freebsd-skq/sys/kern/tty_cons.c
Bruce Evans a2562ad917 Keep track of open devices better to avoid closing the console device when
the physical device is closed.  Previously only the reverse case was handled.
Abuse the cdevsw interface instead of the vfs interface to do this.

Remove unnecessary #includes.
1995-01-21 14:12:15 +00:00

278 lines
6.5 KiB
C

/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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 the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* from: @(#)cons.c 7.2 (Berkeley) 5/9/91
* $Id: cons.c,v 1.19 1994/12/18 19:42:41 joerg Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <machine/cons.h>
#include <machine/stdarg.h>
/* XXX - all this could be autoconfig()ed */
#include "sc.h"
#include "vt.h"
#if NSC > 0 || NVT > 0
int pccnprobe(), pccninit(), pccngetc(), pccncheckc(), pccnputc();
#endif
#include "sio.h"
#if NSIO > 0
int siocnprobe(), siocninit(), siocngetc(), siocncheckc(), siocnputc();
#endif
static struct consdev constab[] = {
#if NSC > 0 || NVT > 0
{ pccnprobe, pccninit, pccngetc, pccncheckc, pccnputc },
#endif
#if NSIO > 0
{ siocnprobe, siocninit, siocngetc, siocncheckc, siocnputc },
#endif
{ 0 },
};
/* end XXX */
struct tty *constty = 0; /* virtual console output device */
struct tty *cn_tty; /* XXX: console tty struct for tprintf */
/* XXX */
typedef u_char bool_t;
typedef int d_close_t __P((dev_t dev, int fflag, int devtype, struct proc *p));
typedef int d_open_t __P((dev_t dev, int oflags, int devtype, struct proc *p));
static bool_t cn_is_open; /* nonzero if logical console is open */
static bool_t cn_phys_is_open; /* nonzero if physical console is open */
static d_close_t *cn_phys_close; /* physical device close function */
static d_open_t *cn_phys_open; /* physical device open function */
static struct consdev *cn_tab; /* physical console device info */
void
cninit()
{
register struct consdev *cp;
struct cdevsw *cdp;
/*
* Collect information about all possible consoles
* and find the one with highest priority
*/
for (cp = constab; cp->cn_probe; cp++) {
(*cp->cn_probe)(cp);
if (cp->cn_pri > CN_DEAD &&
(cn_tab == NULL || cp->cn_pri > cn_tab->cn_pri))
cn_tab = cp;
}
/*
* No console, give up.
*/
if ((cp = cn_tab) == NULL)
return;
/*
* Hook the open and close functions.
*/
cdp = &cdevsw[major(cn_tab->cn_dev)];
cn_phys_close = cdp->d_close;
cdp->d_close = cnclose;
cn_phys_open = cdp->d_open;
cdp->d_open = cnopen;
/*
* Turn on console
*/
cn_tty = cp->cn_tp;
(*cp->cn_init)(cp);
}
int
cnopen(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
dev_t cndev, physdev;
int retval;
if (cn_tab == NULL)
return (0);
cndev = cn_tab->cn_dev;
physdev = (major(dev) == major(cndev) ? dev : cndev);
retval = (*cn_phys_open)(physdev, flag, mode, p);
if (retval == 0) {
if (dev == cndev)
cn_phys_is_open = 1;
else if (physdev == cndev)
cn_is_open = 1;
}
return (retval);
}
int
cnclose(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
dev_t cndev;
if (cn_tab == NULL)
return (0);
cndev = cn_tab->cn_dev;
if (dev == cndev) {
cn_phys_is_open = 0;
if (cn_is_open)
return (0);
} else if (major(dev) != major(cndev)) {
cn_is_open = 0;
if (cn_phys_is_open)
return (0);
dev = cndev;
}
return ((*cn_phys_close)(dev, flag, mode, p));
}
int
cnread(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
if (cn_tab == NULL)
return (0);
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_read)(dev, uio, flag));
}
int
cnwrite(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
if (cn_tab == NULL)
return (0);
if (constty)
dev = constty->t_dev;
else
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_write)(dev, uio, flag));
}
int
cnioctl(dev, cmd, data, flag, p)
dev_t dev;
int cmd;
caddr_t data;
int flag;
struct proc *p;
{
int error;
if (cn_tab == NULL)
return (0);
/*
* Superuser can always use this to wrest control of console
* output from the "virtual" console.
*/
if (cmd == TIOCCONS && constty) {
error = suser(p->p_ucred, (u_short *) NULL);
if (error)
return (error);
constty = NULL;
return (0);
}
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p));
}
/*ARGSUSED*/
int
cnselect(dev, rw, p)
dev_t dev;
int rw;
struct proc *p;
{
if (cn_tab == NULL)
return (1);
return (ttselect(cn_tab->cn_dev, rw, p));
}
int
cngetc()
{
int c;
if (cn_tab == NULL)
return (0);
c = (*cn_tab->cn_getc)(cn_tab->cn_dev);
if (c == '\r') c = '\n'; /* console input is always ICRNL */
return (c);
}
int
cncheckc()
{
if (cn_tab == NULL)
return (0);
return ((*cn_tab->cn_checkc)(cn_tab->cn_dev));
}
void
cnputc(c)
register int c;
{
if (cn_tab == NULL)
return;
if (c) {
(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
if (c == '\n')
(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
}
}
int
pg(const char *p, ...) {
va_list args;
va_start(args, p);
printf("%r\n>", p, args);
return(cngetc());
}