xref: /titanic_50/usr/src/man/man9e/_fini.9e (revision f3390f39074f3a68f54318e83a9801b156b0f5d3)
te
Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
_FINI 9E "Jan 22, 2002"
NAME
_fini, _info, _init - loadable module configuration entry points
SYNOPSIS

#include <sys/modctl.h>



int _fini(void)

int _info(struct modinfo *modinfop);

int _init(void)
INTERFACE LEVEL

Solaris DDI specific (Solaris DDI). These entry points are required. You must write them.

PARAMETERS
"_info(\|)"
modinfop

A pointer to an opaque modinfo structure.

DESCRIPTION

_init() initializes a loadable module. It is called before any other routine in a loadable module. _init() returns the value returned by mod_install(9F). The module may optionally perform some other work before the mod_install(9F) call is performed. If the module has done some setup before the mod_install(9F) function is called, then it should be prepared to undo that setup if mod_install(9F) returns an error.

_info() returns information about a loadable module. _info() returns the value returned by mod_info(9F).

_fini() prepares a loadable module for unloading. It is called when the system wants to unload a module. If the module determines that it can be unloaded, then _fini() returns the value returned by mod_remove(9F). Upon successful return from _fini() no other routine in the module will be called before _init() is called.

RETURN VALUES

_init() should return the appropriate error number if there is an error, otherwise it should return the return value from mod_install(9F).

_info() should return the return value from mod_info(9F)

_fini() should return the return value from mod_remove(9F). _fini() is permitted to return EBUSY prior to calling mod_remove(9F) if the driver should not be unloaded. Driver global resources, such as mutexes and calls to ddi_soft_state_fini(9F), should only be destroyed in _fini() after mod_remove() returns successfully.

EXAMPLES

Example 1 Initializing and Freeing a Mutex

The following example demonstrates how to initialize and free a mutex(9F).

#include <sys/modctl.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
static struct dev_ops drv_ops;
/*
 * Module linkage information for the kernel.
 */
static struct modldrv modldrv = {
 &mod_driverops, /* Type of module. This one is a driver */
 "Sample Driver",
 &drv_ops /* driver ops */
};

static struct modlinkage modlinkage = {
 MODREV_1,
 &modldrv,
 NULL
};


/*
 * Global driver mutex
 */
static kmutex_t xx_global_mutex;


int
_init(void)
{
 int i;

 /*
 * Initialize global mutex before mod_install'ing driver.
 * If mod_install() fails, must clean up mutex initialization
 */
 mutex_init(&xx_global_mutex, NULL,
 MUTEX_DRIVER, (void *)NULL);

 if ((i = mod_install(&modlinkage)) != 0) {
 mutex_destroy(&xx_global_mutex);
 }

 return (i);
}

int
_info(struct modinfo *modinfop)
{
 return (mod_info(&modlinkage, modinfop));
}


int
_fini(void)
{
 int i;

 /*
 * If mod_remove() is successful, we destroy our global mutex
 */
 if ((i = mod_remove(&modlinkage)) == 0) {
 mutex_destroy(&xx_global_mutex);
 }
 return (i);
}
SEE ALSO

add_drv(1M), mod_info(9F), mod_install(9F), mod_remove(9F), mutex(9F), modldrv(9S), modlinkage(9S), modlstrmod(9S)

Writing Device Drivers

WARNINGS

Do not change the structures referred to by the modlinkage structure after the call to mod_install(), as the system may copy or change them.

NOTES

Even though the identifiers _fini(), _info(), and _init() appear to be declared as globals, their scope is restricted by the kernel to the module that they are defined in.

BUGS

On some implementations _info() may be called before _init().