V4L/DVB (10978): Report tuning algorith correctly
[safe/jmp/linux-2.6] / drivers / char / tty_ioctl.c
index 4ad47d3..6f4c7d0 100644 (file)
@@ -20,6 +20,8 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/bitops.h>
+#include <linux/mutex.h>
+#include <linux/smp_lock.h>
 
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #define TERMIOS_FLUSH  1
 #define TERMIOS_WAIT   2
 #define TERMIOS_TERMIO 4
+#define TERMIOS_OLD    8
 
 
 /**
+ *     tty_chars_in_buffer     -       characters pending
+ *     @tty: terminal
+ *
+ *     Return the number of bytes of data in the device private
+ *     output queue. If no private method is supplied there is assumed
+ *     to be no queue on the device.
+ */
+
+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);
+
+/**
+ *     tty_write_room          -       write queue space
+ *     @tty: terminal
+ *
+ *     Return the number of bytes that can be queued to this device
+ *     at the present time. The result should be treated as a guarantee
+ *     and the driver cannot offer a value it later shrinks by more than
+ *     the number of bytes written. If no method is provided 2K is always
+ *     returned and data may be lost as there will be no flow control.
+ */
+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);
+
+/**
+ *     tty_driver_flush_buffer -       discard internal buffer
+ *     @tty: terminal
+ *
+ *     Discard the internal output buffer for this device. If no method
+ *     is provided then either the buffer cannot be hardware flushed or
+ *     there is no buffer driver side.
+ */
+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_throttle            -       flow control
+ *     @tty: terminal
+ *
+ *     Indicate that a tty should stop transmitting data down the stack.
+ */
+
+void tty_throttle(struct tty_struct *tty)
+{
+       /* check TTY_THROTTLED first so it indicates our state */
+       if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
+           tty->ops->throttle)
+               tty->ops->throttle(tty);
+}
+EXPORT_SYMBOL(tty_throttle);
+
+/**
+ *     tty_unthrottle          -       flow control
+ *     @tty: terminal
+ *
+ *     Indicate that a tty may continue transmitting data down the stack.
+ */
+
+void tty_unthrottle(struct tty_struct *tty)
+{
+       if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
+           tty->ops->unthrottle)
+               tty->ops->unthrottle(tty);
+}
+EXPORT_SYMBOL(tty_unthrottle);
+
+/**
  *     tty_wait_until_sent     -       wait for I/O to finish
  *     @tty: tty we are waiting for
  *     @timeout: how long we will wait
  *     Locking: none
  */
 
-void tty_wait_until_sent(struct tty_struct * tty, long timeout)
+void tty_wait_until_sent(struct tty_struct *tty, long timeout)
 {
-       DECLARE_WAITQUEUE(wait, current);
-
 #ifdef TTY_DEBUG_WAIT_UNTIL_SENT
        char buf[64];
-       
+
        printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
 #endif
-       if (!tty->driver->chars_in_buffer)
-               return;
-       add_wait_queue(&tty->write_wait, &wait);
        if (!timeout)
                timeout = MAX_SCHEDULE_TIMEOUT;
-       do {
-#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
-               printk(KERN_DEBUG "waiting %s...(%d)\n", tty_name(tty, buf),
-                      tty->driver->chars_in_buffer(tty));
-#endif
-               set_current_state(TASK_INTERRUPTIBLE);
-               if (signal_pending(current))
-                       goto stop_waiting;
-               if (!tty->driver->chars_in_buffer(tty))
-                       break;
-               timeout = schedule_timeout(timeout);
-       } while (timeout);
-       if (tty->driver->wait_until_sent)
-               tty->driver->wait_until_sent(tty, timeout);
-stop_waiting:
-       set_current_state(TASK_RUNNING);
-       remove_wait_queue(&tty->write_wait, &wait);
+       if (wait_event_interruptible_timeout(tty->write_wait,
+                       !tty_chars_in_buffer(tty), timeout) >= 0) {
+               if (tty->ops->wait_until_sent)
+                       tty->ops->wait_until_sent(tty, timeout);
+       }
 }
-
 EXPORT_SYMBOL(tty_wait_until_sent);
 
-static void unset_locked_termios(struct termios *termios,
-                                struct termios *old,
-                                struct termios *locked)
+
+/*
+ *             Termios Helper Methods
+ */
+
+static void unset_locked_termios(struct ktermios *termios,
+                                struct ktermios *old,
+                                struct ktermios *locked)
 {
        int     i;
-       
-#define NOSET_MASK(x,y,z) (x = ((x) & ~(z)) | ((y) & (z)))
+
+#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
 
