drivers/scsi/scsi_common.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * SCSI functions used by both the initiator and the target code.
  */

 #include <linux/bug.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <uapi/linux/pr.h>
 #include <linux/unaligned.h>
 #include <scsi/scsi_common.h>

 MODULE_DESCRIPTION("SCSI functions used by both the initiator and the target code");
 MODULE_LICENSE("GPL v2");

 /* Command group 3 is reserved and should never be used.  */
 const unsigned char scsi_command_size_tbl[8] = {
 	6, 10, 10, 12, 16, 12, 10, 10
 };
 EXPORT_SYMBOL(scsi_command_size_tbl);

 /* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
  * You may not alter any existing entry (although adding new ones is
  * encouraged once assigned by ANSI/INCITS T10).
  */
 static const char *const scsi_device_types[] = {
 	"Direct-Access    ",
 	"Sequential-Access",
 	"Printer          ",
 	"Processor        ",
 	"WORM             ",
 	"CD-ROM           ",
 	"Scanner          ",
 	"Optical Device   ",
 	"Medium Changer   ",
 	"Communications   ",
 	"ASC IT8          ",
 	"ASC IT8          ",
 	"RAID             ",
 	"Enclosure        ",
 	"Direct-Access-RBC",
 	"Optical card     ",
 	"Bridge controller",
 	"Object storage   ",
 	"Automation/Drive ",
 	"Security Manager ",
 	"Direct-Access-ZBC",
 };

 /**
  * scsi_device_type - Return 17-char string indicating device type.
  * @type: type number to look up
  */
 const char *scsi_device_type(unsigned type)
 {
 	if (type == 0x1e)
 		return "Well-known LUN   ";
 	if (type == 0x1f)
 		return "No Device        ";
 	if (type >= ARRAY_SIZE(scsi_device_types))
 		return "Unknown          ";
 	return scsi_device_types[type];
 }
 EXPORT_SYMBOL(scsi_device_type);

 enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type)
 {
 	switch (type) {
 	case SCSI_PR_WRITE_EXCLUSIVE:
 		return PR_WRITE_EXCLUSIVE;
 	case SCSI_PR_EXCLUSIVE_ACCESS:
 		return PR_EXCLUSIVE_ACCESS;
 	case SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY:
 		return PR_WRITE_EXCLUSIVE_REG_ONLY;
 	case SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY:
 		return PR_EXCLUSIVE_ACCESS_REG_ONLY;
 	case SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS:
 		return PR_WRITE_EXCLUSIVE_ALL_REGS;
 	case SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS:
 		return PR_EXCLUSIVE_ACCESS_ALL_REGS;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(scsi_pr_type_to_block);

 enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
 {
 	switch (type) {
 	case PR_WRITE_EXCLUSIVE:
 		return SCSI_PR_WRITE_EXCLUSIVE;
 	case PR_EXCLUSIVE_ACCESS:
 		return SCSI_PR_EXCLUSIVE_ACCESS;
 	case PR_WRITE_EXCLUSIVE_REG_ONLY:
 		return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
 	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
 		return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
 	case PR_WRITE_EXCLUSIVE_ALL_REGS:
 		return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
 	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
 		return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(block_pr_type_to_scsi);

 /**
  * scsilun_to_int - convert a scsi_lun to an int
  * @scsilun:	struct scsi_lun to be converted.
  *
  * Description:
  *     Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered
  *     integer, and return the result. The caller must check for
  *     truncation before using this function.
  *
  * Notes:
  *     For a description of the LUN format, post SCSI-3 see the SCSI
  *     Architecture Model, for SCSI-3 see the SCSI Controller Commands.
  *
  *     Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
  *     returns the integer: 0x0b03d204
  *
  *     This encoding will return a standard integer LUN for LUNs smaller
  *     than 256, which typically use a single level LUN structure with
  *     addressing method 0.
  */
 u64 scsilun_to_int(struct scsi_lun *scsilun)
 {
 	int i;
 	u64 lun;

 	lun = 0;
 	for (i = 0; i < sizeof(lun); i += 2)
 		lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
 			     ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
 	return lun;
 }
 EXPORT_SYMBOL(scsilun_to_int);

