diff options
Diffstat (limited to 'drivers/scsi/scsi_common.c')
| -rw-r--r-- | drivers/scsi/scsi_common.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_common.c b/drivers/scsi/scsi_common.c new file mode 100644 index 000000000000..2ff092252b76 --- /dev/null +++ b/drivers/scsi/scsi_common.c @@ -0,0 +1,178 @@ +/* + * 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); |