        if (!locked) {
                printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
@@ -101,10 +174,306 @@ static void unset_locked_termios(struct termios *termios,
        NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
        NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
        termios->c_line = locked->c_line ? old->c_line : termios->c_line;
-       for (i=0; i < NCCS; i++)
+       for (i = 0; i < NCCS; i++)
                termios->c_cc[i] = locked->c_cc[i] ?
                        old->c_cc[i] : termios->c_cc[i];
+       /* FIXME: What should we do for i/ospeed */
+}
+
+/*
+ * Routine which returns the baud rate of the tty
+ *
+ * Note that the baud_table needs to be kept in sync with the
+ * include/asm/termbits.h file.
+ */
+static const speed_t baud_table[] = {
+       0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
+       9600, 19200, 38400, 57600, 115200, 230400, 460800,
+#ifdef __sparc__
+       76800, 153600, 307200, 614400, 921600
+#else
+       500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
+       2500000, 3000000, 3500000, 4000000
+#endif
+};
+
+#ifndef __sparc__
+static const tcflag_t baud_bits[] = {
+       B0, B50, B75, B110, B134, B150, B200, B300, B600,
+       B1200, B1800, B2400, B4800, B9600, B19200, B38400,
+       B57600, B115200, B230400, B460800, B500000, B576000,
+       B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
+       B3000000, B3500000, B4000000
+};
+#else
+static const tcflag_t baud_bits[] = {
+       B0, B50, B75, B110, B134, B150, B200, B300, B600,
+       B1200, B1800, B2400, B4800, B9600, B19200, B38400,
+       B57600, B115200, B230400, B460800, B76800, B153600,
+       B307200, B614400, B921600
+};
+#endif
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ *     tty_termios_baud_rate
+ *     @termios: termios structure
+ *
+ *     Convert termios baud rate data into a speed. This should be called
+ *     with the termios lock held if this termios is a terminal termios
+ *     structure. May change the termios data. Device drivers can call this
+ *     function but should use ->c_[io]speed directly as they are updated.
+ *
+ *     Locking: none
+ */
+
+speed_t tty_termios_baud_rate(struct ktermios *termios)
+{
+       unsigned int cbaud;
+
+       cbaud = termios->c_cflag & CBAUD;
+
+#ifdef BOTHER
+       /* Magic token for arbitary speed via c_ispeed/c_ospeed */
+       if (cbaud == BOTHER)
+               return termios->c_ospeed;
+#endif
+       if (cbaud & CBAUDEX) {
+               cbaud &= ~CBAUDEX;
+
+               if (cbaud < 1 || cbaud + 15 > n_baud_table)
+                       termios->c_cflag &= ~CBAUDEX;
+               else
+                       cbaud += 15;
+       }
+       return baud_table[cbaud];
+}
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ *     tty_termios_input_baud_rate
+ *     @termios: termios structure
+ *
+ *     Convert termios baud rate data into a speed. This should be called
+ *     with the termios lock held if this termios is a terminal termios
+ *     structure. May change the termios data. Device drivers can call this
+ *     function but should use ->c_[io]speed directly as they are updated.
+ *
+ *     Locking: none
+ */
+
+speed_t tty_termios_input_baud_rate(struct ktermios *termios)
+{
+#ifdef IBSHIFT
+       unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
+
+       if (cbaud == B0)
+               return tty_termios_baud_rate(termios);
+
+       /* Magic token for arbitary speed via c_ispeed*/
+       if (cbaud == BOTHER)
+               return termios->c_ispeed;
+
+       if (cbaud & CBAUDEX) {
+               cbaud &= ~CBAUDEX;
+
+               if (cbaud < 1 || cbaud + 15 > n_baud_table)
+                       termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
+               else
+                       cbaud += 15;
+       }
+       return baud_table[cbaud];
+#else
+       return tty_termios_baud_rate(termios);
+#endif
+}
+EXPORT_SYMBOL(tty_termios_input_baud_rate);
+
+/**
+ *     tty_termios_encode_baud_rate
+ *     @termios: ktermios structure holding user requested state
+ *     @ispeed: input speed
+ *     @ospeed: output speed
+ *
+ *     Encode the speeds set into the passed termios structure. This is
+ *     used as a library helper for drivers os that they can report back
+ *     the actual speed selected when it differs from the speed requested
+ *
+ *     For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
+ *     we need to carefully set the bits when the user does not get the
+ *     desired speed. We allow small margins and preserve as much of possible
+ *     of the input intent to keep compatiblity.
+ *
+ *     Locking: Caller should hold termios lock. This is already held
+ *     when calling this function from the driver termios handler.
+ *
+ *     The ifdefs deal with platforms whose owners have yet to update them
+ *     and will all go away once this is done.
+ */
+
+void tty_termios_encode_baud_rate(struct ktermios *termios,
+                                 speed_t ibaud, speed_t obaud)
+{
+       int i = 0;
+       int ifound = -1, ofound = -1;
+       int iclose = ibaud/50, oclose = obaud/50;
+       int ibinput = 0;
+
+       if (obaud == 0)                 /* CD dropped             */
+               ibaud = 0;              /* Clear ibaud to be sure */
