Re: [PATCH v5 02/11] scsi: ufs: sysfs: device descriptor

[Jaegeuk Kim <jaegeuk@kernel.org>]

On 02/12, Stanislav Nijnikov wrote:
> 
> 
> > -----Original Message-----
> > From: Jaegeuk Kim [mailto:jaegeuk@kernel.org]
> > Sent: Monday, February 12, 2018 3:08 AM
> > To: Stanislav Nijnikov <Stanislav.Nijnikov@wdc.com>
> > Cc: linux-scsi@vger.kernel.org; linux-kernel@vger.kernel.org;
> > gregkh@linuxfoundation.org; Alex Lemberg <Alex.Lemberg@wdc.com>
> > Subject: Re: [PATCH v5 02/11] scsi: ufs: sysfs: device descriptor
> > 
> > On 02/06, Stanislav Nijnikov wrote:
> > > This patch introduces a sysfs group entry for the UFS device
> > > descriptor parameters. The group adds "device_descriptor" folder under
> > > the UFS driver sysfs entry (/sys/bus/platform/drivers/ufshcd/*). The
> > > parameters are shown as hexadecimal numbers. The full information
> > > about the parameters could be found at UFS specifications 2.1.
> > >
> > > Signed-off-by: Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > ---
> > >  Documentation/ABI/testing/sysfs-driver-ufs | 223
> > +++++++++++++++++++++++++++++
> > >  drivers/scsi/ufs/ufs-sysfs.c               | 116 +++++++++++++++
> > >  drivers/scsi/ufs/ufs.h                     |   8 ++
> > >  drivers/scsi/ufs/ufshcd.c                  |  12 +-
> > >  drivers/scsi/ufs/ufshcd.h                  |   6 +
> > >  5 files changed, 359 insertions(+), 6 deletions(-)  create mode
> > > 100644 Documentation/ABI/testing/sysfs-driver-ufs
> > >
> > > diff --git a/Documentation/ABI/testing/sysfs-driver-ufs
> > > b/Documentation/ABI/testing/sysfs-driver-ufs
> > > new file mode 100644
> > > index 0000000..8da7b84
> > > --- /dev/null
> > > +++ b/Documentation/ABI/testing/sysfs-driver-ufs
> > > @@ -0,0 +1,223 @@
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/device_type
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the device type. This is one of the UFS
> > > +		device descriptor parameters. The full information about
> > > +		the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/device_class
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the device class. This is one of the UFS
> > > +		device descriptor parameters. The full information about
> > > +		the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/device_sub_
> > class
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the UFS storage subclass. This is one of
> > > +		the UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/protocol
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the protocol supported by an UFS device.
> > > +		This is one of the UFS device descriptor parameters.
> > > +		The full information about the descriptor could be found
> > > +		at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/number_of_
> > luns
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows number of logical units. This is one of
> > > +		the UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/number_of_
> > wluns
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows number of well known logical units.
> > > +		This is one of the UFS device descriptor parameters.
> > > +		The full information about the descriptor could be found
> > > +		at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/boot_enable
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows value that indicates whether the device is
> > > +		enabled for boot. This is one of the UFS device descriptor
> > > +		parameters. The full information about the descriptor could
> > > +		be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/descriptor_a
> > ccess_enable
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows value that indicates whether the device
> > > +		descriptor could be read after partial initialization phase
> > > +		of the boot sequence. This is one of the UFS device
> > descriptor
> > > +		parameters. The full information about the descriptor could
> > > +		be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/initial_powe
> > r_mode
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows value that defines the power mode after
> > > +		device initialization or hardware reset. This is one of
> > > +		the UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/high_priority
> > _lun
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the high priority lun. This is one of
> > > +		the UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/secure_rem
> > oval_type
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the secure removal type. This is one of
> > > +		the UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/support_sec
> > urity_lun
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows whether the security lun is supported.
> > > +		This is one of the UFS device descriptor parameters.
> > > +		The full information about the descriptor could be found
> > > +		at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/bkops_termi
> > nation_latency
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the background operations termination
> > > +		latency. This is one of the UFS device descriptor parameters.
> > > +		The full information about the descriptor could be found
> > > +		at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/initial_active
> > _icc_level
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the initial active ICC level. This is one
> > > +		of the UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/specification
> > _version
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the specification version. This is one
> > > +		of the UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/manufacturi
> > ng_date
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the manufacturing date in BCD format.
> > > +		This is one of the UFS device descriptor parameters.
