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/n_tty.c | 103 +++++++++++++++++++++------------------------------ 1 file changed, 43 insertions(+), 60 deletions(-) (limited to 'drivers/char/n_tty.c') diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index e1518e17e09..abc93a93dcd 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -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; } -- cgit v1.2.3-18-g5258