freebsd-dev/sys/dev/bvm/bvm_console.c
Neel Natu f5f87548b9 Fix panic "_mtx_lock_sleep: recursed on non-recursive mutex ttymtx" caused when
acquiring the tty lock in bvm_tty_close(). Instead just assert that the tty
lock is held before calling callout_reset().
2014-03-09 02:07:15 +00:00

238 lines
4.7 KiB
C

/*-
* Copyright (c) 2011 NetApp, Inc.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``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 NETAPP, INC 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/cons.h>
#include <sys/tty.h>
#include <sys/reboot.h>
#include <sys/bus.h>
#include <sys/kdb.h>
#include <ddb/ddb.h>
#ifndef BVMCONS_POLL_HZ
#define BVMCONS_POLL_HZ 4
#endif
#define BVMBURSTLEN 16 /* max number of bytes to write in one chunk */
static tsw_open_t bvm_tty_open;
static tsw_close_t bvm_tty_close;
static tsw_outwakeup_t bvm_tty_outwakeup;
static struct ttydevsw bvm_ttydevsw = {
.tsw_flags = TF_NOPREFIX,
.tsw_open = bvm_tty_open,
.tsw_close = bvm_tty_close,
.tsw_outwakeup = bvm_tty_outwakeup,
};
static int polltime;
static struct callout bvm_timer;
#if defined(KDB)
static int alt_break_state;
#endif
#define BVM_CONS_PORT 0x220
static int bvm_cons_port = BVM_CONS_PORT;
#define BVM_CONS_SIG ('b' << 8 | 'v')
static void bvm_timeout(void *);
static cn_probe_t bvm_cnprobe;
static cn_init_t bvm_cninit;
static cn_term_t bvm_cnterm;
static cn_getc_t bvm_cngetc;
static cn_putc_t bvm_cnputc;
static cn_grab_t bvm_cngrab;
static cn_ungrab_t bvm_cnungrab;
CONSOLE_DRIVER(bvm);
static int
bvm_rcons(u_char *ch)
{
int c;
c = inl(bvm_cons_port);
if (c != -1) {
*ch = (u_char)c;
return (0);
} else
return (-1);
}
static void
bvm_wcons(u_char ch)
{
outl(bvm_cons_port, ch);
}
static void
cn_drvinit(void *unused)
{
struct tty *tp;
if (bvm_consdev.cn_pri != CN_DEAD) {
tp = tty_alloc(&bvm_ttydevsw, NULL);
callout_init_mtx(&bvm_timer, tty_getlock(tp), 0);
tty_makedev(tp, NULL, "bvmcons");
}
}
static int
bvm_tty_open(struct tty *tp)
{
polltime = hz / BVMCONS_POLL_HZ;
if (polltime < 1)
polltime = 1;
callout_reset(&bvm_timer, polltime, bvm_timeout, tp);
return (0);
}
static void
bvm_tty_close(struct tty *tp)
{
tty_lock_assert(tp, MA_OWNED);
callout_stop(&bvm_timer);
}
static void
bvm_tty_outwakeup(struct tty *tp)
{
int len, written;
u_char buf[BVMBURSTLEN];
for (;;) {
len = ttydisc_getc(tp, buf, sizeof(buf));
if (len == 0)
break;
written = 0;
while (written < len)
bvm_wcons(buf[written++]);
}
}
static void
bvm_timeout(void *v)
{
struct tty *tp;
int c;
tp = (struct tty *)v;
tty_lock_assert(tp, MA_OWNED);
while ((c = bvm_cngetc(NULL)) != -1)
ttydisc_rint(tp, c, 0);
ttydisc_rint_done(tp);
callout_reset(&bvm_timer, polltime, bvm_timeout, tp);
}
static void
bvm_cnprobe(struct consdev *cp)
{
int disabled, port;
disabled = 0;
cp->cn_pri = CN_DEAD;
strcpy(cp->cn_name, "bvmcons");
resource_int_value("bvmconsole", 0, "disabled", &disabled);
if (!disabled) {
if (resource_int_value("bvmconsole", 0, "port", &port) == 0)
bvm_cons_port = port;
if (inw(bvm_cons_port) == BVM_CONS_SIG)
cp->cn_pri = CN_REMOTE;
}
}
static void
bvm_cninit(struct consdev *cp)
{
int i;
const char *bootmsg = "Using bvm console.\n";
if (boothowto & RB_VERBOSE) {
for (i = 0; i < strlen(bootmsg); i++)
bvm_cnputc(cp, bootmsg[i]);
}
}
static void
bvm_cnterm(struct consdev *cp)
{
}
static int
bvm_cngetc(struct consdev *cp)
{
unsigned char ch;
if (bvm_rcons(&ch) == 0) {
#if defined(KDB)
kdb_alt_break(ch, &alt_break_state);
#endif
return (ch);
}
return (-1);
}
static void
bvm_cnputc(struct consdev *cp, int c)
{
bvm_wcons(c);
}
static void
bvm_cngrab(struct consdev *cp)
{
}
static void
bvm_cnungrab(struct consdev *cp)
{
}
SYSINIT(cndev, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE, cn_drvinit, NULL);