Hi Daejun, > > On Wed, 2020-12-16 at 11:45 +0900, Daejun Park wrote: > > This is a patch for the HPB initialization and adds HPB function calls to > > UFS core driver. > > > > NAND flash-based storage devices, including UFS, have mechanisms to > > translate logical addresses of IO requests to the corresponding physical > > addresses of the flash storage. > > In UFS, Logical-address-to-Physical-address (L2P) map data, which is > > required to identify the physical address for the requested IOs, can only > > be partially stored in SRAM from NAND flash. Due to this partial loading, > > accessing the flash address area where the L2P information for that address > > is not loaded in the SRAM can result in serious performance degradation. > > > > The basic concept of HPB is to cache L2P mapping entries in host system > > memory so that both physical block address (PBA) and logical block address > > (LBA) can be delivered in HPB read command. > > The HPB READ command allows to read data faster than a read command in UFS > > since it provides the physical address (HPB Entry) of the desired logical > > block in addition to its logical address. The UFS device can access the > > physical block in NAND directly without searching and uploading L2P mapping > > table. This improves read performance because the NAND read operation for > > uploading L2P mapping table is removed. > > > > In HPB initialization, the host checks if the UFS device supports HPB > > feature and retrieves related device capabilities. Then, some HPB > > parameters are configured in the device. > > > > Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx> > > Reviewed-by: Can Guo <cang@xxxxxxxxxxxxxx> > > Acked-by: Avri Altman <Avri.Altman@xxxxxxx> > > Tested-by: Bean Huo <beanhuo@xxxxxxxxxx> > > Signed-off-by: Daejun Park <daejun7.park@xxxxxxxxxxx> > > --- > > Documentation/ABI/testing/sysfs-driver-ufs | 80 +++ > > drivers/scsi/ufs/Kconfig | 9 + > > drivers/scsi/ufs/Makefile | 1 + > > drivers/scsi/ufs/ufs-sysfs.c | 18 + > > drivers/scsi/ufs/ufs.h | 13 + > > drivers/scsi/ufs/ufshcd.c | 48 ++ > > drivers/scsi/ufs/ufshcd.h | 23 +- > > drivers/scsi/ufs/ufshpb.c | 562 +++++++++++++++++++++ > > drivers/scsi/ufs/ufshpb.h | 167 ++++++ > > 9 files changed, 920 insertions(+), 1 deletion(-) > > create mode 100644 drivers/scsi/ufs/ufshpb.c > > create mode 100644 drivers/scsi/ufs/ufshpb.h > > > > diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs > > index d1a352194d2e..8b16a353392c 100644 > > --- a/Documentation/ABI/testing/sysfs-driver-ufs > > +++ b/Documentation/ABI/testing/sysfs-driver-ufs > > @@ -1019,3 +1019,83 @@ Contact: Asutosh Das <asutoshd@xxxxxxxxxxxxxx> > > Description: This entry shows the configured size of WriteBooster buffer. > > 0400h corresponds to 4GB. > > The file is read only. > > + > > +What: /sys/bus/platform/drivers/ufshcd/*/device_descriptor/hpb_version > > +Date: December 2020 > > +Contact: Daejun Park <daejun7.park@xxxxxxxxxxx> > > +Description: This entry shows the HPB specification version. > > + The full information about the descriptor could be found at UFS > > + HPB (Host Performance Booster) Extension specifications. > > + Example: version 1.2.3 = 0123h > > + The file is read only. > > + > > +What: /sys/bus/platform/drivers/ufshcd/*/device_descriptor/hpb_control > > +Date: December 2020 > > +Contact: Daejun Park <daejun7.park@xxxxxxxxxxx> > > +Description: This entry shows an indication of the HPB control mode. > > + 00h: Host control mode > > + 01h: Device control mode > > + The file is read only. > > + > > +What: /sys/bus/platform/drivers/ufshcd/*/geometry_descriptor/hpb_region_size > > +Date: December 2020 > > +Contact: Daejun Park <daejun7.park@xxxxxxxxxxx> > > +Description: This entry shows the bHPBRegionSize which can be calculated > > + as in the following (in bytes): > > + HPB Region size = 512B * 2^bHPBRegionSize > > + The file is read only. > > + > > +What: /sys/bus/platform/drivers/ufshcd/*/geometry_descriptor/hpb_number_lu > > +Date: December 2020 > > +Contact: Daejun Park <daejun7.park@xxxxxxxxxxx> > > +Description: This entry shows the maximum number of HPB LU supported by > > + the device. > > + 00h: HPB is not supported by the device. > > + 01h ~ 20h: Maximum number of HPB LU supported by the device > > + The file is read only. > > + > > +What: /sys/bus/platform/drivers/ufshcd/*/geometry_descriptor/hpb_number_lu > > +Date: December 2020 > > +Contact: Daejun Park <daejun7.park@xxxxxxxxxxx> > > +Description: This entry shows the maximum number of HPB LU supported by > > + the device. > > + 00h: HPB is not supported by the device. > > + 01h ~ 20h: Maximum number of HPB LU supported by the device > > + The file is read only. > > Please remove above duplicated item. > > Thanks, > Stanley Chu OK, I will remove them. Thanks, Daejun
