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mtd: rawnand: protect access to rawnand devices while in suspend

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Prevent rawnand access while in a suspended state.

Commit 013e6292aa ("mtd: rawnand: Simplify the locking") allows the
rawnand layer to return errors rather than waiting in a blocking wait.

Tested on a iMX6ULL.

Fixes: 013e6292aa ("mtd: rawnand: Simplify the locking")
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220208085213.1838273-1-sean@geanix.com
This commit is contained in:
Sean Nyekjaer 2022-02-08 09:52:13 +01:00 committed by Miquel Raynal
parent d430e4acd9
commit 8cba323437
2 changed files with 22 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
drivers/mtd/nand/raw/nand_base.c
View File

@ -338,16 +338,19 @@ static int nand_isbad_bbm(struct nand_chip *chip, loff_t ofs)
*
* Return: -EBUSY if the chip has been suspended, 0 otherwise
*/
static int nand_get_device(struct nand_chip *chip)
static void nand_get_device(struct nand_chip *chip)
{
mutex_lock(&chip->lock);
if (chip->suspended) {
/* Wait until the device is resumed. */
while (1) {
mutex_lock(&chip->lock);
if (!chip->suspended) {
mutex_lock(&chip->controller->lock);
return;
}
mutex_unlock(&chip->lock);
return -EBUSY;
}
mutex_lock(&chip->controller->lock);
return 0;
wait_event(chip->resume_wq, !chip->suspended);
}
}
/**
@ -576,9 +579,7 @@ static int nand_block_markbad_lowlevel(struct nand_chip *chip, loff_t ofs)
nand_erase_nand(chip, &einfo, 0);
/* Write bad block marker to OOB */
ret = nand_get_device(chip);
if (ret)
return ret;
nand_get_device(chip);
ret = nand_markbad_bbm(chip, ofs);
nand_release_device(chip);
@ -3826,9 +3827,7 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from,
ops->mode != MTD_OPS_RAW)
return -ENOTSUPP;
ret = nand_get_device(chip);
if (ret)
return ret;
nand_get_device(chip);
if (!ops->datbuf)
ret = nand_do_read_oob(chip, from, ops);
@ -4415,13 +4414,11 @@ static int nand_write_oob(struct mtd_info *mtd, loff_t to,
struct mtd_oob_ops *ops)
{
struct nand_chip *chip = mtd_to_nand(mtd);
int ret;
int ret = 0;
ops->retlen = 0;
ret = nand_get_device(chip);
if (ret)
return ret;
nand_get_device(chip);
switch (ops->mode) {
case MTD_OPS_PLACE_OOB:
@ -4481,9 +4478,7 @@ int nand_erase_nand(struct nand_chip *chip, struct erase_info *instr,
return -EIO;
/* Grab the lock and see if the device is available */
ret = nand_get_device(chip);
if (ret)
return ret;
nand_get_device(chip);
/* Shift to get first page */
page = (int)(instr->addr >> chip->page_shift);
@ -4570,7 +4565,7 @@ static void nand_sync(struct mtd_info *mtd)
pr_debug("%s: called\n", __func__);
/* Grab the lock and see if the device is available */
WARN_ON(nand_get_device(chip));
nand_get_device(chip);
/* Release it and go back */
nand_release_device(chip);
}
@ -4587,9 +4582,7 @@ static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
int ret;
/* Select the NAND device */
ret = nand_get_device(chip);
if (ret)
return ret;
nand_get_device(chip);
nand_select_target(chip, chipnr);
@ -4660,6 +4653,8 @@ static void nand_resume(struct mtd_info *mtd)
__func__);
}
mutex_unlock(&chip->lock);
wake_up_all(&chip->resume_wq);
}
/**
@ -5438,6 +5433,7 @@ static int nand_scan_ident(struct nand_chip *chip, unsigned int maxchips,
chip->cur_cs = -1;
mutex_init(&chip->lock);
init_waitqueue_head(&chip->resume_wq);
/* Enforce the right timings for reset/detection */
chip->current_interface_config = nand_get_reset_interface_config();

2
include/linux/mtd/rawnand.h
View File

@ -1240,6 +1240,7 @@ struct nand_secure_region {
* @lock: Lock protecting the suspended field. Also used to serialize accesses
* to the NAND device
* @suspended: Set to 1 when the device is suspended, 0 when it's not
* @resume_wq: wait queue to sleep if rawnand is in suspended state.
* @cur_cs: Currently selected target. -1 means no target selected, otherwise we
* should always have cur_cs >= 0 && cur_cs < nanddev_ntargets().
* NAND Controller drivers should not modify this value, but they're
@ -1294,6 +1295,7 @@ struct nand_chip {
/* Internals */
struct mutex lock;
unsigned int suspended : 1;
wait_queue_head_t resume_wq;
int cur_cs;
int read_retries;
struct nand_secure_region *secure_regions;