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freebsd/sys/kern/subr_terminal.c
Jean-Sébastien Pédron 547e74a8be teken, vt(4): New callbacks to lock the terminal once
... to process input, instead of inside each smaller operations such as
appending a character or moving the cursor forward.

In other words, before we were doing (oversimplified):

  teken_input()
    <for each input character>
      vtterm_putchar()
        VTBUF_LOCK()
        VTBUF_UNLOCK()
      vtterm_cursor_position()
        VTBUF_LOCK()
        VTBUF_UNLOCK()

Now, we are doing:

  vtterm_pre_input()
    VTBUF_LOCK()
  teken_input()
    <for each input character>
      vtterm_putchar()
      vtterm_cursor_position()
  vtterm_post_input()
    VTBUF_UNLOCK()

The situation was even worse when the vtterm_copy() and vtterm_fill()
callbacks were involved.

The new callbacks are:
  * struct terminal_class->tc_pre_input()
  * struct terminal_class->tc_post_input()

They are called in teken_input(), surrounding the while() loop.

The goal is to improve input processing speed of vt(4). As a benchmark,
here is the time taken to write a text file of 360 000 lines (26 MiB) on
`ttyv0`:

  * vt(4), unmodified:      1500 ms
  * vt(4), with this patch: 1200 ms
  * syscons(4):              700 ms

This is on a Haswell laptop with a GENERIC-NODEBUG kernel.

At the same time, the locking is changed in the vt_flush() function
which is responsible to draw the text on screen. So instead of
(indirectly) using VTBUF_LOCK() just to read and reset the dirty area
of the internal buffer, the lock is held for about the entire function,
including the drawing part.

The change is mostly visible while content is scrolling fast: before,
lines could appear garbled while scrolling because the internal buffer
was accessed without locks (once the scrolling was finished, the output
was correct). Now, the scrolling appears correct.

In the end, the locking model is closer to what syscons(4) does.

Differential Revision:	https://reviews.freebsd.org/D15302
2018-05-16 09:01:02 +00:00

