freebsd-dev/sys/kern/kern_conf.c
1999-06-01 20:41:26 +00:00

239 lines
5.2 KiB
C

/*-
* Parts Copyright (c) 1995 Terrence R. Lambert
* Copyright (c) 1995 Julian R. Elischer
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Terrence R. Lambert.
* 4. The name Terrence R. Lambert may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY Julian R. Elischer ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: kern_conf.c,v 1.42 1999/06/01 18:56:24 phk Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#define cdevsw_ALLOCSTART (NUMCDEVSW/2)
struct cdevsw *cdevsw[NUMCDEVSW];
int bmaj2cmaj[NUMCDEVSW];
/*
* Routine to convert from character to block device number.
*
* A minimal stub routine can always return NODEV.
*/
dev_t
chrtoblk(dev_t dev)
{
struct cdevsw *cd;
if((cd = devsw(dev)) != NULL) {
if (cd->d_bmaj != -1)
return(makedev(cd->d_bmaj,minor(dev)));
}
return(NODEV);
}
struct cdevsw *
devsw(dev_t dev)
{
return(cdevsw[major(dev)]);
}
struct cdevsw *
bdevsw(dev_t dev)
{
struct cdevsw *c;
int i = major(dev);
if (bmaj2cmaj[i] == 254)
return 0;
c = cdevsw[bmaj2cmaj[major(dev)]];
if (!c) {
printf("bogus bdev dev_t %p, no cdev\n", (void *)dev);
Debugger("Bummer");
return 0;
}
/* CMAJ zero is the console, which has no strategy so this works */
if (c->d_strategy)
return (c);
return (0);
}
/*
* Add a cdevsw entry
*/
int
cdevsw_add(struct cdevsw *newentry)
{
int i;
static int setup;
if (!setup) {
for (i = 0; i < NUMCDEVSW; i++)
if (!bmaj2cmaj[i])
bmaj2cmaj[i] = 254;
setup++;
}
if (newentry->d_maj < 0 || newentry->d_maj >= NUMCDEVSW) {
printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n",
newentry->d_name, newentry->d_maj);
return EINVAL;
}
cdevsw[newentry->d_maj] = newentry;
if (newentry->d_bmaj >= 0 && newentry->d_bmaj < NUMCDEVSW)
bmaj2cmaj[newentry->d_bmaj] = newentry->d_maj;
return 0;
}
int
devsw_module_handler(module_t mod, int what, void* arg)
{
struct devsw_module_data* data = (struct devsw_module_data*) arg;
int error;
if (data->cmaj == NOMAJ)
data->cdev = NODEV;
else
data->cdev = makedev(data->cmaj, 0);
switch (what) {
case MOD_LOAD:
error = cdevsw_add(data->cdevsw);
if (!error && data->cdevsw->d_strategy != nostrategy) {
if (data->bmaj == NOMAJ) {
data->bdev = data->cdev;
data->bmaj = data->cmaj;
} else {
data->bdev = makedev(data->bmaj, 0);
}
data->cdevsw->d_maj = data->bmaj;
bmaj2cmaj[major(data->bdev)] = major(data->cdev);
}
if (!error && data->chainevh)
error = data->chainevh(mod, what, data->chainarg);
return error;
case MOD_UNLOAD:
if (data->chainevh) {
error = data->chainevh(mod, what, data->chainarg);
if (error)
return error;
}
if (data->cdevsw->d_strategy != nostrategy)
bmaj2cmaj[major(data->bdev)] = 0;
return error;
}
if (data->chainevh)
return data->chainevh(mod, what, data->chainarg);
else
return 0;
}
/*
* dev_t and u_dev_t primitives
*/
#define DEVT_FASCIST 1
int
major(dev_t x)
{
uintptr_t i = (uintptr_t)x;
#ifdef DEVT_FASCIST
return(255 - ((i >> 8) & 0xff));
#else
return((i >> 8) & 0xff);
#endif
}
int
minor(dev_t x)
{
uintptr_t i = (uintptr_t)x;
return(i & 0xffff00ff);
}
dev_t
makebdev(int x, int y)
{
return (makedev(x, y));
}
dev_t
makedev(int x, int y)
{
#ifdef DEVT_FASCIST
return ((dev_t) (((255 - x) << 8) | y));
#else
return ((dev_t) ((x << 8) | y));
#endif
}
udev_t
dev2udev(dev_t x)
{
return umakedev(major(x), minor(x));
}
dev_t
udev2dev(udev_t x, int b)
{
return makedev(umajor(x), uminor(x));
}
int
uminor(udev_t dev)
{
return(dev & 0xffff00ff);
}
int
umajor(udev_t dev)
{
return((dev & 0xff00) >> 8);
}
udev_t
umakedev(int x, int y)
{
return ((x << 8) | y);
}