 /**
  * int_to_scsilun - reverts an int into a scsi_lun
  * @lun:        integer to be reverted
  * @scsilun:	struct scsi_lun to be set.
  *
  * Description:
  *     Reverts the functionality of the scsilun_to_int, which packed
  *     an 8-byte lun value into an int. This routine unpacks the int
  *     back into the lun value.
  *
  * Notes:
  *     Given an integer : 0x0b03d204, this function returns a
  *     struct scsi_lun of: d2 04 0b 03 00 00 00 00
  *
  */
 void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
 {
 	int i;

 	memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));

 	for (i = 0; i < sizeof(lun); i += 2) {
 		scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
 		scsilun->scsi_lun[i+1] = lun & 0xFF;
 		lun = lun >> 16;
 	}
 }
 EXPORT_SYMBOL(int_to_scsilun);

 /**
  * scsi_normalize_sense - normalize main elements from either fixed or
  *			descriptor sense data format into a common format.
  *
  * @sense_buffer:	byte array containing sense data returned by device
  * @sb_len:		number of valid bytes in sense_buffer
  * @sshdr:		pointer to instance of structure that common
  *			elements are written to.
  *
  * Notes:
  *	The "main elements" from sense data are: response_code, sense_key,
  *	asc, ascq and additional_length (only for descriptor format).
  *
  *	Typically this function can be called after a device has
  *	responded to a SCSI command with the CHECK_CONDITION status.
  *
  * Return value:
  *	true if valid sense data information found, else false;
  */
 bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
 			  struct scsi_sense_hdr *sshdr)
 {
 	memset(sshdr, 0, sizeof(struct scsi_sense_hdr));

 	if (!sense_buffer || !sb_len)
 		return false;

 	sshdr->response_code = (sense_buffer[0] & 0x7f);

 	if (!scsi_sense_valid(sshdr))
 		return false;

 	if (sshdr->response_code >= 0x72) {
 		/*
 		 * descriptor format
 		 */
 		if (sb_len > 1)
 			sshdr->sense_key = (sense_buffer[1] & 0xf);
 		if (sb_len > 2)
 			sshdr->asc = sense_buffer[2];
 		if (sb_len > 3)
 			sshdr->ascq = sense_buffer[3];
 		if (sb_len > 7)
 			sshdr->additional_length = sense_buffer[7];
 	} else {
 		/*
 		 * fixed format
 		 */
 		if (sb_len > 2)
 			sshdr->sense_key = (sense_buffer[2] & 0xf);
 		if (sb_len > 7) {
 			sb_len = min(sb_len, sense_buffer[7] + 8);
 			if (sb_len > 12)
 				sshdr->asc = sense_buffer[12];
 			if (sb_len > 13)
 				sshdr->ascq = sense_buffer[13];
 		}
 	}

 	return true;
 }
 EXPORT_SYMBOL(scsi_normalize_sense);

 /**
  * scsi_sense_desc_find - search for a given descriptor type in	descriptor sense data format.
  * @sense_buffer:	byte array of descriptor format sense data
  * @sb_len:		number of valid bytes in sense_buffer
  * @desc_type:		value of descriptor type to find
  *			(e.g. 0 -> information)
  *
  * Notes:
  *	only valid when sense data is in descriptor format
  *
  * Return value:
  *	pointer to start of (first) descriptor if found else NULL
  */
 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
 				int desc_type)
 {
 	int add_sen_len, add_len, desc_len, k;
 	const u8 * descp;

 	if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
 		return NULL;
 	if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
 		return NULL;
 	add_sen_len = (add_sen_len < (sb_len - 8)) ?
 			add_sen_len : (sb_len - 8);
 	descp = &sense_buffer[8];
 	for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
 		descp += desc_len;
 		add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
 		desc_len = add_len + 2;
 		if (descp[0] == desc_type)
 			return descp;
 		if (add_len < 0) // short descriptor ??
 			break;
 	}
 	return NULL;
 }
 EXPORT_SYMBOL(scsi_sense_desc_find);