681 lines
15 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2009 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Ed Schouten under sponsorship from the
* FreeBSD Foundation.
*
* 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/consio.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <sys/terminal.h>
#include <sys/tty.h>
#include <machine/stdarg.h>
static MALLOC_DEFINE(M_TERMINAL, "terminal", "terminal device");
/*
* Locking.
*
* Normally we don't need to lock down the terminal emulator, because
* the TTY lock is already held when calling teken_input().
* Unfortunately this is not the case when the terminal acts as a
* console device, because cnputc() can be called at the same time.
* This means terminals may need to be locked down using a spin lock.
*/
#define TERMINAL_LOCK(tm) do { \
if ((tm)->tm_flags & TF_CONS) \
mtx_lock_spin(&(tm)->tm_mtx); \
else if ((tm)->tm_tty != NULL) \
tty_lock((tm)->tm_tty); \
} while (0)
#define TERMINAL_UNLOCK(tm) do { \
if ((tm)->tm_flags & TF_CONS) \
mtx_unlock_spin(&(tm)->tm_mtx); \
else if ((tm)->tm_tty != NULL) \
tty_unlock((tm)->tm_tty); \
} while (0)
#define TERMINAL_LOCK_TTY(tm) do { \
if ((tm)->tm_flags & TF_CONS) \
mtx_lock_spin(&(tm)->tm_mtx); \
} while (0)
#define TERMINAL_UNLOCK_TTY(tm) do { \
if ((tm)->tm_flags & TF_CONS) \
mtx_unlock_spin(&(tm)->tm_mtx); \
} while (0)
#define TERMINAL_LOCK_CONS(tm) mtx_lock_spin(&(tm)->tm_mtx)
#define TERMINAL_UNLOCK_CONS(tm) mtx_unlock_spin(&(tm)->tm_mtx)
/*
* TTY routines.
*/
static tsw_open_t termtty_open;
static tsw_close_t termtty_close;
static tsw_outwakeup_t termtty_outwakeup;
static tsw_ioctl_t termtty_ioctl;
static tsw_mmap_t termtty_mmap;
static struct ttydevsw terminal_tty_class = {
.tsw_open = termtty_open,
.tsw_close = termtty_close,
.tsw_outwakeup = termtty_outwakeup,
.tsw_ioctl = termtty_ioctl,
.tsw_mmap = termtty_mmap,
};
/*
* Terminal emulator routines.
*/
static tf_bell_t termteken_bell;
static tf_cursor_t termteken_cursor;
static tf_putchar_t termteken_putchar;
static tf_fill_t termteken_fill;
static tf_copy_t termteken_copy;
static tf_pre_input_t termteken_pre_input;
static tf_post_input_t termteken_post_input;
static tf_param_t termteken_param;
static tf_respond_t termteken_respond;
static teken_funcs_t terminal_drawmethods = {
.tf_bell = termteken_bell,
.tf_cursor = termteken_cursor,
.tf_putchar = termteken_putchar,
.tf_fill = termteken_fill,
.tf_copy = termteken_copy,
.tf_pre_input = termteken_pre_input,
.tf_post_input = termteken_post_input,
.tf_param = termteken_param,
.tf_respond = termteken_respond,
};
/* Kernel message formatting. */
static const teken_attr_t kernel_message = {
.ta_fgcolor = TCHAR_FGCOLOR(TERMINAL_KERN_ATTR),
.ta_bgcolor = TCHAR_BGCOLOR(TERMINAL_KERN_ATTR),
.ta_format = TCHAR_FORMAT(TERMINAL_KERN_ATTR)
};
static const teken_attr_t default_message = {
.ta_fgcolor = TCHAR_FGCOLOR(TERMINAL_NORM_ATTR),
.ta_bgcolor = TCHAR_BGCOLOR(TERMINAL_NORM_ATTR),
.ta_format = TCHAR_FORMAT(TERMINAL_NORM_ATTR)
};
/* Fudge fg brightness as TF_BOLD (shifted). */
#define TCOLOR_FG_FUDGED(color) __extension__ ({ \
teken_color_t _c; \
\
_c = (color); \
TCOLOR_FG(_c & 7) | ((_c & 8) << 18); \
})
/* Fudge bg brightness as TF_BLINK (shifted). */
