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Diffstat (limited to 'drivers/serial/serial_core.c')
-rw-r--r--drivers/serial/serial_core.c288
1 files changed, 136 insertions, 152 deletions
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 7f2830709512..cd8511298bcb 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -58,9 +58,9 @@ static struct lock_class_key port_lock_key;
#define uart_console(port) (0)
#endif
-static void uart_change_speed(struct uart_state *state,
+static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
struct ktermios *old_termios);
-static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
+static void __uart_wait_until_sent(struct uart_port *port, int timeout);
static void uart_change_pm(struct uart_state *state, int pm_state);
/*
@@ -137,7 +137,7 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
* Startup the port. This will be called once per open. All calls
* will be serialised by the per-port mutex.
*/
-static int uart_startup(struct uart_state *state, int init_hw)
+static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
{
struct uart_port *uport = state->uart_port;
struct tty_port *port = &state->port;
@@ -152,7 +152,7 @@ static int uart_startup(struct uart_state *state, int init_hw)
* once we have successfully opened the port. Also set
* up the tty->alt_speed kludge
*/
- set_bit(TTY_IO_ERROR, &port->tty->flags);
+ set_bit(TTY_IO_ERROR, &tty->flags);
if (uport->type == PORT_UNKNOWN)
return 0;
@@ -177,26 +177,26 @@ static int uart_startup(struct uart_state *state, int init_hw)
/*
* Initialise the hardware port settings.
*/
- uart_change_speed(state, NULL);
+ uart_change_speed(tty, state, NULL);
/*
* Setup the RTS and DTR signals once the
* port is open and ready to respond.
*/
- if (port->tty->termios->c_cflag & CBAUD)
+ if (tty->termios->c_cflag & CBAUD)
uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
}
if (port->flags & ASYNC_CTS_FLOW) {
spin_lock_irq(&uport->lock);
if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
- port->tty->hw_stopped = 1;
+ tty->hw_stopped = 1;
spin_unlock_irq(&uport->lock);
}
set_bit(ASYNCB_INITIALIZED, &port->flags);
- clear_bit(TTY_IO_ERROR, &port->tty->flags);
+ clear_bit(TTY_IO_ERROR, &tty->flags);
}
if (retval && capable(CAP_SYS_ADMIN))
@@ -210,11 +210,10 @@ static int uart_startup(struct uart_state *state, int init_hw)
* DTR is dropped if the hangup on close termio flag is on. Calls to
* uart_shutdown are serialised by the per-port semaphore.
*/
-static void uart_shutdown(struct uart_state *state)
+static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
{
struct uart_port *uport = state->uart_port;
struct tty_port *port = &state->port;
- struct tty_struct *tty = port->tty;
/*
* Set the TTY IO error marker
@@ -430,11 +429,10 @@ uart_get_divisor(struct uart_port *port, unsigned int baud)
EXPORT_SYMBOL(uart_get_divisor);
/* FIXME: Consistent locking policy */
-static void
-uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
+static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
+ struct ktermios *old_termios)
{
struct tty_port *port = &state->port;
- struct tty_struct *tty = port->tty;
struct uart_port *uport = state->uart_port;
struct ktermios *termios;
@@ -463,8 +461,8 @@ uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
uport->ops->set_termios(uport, termios, old_termios);
}
-static inline int
-__uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
+static inline int __uart_put_char(struct uart_port *port,
+ struct circ_buf *circ, unsigned char c)
{
unsigned long flags;
int ret = 0;
@@ -494,8 +492,8 @@ static void uart_flush_chars(struct tty_struct *tty)
uart_start(tty);
}
-static int
-uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
+static int uart_write(struct tty_struct *tty,
+ const unsigned char *buf, int count)
{
struct uart_state *state = tty->driver_data;
struct uart_port *port;
@@ -675,7 +673,7 @@ static int uart_get_info(struct uart_state *state,
return 0;
}
-static int uart_set_info(struct uart_state *state,
+static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
struct serial_struct __user *newinfo)
{
struct serial_struct new_serial;
@@ -770,7 +768,7 @@ static int uart_set_info(struct uart_state *state,
* We need to shutdown the serial port at the old
* port/type/irq combination.
*/
- uart_shutdown(state);
+ uart_shutdown(tty, state);
}
if (change_port) {
@@ -869,25 +867,27 @@ static int uart_set_info(struct uart_state *state,
"is deprecated.\n", current->comm,
tty_name(port->tty, buf));
}
- uart_change_speed(state, NULL);
+ uart_change_speed(tty, state, NULL);
}
} else
- retval = uart_startup(state, 1);
+ retval = uart_startup(tty, state, 1);
exit:
mutex_unlock(&port->mutex);
return retval;
}
-
-/*
- * uart_get_lsr_info - get line status register info.