 /**
  * scsi_build_sense_buffer - build sense data in a buffer
  * @desc:	Sense format (non-zero == descriptor format,
  *              0 == fixed format)
  * @buf:	Where to build sense data
  * @key:	Sense key
  * @asc:	Additional sense code
  * @ascq:	Additional sense code qualifier
  *
  **/
 void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
 {
 	if (desc) {
 		buf[0] = 0x72;	/* descriptor, current */
 		buf[1] = key;
 		buf[2] = asc;
 		buf[3] = ascq;
 		buf[7] = 0;
 	} else {
 		buf[0] = 0x70;	/* fixed, current */
 		buf[2] = key;
 		buf[7] = 0xa;
 		buf[12] = asc;
 		buf[13] = ascq;
 	}
 }
 EXPORT_SYMBOL(scsi_build_sense_buffer);

 /**
  * scsi_set_sense_information - set the information field in a
  *		formatted sense data buffer
  * @buf:	Where to build sense data
  * @buf_len:    buffer length
  * @info:	64-bit information value to be set
  *
  * Return value:
  *	0 on success or -EINVAL for invalid sense buffer length
  **/
 int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
 {
 	if ((buf[0] & 0x7f) == 0x72) {
 		u8 *ucp, len;

 		len = buf[7];
 		ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
 		if (!ucp) {
 			buf[7] = len + 0xc;
 			ucp = buf + 8 + len;
 		}

 		if (buf_len < len + 0xc)
 			/* Not enough room for info */
 			return -EINVAL;

 		ucp[0] = 0;
 		ucp[1] = 0xa;
 		ucp[2] = 0x80; /* Valid bit */
 		ucp[3] = 0;
 		put_unaligned_be64(info, &ucp[4]);
 	} else if ((buf[0] & 0x7f) == 0x70) {
 		/*
 		 * Only set the 'VALID' bit if we can represent the value
 		 * correctly; otherwise just fill out the lower bytes and
 		 * clear the 'VALID' flag.
 		 */
 		if (info <= 0xffffffffUL)
 			buf[0] |= 0x80;
 		else
 			buf[0] &= 0x7f;
 		put_unaligned_be32((u32)info, &buf[3]);
 	}

 	return 0;
 }
 EXPORT_SYMBOL(scsi_set_sense_information);

 /**
  * scsi_set_sense_field_pointer - set the field pointer sense key
  *		specific information in a formatted sense data buffer
  * @buf:	Where to build sense data
  * @buf_len:    buffer length
  * @fp:		field pointer to be set
  * @bp:		bit pointer to be set
  * @cd:		command/data bit
  *
  * Return value:
  *	0 on success or -EINVAL for invalid sense buffer length
  */
 int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
 {
 	u8 *ucp, len;

 	if ((buf[0] & 0x7f) == 0x72) {
 		len = buf[7];
 		ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
 		if (!ucp) {
 			buf[7] = len + 8;
 			ucp = buf + 8 + len;
 		}

 		if (buf_len < len + 8)
 			/* Not enough room for info */
 			return -EINVAL;

 		ucp[0] = 2;
 		ucp[1] = 6;
 		ucp[4] = 0x80; /* Valid bit */
 		if (cd)
 			ucp[4] |= 0x40;
 		if (bp < 0x8)
 			ucp[4] |= 0x8 | bp;
 		put_unaligned_be16(fp, &ucp[5]);
 	} else if ((buf[0] & 0x7f) == 0x70) {
 		len = buf[7];
 		if (len < 18)
 			buf[7] = 18;

 		buf[15] = 0x80;
 		if (cd)
 			buf[15] |= 0x40;
 		if (bp < 0x8)
 			buf[15] |= 0x8 | bp;
 		put_unaligned_be16(fp, &buf[16]);
 	}

 	return 0;
 }
 EXPORT_SYMBOL(scsi_set_sense_field_pointer);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* SCSI functions used by both the initiator and the target code.
	*/

