tty: The big operations rework
- 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>
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index e1518e1..abc93a9 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -149,8 +149,8 @@
{
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 @@
{
int space, spaces;
- space = tty->driver->write_room(tty);
+ space = tty_write_room(tty);
if (!space)
return -1;
@@ -286,7 +286,7 @@
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 @@
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 @@
break;
}
}
- tty->driver->put_char(tty, c);
+ tty_put_char(tty, c);
unlock_kernel();
return 0;
}
@@ -352,7 +352,7 @@
int i;
const unsigned char *cp;
- space = tty->driver->write_room(tty);
+ space = tty_write_room(tty);
if (!space)
return 0;
if (nr > space)
@@ -390,28 +390,15 @@
}
}
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
* @tty: terminal device
@@ -423,8 +410,8 @@
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 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 @@
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 @@
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 @@
/* 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 @@
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 @@
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 @@
*/
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 @@
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 @@
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 @@
*/
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
*
* 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 @@
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;
}