- * Note: uart_ioctl protects us against hangups.
+/**
+ * uart_get_lsr_info - get line status register info
+ * @tty: tty associated with the UART
+ * @state: UART being queried
+ * @value: returned modem value
+ *
+ * Note: uart_ioctl protects us against hangups.
*/
-static int uart_get_lsr_info(struct uart_state *state,
- unsigned int __user *value)
+static int uart_get_lsr_info(struct tty_struct *tty,
+ struct uart_state *state, unsigned int __user *value)
{
struct uart_port *uport = state->uart_port;
- struct tty_port *port = &state->port;
unsigned int result;
result = uport->ops->tx_empty(uport);
@@ -900,7 +900,7 @@ static int uart_get_lsr_info(struct uart_state *state,
*/
if (uport->x_char ||
((uart_circ_chars_pending(&state->xmit) > 0) &&
- !port->tty->stopped && !port->tty->hw_stopped))
+ !tty->stopped && !tty->hw_stopped))
result &= ~TIOCSER_TEMT;
return put_user(result, value);
@@ -961,7 +961,7 @@ static int uart_break_ctl(struct tty_struct *tty, int break_state)
return 0;
}
-static int uart_do_autoconfig(struct uart_state *state)
+static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
{
struct uart_port *uport = state->uart_port;
struct tty_port *port = &state->port;
@@ -980,7 +980,7 @@ static int uart_do_autoconfig(struct uart_state *state)
ret = -EBUSY;
if (tty_port_users(port) == 1) {
- uart_shutdown(state);
+ uart_shutdown(tty, state);
/*
* If we already have a port type configured,
@@ -999,7 +999,7 @@ static int uart_do_autoconfig(struct uart_state *state)
*/
uport->ops->config_port(uport, flags);
- ret = uart_startup(state, 1);
+ ret = uart_startup(tty, state, 1);
}
mutex_unlock(&port->mutex);
return ret;
@@ -1122,11 +1122,11 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
break;
case TIOCSSERIAL:
- ret = uart_set_info(state, uarg);
+ ret = uart_set_info(tty, state, uarg);
break;
case TIOCSERCONFIG:
- ret = uart_do_autoconfig(state);
+ ret = uart_do_autoconfig(tty, state);
break;
case TIOCSERGWILD: /* obsolete */
@@ -1172,7 +1172,7 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
*/
switch (cmd) {
case TIOCSERGETLSR: /* Get line status register */
- ret = uart_get_lsr_info(state, uarg);
+ ret = uart_get_lsr_info(tty, state, uarg);
break;
default: {
@@ -1194,7 +1194,7 @@ static void uart_set_ldisc(struct tty_struct *tty)
struct uart_port *uport = state->uart_port;
if (uport->ops->set_ldisc)
- uport->ops->set_ldisc(uport);
+ uport->ops->set_ldisc(uport, tty->termios->c_line);
}
static void uart_set_termios(struct tty_struct *tty,
@@ -1219,7 +1219,7 @@ static void uart_set_termios(struct tty_struct *tty,
return;
}
- uart_change_speed(state, old_termios);
+ uart_change_speed(tty, state, old_termios);
/* Handle transition to B0 status */
if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
@@ -1272,8 +1272,9 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
struct uart_state *state = tty->driver_data;
struct tty_port *port;
struct uart_port *uport;
+ unsigned long flags;
- BUG_ON(!kernel_locked());
+ BUG_ON(!tty_locked());
if (!state)
return;
@@ -1284,9 +1285,12 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
pr_debug("uart_close(%d) called\n", uport->line);
mutex_lock(&port->mutex);
+ spin_lock_irqsave(&port->lock, flags);
- if (tty_hung_up_p(filp))
+ if (tty_hung_up_p(filp)) {
+ spin_unlock_irqrestore(&port->lock, flags);
goto done;
+ }
if ((tty->count == 1) && (port->count != 1)) {
/*
@@ -1305,8 +1309,10 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
tty->name, port->count);
port->count = 0;
}
- if (port->count)
+ if (port->count) {
+ spin_unlock_irqrestore(&port->lock, flags);
goto done;
+ }
/*
* Now we wait for the transmit buffer to clear; and we notify
@@ -1314,9 +1320,18 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
* setting tty->closing.
*/
tty->closing = 1;
+ spin_unlock_irqrestore(&port->lock, flags);
- if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
- tty_wait_until_sent(tty, msecs_to_jiffies(port->closing_wait));
+ if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
+ /*
+ * hack: open-coded tty_wait_until_sent to avoid
+ * recursive tty_lock
+ */
+ long timeout = msecs_to_jiffies(port->closing_wait);
+ if (wait_event_interruptible_timeout(tty->write_wait,
+ !tty_chars_in_buffer(tty), timeout) >= 0)
+ __uart_wait_until_sent(uport, timeout);
+ }
/*
* At this point, we stop accepting input. To do this, we
@@ -1332,45 +1347,47 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
* has completely drained; this is especially
* important if there is a transmit FIFO!