> > > +		The full information about the descriptor could be found
> > > +		at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/manufacture
> > r_id
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the manufacturee ID. This is one of the
> > > +		UFS device descriptor parameters. The full information about
> > > +		the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/rtt_capabilit
> > y
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the maximum number of outstanding RTTs
> > > +		supported by the device. This is one of the UFS device
> > > +		descriptor parameters. The full information about
> > > +		the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/rtc_update
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the frequency and method of the realtime
> > > +		clock update. This is one of the UFS device descriptor
> > > +		parameters. The full information about the descriptor
> > > +		could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/ufs_features
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows which features are supported by the device.
> > > +		This is one of the UFS device descriptor parameters.
> > > +		The full information about the descriptor could be
> > > +		found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/ffu_timeout
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the FFU timeout. This is one of the
> > > +		UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/queue_dept
> > h
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the device queue depth. This is one of the
> > > +		UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/device_versi
> > on
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the device version. This is one of the
> > > +		UFS device descriptor parameters. The full information
> > > +		about the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/number_of_
> > secure_wpa
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows number of secure write protect areas
> > > +		supported by the device. This is one of the UFS device
> > > +		descriptor parameters. The full information about
> > > +		the descriptor could be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/psa_max_da
> > ta_size
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the maximum amount of data that may be
> > > +		written during the pre-soldering phase of the PSA flow.
> > > +		This is one of the UFS device descriptor parameters.
> > > +		The full information about the descriptor could be found
> > > +		at UFS specifications 2.1.
> > > +		The file is read only.
> > > +
> > > +What:
> > 	/sys/bus/platform/drivers/ufshcd/*/device_descriptor/psa_state_ti
> > meout
> > > +Date:		February 2018
> > > +Contact:	Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
> > > +Description:	This file shows the command maximum timeout for a change
> > > +		in PSA state. This is one of the UFS device descriptor
> > > +		parameters. The full information about the descriptor could
> > > +		be found at UFS specifications 2.1.
> > > +		The file is read only.
> > > diff --git a/drivers/scsi/ufs/ufs-sysfs.c
> > > b/drivers/scsi/ufs/ufs-sysfs.c index ce8dcb6..aa2779a 100644
> > > --- a/drivers/scsi/ufs/ufs-sysfs.c
> > > +++ b/drivers/scsi/ufs/ufs-sysfs.c
> > > @@ -3,7 +3,9 @@
> > >
> > >  #include <linux/err.h>
> > >  #include <linux/string.h>
> > > +#include <asm/unaligned.h>
> > >
> > > +#include "ufs.h"
> > >  #include "ufs-sysfs.h"
> > >
> > >  static const char *ufschd_uic_link_state_to_string( @@ -134,8
> > > +136,122 @@ static const struct attribute_group ufs_sysfs_default_group
> > = {
> > >  	.attrs = ufs_sysfs_ufshcd_attrs,
> > >  };
> > >
> > > +static ssize_t ufs_sysfs_read_desc_param(struct ufs_hba *hba,
> > > +				  enum desc_idn desc_id,
> > > +				  u8 desc_index,