#define TCOLOR_BG_FUDGED(color) __extension__ ({ \
teken_color_t _c; \
\
_c = (color); \
TCOLOR_BG(_c & 7) | ((_c & 8) << 20); \
})
#define TCOLOR_256TO16(color) __extension__ ({ \
teken_color_t _c; \
\
_c = (color); \
if (_c >= 16) \
_c = teken_256to16(_c); \
_c; \
})
#define TCHAR_CREATE(c, a) ((c) | TFORMAT((a)->ta_format) | \
TCOLOR_FG_FUDGED(TCOLOR_256TO16((a)->ta_fgcolor)) | \
TCOLOR_BG_FUDGED(TCOLOR_256TO16((a)->ta_bgcolor)))
static void
terminal_init(struct terminal *tm)
{
if (tm->tm_flags & TF_CONS)
mtx_init(&tm->tm_mtx, "trmlck", NULL, MTX_SPIN);
teken_init(&tm->tm_emulator, &terminal_drawmethods, tm);
teken_set_defattr(&tm->tm_emulator, &default_message);
}
struct terminal *
terminal_alloc(const struct terminal_class *tc, void *softc)
{
struct terminal *tm;
tm = malloc(sizeof(struct terminal), M_TERMINAL, M_WAITOK|M_ZERO);
terminal_init(tm);
tm->tm_class = tc;
tm->tm_softc = softc;
return (tm);
}
static void
terminal_sync_ttysize(struct terminal *tm)
{
struct tty *tp;
tp = tm->tm_tty;
if (tp == NULL)
return;
tty_lock(tp);
tty_set_winsize(tp, &tm->tm_winsize);
tty_unlock(tp);
}
void
terminal_maketty(struct terminal *tm, const char *fmt, ...)
{
struct tty *tp;
char name[8];
va_list ap;
va_start(ap, fmt);
vsnrprintf(name, sizeof name, 32, fmt, ap);
va_end(ap);
tp = tty_alloc(&terminal_tty_class, tm);
tty_makedev(tp, NULL, "%s", name);
tm->tm_tty = tp;
terminal_sync_ttysize(tm);
}
void
terminal_set_cursor(struct terminal *tm, const term_pos_t *pos)
{
teken_set_cursor(&tm->tm_emulator, pos);
}
void
terminal_set_winsize_blank(struct terminal *tm, const struct winsize *size,
int blank, const term_attr_t *attr)
{
term_rect_t r;
tm->tm_winsize = *size;
r.tr_begin.tp_row = r.tr_begin.tp_col = 0;
r.tr_end.tp_row = size->ws_row;
r.tr_end.tp_col = size->ws_col;
TERMINAL_LOCK(tm);
if (blank == 0)
teken_set_winsize_noreset(&tm->tm_emulator, &r.tr_end);
else
teken_set_winsize(&tm->tm_emulator, &r.tr_end);
TERMINAL_UNLOCK(tm);
if ((blank != 0) && !(tm->tm_flags & TF_MUTE))
tm->tm_class->tc_fill(tm, &r,
TCHAR_CREATE((teken_char_t)' ', attr));
terminal_sync_ttysize(tm);
}
void
terminal_set_winsize(struct terminal *tm, const struct winsize *size)
{
terminal_set_winsize_blank(tm, size, 1,
(const term_attr_t *)&default_message);
}
/*
* XXX: This function is a kludge. Drivers like vt(4) need to
* temporarily stop input when resizing, etc. This should ideally be
* handled within the driver.
*/
void
terminal_mute(struct terminal *tm, int yes)
{
TERMINAL_LOCK(tm);
if (yes)
tm->tm_flags |= TF_MUTE;
else
tm->tm_flags &= ~TF_MUTE;
TERMINAL_UNLOCK(tm);
}
void
terminal_input_char(struct terminal *tm, term_char_t c)
{
struct tty *tp;
tp = tm->tm_tty;
if (tp == NULL)
return;
/*
* Strip off any attributes. Also ignore input of second part of
* CJK fullwidth characters, as we don't want to return these
* characters twice.
*/
if (TCHAR_FORMAT(c) & TF_CJK_RIGHT)
return;
c = TCHAR_CHARACTER(c);
tty_lock(tp);
/*
* Conversion to UTF-8.
*/
if (c < 0x80) {
ttydisc_rint(tp, c, 0);
} else if (c < 0x800) {
char str[2] = {
0xc0 | (c >> 6),
0x80 | (c & 0x3f)
};
ttydisc_rint_simple(tp, str, sizeof str);
} else if (c < 0x10000) {
char str[3] = {
0xe0 | (c >> 12),
0x80 | ((c >> 6) & 0x3f),
