'\" te
.\"  Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved
.TH _fini 9E "22 Jan 2002" "SunOS 5.11" "Driver Entry Points"
.SH NAME
_fini, _info, _init \- loadable module configuration entry points
.SH SYNOPSIS
.LP
.nf
#include <sys/modctl.h>

\fBint\fR \fB_fini\fR(void)
.fi

.LP
.nf
\fBint\fR \fB_info\fR(\fBstruct modinfo *\fR\fImodinfop\fR);
.fi

.LP
.nf
\fBint\fR \fB_init\fR(void)
.fi

.SH INTERFACE LEVEL
.sp
.LP
Solaris DDI specific (Solaris DDI). These entry points are required. You must write them.
.SH PARAMETERS
.SS "_info(\|)"
.sp
.ne 2
.mk
.na
\fB\fImodinfop\fR \fR
.ad
.RS 13n
.rt  
A pointer to an opaque \fBmodinfo\fR structure.
.RE

.SH DESCRIPTION
.sp
.LP
\fB_init()\fR initializes a loadable module. It is called before any other routine in a loadable module. \fB_init()\fR returns the value returned by \fBmod_install\fR(9F). The module may optionally perform some other work before the \fBmod_install\fR(9F) call is performed. If the module has done some setup before the \fBmod_install\fR(9F) function is called, then it should be prepared to undo that setup if \fBmod_install\fR(9F) returns an error.
.sp
.LP
\fB_info()\fR returns information about a loadable module. \fB_info()\fR returns the value returned by \fBmod_info\fR(9F). 
.sp
.LP
\fB_fini()\fR 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 \fB_fini()\fR returns the value returned by \fBmod_remove\fR(9F). Upon successful return from \fB_fini()\fR no other routine in the module will be called before \fB_init()\fR is called.
.SH RETURN VALUES
.sp
.LP
\fB_init()\fR should return the appropriate error number if there is an error, otherwise it should return the return value from \fBmod_install\fR(9F). 
.sp
.LP
\fB_info()\fR should return the return value from \fBmod_info\fR(9F) 
.sp
.LP
\fB_fini()\fR should return the return value from \fBmod_remove\fR(9F). \fB_fini()\fR is permitted to return \fBEBUSY\fR prior to calling \fBmod_remove\fR(9F) if the driver should not be unloaded. Driver global resources, such as mutexes and calls to \fBddi_soft_state_fini\fR(9F), should only be destroyed in \fB_fini()\fR after \fBmod_remove()\fR returns successfully. 
.SH EXAMPLES
.LP
\fBExample 1 \fRInitializing and Freeing a Mutex
.sp
.LP
The following example demonstrates how to initialize and free a \fBmutex\fR(9F).

.sp
.in +2
.nf
#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);
}
.fi
.in -2

.SH SEE ALSO
.sp
.LP
\fBadd_drv\fR(1M), \fBmod_info\fR(9F), \fBmod_install\fR(9F), \fBmod_remove\fR(9F), \fBmutex\fR(9F), \fBmodldrv\fR(9S), \fBmodlinkage\fR(9S), \fBmodlstrmod\fR(9S) 
.sp
.LP
\fIWriting Device Drivers for Oracle Solaris 11.2\fR 
.SH WARNINGS
.sp
.LP
Do not change the structures referred to by the \fBmodlinkage\fR structure after the call to \fBmod_install()\fR, as the system may copy or change them.
.SH NOTES
.sp
.LP
Even though the identifiers \fB_fini()\fR, \fB_info()\fR, and \fB_init()\fR appear to be declared as globals, their scope is restricted by the kernel to the module that they are defined in.
.SH BUGS
.sp
.LP
On some implementations \fB_info()\fR may be called before \fB_init()\fR.