+
+       termios->c_ispeed = ibaud;
+       termios->c_ospeed = obaud;
+
+#ifdef BOTHER
+       /* If the user asked for a precise weird speed give a precise weird
+          answer. If they asked for a Bfoo speed they many have problems
+          digesting non-exact replies so fuzz a bit */
+
+       if ((termios->c_cflag & CBAUD) == BOTHER)
+               oclose = 0;
+       if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
+               iclose = 0;
+       if ((termios->c_cflag >> IBSHIFT) & CBAUD)
+               ibinput = 1;    /* An input speed was specified */
+#endif
+       termios->c_cflag &= ~CBAUD;
+
+       /*
+        *      Our goal is to find a close match to the standard baud rate
+        *      returned. Walk the baud rate table and if we get a very close
+        *      match then report back the speed as a POSIX Bxxxx value by
+        *      preference
+        */
+
+       do {
+               if (obaud - oclose <= baud_table[i] &&
+                   obaud + oclose >= baud_table[i]) {
+                       termios->c_cflag |= baud_bits[i];
+                       ofound = i;
+               }
+               if (ibaud - iclose <= baud_table[i] &&
+                   ibaud + iclose >= baud_table[i]) {
+                       /* For the case input == output don't set IBAUD bits
+                          if the user didn't do so */
+                       if (ofound == i && !ibinput)
+                               ifound  = i;
+#ifdef IBSHIFT
+                       else {
+                               ifound = i;
+                               termios->c_cflag |= (baud_bits[i] << IBSHIFT);
+                       }
+#endif
+               }
+       } while (++i < n_baud_table);
+
+       /*
+        *      If we found no match then use BOTHER if provided or warn
+        *      the user their platform maintainer needs to wake up if not.
+        */
+#ifdef BOTHER
+       if (ofound == -1)
+               termios->c_cflag |= BOTHER;
+       /* Set exact input bits only if the input and output differ or the
+          user already did */
+       if (ifound == -1 && (ibaud != obaud || ibinput))
+               termios->c_cflag |= (BOTHER << IBSHIFT);
+#else
+       if (ifound == -1 || ofound == -1) {
+               static int warned;
+               if (!warned++)
+                       printk(KERN_WARNING "tty: Unable to return correct "
+                         "speed data as your architecture needs updating.\n");
+       }
+#endif
+}
+EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
+
+/**
+ *     tty_encode_baud_rate            -       set baud rate of the tty
+ *     @ibaud: input baud rate
+ *     @obad: output baud rate
+ *
+ *     Update the current termios data for the tty with the new speed
+ *     settings. The caller must hold the termios_mutex for the tty in
+ *     question.
+ */
+
+void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
+{
+       tty_termios_encode_baud_rate(tty->termios, ibaud, obaud);
+}
+EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
+
+/**
+ *     tty_get_baud_rate       -       get tty bit rates
+ *     @tty: tty to query
+ *
+ *     Returns the baud rate as an integer for this terminal. The
+ *     termios lock must be held by the caller and the terminal bit
+ *     flags may be updated.
+ *
+ *     Locking: none
+ */
+
+speed_t tty_get_baud_rate(struct tty_struct *tty)
+{
+       speed_t baud = tty_termios_baud_rate(tty->termios);
+
+       if (baud == 38400 && tty->alt_speed) {
+               if (!tty->warned) {
+                       printk(KERN_WARNING "Use of setserial/setrocket to "
+                                           "set SPD_* flags is deprecated\n");
+                       tty->warned = 1;
+               }
+               baud = tty->alt_speed;
+       }
+
+       return baud;
+}
+EXPORT_SYMBOL(tty_get_baud_rate);
+
+/**
+ *     tty_termios_copy_hw     -       copy hardware settings
+ *     @new: New termios
+ *     @old: Old termios
+ *
+ *     Propogate the hardware specific terminal setting bits from
+ *     the old termios structure to the new one. This is used in cases
+ *     where the hardware does not support reconfiguration or as a helper
+ *     in some cases where only minimal reconfiguration is supported
+ */
+
+void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
+{
+       /* The bits a dumb device handles in software. Smart devices need
+          to always provide a set_termios method */
+       new->c_cflag &= HUPCL | CREAD | CLOCAL;
+       new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
+       new->c_ispeed = old->c_ispeed;
+       new->c_ospeed = old->c_ospeed;
+}
+EXPORT_SYMBOL(tty_termios_copy_hw);
+
+/**
+ *     tty_termios_hw_change   -       check for setting change
+ *     @a: termios
+ *     @b: termios to compare
+ *
+ *     Check if any of the bits that affect a dumb device have changed
+ *     between the two termios structures, or a speed change is needed.
+ */
+
+int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
+{
+       if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
+               return 1;
+       if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
+               return 1;
+       return 0;
 }
+EXPORT_SYMBOL(tty_termios_hw_change);
 
