openwrt/target/linux/generic/backport-5.15/423-v6.1-0003-mtd-add-ECC-error-accounting-for-each-read-request.patch
Michał Kępień fa4dc86e98
kernel: backport MEMREAD ioctl
MEMREAD is a new ioctl for MTD character devices that was first included
in Linux 6.1.  It allows userspace applications to use the Linux
kernel's OOB autoplacement mechanism while reading data from NAND
devices.  The Yafut tool needs this ioctl to do its job.

Signed-off-by: Michał Kępień <openwrt@kempniu.pl>
2023-04-18 13:53:03 +02:00

173 lines
5.3 KiB
Diff

From 2ed18d818d1f7492172f8dd5904344c7d367e8ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20K=C4=99pie=C5=84?= <kernel@kempniu.pl>
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 <boris.brezillon@collabora.com>
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
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;
};