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| author | Daejun Park <daejun7.park@samsung.com> | 2021-07-12 12:00:25 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2021-08-01 23:05:07 +0300 |
| commit | 41d8a9333cc96f5ad4dd7a52786585338257d9f1 (patch) | |
| tree | 595fc1295e8565f6220fcc7ee18bf8a400c028a5 /Documentation/ABI/testing/sysfs-driver-ufs | |
| parent | 2fff76f87542fae2366448ec8b01dbff415a7d22 (diff) | |
| download | linux-41d8a9333cc96f5ad4dd7a52786585338257d9f1.tar.xz | |
scsi: ufs: ufshpb: Add HPB 2.0 support
Version 2.0 of HBP supports reads of varying sizes from 4KB to 1MB.
A read operation <= 32KB is supported as single HPB read. A read between
36KB and 1MB is supported by a combination of write buffer command and HPB
read command to deliver more PPN. The write buffer commands may not be
issued immediately due to busy tags. To use HPB read more aggressively, the
driver can requeue the write buffer command. The requeue threshold is
implemented as timeout and can be modified with requeue_timeout_ms entry in
sysfs.
[mkp: REQ_OP_DRV_* and blk_rq_is_passthrough()]
Link: https://lore.kernel.org/r/20210712090025epcms2p3b3d94f6f1b2cfa394e3d9ba130ca0fa7@epcms2p3
Tested-by: Can Guo <cang@codeaurora.org>
Tested-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-driver-ufs')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-driver-ufs | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs index 4c1a5d28408d..929460738651 100644 --- a/Documentation/ABI/testing/sysfs-driver-ufs +++ b/Documentation/ABI/testing/sysfs-driver-ufs @@ -1425,3 +1425,38 @@ Description: This entry shows the number of read buffer commands for activating sub-regions recommended by response UPIUs. The file is read only. + +What: /sys/class/scsi_device/*/device/hpb_params/requeue_timeout_ms +Date: June 2021 +Contact: Daejun Park <daejun7.park@samsung.com> +Description: This entry shows the requeue timeout threshold for write buffer + command in ms. The value can be changed by writing an integer to + this entry. + +What: /sys/bus/platform/drivers/ufshcd/*/attributes/max_data_size_hpb_single_cmd +Date: June 2021 +Contact: Daejun Park <daejun7.park@samsung.com> +Description: This entry shows the maximum HPB data size for using a single HPB + command. + + === ======== + 00h 4KB + 01h 8KB + 02h 12KB + ... + FFh 1024KB + === ======== + + The file is read only. + +What: /sys/bus/platform/drivers/ufshcd/*/flags/wb_enable +Date: June 2021 +Contact: Daejun Park <daejun7.park@samsung.com> +Description: This entry shows the status of HPB. + + == ============================ + 0 HPB is not enabled. + 1 HPB is enabled + == ============================ + + The file is read only. |