freebsd-dev/sys/dev/gxemul/cons/gxemul_cons.c
Jung-uk Kim fd90e2ed54 CALLOUT_MPSAFE has lost its meaning since r141428, i.e., for more than ten
years for head.  However, it is continuously misused as the mpsafe argument
for callout_init(9).  Deprecate the flag and clean up callout_init() calls
to make them more consistent.

Differential Revision:	https://reviews.freebsd.org/D2613
Reviewed by:	jhb
MFC after:	2 weeks
2015-05-22 17:05:21 +00:00

334 lines
6.9 KiB
C

/*-
* Copyright (c) 2011-2012 Robert N. M. Watson
* All rights reserved.
*
* This software was developed by SRI International and the University of
* Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
* ("CTSRD"), as part of the DARPA CRASH research programme.
*
* 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 THE AUTHOR 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 AUTHOR 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/cons.h>
#include <sys/endian.h>
#include <sys/kdb.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/reboot.h>
#include <sys/tty.h>
#include <ddb/ddb.h>
#include <machine/cpuregs.h>
#define GC_LOCK_INIT() mtx_init(&gc_lock, "gc_lock", NULL, MTX_SPIN)
#define GC_LOCK() do { \
if (!kdb_active) \
mtx_lock_spin(&gc_lock); \
} while (0)
#define GC_LOCK_ASSERT() do { \
if (!kdb_active) \
mtx_assert(&gc_lock, MA_OWNED); \
} while (0)
#define GC_UNLOCK() do { \
if (!kdb_active) \
mtx_unlock_spin(&gc_lock); \
} while (0)
static struct mtx gc_lock;
/*
* Low-level console driver functions.
*/
static cn_probe_t gxemul_cons_cnprobe;
static cn_init_t gxemul_cons_cninit;
static cn_term_t gxemul_cons_cnterm;
static cn_getc_t gxemul_cons_cngetc;
static cn_putc_t gxemul_cons_cnputc;
static cn_grab_t gxemul_cons_cngrab;
static cn_ungrab_t gxemul_cons_cnungrab;
/*
* TTY-level fields.
*/
static tsw_outwakeup_t gxemul_cons_outwakeup;
static struct ttydevsw gxemul_cons_ttydevsw = {
.tsw_flags = TF_NOPREFIX,
.tsw_outwakeup = gxemul_cons_outwakeup,
};
static struct callout gxemul_cons_callout;
static u_int gxemul_cons_polltime = 10;
#ifdef KDB
static int gxemul_cons_alt_break_state;
#endif
static void gxemul_cons_timeout(void *);
/*
* I/O routines lifted from Deimos.
*
* XXXRW: Should be using FreeBSD's bus routines here, but they are not
* available until later in the boot.
*/
static inline vm_offset_t
mips_phys_to_uncached(vm_paddr_t phys)
{
return (MIPS_PHYS_TO_DIRECT_UNCACHED(phys));
}
static inline uint8_t
mips_ioread_uint8(vm_offset_t vaddr)
{
uint8_t v;
__asm__ __volatile__ ("lbu %0, 0(%1)" : "=r" (v) : "r" (vaddr));
return (v);
}
static inline void
mips_iowrite_uint8(vm_offset_t vaddr, uint8_t v)
{
__asm__ __volatile__ ("sb %0, 0(%1)" : : "r" (v), "r" (vaddr));
}
/*
* gxemul-specific constants.
*/
#define GXEMUL_CONS_BASE 0x10000000 /* gxemul console device. */
/*
* Routines for interacting with the gxemul test console. Programming details
* are a result of manually inspecting the source code for gxemul's
* dev_cons.cc and dev_cons.h.
*
* Offsets of I/O channels relative to the base.
