7d82f624de
For some reason the nmdm(4) driver doesn't use CALLOUT_MPSAFE, even though we live in the MPSAFE TTY era. Add the CALLOUT_MPSAFE flags. System survives.
373 lines
8.5 KiB
C
373 lines
8.5 KiB
C
/*-
|
|
* Copyright (c) 1982, 1986, 1989, 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.
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
/*
|
|
* Pseudo-nulmodem driver
|
|
* Mighty handy for use with serial console in Vmware
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/priv.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/tty.h>
|
|
#include <sys/conf.h>
|
|
#include <sys/fcntl.h>
|
|
#include <sys/poll.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/limits.h>
|
|
#include <sys/module.h>
|
|
#include <sys/serial.h>
|
|
#include <sys/signalvar.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/taskqueue.h>
|
|
|
|
MALLOC_DEFINE(M_NMDM, "nullmodem", "nullmodem data structures");
|
|
|
|
static tsw_inwakeup_t nmdm_outwakeup;
|
|
static tsw_outwakeup_t nmdm_inwakeup;
|
|
static tsw_param_t nmdm_param;
|
|
static tsw_modem_t nmdm_modem;
|
|
|
|
static struct ttydevsw nmdm_class = {
|
|
.tsw_flags = TF_NOPREFIX,
|
|
.tsw_inwakeup = nmdm_inwakeup,
|
|
.tsw_outwakeup = nmdm_outwakeup,
|
|
.tsw_param = nmdm_param,
|
|
.tsw_modem = nmdm_modem,
|
|
};
|
|
|
|
static void nmdm_task_tty(void *, int);
|
|
|
|
struct nmdmsoftc;
|
|
|
|
struct nmdmpart {
|
|
struct tty *np_tty;
|
|
int np_dcd;
|
|
struct task np_task;
|
|
struct nmdmpart *np_other;
|
|
struct nmdmsoftc *np_pair;
|
|
struct callout np_callout;
|
|
u_long np_quota;
|
|
u_long np_accumulator;
|
|
int np_rate;
|
|
int np_credits;
|
|
|
|
#define QS 8 /* Quota shift */
|
|
};
|
|
|
|
struct nmdmsoftc {
|
|
struct nmdmpart ns_part1;
|
|
struct nmdmpart ns_part2;
|
|
struct mtx ns_mtx;
|
|
};
|
|
|
|
static int nmdm_count = 0;
|
|
|
|
static struct nmdmsoftc *
|
|
nmdm_alloc(unsigned long unit)
|
|
{
|
|
struct nmdmsoftc *ns;
|
|
struct tty *tp;
|
|
|
|
atomic_add_acq_int(&nmdm_count, 1);
|
|
|
|
ns = malloc(sizeof(*ns), M_NMDM, M_WAITOK|M_ZERO);
|
|
mtx_init(&ns->ns_mtx, "nmdm", NULL, MTX_DEF);
|
|
|
|
/* Hook the pairs together. */
|
|
ns->ns_part1.np_pair = ns;
|
|
ns->ns_part1.np_other = &ns->ns_part2;
|
|
TASK_INIT(&ns->ns_part1.np_task, 0, nmdm_task_tty, &ns->ns_part1);
|
|
callout_init(&ns->ns_part1.np_callout, CALLOUT_MPSAFE);
|
|
|
|
ns->ns_part2.np_pair = ns;
|
|
ns->ns_part2.np_other = &ns->ns_part1;
|
|
TASK_INIT(&ns->ns_part2.np_task, 0, nmdm_task_tty, &ns->ns_part2);
|
|
callout_init(&ns->ns_part2.np_callout, CALLOUT_MPSAFE);
|
|
|
|
/* Create device nodes. */
|
|
tp = ns->ns_part1.np_tty = tty_alloc(&nmdm_class, &ns->ns_part1,
|
|
&ns->ns_mtx);
|
|
tty_makedev(tp, NULL, "nmdm%luA", unit);
|
|
|
|
tp = ns->ns_part2.np_tty = tty_alloc(&nmdm_class, &ns->ns_part2,
|
|
&ns->ns_mtx);
|
|
tty_makedev(tp, NULL, "nmdm%luB", unit);
|
|
|
|
return (ns);
|
|
}
|
