linux/drivers/scsi/scsi_common.c

// 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 <asm/unaligned.h>
#include <scsi/scsi_common.h>

MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;

/* Command group 3 is reserved and should never be used.  */
const unsigned char scsi_command_size_tbl[8] = …;
EXPORT_SYMBOL(…);

/* 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[] = …;

/**
 * scsi_device_type - Return 17-char string indicating device type.
 * @type: type number to look up
 */
const char *scsi_device_type(unsigned type)
{ … }
EXPORT_SYMBOL(…);

enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type)
{ … }
EXPORT_SYMBOL_GPL(…);

enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);