 /**
  *     change_termios          -       update termios values
@@ -115,41 +484,28 @@ static void unset_locked_termios(struct termios *termios,
  *     is a bit of layering violation here with n_tty in terms of the
  *     internal knowledge of this function.
  *
- *     Locking: termios_sem
+ *     Locking: termios_mutex
  */
 
-static void change_termios(struct tty_struct * tty, struct termios * new_termios)
+static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
 {
-       int canon_change;
-       struct termios old_termios = *tty->termios;
+       struct ktermios old_termios;
        struct tty_ldisc *ld;
-       
+       unsigned long flags;
+
        /*
         *      Perform the actual termios internal changes under lock.
         */
-        
+
 
        /* 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);
+       old_termios = *tty->termios;
        *tty->termios = *new_termios;
        unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
-       canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
-       if (canon_change) {
-               memset(&tty->read_flags, 0, sizeof tty->read_flags);
-               tty->canon_head = tty->read_tail;
-               tty->canon_data = 0;
-               tty->erasing = 0;
-       }
-       
-       
-       if (canon_change && !L_ICANON(tty) && tty->read_cnt)
-               /* Get characters left over from canonical mode. */
-               wake_up_interruptible(&tty->read_wait);
 
        /* See if packet mode change of state. */
-
        if (tty->link && tty->link->packet) {
                int old_flow = ((old_termios.c_iflag & IXON) &&
                                (old_termios.c_cc[VSTOP] == '\023') &&
@@ -158,25 +514,29 @@ static void change_termios(struct tty_struct * tty, struct termios * new_termios
                                STOP_CHAR(tty) == '\023' &&
                                START_CHAR(tty) == '\021');
                if (old_flow != new_flow) {
+                       spin_lock_irqsave(&tty->ctrl_lock, flags);
                        tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
                        if (new_flow)
                                tty->ctrl_status |= TIOCPKT_DOSTOP;
                        else
                                tty->ctrl_status |= TIOCPKT_NOSTOP;
+                       spin_unlock_irqrestore(&tty->ctrl_lock, flags);
                        wake_up_interruptible(&tty->link->read_wait);
                }
        }
-          
-       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);
 
        ld = tty_ldisc_ref(tty);
        if (ld != NULL) {
-               if (ld->set_termios)
-                       (ld->set_termios)(tty, &old_termios);
+               if (ld->ops->set_termios)
+                       (ld->ops->set_termios)(tty, &old_termios);
                tty_ldisc_deref(ld);
        }
-       up(&tty->termios_sem);
+       mutex_unlock(&tty->termios_mutex);
 }
 
 /**
@@ -185,41 +545,59 @@ static void change_termios(struct tty_struct * tty, struct termios * new_termios
  *     @arg: user data
  *     @opt: option information
  *
- *     Helper function to prepare termios data and run neccessary other
+ *     Helper function to prepare termios data and run necessary other
  *     functions before using change_termios to do the actual changes.
  *
  *     Locking:
- *             Called functions take ldisc and termios_sem locks
+ *             Called functions take ldisc and termios_mutex locks
  */
 
-static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
+static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
 {
-       struct termios tmp_termios;
+       struct ktermios tmp_termios;
        struct tty_ldisc *ld;
        int retval = tty_check_change(tty);
 
        if (retval)
                return retval;
 
+       mutex_lock(&tty->termios_mutex);
+       memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
+       mutex_unlock(&tty->termios_mutex);
+
        if (opt & TERMIOS_TERMIO) {
-               memcpy(&tmp_termios, tty->termios, sizeof(struct termios));
                if (user_termio_to_kernel_termios(&tmp_termios,
                                                (struct termio __user *)arg))
                        return -EFAULT;
+#ifdef TCGETS2
+       } else if (opt & TERMIOS_OLD) {
+               if (user_termios_to_kernel_termios_1(&tmp_termios,
+                                               (struct termios __user *)arg))
+                       return -EFAULT;
        } else {
                if (user_termios_to_kernel_termios(&tmp_termios,
-                                               (struct termios __user *)arg))
+                                               (struct termios2 __user *)arg))
                        return -EFAULT;
        }
+#else
+       } else if (user_termios_to_kernel_termios(&tmp_termios,
+                                       (struct termios __user *)arg))
+               return -EFAULT;
+#endif
+
+       /* If old style Bfoo values are used then load c_ispeed/c_ospeed
+        * with the real speed so its unconditionally usable */
+       tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
+       tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
 
        ld = tty_ldisc_ref(tty);
-       
+
        if (ld != NULL) {
-               if ((opt & TERMIOS_FLUSH) && ld->flush_buffer)
-                       ld->flush_buffer(tty);
+               if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+                       ld->ops->flush_buffer(tty);
                tty_ldisc_deref(ld);
        }
-       
+
        if (opt & TERMIOS_WAIT) {
                tty_wait_until_sent(tty, 0);
                if (signal_pending(current))
@@ -227,42 +605,73 @@ static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
        }
 
        change_termios(tty, &tmp_termios);
+
+       /* FIXME: Arguably if tmp_termios == tty->termios AND the
+          actual requested termios was not tmp_termios then we may
+          want to return an error as no user requested change has
+          succeeded */
        return 0;
 }
 
-static int get_termio(struct tty_struct * tty, struct termio __user * termio)
+static int get_termio(struct tty_struct *tty, struct termio __user *termio)
 {
        if (kernel_termios_to_user_termio(termio, tty->termios))
                return -EFAULT;
        return 0;
 }
 