*/
#define GXEMUL_PUTGETCHAR_OFF 0x00000000
#define GXEMUL_CONS_HALT 0x00000010
/*
* One-byte buffer as we can't check whether the console is readable without
* actually reading from it.
*/
static char buffer_data;
static int buffer_valid;
/*
* Low-level read and write routines.
*/
static inline uint8_t
gxemul_cons_data_read(void)
{
return (mips_ioread_uint8(mips_phys_to_uncached(GXEMUL_CONS_BASE +
GXEMUL_PUTGETCHAR_OFF)));
}
static inline void
gxemul_cons_data_write(uint8_t v)
{
mips_iowrite_uint8(mips_phys_to_uncached(GXEMUL_CONS_BASE +
GXEMUL_PUTGETCHAR_OFF), v);
}
static int
gxemul_cons_writable(void)
{
return (1);
}
static int
gxemul_cons_readable(void)
{
uint32_t v;
GC_LOCK_ASSERT();
if (buffer_valid)
return (1);
v = gxemul_cons_data_read();
if (v != 0) {
buffer_valid = 1;
buffer_data = v;
return (1);
}
return (0);
}
static void
gxemul_cons_write(char ch)
{
GC_LOCK_ASSERT();
while (!gxemul_cons_writable());
gxemul_cons_data_write(ch);
}
static char
gxemul_cons_read(void)
{
GC_LOCK_ASSERT();
while (!gxemul_cons_readable());
buffer_valid = 0;
return (buffer_data);
}
/*
* Implementation of a FreeBSD low-level, polled console driver.
*/
static void
gxemul_cons_cnprobe(struct consdev *cp)
{
sprintf(cp->cn_name, "ttyu0");
cp->cn_pri = (boothowto & RB_SERIAL) ? CN_REMOTE : CN_NORMAL;
}
static void
gxemul_cons_cninit(struct consdev *cp)
{
GC_LOCK_INIT();
}
static void
gxemul_cons_cnterm(struct consdev *cp)
{
}
static int
gxemul_cons_cngetc(struct consdev *cp)
{
int ret;
GC_LOCK();
ret = gxemul_cons_read();
GC_UNLOCK();
return (ret);
}
static void
gxemul_cons_cnputc(struct consdev *cp, int c)
{
GC_LOCK();
gxemul_cons_write(c);
GC_UNLOCK();
}
static void
gxemul_cons_cngrab(struct consdev *cp)
{
}
static void
gxemul_cons_cnungrab(struct consdev *cp)
{
}
CONSOLE_DRIVER(gxemul_cons);
/*
* TTY-level functions for gxemul_cons.
*/
static void
gxemul_cons_ttyinit(void *unused)
{
struct tty *tp;
tp = tty_alloc(&gxemul_cons_ttydevsw, NULL);
tty_init_console(tp, 0);
tty_makedev(tp, NULL, "%s", "ttyu0");
callout_init(&gxemul_cons_callout, 1);
callout_reset(&gxemul_cons_callout, gxemul_cons_polltime,
gxemul_cons_timeout, tp);
}
SYSINIT(gxemul_cons_ttyinit, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE,
gxemul_cons_ttyinit, NULL);
static void
gxemul_cons_outwakeup(struct tty *tp)
{
int len;
u_char ch;
/*
* XXXRW: Would be nice not to do blocking writes to the console here,
* rescheduling on our timer tick if work remains to be done..
*/
for (;;) {
len = ttydisc_getc(tp, &ch, sizeof(ch));
if (len == 0)
break;
GC_LOCK();
gxemul_cons_write(ch);
GC_UNLOCK();
}
}
static void
gxemul_cons_timeout(void *v)
{
struct tty *tp;
int c;
tp = v;
tty_lock(tp);
GC_LOCK();
while (gxemul_cons_readable()) {
c = gxemul_cons_read();
GC_UNLOCK();
#ifdef KDB
kdb_alt_break(c, &gxemul_cons_alt_break_state);
#endif
ttydisc_rint(tp, c, 0);
GC_LOCK();
}
GC_UNLOCK();
ttydisc_rint_done(tp);
tty_unlock(tp);
callout_reset(&gxemul_cons_callout, gxemul_cons_polltime,
gxemul_cons_timeout, tp);
}