0x80 | (c & 0x3f)
};
ttydisc_rint_simple(tp, str, sizeof str);
} else {
char str[4] = {
0xf0 | (c >> 18),
0x80 | ((c >> 12) & 0x3f),
0x80 | ((c >> 6) & 0x3f),
0x80 | (c & 0x3f)
};
ttydisc_rint_simple(tp, str, sizeof str);
}
ttydisc_rint_done(tp);
tty_unlock(tp);
}
void
terminal_input_raw(struct terminal *tm, char c)
{
struct tty *tp;
tp = tm->tm_tty;
if (tp == NULL)
return;
tty_lock(tp);
ttydisc_rint(tp, c, 0);
ttydisc_rint_done(tp);
tty_unlock(tp);
}
void
terminal_input_special(struct terminal *tm, unsigned int k)
{
struct tty *tp;
const char *str;
tp = tm->tm_tty;
if (tp == NULL)
return;
str = teken_get_sequence(&tm->tm_emulator, k);
if (str == NULL)
return;
tty_lock(tp);
ttydisc_rint_simple(tp, str, strlen(str));
ttydisc_rint_done(tp);
tty_unlock(tp);
}
/*
* Binding with the TTY layer.
*/
static int
termtty_open(struct tty *tp)
{
struct terminal *tm = tty_softc(tp);
tm->tm_class->tc_opened(tm, 1);
return (0);
}
static void
termtty_close(struct tty *tp)
{
struct terminal *tm = tty_softc(tp);
tm->tm_class->tc_opened(tm, 0);
}
static void
termtty_outwakeup(struct tty *tp)
{
struct terminal *tm = tty_softc(tp);
char obuf[128];
size_t olen;
unsigned int flags = 0;
while ((olen = ttydisc_getc(tp, obuf, sizeof obuf)) > 0) {
TERMINAL_LOCK_TTY(tm);
if (!(tm->tm_flags & TF_MUTE)) {
tm->tm_flags &= ~TF_BELL;
teken_input(&tm->tm_emulator, obuf, olen);
flags |= tm->tm_flags;
}
TERMINAL_UNLOCK_TTY(tm);
}
TERMINAL_LOCK_TTY(tm);
if (!(tm->tm_flags & TF_MUTE))
tm->tm_class->tc_done(tm);
TERMINAL_UNLOCK_TTY(tm);
if (flags & TF_BELL)
tm->tm_class->tc_bell(tm);
}
static int
termtty_ioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
{
struct terminal *tm = tty_softc(tp);
int error;
switch (cmd) {
case CONS_GETINFO: {
vid_info_t *vi = (vid_info_t *)data;
const teken_pos_t *p;
int fg, bg;
if (vi->size != sizeof(vid_info_t))
return (EINVAL);
/* Already help the console driver by filling in some data. */
p = teken_get_cursor(&tm->tm_emulator);
vi->mv_row = p->tp_row;
vi->mv_col = p->tp_col;
p = teken_get_winsize(&tm->tm_emulator);
vi->mv_rsz = p->tp_row;
vi->mv_csz = p->tp_col;
teken_get_defattr_cons25(&tm->tm_emulator, &fg, &bg);
vi->mv_norm.fore = fg;
vi->mv_norm.back = bg;
/* XXX: keep vidcontrol happy; bold backgrounds. */
vi->mv_rev.fore = bg;
vi->mv_rev.back = fg & 0x7;
break;
}
}
/*
* Unlike various other drivers, this driver will never
* deallocate TTYs. This means it's safe to temporarily unlock
* the TTY when handling ioctls.
*/
tty_unlock(tp);
error = tm->tm_class->tc_ioctl(tm, cmd, data, td);
tty_lock(tp);
return (error);
}
static int
termtty_mmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t * paddr,
int nprot, vm_memattr_t *memattr)
{
struct terminal *tm = tty_softc(tp);
return (tm->tm_class->tc_mmap(tm, offset, paddr, nprot, memattr));
}
/*
* Binding with the kernel and debug console.
*/
static cn_probe_t termcn_cnprobe;
static cn_init_t termcn_cninit;
static cn_term_t termcn_cnterm;
static cn_getc_t termcn_cngetc;
static cn_putc_t termcn_cnputc;
static cn_grab_t termcn_cngrab;
static cn_ungrab_t termcn_cnungrab;
const struct consdev_ops termcn_cnops = {
.cn_probe = termcn_cnprobe,
.cn_init = termcn_cninit,
.cn_term = termcn_cnterm,
.cn_getc = termcn_cngetc,