-static unsigned long inq_canon(struct tty_struct * tty)
+
+#ifdef TCGETX
+
+/**
+ *     set_termiox     -       set termiox fields if possible
+ *     @tty: terminal
+ *     @arg: termiox structure from user
+ *     @opt: option flags for ioctl type
+ *
+ *     Implement the device calling points for the SYS5 termiox ioctl
+ *     interface in Linux
+ */
+
+static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
 {
-       int nr, head, tail;
+       struct termiox tnew;
+       struct tty_ldisc *ld;
 
-       if (!tty->canon_data || !tty->read_buf)
-               return 0;
-       head = tty->canon_head;
-       tail = tty->read_tail;
-       nr = (head - tail) & (N_TTY_BUF_SIZE-1);
-       /* Skip EOF-chars.. */
-       while (head != tail) {
-               if (test_bit(tail, tty->read_flags) &&
-                   tty->read_buf[tail] == __DISABLED_CHAR)
-                       nr--;
-               tail = (tail+1) & (N_TTY_BUF_SIZE-1);
+       if (tty->termiox == NULL)
+               return -EINVAL;
+       if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
+               return -EFAULT;
+
+       ld = tty_ldisc_ref(tty);
+       if (ld != NULL) {
+               if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+                       ld->ops->flush_buffer(tty);
+               tty_ldisc_deref(ld);
        }
-       return nr;
+       if (opt & TERMIOS_WAIT) {
+               tty_wait_until_sent(tty, 0);
+               if (signal_pending(current))
+                       return -EINTR;
+       }
+
+       mutex_lock(&tty->termios_mutex);
+       if (tty->ops->set_termiox)
+               tty->ops->set_termiox(tty, &tnew);
+       mutex_unlock(&tty->termios_mutex);
+       return 0;
 }
 
+#endif
+
+
 #ifdef TIOCGETP
 /*
  * These are deprecated, but there is limited support..
  *
  * The "sg_flags" translation is a joke..
  */
-static int get_sgflags(struct tty_struct * tty)
+static int get_sgflags(struct tty_struct *tty)
 {
        int flags = 0;
 
@@ -280,22 +689,22 @@ static int get_sgflags(struct tty_struct * tty)
        return flags;
 }
 
-static int get_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
+static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
 {
        struct sgttyb tmp;
 
-       down(&tty->termios_sem);
-       tmp.sg_ispeed = 0;
-       tmp.sg_ospeed = 0;
+       mutex_lock(&tty->termios_mutex);
+       tmp.sg_ispeed = tty->termios->c_ispeed;
+       tmp.sg_ospeed = tty->termios->c_ospeed;
        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;
 }
 
-static void set_sgflags(struct termios * termios, int flags)
+static void set_sgflags(struct ktermios *termios, int flags)
 {
        termios->c_iflag = ICRNL | IXON;
        termios->c_oflag = 0;
@@ -329,90 +738,107 @@ static void set_sgflags(struct termios * termios, int flags)
  *     Updates a terminal from the legacy BSD style terminal information
  *     structure.
  *
- *     Locking: termios_sem
+ *     Locking: termios_mutex
  */
 
-static int set_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
+static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
 {
        int retval;
        struct sgttyb tmp;
-       struct termios termios;
+       struct ktermios termios;
 
        retval = tty_check_change(tty);
        if (retval)
                return retval;
-       
+
        if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
                return -EFAULT;
 
-       down(&tty->termios_sem);                
-       termios =  *tty->termios;
+       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);
+       /* Try and encode into Bfoo format */
+#ifdef BOTHER
+       tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
+                                               termios.c_ospeed);
+#endif
+       mutex_unlock(&tty->termios_mutex);
        change_termios(tty, &termios);
        return 0;
 }
 #endif
 
 #ifdef TIOCGETC
-static int get_tchars(struct tty_struct * tty, struct tchars __user * tchars)
+static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
 {
        struct tchars tmp;
 
+       mutex_lock(&tty->termios_mutex);
        tmp.t_intrc = tty->termios->c_cc[VINTR];
        tmp.t_quitc = tty->termios->c_cc[VQUIT];
        tmp.t_startc = tty->termios->c_cc[VSTART];
        tmp.t_stopc = tty->termios->c_cc[VSTOP];
        tmp.t_eofc = tty->termios->c_cc[VEOF];
        tmp.t_brkc = tty->termios->c_cc[VEOL2]; /* what is brkc anyway? */
+       mutex_unlock(&tty->termios_mutex);
        return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
 
-static int set_tchars(struct tty_struct * tty, struct tchars __user * tchars)
+static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
 {
        struct tchars tmp;
 
        if (copy_from_user(&tmp, tchars, sizeof(tmp)))
                return -EFAULT;
+       mutex_lock(&tty->termios_mutex);
        tty->termios->c_cc[VINTR] = tmp.t_intrc;
        tty->termios->c_cc[VQUIT] = tmp.t_quitc;
        tty->termios->c_cc[VSTART] = tmp.t_startc;
        tty->termios->c_cc[VSTOP] = tmp.t_stopc;
        tty->termios->c_cc[VEOF] = tmp.t_eofc;
        tty->termios->c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
+       mutex_unlock(&tty->termios_mutex);
        return 0;
 }
 #endif
 
 #ifdef TIOCGLTC
-static int get_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
+static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
 {
        struct ltchars tmp;
 
