned int corrected_bitflips; unsigned int max_bitflips; };