HPUX scsi[7]
scsi(7) scsi(7)
NAME
scsi - Small Computer System Interface device drivers
DESCRIPTION
The Small Computer System Interface (SCSI) is an American National
Standard for interconnecting computers and peripheral devices (see
ANSI Std X3.131-199X, ``SCSI-2''). The SCSI standard includes
specifications for a variety of device types. This section describes
the general SCSI interface for all SCSI device drivers. Information
about specific device types can be found in the manual sections which
describe SCSI peripheral device drivers for those device types.
The SIOC_INQUIRY ioctl is supported by all SCSI device drivers. This
ioctl returns the SCSI device-specific INQUIRY command data. This
data contains device identification and capability information. Since
there have been multiple versions of the SCSI standard for inquiry
data, multiple versions of the inquiry data declaration are provided.
The SCSI-1 version is provided for backward compatibility only.
The SIOC_CAPACITY ioctl indicates the current device size. A device
size is defined to be a logical block size and some number of logical
blocks. The means of determining this device-size data is particular
to the specific device type. Logical block size and/or number of
logical blocks equal to zero indicates: the device size is unknown,
the device is not currently capable of I/O operations, or I/O
operations are not meaningful for the device.
The header file <sys/scsi.h> has useful information for SCSI devices.
The following is included from <sys/scsi.h>:
#define SIOC_INQUIRY _IOR('S', 2, union inquiry_data)
#define SIOC_CAPACITY _IOR('S', 3, struct capacity)
/* SCSI-1 inquiry structure */
struct inquiry {
unsigned char dev_type;
unsigned char rmb:1;
unsigned char dtq:7;
unsigned char iso:2;
unsigned char ecma:3;
unsigned char ansi:3;
unsigned char resv:4;
unsigned char rdf:4;
unsigned char added_len;
unsigned char dev_class[3];
char vendor_id[8];
char product_id[16];
char rev_num[4];
unsigned char vendor_spec[20];
unsigned char resv4[40];
unsigned char vendor_parm_bytes[32];
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};
/* SCSI-2 inquiry structure */
struct inquiry_2 {
unsigned char periph_qualifier:3;
unsigned char dev_type:5;
unsigned char rmb:1;
unsigned char dtq:7;
unsigned char iso:2;
unsigned char ecma:3;
unsigned char ansi:3;
unsigned char aenc:1;
unsigned char trmiop:1;
unsigned char resv1:2;
unsigned char rdf:4;
unsigned char added_len;
unsigned char resv2[2];
unsigned char reladr:1;
unsigned char wbus32:1;
unsigned char wbus16:1;
unsigned char sync:1;
unsigned char linked:1;
unsigned char resv3:1;
unsigned char cmdque:1;
unsigned char sftre:1;
char vendor_id[8];
char product_id[16];
char rev_num[4];
unsigned char vendor_spec[20];
unsigned char resv4[40];
unsigned char vendor_parm_bytes[32];
};
/* union for SIOC_INQUIRY ioctl */
union inquiry_data {
struct inquiry inq1; /* SCSI-1 inquiry */
struct inquiry_2 inq2; /* SCSI-2 inquiry */
};
/* structure for SIOC_CAPACITY ioctl */
struct capacity {
int lba;
int blksz;
};
DEPENDENCIES
Series 300/400/700
The SIOC_XSENSE ioctl returns detailed information about device status
and errors when such information is available. Since there have been
multiple versions of the SCSI standard for sense (status) data,
multiple versions of the sense data declaration are provided. The
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SCSI-1 and non-aligned versions are provided for backward
compatibility only. If no new CHECK-CONDITION-caused REQUEST SENSE
command data has been obtained since the last SIOC_XSENSE ioctl call,
the xsense_aligned.error_class and sense_2_aligned.error_code fields
will contain the value zero. Applications which require more accurate
REQUEST SENSE data handling should use the SCSI device-control driver
(see scsi_ctl(7)).