+       mutex_lock(&tty->termios_mutex);
        tmp.t_suspc = tty->termios->c_cc[VSUSP];
-       tmp.t_dsuspc = tty->termios->c_cc[VSUSP];       /* what is dsuspc anyway? */
+       /* what is dsuspc anyway? */
+       tmp.t_dsuspc = tty->termios->c_cc[VSUSP];
        tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
-       tmp.t_flushc = tty->termios->c_cc[VEOL2];       /* what is flushc anyway? */
+       /* what is flushc anyway? */
+       tmp.t_flushc = tty->termios->c_cc[VEOL2];
        tmp.t_werasc = tty->termios->c_cc[VWERASE];
        tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
+       mutex_unlock(&tty->termios_mutex);
        return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
 
-static int set_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
+static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
 {
        struct ltchars tmp;
 
        if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
                return -EFAULT;
 
+       mutex_lock(&tty->termios_mutex);
        tty->termios->c_cc[VSUSP] = tmp.t_suspc;
-       tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;       /* what is dsuspc anyway? */
+       /* what is dsuspc anyway? */
+       tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;
        tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
-       tty->termios->c_cc[VEOL2] = tmp.t_flushc;       /* what is flushc anyway? */
+       /* what is flushc anyway? */
+       tty->termios->c_cc[VEOL2] = tmp.t_flushc;
        tty->termios->c_cc[VWERASE] = tmp.t_werasc;
        tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
+       mutex_unlock(&tty->termios_mutex);
        return 0;
 }
 #endif
@@ -422,33 +848,75 @@ static int set_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
  *
  *     Send a high priority character to the tty even if stopped
  *
- *     Locking: none
- *
- *     FIXME: overlapping calls with start/stop tty lose state of tty
+ *     Locking: none for xchar method, write ordering for write method.
  */
 
-static 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;
+       if (tty->ops->send_xchar) {
+               tty->ops->send_xchar(tty, ch);
+               return 0;
        }
+
+       if (tty_write_lock(tty, 0) < 0)
+               return -ERESTARTSYS;
+
        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);
+       return 0;
 }
 
-int n_tty_ioctl(struct tty_struct * tty, struct file * file,
-                      unsigned int cmd, unsigned long arg)
+/**
+ *     tty_change_softcar      -       carrier change ioctl helper
+ *     @tty: tty to update
+ *     @arg: enable/disable CLOCAL
+ *
+ *     Perform a change to the CLOCAL state and call into the driver
+ *     layer to make it visible. All done with the termios mutex
+ */
+
+static int tty_change_softcar(struct tty_struct *tty, int arg)
+{
+       int ret = 0;
+       int bit = arg ? CLOCAL : 0;
+       struct ktermios old;
+
+       mutex_lock(&tty->termios_mutex);
+       old = *tty->termios;
+       tty->termios->c_cflag &= ~CLOCAL;
+       tty->termios->c_cflag |= bit;
+       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);
+       return ret;
+}
+
+/**
+ *     tty_mode_ioctl          -       mode related ioctls
+ *     @tty: tty for the ioctl
+ *     @file: file pointer for the tty
+ *     @cmd: command
+ *     @arg: ioctl argument
+ *
+ *     Perform non line discipline specific mode control ioctls. This
+ *     is designed to be called by line disciplines to ensure they provide
+ *     consistent mode setting.
+ */
+
+int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
+                       unsigned int cmd, unsigned long arg)
 {
-       struct tty_struct * real_tty;
+       struct tty_struct *real_tty;
        void __user *p = (void __user *)arg;
-       int retval;
-       struct tty_ldisc *ld;
+       int ret = 0;
 
        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
            tty->driver->subtype == PTY_TYPE_MASTER)
@@ -458,149 +926,220 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file,
 
