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tty: The big operations rework

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- Operations are now a shared const function block as with most other Linux
  objects

- Introduce wrappers for some optional functions to get consistent behaviour

- Wrap put_char which used to be patched by the tty layer

- Document which functions are needed/optional

- Make put_char report success/fail

- Cache the driver->ops pointer in the tty as tty->ops

- Remove various surplus lock calls we no longer need

- Remove proc_write method as noted by Alexey Dobriyan

- Introduce some missing sanity checks where certain driver/ldisc
  combinations would oops as they didn't check needed methods were present

[akpm@linux-foundation.org: fix fs/compat_ioctl.c build]
[akpm@linux-foundation.org: fix isicom]
[akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build]
[akpm@linux-foundation.org: fix kgdb]
Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alan Cox
2008-04-30 00:54:13 -07:00
committed by Linus Torvalds
parent 251b8dd7ee
commit f34d7a5b70
30 changed files with 539 additions and 666 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/char/n_tty.c
+43 -60
View File
@@ -149,8 +149,8 @@ static void check_unthrottle(struct tty_struct *tty)
{
if (tty->count &&
test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
tty->driver->unthrottle)
tty->driver->unthrottle(tty);
tty->ops->unthrottle)
tty->ops->unthrottle(tty);
}
/**
@@ -273,7 +273,7 @@ static int opost(unsigned char c, struct tty_struct *tty)
{
int space, spaces;
space = tty->driver->write_room(tty);
space = tty_write_room(tty);
if (!space)
return -1;
@@ -286,7 +286,7 @@ static int opost(unsigned char c, struct tty_struct *tty)
if (O_ONLCR(tty)) {
if (space < 2)
return -1;
tty->driver->put_char(tty, '\r');
tty_put_char(tty, '\r');
tty->column = 0;
}
tty->canon_column = tty->column;
@@ -308,7 +308,7 @@ static int opost(unsigned char c, struct tty_struct *tty)
if (space < spaces)
return -1;
tty->column += spaces;
tty->driver->write(tty, " ", spaces);
tty->ops->write(tty, " ", spaces);
return 0;
}
tty->column += spaces;
@@ -325,7 +325,7 @@ static int opost(unsigned char c, struct tty_struct *tty)
break;
}
}
tty->driver->put_char(tty, c);
tty_put_char(tty, c);
unlock_kernel();
return 0;
}
@@ -352,7 +352,7 @@ static ssize_t opost_block(struct tty_struct *tty,
int i;
const unsigned char *cp;
space = tty->driver->write_room(tty);
space = tty_write_room(tty);
if (!space)
return 0;
if (nr > space)
@@ -390,27 +390,14 @@ static ssize_t opost_block(struct tty_struct *tty,
}
}
break_out:
if (tty->driver->flush_chars)
tty->driver->flush_chars(tty);
i = tty->driver->write(tty, buf, i);
if (tty->ops->flush_chars)
tty->ops->flush_chars(tty);
i = tty->ops->write(tty, buf, i);
unlock_kernel();
return i;
}
/**
* put_char - write character to driver
* @c: character (or part of unicode symbol)
* @tty: terminal device
*
* Queue a byte to the driver layer for output
*/
static inline void put_char(unsigned char c, struct tty_struct *tty)
{
tty->driver->put_char(tty, c);
}
/**
* echo_char - echo characters
* @c: unicode byte to echo
@@ -423,8 +410,8 @@ static inline void put_char(unsigned char c, struct tty_struct *tty)
static void echo_char(unsigned char c, struct tty_struct *tty)
{
if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') {
put_char('^', tty);
put_char(c ^ 0100, tty);
tty_put_char(tty, '^');
tty_put_char(tty, c ^ 0100);
tty->column += 2;
} else
opost(c, tty);
@@ -433,7 +420,7 @@ static void echo_char(unsigned char c, struct tty_struct *tty)
static inline void finish_erasing(struct tty_struct *tty)
{
if (tty->erasing) {
put_char('/', tty);
tty_put_char(tty, '/');
tty->column++;
tty->erasing = 0;
}
@@ -517,7 +504,7 @@ static void eraser(unsigned char c, struct tty_struct *tty)
if (L_ECHO(tty)) {
if (L_ECHOPRT(tty)) {
if (!tty->erasing) {
put_char('\\', tty);
tty_put_char(tty, '\\');
tty->column++;
tty->erasing = 1;
}
@@ -525,7 +512,7 @@ static void eraser(unsigned char c, struct tty_struct *tty)
echo_char(c, tty);
while (--cnt > 0) {
head = (head+1) & (N_TTY_BUF_SIZE-1);
put_char(tty->read_buf[head], tty);
tty_put_char(tty, tty->read_buf[head]);
}
} else if (kill_type == ERASE && !L_ECHOE(tty)) {
echo_char(ERASE_CHAR(tty), tty);
@@ -553,22 +540,22 @@ static void eraser(unsigned char c, struct tty_struct *tty)