|
|
|
static void
|
|
nmdm_clone(void *arg, struct ucred *cred, char *name, int nameen,
|
|
struct cdev **dev)
|
|
{
|
|
unsigned long unit;
|
|
char *end;
|
|
struct nmdmsoftc *ns;
|
|
|
|
if (*dev != NULL)
|
|
return;
|
|
if (strncmp(name, "nmdm", 4) != 0)
|
|
return;
|
|
|
|
/* Device name must be "nmdm%lu%c", where %c is 'A' or 'B'. */
|
|
name += 4;
|
|
unit = strtoul(name, &end, 10);
|
|
if (unit == ULONG_MAX || name == end)
|
|
return;
|
|
if ((end[0] != 'A' && end[0] != 'B') || end[1] != '\0')
|
|
return;
|
|
|
|
/* XXX: pass privileges? */
|
|
ns = nmdm_alloc(unit);
|
|
|
|
if (end[0] == 'A')
|
|
*dev = ns->ns_part1.np_tty->t_dev;
|
|
else
|
|
*dev = ns->ns_part2.np_tty->t_dev;
|
|
}
|
|
|
|
static void
|
|
nmdm_timeout(void *arg)
|
|
{
|
|
struct nmdmpart *np = arg;
|
|
|
|
if (np->np_rate == 0)
|
|
return;
|
|
|
|
/*
|
|
* Do a simple Floyd-Steinberg dither here to avoid FP math.
|
|
* Wipe out unused quota from last tick.
|
|
*/
|
|
np->np_accumulator += np->np_credits;
|
|
np->np_quota = np->np_accumulator >> QS;
|
|
np->np_accumulator &= ((1 << QS) - 1);
|
|
|
|
taskqueue_enqueue(taskqueue_swi, &np->np_task);
|
|
callout_reset(&np->np_callout, np->np_rate, nmdm_timeout, np);
|
|
}
|
|
|
|
static void
|
|
nmdm_task_tty(void *arg, int pending __unused)
|
|
{
|
|
struct tty *tp, *otp;
|
|
struct nmdmpart *np = arg;
|
|
char c;
|
|
|
|
tp = np->np_tty;
|
|
tty_lock(tp);
|
|
|
|
otp = np->np_other->np_tty;
|
|
KASSERT(otp != NULL, ("NULL otp in nmdmstart"));
|
|
KASSERT(otp != tp, ("NULL otp == tp nmdmstart"));
|
|
if (np->np_other->np_dcd) {
|
|
if (!tty_opened(tp)) {
|
|
np->np_other->np_dcd = 0;
|
|
ttydisc_modem(otp, 0);
|
|
}
|
|
} else {
|
|
if (tty_opened(tp)) {
|
|
np->np_other->np_dcd = 1;
|
|
ttydisc_modem(otp, 1);
|
|
}
|
|
}
|
|
|
|
while (ttydisc_rint_poll(otp) > 0) {
|
|
if (np->np_rate && !np->np_quota)
|
|
break;
|
|
if (ttydisc_getc(tp, &c, 1) != 1)
|
|
break;
|
|
np->np_quota--;
|
|
ttydisc_rint(otp, c, 0);
|
|
}
|
|
|
|
ttydisc_rint_done(otp);
|
|
|
|
tty_unlock(tp);
|
|
}
|
|
|
|
static int
|
|
bits_per_char(struct termios *t)
|
|
{
|
|
int bits;
|
|
|
|
bits = 1; /* start bit */
|
|
switch (t->c_cflag & CSIZE) {
|
|
case CS5: bits += 5; break;
|
|
case CS6: bits += 6; break;
|
|
case CS7: bits += 7; break;
|
|
case CS8: bits += 8; break;
|
|
}
|
|
bits++; /* stop bit */
|
|
if (t->c_cflag & PARENB)
|
|
bits++;
|
|
if (t->c_cflag & CSTOPB)
|
|
bits++;
|
|
return (bits);
|
|
}
|
|
|
|
static int
|
|
nmdm_param(struct tty *tp, struct termios *t)
|
|
{
|
|
struct nmdmpart *np = tty_softc(tp);
|
|
struct tty *tp2;
|
|
int bpc, rate, speed, i;
|
|
|
|
tp2 = np->np_other->np_tty;
|
|
|
|
if (!((t->c_cflag | tp2->t_termios.c_cflag) & CDSR_OFLOW)) {
|
|
np->np_rate = 0;
|
|
np->np_other->np_rate = 0;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* DSRFLOW one either side enables rate-simulation for both
|
|
* directions.