.cn_putc = termcn_cnputc,
.cn_grab = termcn_cngrab,
.cn_ungrab = termcn_cnungrab,
};
void
termcn_cnregister(struct terminal *tm)
{
struct consdev *cp;
cp = tm->consdev;
if (cp == NULL) {
cp = malloc(sizeof(struct consdev), M_TERMINAL,
M_WAITOK|M_ZERO);
cp->cn_ops = &termcn_cnops;
cp->cn_arg = tm;
cp->cn_pri = CN_INTERNAL;
sprintf(cp->cn_name, "ttyv0");
tm->tm_flags = TF_CONS;
tm->consdev = cp;
terminal_init(tm);
}
/* Attach terminal as console. */
cnadd(cp);
}
static void
termcn_cngrab(struct consdev *cp)
{
struct terminal *tm = cp->cn_arg;
tm->tm_class->tc_cngrab(tm);
}
static void
termcn_cnungrab(struct consdev *cp)
{
struct terminal *tm = cp->cn_arg;
tm->tm_class->tc_cnungrab(tm);
}
static void
termcn_cnprobe(struct consdev *cp)
{
struct terminal *tm = cp->cn_arg;
if (tm == NULL) {
cp->cn_pri = CN_DEAD;
return;
}
tm->consdev = cp;
terminal_init(tm);
tm->tm_class->tc_cnprobe(tm, cp);
}
static void
termcn_cninit(struct consdev *cp)
{
}
static void
termcn_cnterm(struct consdev *cp)
{
}
static int
termcn_cngetc(struct consdev *cp)
{
struct terminal *tm = cp->cn_arg;
return (tm->tm_class->tc_cngetc(tm));
}
static void
termcn_cnputc(struct consdev *cp, int c)
{
struct terminal *tm = cp->cn_arg;
teken_attr_t backup;
char cv = c;
TERMINAL_LOCK_CONS(tm);
if (!(tm->tm_flags & TF_MUTE)) {
backup = *teken_get_curattr(&tm->tm_emulator);
teken_set_curattr(&tm->tm_emulator, &kernel_message);
teken_input(&tm->tm_emulator, &cv, 1);
teken_set_curattr(&tm->tm_emulator, &backup);
tm->tm_class->tc_done(tm);
}
TERMINAL_UNLOCK_CONS(tm);
}
/*
* Binding with the terminal emulator.
*/
static void
termteken_bell(void *softc)
{
struct terminal *tm = softc;
tm->tm_flags |= TF_BELL;
}
static void
termteken_cursor(void *softc, const teken_pos_t *p)
{
struct terminal *tm = softc;
tm->tm_class->tc_cursor(tm, p);
}
static void
termteken_putchar(void *softc, const teken_pos_t *p, teken_char_t c,
const teken_attr_t *a)
{
struct terminal *tm = softc;
tm->tm_class->tc_putchar(tm, p, TCHAR_CREATE(c, a));
}
static void
termteken_fill(void *softc, const teken_rect_t *r, teken_char_t c,
const teken_attr_t *a)
{
struct terminal *tm = softc;
tm->tm_class->tc_fill(tm, r, TCHAR_CREATE(c, a));
}
static void
termteken_copy(void *softc, const teken_rect_t *r, const teken_pos_t *p)
{
struct terminal *tm = softc;
tm->tm_class->tc_copy(tm, r, p);
}
static void
termteken_pre_input(void *softc)
{
struct terminal *tm = softc;
tm->tm_class->tc_pre_input(tm);
}
static void
termteken_post_input(void *softc)
{
struct terminal *tm = softc;
tm->tm_class->tc_post_input(tm);
}
static void
termteken_param(void *softc, int cmd, unsigned int arg)
{
struct terminal *tm = softc;
tm->tm_class->tc_param(tm, cmd, arg);
}
static void
termteken_respond(void *softc, const void *buf, size_t len)
{
#if 0
struct terminal *tm = softc;
struct tty *tp;
/*
* Only inject a response into the TTY if the data actually
* originated from the TTY.
*
* XXX: This cannot be done right now. The TTY could pick up
* other locks. It could also in theory cause loops, when the
* TTY performs echoing of a command that generates even more
* input.
*/
tp = tm->tm_tty;
if (tp == NULL)
return;
ttydisc_rint_simple(tp, buf, len);
ttydisc_rint_done(tp);
#endif
}