	#include <linux/bug.h>
	#include <linux/kernel.h>
	#include <linux/string.h>
	#include <linux/errno.h>
	#include <linux/module.h>
	#include <uapi/linux/pr.h>
	#include <linux/unaligned.h>
	#include <scsi/scsi_common.h>

	MODULE_DESCRIPTION("SCSI functions used by both the initiator and the target code");
	MODULE_LICENSE("GPL v2");

	/* Command group 3 is reserved and should never be used. */
	const unsigned char scsi_command_size_tbl[8] = {
	6, 10, 10, 12, 16, 12, 10, 10
	};
	EXPORT_SYMBOL(scsi_command_size_tbl);

	/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
	* You may not alter any existing entry (although adding new ones is
	* encouraged once assigned by ANSI/INCITS T10).
	*/
	static const char *const scsi_device_types[] = {
	"Direct-Access ",
	"Sequential-Access",
	"Printer ",
	"Processor ",
	"WORM ",
	"CD-ROM ",
	"Scanner ",
	"Optical Device ",
	"Medium Changer ",
	"Communications ",
	"ASC IT8 ",
	"ASC IT8 ",
	"RAID ",
	"Enclosure ",
	"Direct-Access-RBC",
	"Optical card ",
	"Bridge controller",
	"Object storage ",
	"Automation/Drive ",
	"Security Manager ",
	"Direct-Access-ZBC",
	};

	/**
	* scsi_device_type - Return 17-char string indicating device type.
	* @type: type number to look up
	*/
	const char *scsi_device_type(unsigned type)
	{
	if (type == 0x1e)
	return "Well-known LUN ";
	if (type == 0x1f)
	return "No Device ";
	if (type >= ARRAY_SIZE(scsi_device_types))
	return "Unknown ";
	return scsi_device_types[type];
	}
	EXPORT_SYMBOL(scsi_device_type);

	enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type)
	{
	switch (type) {
	case SCSI_PR_WRITE_EXCLUSIVE:
	return PR_WRITE_EXCLUSIVE;
	case SCSI_PR_EXCLUSIVE_ACCESS:
	return PR_EXCLUSIVE_ACCESS;
	case SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY:
	return PR_WRITE_EXCLUSIVE_REG_ONLY;
	case SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY:
	return PR_EXCLUSIVE_ACCESS_REG_ONLY;
	case SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS:
	return PR_WRITE_EXCLUSIVE_ALL_REGS;
	case SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS:
	return PR_EXCLUSIVE_ACCESS_ALL_REGS;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(scsi_pr_type_to_block);

	enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
	{
	switch (type) {
	case PR_WRITE_EXCLUSIVE:
	return SCSI_PR_WRITE_EXCLUSIVE;
	case PR_EXCLUSIVE_ACCESS:
	return SCSI_PR_EXCLUSIVE_ACCESS;
	case PR_WRITE_EXCLUSIVE_REG_ONLY:
	return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
	return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
	case PR_WRITE_EXCLUSIVE_ALL_REGS:
	return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
	return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(block_pr_type_to_scsi);

	/**
	* scsilun_to_int - convert a scsi_lun to an int
	* @scsilun: struct scsi_lun to be converted.
	*
	* Description:
	* Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered
	* integer, and return the result. The caller must check for
	* truncation before using this function.
	*
	* Notes:
	* For a description of the LUN format, post SCSI-3 see the SCSI
	* Architecture Model, for SCSI-3 see the SCSI Controller Commands.
	*
	* Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
	* returns the integer: 0x0b03d204
	*
	* This encoding will return a standard integer LUN for LUNs smaller
	* than 256, which typically use a single level LUN structure with
	* addressing method 0.
	*/
	u64 scsilun_to_int(struct scsi_lun *scsilun)
	{
	int i;
	u64 lun;

	lun = 0;
	for (i = 0; i < sizeof(lun); i += 2)
	lun = lun \| (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) \|
	((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
	return lun;
	}
	EXPORT_SYMBOL(scsilun_to_int);