/* Now backup to that column. */
while (tty->column > col) {
/* Can't use opost here. */
put_char('\b', tty);
tty_put_char(tty, '\b');
if (tty->column > 0)
tty->column--;
}
} else {
if (iscntrl(c) && L_ECHOCTL(tty)) {
put_char('\b', tty);
put_char(' ', tty);
put_char('\b', tty);
tty_put_char(tty, '\b');
tty_put_char(tty, ' ');
tty_put_char(tty, '\b');
if (tty->column > 0)
tty->column--;
}
if (!iscntrl(c) || L_ECHOCTL(tty)) {
put_char('\b', tty);
put_char(' ', tty);
put_char('\b', tty);
tty_put_char(tty, '\b');
tty_put_char(tty, ' ');
tty_put_char(tty, '\b');
if (tty->column > 0)
tty->column--;
}
@@ -599,8 +586,7 @@ static inline void isig(int sig, struct tty_struct *tty, int flush)
kill_pgrp(tty->pgrp, sig, 1);
if (flush || !L_NOFLSH(tty)) {
n_tty_flush_buffer(tty);
if (tty->driver->flush_buffer)
tty->driver->flush_buffer(tty);
tty_driver_flush_buffer(tty);
}
}
@@ -732,7 +718,7 @@ static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
tty->lnext = 0;
if (L_ECHO(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
put_char('\a', tty); /* beep if no space */
tty_put_char(tty, '\a'); /* beep if no space */
return;
}
/* Record the column of first canon char. */
@@ -776,8 +762,7 @@ send_signal:
*/
if (!L_NOFLSH(tty)) {
n_tty_flush_buffer(tty);
if (tty->driver->flush_buffer)
tty->driver->flush_buffer(tty);
tty_driver_flush_buffer(tty);
}
if (L_ECHO(tty))
echo_char(c, tty);
@@ -806,8 +791,8 @@ send_signal:
if (L_ECHO(tty)) {
finish_erasing(tty);
if (L_ECHOCTL(tty)) {
put_char('^', tty);
put_char('\b', tty);
tty_put_char(tty, '^');
tty_put_char(tty, '\b');
}
}
return;
@@ -828,7 +813,7 @@ send_signal:
if (c == '\n') {
if (L_ECHO(tty) || L_ECHONL(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1)
put_char('\a', tty);
tty_put_char(tty, '\a');
opost('\n', tty);
}
goto handle_newline;
@@ -846,7 +831,7 @@ send_signal:
*/
if (L_ECHO(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1)
put_char('\a', tty);
tty_put_char(tty, '\a');
/* Record the column of first canon char. */
if (tty->canon_head == tty->read_head)
tty->canon_column = tty->column;
@@ -876,7 +861,7 @@ handle_newline:
finish_erasing(tty);
if (L_ECHO(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
put_char('\a', tty); /* beep if no space */
tty_put_char(tty, '\a'); /* beep if no space */
return;
}
if (c == '\n')
@@ -980,8 +965,8 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
break;
}
}
if (tty->driver->flush_chars)
tty->driver->flush_chars(tty);
if (tty->ops->flush_chars)
tty->ops->flush_chars(tty);
}
n_tty_set_room(tty);
@@ -1000,8 +985,8 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
if (tty->receive_room < TTY_THRESHOLD_THROTTLE) {
/* check TTY_THROTTLED first so it indicates our state */
if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
tty->driver->throttle)
tty->driver->throttle(tty);
tty->ops->throttle)
tty->ops->throttle(tty);
}
}
@@ -1086,6 +1071,9 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
tty->real_raw = 0;
}
n_tty_set_room(tty);
/* The termios change make the tty ready for I/O */
wake_up_interruptible(&tty->write_wait);
wake_up_interruptible(&tty->read_wait);
}
/**
@@ -1513,11 +1501,11 @@ static ssize_t write_chan(struct tty_struct *tty, struct file *file,
break;
b++; nr--;
}
if (tty->driver->flush_chars)
tty->driver->flush_chars(tty);
if (tty->ops->flush_chars)
tty->ops->flush_chars(tty);
} else {
while (nr > 0) {
c = tty->driver->write(tty, b, nr);
c = tty->ops->write(tty, b, nr);
if (c < 0) {
retval = c;
goto break_out;
@@ -1554,11 +1542,6 @@ break_out:
*
* This code must be sure never to sleep through a hangup.
* Called without the kernel lock held - fine
*
* FIXME: if someone changes the VMIN or discipline settings for the
* terminal while another process is in poll() the poll does not
* recompute the new limits. Possibly set_termios should issue
* a read wakeup to fix this bug.
*/
static unsigned int normal_poll(struct tty_struct *tty, struct file *file,
@@ -1582,9 +1565,9 @@ static unsigned int normal_poll(struct tty_struct *tty, struct file *file,
else
tty->minimum_to_wake = 1;
}
if (!tty_is_writelocked(tty) &&
tty->driver->chars_in_buffer(tty) < WAKEUP_CHARS &&
tty->driver->write_room(tty) > 0)
if (tty->ops->write && !tty_is_writelocked(tty) &&
tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
tty_write_room(tty) > 0)
mask |= POLLOUT | POLLWRNORM;
return mask;
}