linux/drivers/scsi/scsi_common.c
Bart Van Assche 07e3842055 Move code that is used both by initiator and target drivers
Move the functions that are used by both the initiator and target
subsystems into scsi_common.c/.h. This change will allow to remove
the initiator SCSI header include directives from most SCSI target
source files in a later patch.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-06-01 07:32:43 -07:00

179 lines
4.7 KiB
C

/*
* SCSI functions used by both the initiator and the target code.
*/
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <scsi/scsi_common.h>
/* 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);
/**
* 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)
{
if (!sense_buffer || !sb_len)
return false;
memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
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 = (sb_len < (sense_buffer[7] + 8)) ?
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);