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Files Reference
Provides access to multiprotocol
adapters by way of the Multiprotocol Quad Port (MPQP) device
handler.
The
/dev/mpqn character special file provides access to the
MPQP device handler for the purpose of providing access to a synchronous
network. The MPQP device handler supports multiple adapters.
When accessing the MPQP device
handler, the following should be taken into account:
The device handler may be loaded
and unloaded. The handler supports the configuration calls to
initialize and terminate itself.
Calls other than the open and close
subroutine calls are discussed in relation to the mode in which the device
handler is operating.
The MPQP device handler supports
the open, close, read, write, and ioctl subroutines in the following
manner:
- The open and
close subroutines
The device handler supports the /dev/mpqn special
file as a character-multiplex special file. The special file must be
opened for both reading and writing (O_RDWR). There are no particular
considerations for closing the special file. Which special file name is
used in an open call depends on how the device is to be
opened. Types of special file names are:
| /dev/mpqn
| Starts the device handler for the selected port.
|
| /dev/mpqn/D
| Starts the device handler in Diagnostic mode for the selected
port.
|
- The read
subroutine
Can take the form of a read,
readx, readv, or readvx subroutine call.
For this call, the device handler copies the data into the buffer specified by
the caller.
- The write
subroutine
Can take the form of a write,
writex, writev, or writevx subroutine
call. For this call, the device handler copies the user data into a
buffer and transmits the data on the LAN.
- The ioctl
subroutine
| CIO_START
| Starts a session and registers a network ID.
|
| CIO_HALT
| Halts a session and removes a network ID.
|
| CIO_QUERY
| Returns the current RAS counter values. These values are defined
in the /usr/include/sys/comio.h file.
|
| CIO_GET_STAT
| Returns the current adapter and device handler status.
|
| MP_START_AR
| Puts the MPQP port into Autoresponse mode.
|
| MP_STOP_AR
| Permits the MPQP port to exit Autoresponse mode.
|
| MP_CHG_PARMS
| Permits the data link control (DLC) to change certain profile parameters
after the MPQP device has been started.
|
| MP_SET_DELAY
| Sets the value of NDELAY.
|
The following error codes may be
returned when accessing the device handler through the
/dev/mpqn special file:
| ECHRNG
| Indicates that the channel number is out of range.
|
| EAGAIN
| Indicates that the maximum number of direct memory accesses (DMAs) was
reached, so that the handler cannot get memory for internal control
structures.
|
| EBUSY
| Indicates one of the following:
- The port is not in correct state.
- The port should be configured, but is not opened or
started.
- The port state is not opened for start of an ioctl
operation.
- The port is not started or is not in data-transfer
state.
|
| EIO
| Indicates that the handler could not queue the request to the
adapter.
|
| EFAULT
| Indicates that the cross-memory copy service failed.
|
| EINTR
| Indicates that the sleep was interrupted by a signal.
|
| EINVAL
| Indicates one of the following:
- The port not set up properly.
- The handler could not set up structures for write.
- The port is not valid.
- A select operation was called by a kernel process.
- The specified physical-link parameter is not valid for
that port.
- The read was called by a kernel process.
|
| ENOMEM
| Indicates one of the following:
- No mbuf or mbuf clusters are available.
- The total data length is more than a page.
- There is no memory for internal structures.
|
| ENOMSG
| Indicates that the status-queue pointer is null, and there are no
entries.
|
| ENOTREADY
| Indicates that the port state in define device structure (DDS) is not in
Data Transfer mode or that the implicit halt of port failed.
|
| ENXIO
| Indicates one of the following:
- The port has not been started successfully.
- An invalid adapter number was specified.
- The channel number is illegal.
- The adapter is already open in Diagnostic mode.
- The adapter control block (ACB) pointer is null or does
not exist.
- The registration of the interrupt handler failed.
- The port does not exist or is not in proper state.
- The adapter number is out of range.
|
The communication device handler
chapter defines specific errors returned on each subroutine call.
This file functions with the Multiprotocol device handler.
The close subroutine, open subroutine, read or readx subroutine, write or writex subroutine, ioctl subroutine.
MPQP Device
Handler Interface Overview in AIX 5L Version 5.1 Kernel
Extensions and Device Support Programming Concepts.
Special Files Overview
.
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