Re: [PATCH v1 3/3] scsi: ufs: Utilize Transfer Request List Completion Notification Register
From: Stanley Chu <hidden>
Date: 2021-06-03 02:55:05
Also in:
linux-arm-kernel, linux-mediatek, lkml
Hi Can, On Mon, 2021-05-24 at 01:36 -0700, Can Guo wrote:
By reading the UTP Transfer Request List Completion Notification Register, which is added in UFSHCI Ver 3.0, SW can easily get the compeleted transfer requests. Thus, SW can get rid of host lock, which is used to synchronize the tr_doorbell and outstanding_reqs, on transfer requests dispatch and completion paths. This can further benefit random read/write performance. Cc: Stanley Chu <redacted> Co-developed-by: Asutosh Das <redacted> Signed-off-by: Asutosh Das <redacted> Signed-off-by: Can Guo <redacted>
Reviewed-by: Stanley Chu <redacted>
quoted hunk ↗ jump to hunk
+++ b/drivers/scsi/ufs/ufshci.h@@ -39,6 +39,7 @@ enum { REG_UTP_TRANSFER_REQ_DOOR_BELL = 0x58, REG_UTP_TRANSFER_REQ_LIST_CLEAR = 0x5C, REG_UTP_TRANSFER_REQ_LIST_RUN_STOP = 0x60, + REG_UTP_TRANSFER_REQ_LIST_COMPL = 0x64, REG_UTP_TASK_REQ_LIST_BASE_L = 0x70, REG_UTP_TASK_REQ_LIST_BASE_H = 0x74, REG_UTP_TASK_REQ_DOOR_BELL = 0x78,