        switch (cmd) {
 #ifdef TIOCGETP
-               case TIOCGETP:
-                       return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
-               case TIOCSETP:
-               case TIOCSETN:
-                       return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
+       case TIOCGETP:
+               return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
+       case TIOCSETP:
+       case TIOCSETN:
+               return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
 #endif
 #ifdef TIOCGETC
-               case TIOCGETC:
-                       return get_tchars(real_tty, p);
-               case TIOCSETC:
-                       return set_tchars(real_tty, p);
+       case TIOCGETC:
+               return get_tchars(real_tty, p);
+       case TIOCSETC:
+               return set_tchars(real_tty, p);
 #endif
 #ifdef TIOCGLTC
-               case TIOCGLTC:
-                       return get_ltchars(real_tty, p);
-               case TIOCSLTC:
-                       return set_ltchars(real_tty, p);
+       case TIOCGLTC:
+               return get_ltchars(real_tty, p);
+       case TIOCSLTC:
+               return set_ltchars(real_tty, p);
 #endif
-               case TCGETS:
-                       if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
-                               return -EFAULT;
-                       return 0;
-               case TCSETSF:
-                       return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
-               case TCSETSW:
-                       return set_termios(real_tty, p, TERMIOS_WAIT);
-               case TCSETS:
-                       return set_termios(real_tty, p, 0);
-               case TCGETA:
-                       return get_termio(real_tty, p);
-               case TCSETAF:
-                       return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
-               case TCSETAW:
-                       return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
-               case TCSETA:
-                       return set_termios(real_tty, p, TERMIOS_TERMIO);
-               case TCXONC:
-                       retval = tty_check_change(tty);
-                       if (retval)
-                               return retval;
-                       switch (arg) {
-                       case TCOOFF:
-                               if (!tty->flow_stopped) {
-                                       tty->flow_stopped = 1;
-                                       stop_tty(tty);
-                               }
-                               break;
-                       case TCOON:
-                               if (tty->flow_stopped) {
-                                       tty->flow_stopped = 0;
-                                       start_tty(tty);
-                               }
-                               break;
-                       case TCIOFF:
-                               if (STOP_CHAR(tty) != __DISABLED_CHAR)
-                                       send_prio_char(tty, STOP_CHAR(tty));
-                               break;
-                       case TCION:
-                               if (START_CHAR(tty) != __DISABLED_CHAR)
-                                       send_prio_char(tty, START_CHAR(tty));
-                               break;
-                       default:
-                               return -EINVAL;
+       case TCSETSF:
+               return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
+       case TCSETSW:
+               return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
+       case TCSETS:
+               return set_termios(real_tty, p, TERMIOS_OLD);
+#ifndef TCGETS2
+       case TCGETS:
+               mutex_lock(&real_tty->termios_mutex);
+               if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
+                       ret = -EFAULT;
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+#else
+       case TCGETS:
+               mutex_lock(&real_tty->termios_mutex);
+               if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios))
+                       ret = -EFAULT;
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+       case TCGETS2:
+               mutex_lock(&real_tty->termios_mutex);
+               if (kernel_termios_to_user_termios((struct termios2 __user *)arg, real_tty->termios))
+                       ret = -EFAULT;
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+       case TCSETSF2:
+               return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
+       case TCSETSW2:
+               return set_termios(real_tty, p, TERMIOS_WAIT);
+       case TCSETS2:
+               return set_termios(real_tty, p, 0);
+#endif
+       case TCGETA:
+               return get_termio(real_tty, p);
+       case TCSETAF:
+               return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
+       case TCSETAW:
+               return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
+       case TCSETA:
+               return set_termios(real_tty, p, TERMIOS_TERMIO);
+#ifndef TCGETS2
+       case TIOCGLCKTRMIOS:
+               mutex_lock(&real_tty->termios_mutex);
+               if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
+                       ret = -EFAULT;
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+       case TIOCSLCKTRMIOS:
+               if (!capable(CAP_SYS_ADMIN))
+                       return -EPERM;
+               mutex_lock(&real_tty->termios_mutex);
+               if (user_termios_to_kernel_termios(real_tty->termios_locked,
+                                              (struct termios __user *) arg))
+                       ret = -EFAULT;
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+#else
+       case TIOCGLCKTRMIOS:
+               mutex_lock(&real_tty->termios_mutex);
+               if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios_locked))
+                       ret = -EFAULT;
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+       case TIOCSLCKTRMIOS:
+               if (!capable(CAP_SYS_ADMIN))
+                       ret = -EPERM;
+               mutex_lock(&real_tty->termios_mutex);
+               if (user_termios_to_kernel_termios_1(real_tty->termios_locked,
+                                              (struct termios __user *) arg))
+                       ret = -EFAULT;
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+#endif
+#ifdef TCGETX
+       case TCGETX:
+               if (real_tty->termiox == NULL)
+                       return -EINVAL;
+               mutex_lock(&real_tty->termios_mutex);
+               if (copy_to_user(p, real_tty->termiox, sizeof(struct termiox)))
+                       ret = -EFAULT;
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+       case TCSETX:
+               return set_termiox(real_tty, p, 0);
+       case TCSETXW:
+               return set_termiox(real_tty, p, TERMIOS_WAIT);
+       case TCSETXF:
+               return set_termiox(real_tty, p, TERMIOS_FLUSH);
+#endif         
+       case TIOCGSOFTCAR:
+               mutex_lock(&real_tty->termios_mutex);
+               ret = put_user(C_CLOCAL(real_tty) ? 1 : 0,
