[PATCH] mtd: Add locking to cfi_cmdset_001:do_getlockstatus_oneblock

[Joakim Tjernlund]

On Fri, 2015-11-06 at 14:49 +0100, Mark Marshall wrote:
> The function (do_getlockstatus_oneblock) switches the flash out of
> array-read mode and into query mode.  It should not run in parallel to
> another function that uses array-read mode.  We therefore need to
> acquire the chip mutex and call get_chip(..., FL_JEDEC_QUERY).
> 
Hmm, this mail has NL breaks in it for long lines and won't apply.
Is it on my end or yours?

>  drivers/mtd/chips/cfi_cmdset_0001.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c
> b/drivers/mtd/chips/cfi_cmdset_0001.c
> index 286b97a..d675efb 100644
> --- a/drivers/mtd/chips/cfi_cmdset_0001.c
> +++ b/drivers/mtd/chips/cfi_cmdset_0001.c
> @@ -2051,13 +2051,32 @@ static int __xipram
> do_getlockstatus_oneblock(struct map_info *map,
>  {
>  > 	> struct cfi_private *cfi = map->fldrv_priv;
>  > 	> int status, ofs_factor = cfi->interleave * cfi->device_type;
> +> 	> int ret;
> 
>  > 	> adr += chip->start;
> +
> +> 	> mutex_lock(&chip->mutex);
> +> 	> ret = get_chip(map, chip, adr, FL_JEDEC_QUERY);
> +> 	> if (ret) {
> +> 	> 	> mutex_unlock(&chip->mutex);
> +> 	> 	> return ret;
> +> 	> }
> +
> +> 	> /* let's ensure we're not reading back cached data from array mode */
> +> 	> INVALIDATE_CACHED_RANGE(map, adr+(2*ofs_factor), 1);
> +
>  > 	> xip_disable(map, chip, adr+(2*ofs_factor));
>  > 	> map_write(map, CMD(0x90), adr+(2*ofs_factor));
>  > 	> chip->state = FL_JEDEC_QUERY;
>  > 	> status = cfi_read_query(map, adr+(2*ofs_factor));
>  > 	> xip_enable(map, chip, 0);
> +
> +> 	> /* then ensure we don't keep query data in the cache */
> +> 	> INVALIDATE_CACHED_RANGE(map, adr+(2*ofs_factor), 1);
> +
> +> 	> put_chip(map, chip, adr);
> +> 	> mutex_unlock(&chip->mutex);
> +
>  > 	> return status;
>  }
>