> From: Stanley Chu <stanley.chu@xxxxxxxxxxxx> > Sent: Monday, May 4, 2020 4:56 PM > To: linux-scsi@xxxxxxxxxxxxxxx; martin.petersen@xxxxxxxxxx; > avri.altman@xxxxxxx; alim.akhtar@xxxxxxxxxxx; jejb@xxxxxxxxxxxxx; > asutoshd@xxxxxxxxxxxxxx > Cc: Bean Huo (beanhuo) <beanhuo@xxxxxxxxxx>; cang@xxxxxxxxxxxxxx; > matthias.bgg@xxxxxxxxx; bvanassche@xxxxxxx; linux- > mediatek@xxxxxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; kuohong.wang@xxxxxxxxxxxx; > peter.wang@xxxxxxxxxxxx; chun-hung.wu@xxxxxxxxxxxx; > andy.teng@xxxxxxxxxxxx; Stanley Chu <stanley.chu@xxxxxxxxxxxx> > Subject: [EXT] [PATCH v6 6/8] scsi: ufs: add LU Dedicated buffer mode support > for WriteBooster > > According to UFS specification, there are two WriteBooster mode of > operations: "LU dedicated buffer" mode and "shared buffer" mode. > In the "LU dedicated buffer" mode, the WriteBooster Buffer is dedicated to a > logical unit. > > If the device supports the "LU dedicated buffer" mode, this mode is configured > by setting bWriteBoosterBufferType to 00h. The logical unit WriteBooster Buffer > size is configured by setting the dLUNumWriteBoosterBufferAllocUnits field of > the related Unit Descriptor. Only a value greater than zero enables the > WriteBooster feature in the logical unit. > > Modify ufshcd_wb_probe() as above description to support LU Dedicated buffer > mode. > > Note that according to UFS 3.1 specification, the valid value of > bDeviceMaxWriteBoosterLUs parameter in Geometry Descriptor is 1, which > means at most one LUN can have WriteBooster buffer in "LU dedicated buffer > mode". Therefore this patch supports only one LUN with WriteBooster enabled. > All WriteBooster related sysfs nodes are specifically mapped to the LUN with > WriteBooster enabled in LU Dedicated buffer mode. > > Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx> > Reviewed-by: Avri Altman <avri.altman@xxxxxxx> Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
