#include <linux/string.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/mutex.h>
#include <asm/io.h>
-#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#define TERMIOS_WAIT 2
#define TERMIOS_TERMIO 4
+
+/**
+ * tty_wait_until_sent - wait for I/O to finish
+ * @tty: tty we are waiting for
+ * @timeout: how long we will wait
+ *
+ * Wait for characters pending in a tty driver to hit the wire, or
+ * for a timeout to occur (eg due to flow control)
+ *
+ * Locking: none
+ */
+
void tty_wait_until_sent(struct tty_struct * tty, long timeout)
{
DECLARE_WAITQUEUE(wait, current);
old->c_cc[i] : termios->c_cc[i];
}
+/**
+ * change_termios - update termios values
+ * @tty: tty to update
+ * @new_termios: desired new value
+ *
+ * Perform updates to the termios values set on this terminal. There
+ * is a bit of layering violation here with n_tty in terms of the
+ * internal knowledge of this function.
+ *
+ * Locking: termios_sem
+ */
+
static void change_termios(struct tty_struct * tty, struct termios * new_termios)
{
int canon_change;
/* FIXME: we need to decide on some locking/ordering semantics
for the set_termios notification eventually */
- down(&tty->termios_sem);
+ mutex_lock(&tty->termios_mutex);
*tty->termios = *new_termios;
unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
(ld->set_termios)(tty, &old_termios);
tty_ldisc_deref(ld);
}
- up(&tty->termios_sem);
+ mutex_unlock(&tty->termios_mutex);
}
+/**
+ * set_termios - set termios values for a tty
+ * @tty: terminal device
+ * @arg: user data
+ * @opt: option information
+ *
+ * Helper function to prepare termios data and run neccessary other
+ * functions before using change_termios to do the actual changes.
+ *
+ * Locking:
+ * Called functions take ldisc and termios_sem locks
+ */
+
static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
{
struct termios tmp_termios;
{
struct sgttyb tmp;
- down(&tty->termios_sem);
+ mutex_lock(&tty->termios_mutex);
tmp.sg_ispeed = 0;
tmp.sg_ospeed = 0;
tmp.sg_erase = tty->termios->c_cc[VERASE];
tmp.sg_kill = tty->termios->c_cc[VKILL];
tmp.sg_flags = get_sgflags(tty);
- up(&tty->termios_sem);
+ mutex_unlock(&tty->termios_mutex);
return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}
}
}
+/**
+ * set_sgttyb - set legacy terminal values
+ * @tty: tty structure
+ * @sgttyb: pointer to old style terminal structure
+ *
+ * Updates a terminal from the legacy BSD style terminal information
+ * structure.
+ *
+ * Locking: termios_sem
+ */
+
static int set_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
{
int retval;
if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
return -EFAULT;
- down(&tty->termios_sem);
+ mutex_lock(&tty->termios_mutex);
termios = *tty->termios;
termios.c_cc[VERASE] = tmp.sg_erase;
termios.c_cc[VKILL] = tmp.sg_kill;
set_sgflags(&termios, tmp.sg_flags);
- up(&tty->termios_sem);
+ mutex_unlock(&tty->termios_mutex);
change_termios(tty, &termios);
return 0;
}
}
#endif
-/*
- * Send a high priority character to the tty.
+/**
+ * send_prio_char - send priority character
+ *
+ * Send a high priority character to the tty even if stopped
+ *
+ * Locking: none for xchar method, write ordering for write method.
*/
-void send_prio_char(struct tty_struct *tty, char ch)
+
+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);
- return;
+ return 0;
}
+
+ if (mutex_lock_interruptible(&tty->atomic_write_lock))
+ return -ERESTARTSYS;
+
if (was_stopped)
start_tty(tty);
- tty->driver->write(tty, 0, &ch, 1);
+ tty->driver->write(tty, &ch, 1);
if (was_stopped)
stop_tty(tty);
+ mutex_unlock(&tty->atomic_write_lock);
+ return 0;
}
int n_tty_ioctl(struct tty_struct * tty, struct file * file,
break;
case TCIOFF:
if (STOP_CHAR(tty) != __DISABLED_CHAR)
- send_prio_char(tty, STOP_CHAR(tty));
+ return send_prio_char(tty, STOP_CHAR(tty));
break;
case TCION:
if (START_CHAR(tty) != __DISABLED_CHAR)
- send_prio_char(tty, START_CHAR(tty));
+ return send_prio_char(tty, START_CHAR(tty));
break;
default:
return -EINVAL;
ld = tty_ldisc_ref(tty);
switch (arg) {
case TCIFLUSH:
- if (ld->flush_buffer)
+ if (ld && ld->flush_buffer)
ld->flush_buffer(tty);
break;
case TCIOFLUSH:
- if (ld->flush_buffer)
+ if (ld && ld->flush_buffer)
ld->flush_buffer(tty);
/* fall through */
case TCOFLUSH:
case TIOCSSOFTCAR:
if (get_user(arg, (unsigned int __user *) arg))
return -EFAULT;
- down(&tty->termios_sem);
+ mutex_lock(&tty->termios_mutex);
tty->termios->c_cflag =
((tty->termios->c_cflag & ~CLOCAL) |
(arg ? CLOCAL : 0));
- up(&tty->termios_sem);
+ mutex_unlock(&tty->termios_mutex);
return 0;
default:
return -ENOIOCTLCMD;
git://git.onelab.eu / linux-2.6.git / blobdiff