CIO_GET_FASTWRT (Get Fast Write) entioctl Ethernet Device Handler Operation

Kernel and Subsystems Technical Reference, Volume 2

CIO_GET_FASTWRT (Get Fast Write) entioctl Ethernet Device Handler Operation

Purpose

Returns the parameters required to issue an ent_fastwrt call.

Description

The CIO_GET_FASTWRT operation returns the parameters required to issue the kernel-mode fast write for the Ethernet adapter. The parameters are returned in the cio_get_fastwrt structure, which is defined in the /usr/include/sys/comio.h file. The arg pointer points to the cio_get_fastwrt structure, which contains the following fields:

`status`	Indicates the status condition that occurred; either CIO_OK or CIO_INV_CMD.
`fastwrt_fn`	Indicates the address of the fast write function.
`devno`	Specifies major and minor numbers of the device.

Execution Environment

The CIO_GET_FASTWRT operation can be called from a kernel-mode process only.

Return Values

EINVAL	Indicates that a parameter is not valid.
ENODEV	Indicates that a minor number is not valid.
ENXIO	Indicates an attempt to use an unconfigured device.
EPERM	Indicates the calling process is a user-mode process.
EBUSY	Indicates the maximum number of opens was exceeded.

Implementation Specifics

The CIO_GET_FASTWRT operation works with an Ethernet High-Performance LAN adapter that has been correctly configured for use on a qualified network. Consult adapter specifications for more information on configuring the network adapter and network qualifications.

Related Information

The entwrite entry point, ent_fastwrt entry point.