NAME
iop
-
I2O adapter driver
SYNOPSIS
iop* at pci? dev ? function ?
iopsp* at iop? tid ?
ld* at iop? tid ?
dpti* at iop? tid 0
DESCRIPTION
The
iop
driver provides support for
PCI
I/O processors conforming to the
I2O
specification, revision 1.5 and above.
I2O is a specification that defines a software interface for communicating
with a number of device types. In its basic form, I2O provides the
following:
-
A vendor-neutral interface for communicating with an I/O processor (IOP)
and a number of types of peripherals. In order to achieve this,
hardware-specific device drivers run on the IOP, and hardware-neutral device
drivers run on the host.
-
Reduced I/O overhead for the host. All communication between the host and
the IOP is performed using a high level protocol. The specification also
provides for batching of requests and replies between the host and IOP.
-
An optional vendor-neutral configuration interface. Data from HTTP GET and
POST operations can be channeled to individual devices, and HTML pages
returned.
Five types of devices are well defined by the specification. These are:
-
Random block storage devices (disks).
-
Sequential storage devices (tapes).
-
LAN interfaces, including Ethernet, FDDI, and Token Ring.
-
Bus ports (SCSI).
-
SCSI peripherals.
The
iop
driver's role is to initialize and monitor the IOP, provide a conduit for
messages and replies to and from devices, and provide other common services
for peripheral drivers, such as DMA mapping.
IOCTL INTERFACE
The following structures and constants are defined in
dev/i2o/iopio.h
.
Note that the headers
sys/types.h
,
sys/device.h
and
dev/i2o/i2o.h
are prerequisites and must therefore be included beforehand.
IOPIOCPT
(struct
ioppt)
-
Submit a message to the IOP and return the reply. Note that the return
value of this ioctl is not affected by completion status as indicated by the
reply.
struct ioppt {
void *pt_msg; /* pointer to message buffer */
size_t pt_msglen; /* message buffer size in bytes */
void *pt_reply; /* pointer to reply buffer */
size_t pt_replylen; /* reply buffer size in bytes */
int pt_timo; /* completion timeout in ms */
int pt_nbufs; /* number of transfers */
struct ioppt_buf pt_bufs[IOP_MAX_MSG_XFERS]; /* transfers */
};
struct ioppt_buf {
void *ptb_data; /* pointer to buffer */
size_t ptb_datalen; /* buffer size in bytes */
int ptb_out; /* non-zero if transfer is to IOP */
};
The minimum timeout value that may be specified is 1000ms. All other values
must not exceed the
iop
driver's operational limits.
The initiator context and transaction context fields in the message frame
will be filled by the
iop
driver. As such, this ioctl may not be used to send messages without a
transaction context payload.
IOPIOCGSTATUS
(struct
iovec)
-
Request the latest available status record from the IOP. This special-case
ioctl is provided as the I2O_EXEC_STATUS_GET message does not post replies,
and can therefore not be safely issued using the IOPIOCPT ioctl.
The following ioctls may block while attempting to acquire the
iop
driver's configuration lock, and may fail if the acquisition times out.
IOPIOCGLCT
(struct
iovec)
-
Retrieve the
iop
driver's copy of the logical configuration table. This copy of the LCT
matches the current device configuration, but is not necessarily the latest
available version of the LCT.
IOPIOCRECONFIG
-
Request that the
iop
driver scan all bus ports, retrieve the latest version of the LCT, and
attach or detach devices as necessary. Note that higher-level
reconfiguration tasks (such as logically re-scanning SCSI busses) will not
be performed by this ioctl.
IOPIOCGTIDMAP
(struct
iovec)
-
Retrieve the TID to device map. This map indicates which targets are
configured, and what the corresponding device name for each is. Although at
any given point it contains the same number of entries as the LCT, the number
of entries should be determined using the iov_len field from the returned
iovec.
struct iop_tidmap {
u_short it_tid;
u_short it_flags;
char it_dvname[sizeof(((struct device *)NULL)->dv_xname)];
};
#define IT_CONFIGURED 0x02 /* target configured */
FILES
/dev/iop
u-
control device for IOP unit
u
SEE ALSO
dpti(4),
intro(4),
iopsp(4),
ld(4),
iopctl(8)
http://www.intelligent-io.com/
HISTORY
The
iop
driver first appeared in
NetBSD1.5.3.