From f34d7a5b7010b82fe97da95496b9971435530062 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 30 Apr 2008 00:54:13 -0700 Subject: 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 Acked-by: Greg Kroah-Hartman Cc: Jason Wessel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/tty_ioctl.c | 62 ++++++++++++++++++++++++++++++++---------------- 1 file changed, 42 insertions(+), 20 deletions(-) (limited to 'drivers/char/tty_ioctl.c') diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c index 8c4bf3e48d5b..c10d40c4c5ca 100644 --- a/drivers/char/tty_ioctl.c +++ b/drivers/char/tty_ioctl.c @@ -40,6 +40,34 @@ #define TERMIOS_OLD 8 +int tty_chars_in_buffer(struct tty_struct *tty) +{ + if (tty->ops->chars_in_buffer) + return tty->ops->chars_in_buffer(tty); + else + return 0; +} + +EXPORT_SYMBOL(tty_chars_in_buffer); + +int tty_write_room(struct tty_struct *tty) +{ + if (tty->ops->write_room) + return tty->ops->write_room(tty); + return 2048; +} + +EXPORT_SYMBOL(tty_write_room); + +void tty_driver_flush_buffer(struct tty_struct *tty) +{ + if (tty->ops->flush_buffer) + tty->ops->flush_buffer(tty); +} + +EXPORT_SYMBOL(tty_driver_flush_buffer); + + /** * tty_wait_until_sent - wait for I/O to finish * @tty: tty we are waiting for @@ -58,17 +86,13 @@ void tty_wait_until_sent(struct tty_struct *tty, long timeout) printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf)); #endif - if (!tty->driver->chars_in_buffer) - return; if (!timeout) timeout = MAX_SCHEDULE_TIMEOUT; - lock_kernel(); if (wait_event_interruptible_timeout(tty->write_wait, - !tty->driver->chars_in_buffer(tty), timeout) >= 0) { - if (tty->driver->wait_until_sent) - tty->driver->wait_until_sent(tty, timeout); + !tty_chars_in_buffer(tty), timeout) >= 0) { + if (tty->ops->wait_until_sent) + tty->ops->wait_until_sent(tty, timeout); } - unlock_kernel(); } EXPORT_SYMBOL(tty_wait_until_sent); @@ -444,8 +468,8 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios) } } - if (tty->driver->set_termios) - (*tty->driver->set_termios)(tty, &old_termios); + if (tty->ops->set_termios) + (*tty->ops->set_termios)(tty, &old_termios); else tty_termios_copy_hw(tty->termios, &old_termios); @@ -748,8 +772,8 @@ static int send_prio_char(struct tty_struct *tty, char ch) { int was_stopped = tty->stopped; - if (tty->driver->send_xchar) { - tty->driver->send_xchar(tty, ch); + if (tty->ops->send_xchar) { + tty->ops->send_xchar(tty, ch); return 0; } @@ -758,7 +782,7 @@ static int send_prio_char(struct tty_struct *tty, char ch) if (was_stopped) start_tty(tty); - tty->driver->write(tty, &ch, 1); + tty->ops->write(tty, &ch, 1); if (was_stopped) stop_tty(tty); tty_write_unlock(tty); @@ -778,13 +802,14 @@ static int tty_change_softcar(struct tty_struct *tty, int arg) { int ret = 0; int bit = arg ? CLOCAL : 0; - struct ktermios old = *tty->termios; + struct ktermios old; mutex_lock(&tty->termios_mutex); + old = *tty->termios; tty->termios->c_cflag &= ~CLOCAL; tty->termios->c_cflag |= bit; - if (tty->driver->set_termios) - tty->driver->set_termios(tty, &old); + if (tty->ops->set_termios) + tty->ops->set_termios(tty, &old); if ((tty->termios->c_cflag & CLOCAL) != bit) ret = -EINVAL; mutex_unlock(&tty->termios_mutex); @@ -926,8 +951,7 @@ int tty_perform_flush(struct tty_struct *tty, unsigned long arg) ld->flush_buffer(tty); /* fall through */ case TCOFLUSH: - if (tty->driver->flush_buffer) - tty->driver->flush_buffer(tty); + tty_driver_flush_buffer(tty); break; default: tty_ldisc_deref(ld); @@ -984,9 +1008,7 @@ int n_tty_ioctl(struct tty_struct *tty, struct file *file, case TCFLSH: return tty_perform_flush(tty, arg); case TIOCOUTQ: - return put_user(tty->driver->chars_in_buffer ? - tty->driver->chars_in_buffer(tty) : 0, - (int __user *) arg); + return put_user(tty_chars_in_buffer(tty), (int __user *) arg); case TIOCINQ: retval = tty->read_cnt; if (L_ICANON(tty)) -- cgit v1.2.3