+                                               (int __user *)arg);
+               mutex_unlock(&real_tty->termios_mutex);
+               return ret;
+       case TIOCSSOFTCAR:
+               if (get_user(arg, (unsigned int __user *) arg))
+                       return -EFAULT;
+               return tty_change_softcar(real_tty, arg);
+       default:
+               return -ENOIOCTLCMD;
+       }
+}
+EXPORT_SYMBOL_GPL(tty_mode_ioctl);
+
+int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
+{
+       struct tty_ldisc *ld;
+       int retval = tty_check_change(tty);
+       if (retval)
+               return retval;
+
+       ld = tty_ldisc_ref_wait(tty);
+       switch (arg) {
+       case TCIFLUSH:
+               if (ld && ld->ops->flush_buffer)
+                       ld->ops->flush_buffer(tty);
+               break;
+       case TCIOFLUSH:
+               if (ld && ld->ops->flush_buffer)
+                       ld->ops->flush_buffer(tty);
+               /* fall through */
+       case TCOFLUSH:
+               tty_driver_flush_buffer(tty);
+               break;
+       default:
+               tty_ldisc_deref(ld);
+               return -EINVAL;
+       }
+       tty_ldisc_deref(ld);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(tty_perform_flush);
+
+int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
+                      unsigned int cmd, unsigned long arg)
+{
+       unsigned long flags;
+       int retval;
+
+       switch (cmd) {
+       case TCXONC:
+               retval = tty_check_change(tty);
+               if (retval)
+                       return retval;
+               switch (arg) {
+               case TCOOFF:
+                       if (!tty->flow_stopped) {
+                               tty->flow_stopped = 1;
+                               stop_tty(tty);
                        }
-                       return 0;
-               case TCFLSH:
-                       retval = tty_check_change(tty);
-                       if (retval)
-                               return retval;
-                               
-                       ld = tty_ldisc_ref(tty);
-                       switch (arg) {
-                       case TCIFLUSH:
-                               if (ld && ld->flush_buffer)
-                                       ld->flush_buffer(tty);
-                               break;
-                       case TCIOFLUSH:
-                               if (ld && ld->flush_buffer)
-                                       ld->flush_buffer(tty);
-                               /* fall through */
-                       case TCOFLUSH:
-                               if (tty->driver->flush_buffer)
-                                       tty->driver->flush_buffer(tty);
-                               break;
-                       default:
-                               tty_ldisc_deref(ld);
-                               return -EINVAL;
+                       break;
+               case TCOON:
+                       if (tty->flow_stopped) {
+                               tty->flow_stopped = 0;
+                               start_tty(tty);
                        }
-                       tty_ldisc_deref(ld);
-                       return 0;
-               case TIOCOUTQ:
-                       return put_user(tty->driver->chars_in_buffer ?
-                                       tty->driver->chars_in_buffer(tty) : 0,
-                                       (int __user *) arg);
-               case TIOCINQ:
-                       retval = tty->read_cnt;
-                       if (L_ICANON(tty))
-                               retval = inq_canon(tty);
-                       return put_user(retval, (unsigned int __user *) arg);
-               case TIOCGLCKTRMIOS:
-                       if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
-                               return -EFAULT;
-                       return 0;
-
-               case TIOCSLCKTRMIOS:
-                       if (!capable(CAP_SYS_ADMIN))
-                               return -EPERM;
-                       if (user_termios_to_kernel_termios(real_tty->termios_locked, (struct termios __user *) arg))
-                               return -EFAULT;
-                       return 0;
-
-               case TIOCPKT:
-               {
-                       int pktmode;
-
-                       if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
-                           tty->driver->subtype != PTY_TYPE_MASTER)
-                               return -ENOTTY;
-                       if (get_user(pktmode, (int __user *) arg))
-                               return -EFAULT;
-                       if (pktmode) {
-                               if (!tty->packet) {
-                                       tty->packet = 1;
-                                       tty->link->ctrl_status = 0;
-                               }
-                       } else
-                               tty->packet = 0;
-                       return 0;
-               }
-               case TIOCGSOFTCAR:
-                       return put_user(C_CLOCAL(tty) ? 1 : 0, (int __user *)arg);
-               case TIOCSSOFTCAR:
-                       if (get_user(arg, (unsigned int __user *) arg))
-                               return -EFAULT;
-                       down(&tty->termios_sem);
-                       tty->termios->c_cflag =
-                               ((tty->termios->c_cflag & ~CLOCAL) |
-                                (arg ? CLOCAL : 0));
-                       up(&tty->termios_sem);
-                       return 0;
+                       break;
+               case TCIOFF:
+                       if (STOP_CHAR(tty) != __DISABLED_CHAR)
+                               return send_prio_char(tty, STOP_CHAR(tty));
+                       break;
+               case TCION:
+                       if (START_CHAR(tty) != __DISABLED_CHAR)
+                               return send_prio_char(tty, START_CHAR(tty));
+                       break;
                default:
-                       return -ENOIOCTLCMD;
+                       return -EINVAL;
                }
-}
+               return 0;
+       case TCFLSH:
+               return tty_perform_flush(tty, arg);
+       case TIOCPKT:
+       {
+               int pktmode;
 
-EXPORT_SYMBOL(n_tty_ioctl);
+               if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
+                   tty->driver->subtype != PTY_TYPE_MASTER)
+                       return -ENOTTY;
+               if (get_user(pktmode, (int __user *) arg))
+                       return -EFAULT;
+               spin_lock_irqsave(&tty->ctrl_lock, flags);
+               if (pktmode) {
+                       if (!tty->packet) {
+                               tty->packet = 1;
+                               tty->link->ctrl_status = 0;
+                       }
+               } else
+                       tty->packet = 0;
+               spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+               return 0;
+       }
+       default:
+               /* Try the mode commands */
+               return tty_mode_ioctl(tty, file, cmd, arg);
+       }
+}
+EXPORT_SYMBOL(n_tty_ioctl_helper);