From 00d2fa28da0aa371ad215e92ebf5297c0e7d4861 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 21 Sep 2023 12:22:49 -0700 Subject: [PATCH] scsi: ufs: core: Set the Command Priority (CP) flag for RT requests 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 Link: https://lore.kernel.org/r/20230921192335.676924-5-bvanassche@acm.org Reviewed-by: Avri Altman Signed-off-by: Martin K. Petersen --- 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 13957ca8055b..d430e2e7fb39 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, }; -- 2.25.1