> > > +				  u8 param_offset,
> > > +				  u8 *sysfs_buf,
> > > +				  u8 param_size)
> > > +{
> > > +	u8 desc_buf[8] = {0};
> > > +	int ret;
> > > +
> > > +	if (param_size > 8)
> > > +		return -EINVAL;
> > > +
> > > +	ret = ufshcd_read_desc_param(hba, desc_id, desc_index,
> > > +				param_offset, desc_buf, param_size);
> > > +	if (ret)
> > > +		return -EINVAL;
> > > +	switch (param_size) {
> > > +	case 1:
> > > +		ret = sprintf(sysfs_buf, "0x%02X\n", *desc_buf);
> > > +		break;
> > > +	case 2:
> > > +		ret = sprintf(sysfs_buf, "0x%04X\n",
> > > +			get_unaligned_be16(desc_buf));
> > > +		break;
> > > +	case 4:
> > > +		ret = sprintf(sysfs_buf, "0x%08X\n",
> > > +			get_unaligned_be32(desc_buf));
> > > +		break;
> > > +	case 8:
> > > +		ret = sprintf(sysfs_buf, "0x%016llX\n",
> > > +			get_unaligned_be64(desc_buf));
> > > +		break;
> > > +	}
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +#define UFS_DESC_PARAM(_name, _puname, _duname, _size)
> > 		\
> > > +static ssize_t _name##_show(struct device *dev,
> > 	\
> > > +	struct device_attribute *attr, char *buf)			\
> > > +{									\
> > > +	struct ufs_hba *hba = dev_get_drvdata(dev);			\
> > > +	return ufs_sysfs_read_desc_param(hba,
> > QUERY_DESC_IDN_##_duname,	\
> > > +		0, _duname##_DESC_PARAM##_puname, buf, _size);
> > 	\
> > > +}									\
> > > +static DEVICE_ATTR_RO(_name)
> > > +
> > > +#define UFS_DEVICE_DESC_PARAM(_name, _uname, _size)
> > 		\
> > > +	UFS_DESC_PARAM(_name, _uname, DEVICE, _size)
> > > +
> > > +UFS_DEVICE_DESC_PARAM(device_type, _DEVICE_TYPE, 1);
> > > +UFS_DEVICE_DESC_PARAM(device_class, _DEVICE_CLASS, 1);
> > > +UFS_DEVICE_DESC_PARAM(device_sub_class, _DEVICE_SUB_CLASS, 1);
> > > +UFS_DEVICE_DESC_PARAM(protocol, _PRTCL, 1);
> > > +UFS_DEVICE_DESC_PARAM(number_of_luns, _NUM_LU, 1);
> > > +UFS_DEVICE_DESC_PARAM(number_of_wluns, _NUM_WLU, 1);
> > > +UFS_DEVICE_DESC_PARAM(boot_enable, _BOOT_ENBL, 1);
> > > +UFS_DEVICE_DESC_PARAM(descriptor_access_enable,
> > _DESC_ACCSS_ENBL, 1);
> > > +UFS_DEVICE_DESC_PARAM(initial_power_mode, _INIT_PWR_MODE, 1);
> > > +UFS_DEVICE_DESC_PARAM(high_priority_lun, _HIGH_PR_LUN, 1);
> > > +UFS_DEVICE_DESC_PARAM(secure_removal_type, _SEC_RMV_TYPE, 1);
> > > +UFS_DEVICE_DESC_PARAM(support_security_lun, _SEC_LU, 1);
> > > +UFS_DEVICE_DESC_PARAM(bkops_termination_latency,
> > _BKOP_TERM_LT, 1);
> > > +UFS_DEVICE_DESC_PARAM(initial_active_icc_level, _ACTVE_ICC_LVL, 1);
> > > +UFS_DEVICE_DESC_PARAM(specification_version, _SPEC_VER, 2);
> > > +UFS_DEVICE_DESC_PARAM(manufacturing_date, _MANF_DATE, 2);
> > > +UFS_DEVICE_DESC_PARAM(manufacturer_id, _MANF_ID, 2);
> > > +UFS_DEVICE_DESC_PARAM(rtt_capability, _RTT_CAP, 1);
> > > +UFS_DEVICE_DESC_PARAM(rtc_update, _FRQ_RTC, 2);
> > > +UFS_DEVICE_DESC_PARAM(ufs_features, _UFS_FEAT, 1);
> > > +UFS_DEVICE_DESC_PARAM(ffu_timeout, _FFU_TMT, 1);
> > > +UFS_DEVICE_DESC_PARAM(queue_depth, _Q_DPTH, 1);
> > > +UFS_DEVICE_DESC_PARAM(device_version, _DEV_VER, 2);
> > > +UFS_DEVICE_DESC_PARAM(number_of_secure_wpa, _NUM_SEC_WPA,
> > 1);
> > > +UFS_DEVICE_DESC_PARAM(psa_max_data_size, _PSA_MAX_DATA, 4);
> > > +UFS_DEVICE_DESC_PARAM(psa_state_timeout, _PSA_TMT, 1);
> > 
> > Could you add this case as well?
> > 
> > DEVICE_DESC_PARAM_PRDCT_REV		= 0x2A,
> > 
> 
> This value was omitted intentionally. It holds an index of the string descriptor with the
> product revision. There are 4 more such fields in the device descriptor:
>  - DEVICE_DESC_PARAM_MANF_NAME = 0x14
>  - DEVICE_DESC_PARAM_PRDCT_NAME  = 0x15,
>  - DEVICE_DESC_PARAM_SN = 0x16,
>  - DEVICE_DESC_PARAM_OEM_ID  = 0x17,
> The indexes itself don't provide any useful information to users and the
> corresponding strings are shown by the string descriptors (see "[PATCH v5 07/11] 
> scsi: ufs: sysfs: string descriptors")

Ah, I see, right. :)