|
|
* NB: the two directions may run at different rates.
|
|
*/
|
|
|
|
/* Find the larger of the number of bits transmitted */
|
|
bpc = imax(bits_per_char(t), bits_per_char(&tp2->t_termios));
|
|
|
|
for (i = 0; i < 2; i++) {
|
|
/* Use the slower of our receive and their transmit rate */
|
|
speed = imin(tp2->t_termios.c_ospeed, t->c_ispeed);
|
|
if (speed == 0) {
|
|
np->np_rate = 0;
|
|
np->np_other->np_rate = 0;
|
|
return (0);
|
|
}
|
|
|
|
speed <<= QS; /* [bit/sec, scaled] */
|
|
speed /= bpc; /* [char/sec, scaled] */
|
|
rate = (hz << QS) / speed; /* [hz per callout] */
|
|
if (rate == 0)
|
|
rate = 1;
|
|
|
|
speed *= rate;
|
|
speed /= hz; /* [(char/sec)/tick, scaled */
|
|
|
|
np->np_credits = speed;
|
|
np->np_rate = rate;
|
|
callout_reset(&np->np_callout, rate, nmdm_timeout, np);
|
|
|
|
/*
|
|
* swap pointers for second pass so the other end gets
|
|
* updated as well.
|
|
*/
|
|
np = np->np_other;
|
|
t = &tp2->t_termios;
|
|
tp2 = tp;
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
nmdm_modem(struct tty *tp, int sigon, int sigoff)
|
|
{
|
|
struct nmdmpart *np = tty_softc(tp);
|
|
int i = 0;
|
|
|
|
if (sigon || sigoff) {
|
|
if (sigon & SER_DTR)
|
|
np->np_other->np_dcd = 1;
|
|
if (sigoff & SER_DTR)
|
|
np->np_other->np_dcd = 0;
|
|
|
|
ttydisc_modem(np->np_other->np_tty, np->np_other->np_dcd);
|
|
|
|
return (0);
|
|
} else {
|
|
if (np->np_dcd)
|
|
i |= SER_DCD;
|
|
if (np->np_other->np_dcd)
|
|
i |= SER_DTR;
|
|
|
|
return (i);
|
|
}
|
|
}
|
|
|
|
static void
|
|
nmdm_inwakeup(struct tty *tp)
|
|
{
|
|
struct nmdmpart *np = tty_softc(tp);
|
|
|
|
/* We can receive again, so wake up the other side. */
|
|
taskqueue_enqueue(taskqueue_swi, &np->np_other->np_task);
|
|
}
|
|
|
|
static void
|
|
nmdm_outwakeup(struct tty *tp)
|
|
{
|
|
struct nmdmpart *np = tty_softc(tp);
|
|
|
|
/* We can transmit again, so wake up our side. */
|
|
taskqueue_enqueue(taskqueue_swi, &np->np_task);
|
|
}
|
|
|
|
/*
|
|
* Module handling
|
|
*/
|
|
static int
|
|
nmdm_modevent(module_t mod, int type, void *data)
|
|
{
|
|
static eventhandler_tag tag;
|
|
|
|
switch(type) {
|
|
case MOD_LOAD:
|
|
tag = EVENTHANDLER_REGISTER(dev_clone, nmdm_clone, 0, 1000);
|
|
if (tag == NULL)
|
|
return (ENOMEM);
|
|
break;
|
|
|
|
case MOD_SHUTDOWN:
|
|
break;
|
|
|
|
case MOD_UNLOAD:
|
|
if (nmdm_count != 0)
|
|
return (EBUSY);
|
|
EVENTHANDLER_DEREGISTER(dev_clone, tag);
|
|
break;
|
|
|
|
default:
|
|
return (EOPNOTSUPP);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
DEV_MODULE(nmdm, nmdm_modevent, NULL);
|