Re: [PATCH V6] scsi: ufs: Add configfs support for UFS provisioning

[Sayali Lokhande]

On 7/17/2018 6:36 PM, Adrian Hunter wrote:
> On 16/07/18 12:43, Sayali Lokhande wrote:
> > This patch adds configfs support to provision UFS device at
> > runtime. This feature can be primarily useful in factory or
> > assembly line as some devices may be required to be configured
> > multiple times during initial system development phase.
> > Configuration Descriptors can be written multiple times until
> > bConfigDescrLock attribute is zero.
> >
> > Configuration descriptor buffer consists of Device and Unit
> > descriptor configurable parameters which are parsed from vendor
> > specific provisioning file and then passed via configfs node at
> > runtime to provision ufs device.
> > CONFIG_CONFIGFS_FS needs to be enabled for using this feature.
> >
> > Usage:
> > 1) To read current configuration descriptor :
> >     cat /config/XXXX.ufshc/ufs_provision
> > 2) To provision ufs device:
> >     echo <config_desc_buf> > /config/XXXX.ufshc/ufs_provision
> >
> > Signed-off-by: Sayali Lokhande <sayalil@xxxxxxxxxxxxxx>
> > ---
> >   Documentation/ABI/testing/configfs-driver-ufs |  18 +++
> >   drivers/scsi/ufs/Kconfig                      |  10 ++
> >   drivers/scsi/ufs/Makefile                     |   1 +
> >   drivers/scsi/ufs/ufs-configfs.c               | 162 ++++++++++++++++++++++++++
> >   drivers/scsi/ufs/ufshcd.c                     |   2 +
> >   drivers/scsi/ufs/ufshcd.h                     |  19 +++
> >   6 files changed, 212 insertions(+)
> >   create mode 100644 Documentation/ABI/testing/configfs-driver-ufs
> >   create mode 100644 drivers/scsi/ufs/ufs-configfs.c
> >
> > diff --git a/Documentation/ABI/testing/configfs-driver-ufs b/Documentation/ABI/testing/configfs-driver-ufs
> > new file mode 100644
> > index 0000000..eeee499c
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/configfs-driver-ufs
> > @@ -0,0 +1,18 @@
> > +What:		/config/ufshcd/ufs_provision
> > +Date:		Jun 2018
> > +KernelVersion:	4.14
> > +Description:
> > +		This file shows the current ufs configuration descriptor set in device.
> > +		This can be used to provision ufs device if bConfigDescrLock is 0.
> > +		For more details, refer 14.1.6.3 Configuration Descriptor and
> > +		Table 14-12 - Unit Descriptor configurable parameters from specs for
> > +		description of each configuration descriptor parameter.
> > +		Configuration descriptor buffer needs to be passed in space separated
> > +		format specificied as below:
> > +		echo <bLength> <bDescriptorIDN> <bConfDescContinue> <bBootEnable>
> > +		<bDescrAccessEn> <bInitPowerMode> <bHighPriorityLUN>
> > +		<bSecureRemovalType> <bInitActiveICCLevel> <wPeriodicRTCUpdate>
> > +		<0Bh:0Fh_ReservedAs_0> <bLUEnable> <bBootLunID> <bLUWriteProtect>
> > +		<bMemoryType> <dNumAllocUnits> <bDataReliability> <bLogicalBlockSize>
> > +		<bProvisioningType> <wContextCapabilities> <0Dh:0Fh_ReservedAs_0>
> > +		> /config/XXXX.ufshc/ufs_provision
> > diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
> > index e27b4d4..34d89c2 100644
> > --- a/drivers/scsi/ufs/Kconfig
> > +++ b/drivers/scsi/ufs/Kconfig
> > @@ -100,3 +100,13 @@ config SCSI_UFS_QCOM
> >   
> >   	  Select this if you have UFS controller on QCOM chipset.
> >   	  If unsure, say N.
> > +
> > +config UFS_PROVISION
> > +	tristate "Runtime UFS Provisioning support"
> > +	depends on SCSI_UFSHCD_PLATFORM && CONFIGFS_FS
> Why SCSI_UFSHCD_PLATFORM instead of SCSI_UFSHCD?
SCSI_UFSHCD_PLATFORM in turn depends on SCSI_UFSHCD hence used it, no 
specific reason as such.
I will update it to SCSI_UFSHCD (as provisioning is meant for UFS device 
and scsi_ufshcd config ensures support for ufs devices).
> Also please cc me in future revisions.
will do.