> This functionality is needed by UFS drivers to e.g. suspend SCSI command
> processing while reprogramming encryption keys if the hardware does not
> support concurrent I/O and key reprogramming.
>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
> ---
> drivers/ufs/core/ufshcd.c | 20 ++++++++++++++++++++
> include/ufs/ufshcd.h | 3 +++
> 2 files changed, 23 insertions(+)
>
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 5739e9d1b970..8363d2ff622c 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -1700,6 +1700,26 @@ static void ufshcd_ungate_work(struct
> work_struct *work)
> ufshcd_scsi_unblock_requests(hba);
> }
>
> +/*
> + * Block processing of new SCSI commands and wait until pending SCSI
> + * commands and TMFs have finished. ufshcd_exec_dev_cmd() and
> + * ufshcd_issue_devman_upiu_cmd() are not affected by this function.
> + *
> + * Return: 0 upon success; -EBUSY upon timeout.
> + */
> +int ufshcd_freeze_scsi_devs(struct ufs_hba *hba, u64 timeout_us)
> +{
> + return ufshcd_clock_scaling_prepare(hba, timeout_us);
> +}
> +EXPORT_SYMBOL_GPL(ufshcd_freeze_scsi_devs);
> +
> +/* Resume processing of SCSI commands. */
> +void ufshcd_unfreeze_scsi_devs(struct ufs_hba *hba)
> +{
> + ufshcd_clock_scaling_unprepare(hba, true);
> +}
> +EXPORT_SYMBOL_GPL(ufshcd_unfreeze_scsi_devs);
> +
> /**
> * ufshcd_hold - Enable clocks that were gated earlier due to ufshcd_release.
> * Also, exit from hibern8 mode and set the link as active.
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index 7fe1a926cd99..6d78bcbedb9e 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -1194,6 +1194,9 @@ void ufshcd_release(struct ufs_hba *hba);
>
> void ufshcd_clkgate_delay_set(struct device *dev, unsigned long value);
>
> +int ufshcd_freeze_scsi_devs(struct ufs_hba *hba, u64 timeout_us);
> +void ufshcd_unfreeze_scsi_devs(struct ufs_hba *hba);
> +
> void ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum desc_idn
> desc_id,
> int *desc_length);