The following information is included from <sys/scsi.h>:
#define SIOC_XSENSE _IOR('S', 7, union sense_data)
/* structure for SIOC_XSENSE ioctl */
union sense_data {
struct xsense_aligned r_sense1a; /* SCSI and CCS devices */
struct sense_2_aligned r_sense2a; /* SCSI-2 devices */
};
/* structure for SCSI-1 and SCSI-CCS sense data */
struct xsense_aligned {
unsigned char valid:1;
unsigned char error_class:3;
unsigned char error_code:4;
unsigned char seg_num;
unsigned char parms:4;
unsigned char sense_key:4;
unsigned char lba[4];
unsigned char add_len;
unsigned char copysearch[4];
unsigned char sense_code;
unsigned char resv;
unsigned char fru;
unsigned char field;
unsigned char field_ptr[2];
unsigned char dev_error[4];
unsigned char misc_bytes[106];
};
/* structure for SCSI-2 sense data */
struct sense_2_aligned {
unsigned char info_valid:1;
unsigned char error_code:7;
unsigned char seg_num;
unsigned char filemark:1;
unsigned char eom:1;
unsigned char ili:1;
unsigned char resv:1;
unsigned char key:4;
unsigned char info[4];
unsigned char add_len;
unsigned char cmd_info[4];
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unsigned char code;
unsigned char qualifier;
unsigned char fru;
unsigned char key_specific[3];
unsigned char add_sense_bytes[113];
};
Series 700
The SIOC_EXCLUSIVE ioctl may be used to obtain and release exclusive
access. Exclusive access, which prevents simultaneous access by other
applications, is required for some operations and may be desirable in
other circumstances. The following exclusive access control arguments
are supported:
0 Release exclusive access to logical unit (LUN).
1 Gain exclusive access to logical unit (LUN).
2 Release exclusive access to associated SCSI target.
3 Gain exclusive access to associated SCSI target.
4 Release exclusive access to associated SCSI bus.
5 Gain exclusive access to associated SCSI bus.
The SIOC_MEDIUM_CHANGED ioctl indicates when the media in a
removable-media device may have changed. A value of ``1'' indicates
the device media may have changed since the last SIOC_MEDIUM_CHANGED
ioctl call. Note that only the first such call after a media change
receives this indication. This means that media changes are likely to
be missed if multiple applications are attempting to detect media
changes. Exclusive access, obtained through use of the SIOC_EXCLUSIVE
ioctl, can be used to avoid this problem.
The following information is included from <sys/scsi.h>:
#define SIOC_MEDIUM_CHANGED _IOR('S', 42, int)
#define SIOC_EXCLUSIVE _IOR('S', 68, int)
Series 800
The SIOC_VPD_INQUIRY ioctl allows access to detailed device specific
information. The page_code field specifies which SCSI vital product
data page is requested. The page_buf field is filled with the
requested page data.
The following information is included from <sys/scsi.h>:
#define SIOC_VPD_INQUIRY _IOWR('S', 10, struct vpd_inquiry)
/* union for SIOC_VPD_INQUIRY ioctl */
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struct vpd_inquiry {
char page_code; /* VPD page code */
char page_buf[126]; /* buffer for VPD page info */
};
WARNINGS
Use of devices that are not officially supported can cause data loss,
system panics and device damage. HP-UX device drivers expect devices
to be SCSI-2 compliant. Unsupported devices that are only SCSI-CCS
compliant may work but their use is discouraged. Use of unsupported
devices that are only SCSI-1 compliant is strongly discouraged.
Changing SCSI bus connectivity (recabling) while the system is running
is not supported. Switching SCSI device power on or off while the
device is connected to a system that does not support powerfail
recovery is not supported. These activities are known to cause data
loss and system panics.
On systems that support the scsi_ctl interface, the SIOC_CMD_MODE,
SIOC_SET_CMD, and SIOC_RETURN_STATUS ioctls are obsolete (see
scsi_ctl(7)). Direct manipulation of SCSI devices via the scsi_ctl
interface provides a more functionally complete and easier-to-use
means of low level SCSI device control (see scsi_ctl(7)).
Drivers that support only devices which have no meaningful size may
not support the SIOC_CAPACITY ioctl. Total device size in bytes may
exceed 2**32-1 for some devices.
ERRORS
The following errors may result from a call to a SCSI device driver:
[EACCES] Required permission is denied for the the device
or operation.
[ENXIO] If resulting from an open call, this indicates
there is no device at the specified address. For
other calls, this indicates the specified address
is out of range or the device may no longer be
accessed.
[EINVAL] If resulting from an open call, this indicates the
device is not supported by the device driver (e.g.
incorrect device type). For other calls, this
indicates the request or some request argument is
invalid.
[EBUSY] This indicates the device is not ready for use or
that the requested operation conflicts with other
operations (e.g. the device is currently open via
another device driver or exclusive access is in
effect).
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[EIO] Indicates a SCSI protocol or communication problem
has occurred, or that a SCSI command resulted in a
non-good status.
Manual entries that describe specific SCSI peripheral device drivers
may provide additional qualification of error results.
SEE ALSO
scsi_disk(7), scsi_tape(7), scsi_changer(7), scsi_ctl(7),
diskinfo(1M).
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