	/**
	* int_to_scsilun - reverts an int into a scsi_lun
	* @lun: integer to be reverted
	* @scsilun: struct scsi_lun to be set.
	*
	* Description:
	* Reverts the functionality of the scsilun_to_int, which packed
	* an 8-byte lun value into an int. This routine unpacks the int
	* back into the lun value.
	*
	* Notes:
	* Given an integer : 0x0b03d204, this function returns a
	* struct scsi_lun of: d2 04 0b 03 00 00 00 00
	*
	*/
	void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
	{
	int i;

	memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));

	for (i = 0; i < sizeof(lun); i += 2) {
	scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
	scsilun->scsi_lun[i+1] = lun & 0xFF;
	lun = lun >> 16;
	}
	}
	EXPORT_SYMBOL(int_to_scsilun);

	/**
	* scsi_normalize_sense - normalize main elements from either fixed or
	* descriptor sense data format into a common format.
	*
	* @sense_buffer: byte array containing sense data returned by device
	* @sb_len: number of valid bytes in sense_buffer
	* @sshdr: pointer to instance of structure that common
	* elements are written to.
	*
	* Notes:
	* The "main elements" from sense data are: response_code, sense_key,
	* asc, ascq and additional_length (only for descriptor format).
	*
	* Typically this function can be called after a device has
	* responded to a SCSI command with the CHECK_CONDITION status.
	*
	* Return value:
	* true if valid sense data information found, else false;
	*/
	bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
	struct scsi_sense_hdr *sshdr)
	{
	memset(sshdr, 0, sizeof(struct scsi_sense_hdr));

	if (!sense_buffer \|\| !sb_len)
	return false;

	sshdr->response_code = (sense_buffer[0] & 0x7f);

	if (!scsi_sense_valid(sshdr))
	return false;

	if (sshdr->response_code >= 0x72) {
	/*
	* descriptor format
	*/
	if (sb_len > 1)
	sshdr->sense_key = (sense_buffer[1] & 0xf);
	if (sb_len > 2)
	sshdr->asc = sense_buffer[2];
	if (sb_len > 3)
	sshdr->ascq = sense_buffer[3];
	if (sb_len > 7)
	sshdr->additional_length = sense_buffer[7];
	} else {
	/*
	* fixed format
	*/
	if (sb_len > 2)
	sshdr->sense_key = (sense_buffer[2] & 0xf);
	if (sb_len > 7) {
	sb_len = min(sb_len, sense_buffer[7] + 8);
	if (sb_len > 12)
	sshdr->asc = sense_buffer[12];
	if (sb_len > 13)
	sshdr->ascq = sense_buffer[13];
	}
	}

	return true;
	}
	EXPORT_SYMBOL(scsi_normalize_sense);

	/**
	* scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
	* @sense_buffer: byte array of descriptor format sense data
	* @sb_len: number of valid bytes in sense_buffer
	* @desc_type: value of descriptor type to find
	* (e.g. 0 -> information)
	*
	* Notes:
	* only valid when sense data is in descriptor format
	*
	* Return value:
	* pointer to start of (first) descriptor if found else NULL
	*/
	const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
	int desc_type)
	{
	int add_sen_len, add_len, desc_len, k;
	const u8 * descp;

	if ((sb_len < 8) \|\| (0 == (add_sen_len = sense_buffer[7])))
	return NULL;
	if ((sense_buffer[0] < 0x72) \|\| (sense_buffer[0] > 0x73))
	return NULL;
	add_sen_len = (add_sen_len < (sb_len - 8)) ?
	add_sen_len : (sb_len - 8);
	descp = &sense_buffer[8];
	for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
	descp += desc_len;
	add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
	desc_len = add_len + 2;
	if (descp[0] == desc_type)
	return descp;
	if (add_len < 0) // short descriptor ??
	break;
	}
	return NULL;
	}
	EXPORT_SYMBOL(scsi_sense_desc_find);

