src/sys/kern/subr_xxx.c

170 lines
3.7 KiB
C

/* $OpenBSD: subr_xxx.c,v 1.17 2019/05/17 03:53:08 visa Exp $ */
/* $NetBSD: subr_xxx.c,v 1.10 1996/02/04 02:16:51 christos Exp $ */
/*
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* @(#)subr_xxx.c 8.1 (Berkeley) 6/10/93
*/
/*
* Miscellaneous trivial functions, including many
* that are often inline-expanded or done in assembler.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/smr.h>
/*
* Unsupported device function (e.g. writing to read-only device).
*/
int
enodev(void)
{
return (ENODEV);
}
/*
* Unconfigured device function; driver not configured.
*/
int
enxio(void)
{
return (ENXIO);
}
/*
* Unsupported ioctl function.
*/
int
enoioctl(void)
{
return (ENOTTY);
}
/*
* Unsupported system function.
* This is used for an otherwise-reasonable operation
* that is not supported by the current system binary.
*/
int
enosys(void)
{
return (ENOSYS);
}
/*
* Return error for operation not supported
* on a specific object or file type.
*/
int
eopnotsupp(void *v)
{
return (EOPNOTSUPP);
}
/*
* Generic null operation, always returns success.
*/
int
nullop(void *v)
{
return (0);
}
struct bdevsw *
bdevsw_lookup(dev_t dev)
{
return (&bdevsw[major(dev)]);
}
struct cdevsw *
cdevsw_lookup(dev_t dev)
{
return (&cdevsw[major(dev)]);
}
/*
* Convert a character device number to a block device number.
*/
dev_t
chrtoblk(dev_t dev)
{
int blkmaj;
if (major(dev) >= nchrdev || major(dev) >= nchrtoblktbl)
return (NODEV);
blkmaj = chrtoblktbl[major(dev)];
if (blkmaj == NODEV)
return (NODEV);
return (makedev(blkmaj, minor(dev)));
}
/*
* Convert a block device number to a character device number.
*/
dev_t
blktochr(dev_t dev)
{
int blkmaj = major(dev);
int i;
if (blkmaj >= nblkdev)
return (NODEV);
for (i = 0; i < nchrtoblktbl; i++)
if (blkmaj == chrtoblktbl[i])
return (makedev(i, minor(dev)));
return (NODEV);
}
/*
* Check that we're in a context where it's okay to sleep.
*/
void
assertwaitok(void)
{
if (panicstr || db_active)
return;
splassert(IPL_NONE);
SMR_ASSERT_NONCRITICAL();
#ifdef DIAGNOSTIC
if (curcpu()->ci_mutex_level != 0)
panic("assertwaitok: non-zero mutex count: %d",
curcpu()->ci_mutex_level);
#endif
}