Thanks,

> 
> Regards
> 
> > > +
> > > +static struct attribute *ufs_sysfs_device_descriptor[] = {
> > > +	&dev_attr_device_type.attr,
> > > +	&dev_attr_device_class.attr,
> > > +	&dev_attr_device_sub_class.attr,
> > > +	&dev_attr_protocol.attr,
> > > +	&dev_attr_number_of_luns.attr,
> > > +	&dev_attr_number_of_wluns.attr,
> > > +	&dev_attr_boot_enable.attr,
> > > +	&dev_attr_descriptor_access_enable.attr,
> > > +	&dev_attr_initial_power_mode.attr,
> > > +	&dev_attr_high_priority_lun.attr,
> > > +	&dev_attr_secure_removal_type.attr,
> > > +	&dev_attr_support_security_lun.attr,
> > > +	&dev_attr_bkops_termination_latency.attr,
> > > +	&dev_attr_initial_active_icc_level.attr,
> > > +	&dev_attr_specification_version.attr,
> > > +	&dev_attr_manufacturing_date.attr,
> > > +	&dev_attr_manufacturer_id.attr,
> > > +	&dev_attr_rtt_capability.attr,
> > > +	&dev_attr_rtc_update.attr,
> > > +	&dev_attr_ufs_features.attr,
> > > +	&dev_attr_ffu_timeout.attr,
> > > +	&dev_attr_queue_depth.attr,
> > > +	&dev_attr_device_version.attr,
> > > +	&dev_attr_number_of_secure_wpa.attr,
> > > +	&dev_attr_psa_max_data_size.attr,
> > > +	&dev_attr_psa_state_timeout.attr,
> > > +	NULL,
> > > +};
> > > +
> > > +static const struct attribute_group ufs_sysfs_device_descriptor_group = {
> > > +	.name = "device_descriptor",
> > > +	.attrs = ufs_sysfs_device_descriptor, };
> > > +
> > >  static const struct attribute_group *ufs_sysfs_groups[] = {
> > >  	&ufs_sysfs_default_group,
> > > +	&ufs_sysfs_device_descriptor_group,
> > >  	NULL,
> > >  };
> > >
> > > diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h index
> > > 54deeb7..6ae1e08 100644
> > > --- a/drivers/scsi/ufs/ufs.h
> > > +++ b/drivers/scsi/ufs/ufs.h
> > > @@ -220,6 +220,14 @@ enum device_desc_param {
> > >  	DEVICE_DESC_PARAM_UD_LEN		= 0x1B,
> > >  	DEVICE_DESC_PARAM_RTT_CAP		= 0x1C,
> > >  	DEVICE_DESC_PARAM_FRQ_RTC		= 0x1D,
> > > +	DEVICE_DESC_PARAM_UFS_FEAT		= 0x1F,
> > > +	DEVICE_DESC_PARAM_FFU_TMT		= 0x20,
> > > +	DEVICE_DESC_PARAM_Q_DPTH		= 0x21,
> > > +	DEVICE_DESC_PARAM_DEV_VER		= 0x22,
> > > +	DEVICE_DESC_PARAM_NUM_SEC_WPA		= 0x24,
> > > +	DEVICE_DESC_PARAM_PSA_MAX_DATA		= 0x25,
> > > +	DEVICE_DESC_PARAM_PSA_TMT		= 0x29,
> > > +	DEVICE_DESC_PARAM_PRDCT_REV		= 0x2A,
> > >  };
> > >
> > >  /*
> > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > > index e7621a0a..540a431 100644
> > > --- a/drivers/scsi/ufs/ufshcd.c
> > > +++ b/drivers/scsi/ufs/ufshcd.c
> > > @@ -2989,12 +2989,12 @@
> > EXPORT_SYMBOL(ufshcd_map_desc_id_to_length);
> > >   *
> > >   * Return 0 in case of success, non-zero otherwise
> > >   */
> > > -static int ufshcd_read_desc_param(struct ufs_hba *hba,
> > > -				  enum desc_idn desc_id,
> > > -				  int desc_index,
> > > -				  u8 param_offset,
> > > -				  u8 *param_read_buf,
> > > -				  u8 param_size)
> > > +int ufshcd_read_desc_param(struct ufs_hba *hba,
> > > +			   enum desc_idn desc_id,
> > > +			   int desc_index,
> > > +			   u8 param_offset,
> > > +			   u8 *param_read_buf,
> > > +			   u8 param_size)
> > >  {
> > >  	int ret;
> > >  	u8 *desc_buf;
> > > diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> > > index 53e2779..38c307d 100644
> > > --- a/drivers/scsi/ufs/ufshcd.h
> > > +++ b/drivers/scsi/ufs/ufshcd.h
> > > @@ -841,6 +841,12 @@ static inline bool ufshcd_is_hs_mode(struct
> > > ufs_pa_layer_attr *pwr_info)  }
> > >
> > >  /* Expose Query-Request API */
> > > +int ufshcd_read_desc_param(struct ufs_hba *hba,
> > > +			   enum desc_idn desc_id,
> > > +			   int desc_index,
> > > +			   u8 param_offset,
> > > +			   u8 *param_read_buf,
> > > +			   u8 param_size);
> > >  int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
> > >  	enum flag_idn idn, bool *flag_res);
> > >  int ufshcd_hold(struct ufs_hba *hba, bool async);
> > > --
> > > 2.7.4