>
> Make the UFS device execute realtime (RT) requests before other requests.
> This will be used in Android to reduce the I/O latency of the foreground app.
>
> Note: UFS devices do not support CDL so using CDL is not a viable
> alternative.
>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
> ---
> drivers/ufs/core/ufshcd.c | 4 ++++
> include/ufs/ufs.h | 3 ++-
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index
> 8561383076e8..c614619f06bd 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -2717,6 +2717,8 @@ static int ufshcd_compose_devman_upiu(struct
> ufs_hba *hba,
> */
> static void ufshcd_comp_scsi_upiu(struct ufs_hba *hba, struct ufshcd_lrb
> *lrbp) {
> + struct request *rq = scsi_cmd_to_rq(lrbp->cmd);
> + unsigned int ioprio_class =
> + IOPRIO_PRIO_CLASS(req_get_ioprio(rq));
> u8 upiu_flags;
>
> if (hba->ufs_version <= ufshci_version(1, 1)) @@ -2726,6 +2728,8 @@
> static void ufshcd_comp_scsi_upiu(struct ufs_hba *hba, struct ufshcd_lrb
> *lrbp)
>
> ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags,
> lrbp->cmd->sc_data_direction, 0);
> + if (ioprio_class == IOPRIO_CLASS_RT)
> + upiu_flags |= UPIU_CMD_FLAGS_CP;
> ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags); }
>
> diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h index
> 0cced88f4531..e77ab1786856 100644
> --- a/include/ufs/ufs.h
> +++ b/include/ufs/ufs.h
> @@ -98,9 +98,10 @@ enum upiu_response_transaction {
> UPIU_TRANSACTION_REJECT_UPIU = 0x3F,
> };
>
> -/* UPIU Read/Write flags */
> +/* UPIU Read/Write flags. See also table "UPIU Flags" in the UFS
> +standard. */
> enum {
> UPIU_CMD_FLAGS_NONE = 0x00,
> + UPIU_CMD_FLAGS_CP = 0x04,
> UPIU_CMD_FLAGS_WRITE = 0x20,
> UPIU_CMD_FLAGS_READ = 0x40,
> };
