tokfastwrt Token-Ring Device Handler Entry Point

Purpose

Note: This function is supported in AIX® 5.1 and earlier only.

Provides the means for kernel users to perform direct-access write operations.

Syntax

#include <sys/device.h>
#include <sys/comio.h>
#include <sys/tokuser.h>
#include <sys/mbuf.h>

int tokfastwrt (devno, m)
dev_t devno;
struct mbuf *m;

Parameters

Description

The tokfastwrt entry point is called from a kernel-mode process to pass a write packet to the token-ring device handler for subsequent transmission. The address of this entry point is provided to the kernel user by the CIO_GET_FASTWRT ioctl entry point.

The tokfastwrt entry point provides for only one data packet to be transmitted for a single tokfastwrt call. The tokfastwrt entry point assumes that the calling user is a valid kernel user and that the mbuf structure contains a valid data packet. The device handler frees the mbuf and does not acknowledge transmit completion.

The tokfastwrt entry point functions with a Token-Ring High-Performance Network Adapter that has been correctly configured for use on a qualified network. Consult adapter specifications for more information on configuring the adapter and network qualifications.

Execution Environment

The tokfastwrt entry point can be called from a kernel process or interrupt level. The operation level of the token-ring device handler is TOK_OPLEVEL. This label is defined in the /usr/include/sys/tokuser.h file. The tokfastwrt entry point treats this path as a trusted path and the device handler does not check the parameters.

Return Values