	/**
	* scsi_build_sense_buffer - build sense data in a buffer
	* @desc: Sense format (non-zero == descriptor format,
	* 0 == fixed format)
	* @buf: Where to build sense data
	* @key: Sense key
	* @asc: Additional sense code
	* @ascq: Additional sense code qualifier
	*
	**/
	void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
	{
	if (desc) {
	buf[0] = 0x72; /* descriptor, current */
	buf[1] = key;
	buf[2] = asc;
	buf[3] = ascq;
	buf[7] = 0;
	} else {
	buf[0] = 0x70; /* fixed, current */
	buf[2] = key;
	buf[7] = 0xa;
	buf[12] = asc;
	buf[13] = ascq;
	}
	}
	EXPORT_SYMBOL(scsi_build_sense_buffer);

	/**
	* scsi_set_sense_information - set the information field in a
	* formatted sense data buffer
	* @buf: Where to build sense data
	* @buf_len: buffer length
	* @info: 64-bit information value to be set
	*
	* Return value:
	* 0 on success or -EINVAL for invalid sense buffer length
	**/
	int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
	{
	if ((buf[0] & 0x7f) == 0x72) {
	u8 *ucp, len;

	len = buf[7];
	ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
	if (!ucp) {
	buf[7] = len + 0xc;
	ucp = buf + 8 + len;
	}

	if (buf_len < len + 0xc)
	/* Not enough room for info */
	return -EINVAL;

	ucp[0] = 0;
	ucp[1] = 0xa;
	ucp[2] = 0x80; /* Valid bit */
	ucp[3] = 0;
	put_unaligned_be64(info, &ucp[4]);
	} else if ((buf[0] & 0x7f) == 0x70) {
	/*
	* Only set the 'VALID' bit if we can represent the value
	* correctly; otherwise just fill out the lower bytes and
	* clear the 'VALID' flag.
	*/
	if (info <= 0xffffffffUL)
	buf[0] \|= 0x80;
	else
	buf[0] &= 0x7f;
	put_unaligned_be32((u32)info, &buf[3]);
	}

	return 0;
	}
	EXPORT_SYMBOL(scsi_set_sense_information);

	/**
	* scsi_set_sense_field_pointer - set the field pointer sense key
	* specific information in a formatted sense data buffer
	* @buf: Where to build sense data
	* @buf_len: buffer length
	* @fp: field pointer to be set
	* @bp: bit pointer to be set
	* @cd: command/data bit
	*
	* Return value:
	* 0 on success or -EINVAL for invalid sense buffer length
	*/
	int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
	{
	u8 *ucp, len;

	if ((buf[0] & 0x7f) == 0x72) {
	len = buf[7];
	ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
	if (!ucp) {
	buf[7] = len + 8;
	ucp = buf + 8 + len;
	}

	if (buf_len < len + 8)
	/* Not enough room for info */
	return -EINVAL;

	ucp[0] = 2;
	ucp[1] = 6;
	ucp[4] = 0x80; /* Valid bit */
	if (cd)
	ucp[4] \|= 0x40;
	if (bp < 0x8)
	ucp[4] \|= 0x8 \| bp;
	put_unaligned_be16(fp, &ucp[5]);
	} else if ((buf[0] & 0x7f) == 0x70) {
	len = buf[7];
	if (len < 18)
	buf[7] = 18;

	buf[15] = 0x80;
	if (cd)
	buf[15] \|= 0x40;
	if (bp < 0x8)
	buf[15] \|= 0x8 \| bp;
	put_unaligned_be16(fp, &buf[16]);
	}

	return 0;
	}
	EXPORT_SYMBOL(scsi_set_sense_field_pointer);