*/
- uart_wait_until_sent(tty, uport->timeout);
+ __uart_wait_until_sent(uport, uport->timeout);
}
- uart_shutdown(state);
+ uart_shutdown(tty, state);
uart_flush_buffer(tty);
tty_ldisc_flush(tty);
- tty->closing = 0;
tty_port_tty_set(port, NULL);
+ spin_lock_irqsave(&port->lock, flags);
+ tty->closing = 0;
if (port->blocked_open) {
+ spin_unlock_irqrestore(&port->lock, flags);
if (port->close_delay)
msleep_interruptible(port->close_delay);
+ spin_lock_irqsave(&port->lock, flags);
} else if (!uart_console(uport)) {
+ spin_unlock_irqrestore(&port->lock, flags);
uart_change_pm(state, 3);
+ spin_lock_irqsave(&port->lock, flags);
}
/*
* Wake up anyone trying to open this port.
*/
clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
+ spin_unlock_irqrestore(&port->lock, flags);
wake_up_interruptible(&port->open_wait);
done:
mutex_unlock(&port->mutex);
}
-static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
+static void __uart_wait_until_sent(struct uart_port *port, int timeout)
{
- struct uart_state *state = tty->driver_data;
- struct uart_port *port = state->uart_port;
unsigned long char_time, expire;
if (port->type == PORT_UNKNOWN || port->fifosize == 0)
return;
- lock_kernel();
-
/*
* Set the check interval to be 1/5 of the estimated time to
* send a single character, and make it at least 1. The check
@@ -1416,7 +1433,16 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
break;
}
set_current_state(TASK_RUNNING); /* might not be needed */
- unlock_kernel();
+}
+
+static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+ struct uart_state *state = tty->driver_data;
+ struct uart_port *port = state->uart_port;
+
+ tty_lock();
+ __uart_wait_until_sent(port, timeout);
+ tty_unlock();
}
/*
@@ -1429,16 +1455,19 @@ static void uart_hangup(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
struct tty_port *port = &state->port;
+ unsigned long flags;
- BUG_ON(!kernel_locked());
+ BUG_ON(!tty_locked());
pr_debug("uart_hangup(%d)\n", state->uart_port->line);
mutex_lock(&port->mutex);
if (port->flags & ASYNC_NORMAL_ACTIVE) {
uart_flush_buffer(tty);
- uart_shutdown(state);
+ uart_shutdown(tty, state);
+ spin_lock_irqsave(&port->lock, flags);
port->count = 0;
clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
+ spin_unlock_irqrestore(&port->lock, flags);
tty_port_tty_set(port, NULL);
wake_up_interruptible(&port->open_wait);
wake_up_interruptible(&port->delta_msr_wait);
@@ -1446,15 +1475,19 @@ static void uart_hangup(struct tty_struct *tty)
mutex_unlock(&port->mutex);
}
-/*
- * Copy across the serial console cflag setting into the termios settings
- * for the initial open of the port. This allows continuity between the
- * kernel settings, and the settings init adopts when it opens the port
- * for the first time.
+/**
+ * uart_update_termios - update the terminal hw settings
+ * @tty: tty associated with UART
+ * @state: UART to update
+ *
+ * Copy across the serial console cflag setting into the termios settings
+ * for the initial open of the port. This allows continuity between the
+ * kernel settings, and the settings init adopts when it opens the port
+ * for the first time.
*/
-static void uart_update_termios(struct uart_state *state)
+static void uart_update_termios(struct tty_struct *tty,
+ struct uart_state *state)
{
- struct tty_struct *tty = state->port.tty;
struct uart_port *port = state->uart_port;
if (uart_console(port) && port->cons->cflag) {
@@ -1471,7 +1504,7 @@ static void uart_update_termios(struct uart_state *state)
/*
* Make termios settings take effect.
*/
- uart_change_speed(state, NULL);
+ uart_change_speed(tty, state, NULL);
/*
* And finally enable the RTS and DTR signals.
@@ -1481,90 +1514,37 @@ static void uart_update_termios(struct uart_state *state)
}
}
-/*
- * Block the open until the port is ready. We must be called with
- * the per-port semaphore held.
- */
-static int
-uart_block_til_ready(struct file *filp, struct uart_state *state)
+static int uart_carrier_raised(struct tty_port *port)
{
- DECLARE_WAITQUEUE(wait, current);
+ struct uart_state *state = container_of(port, struct uart_state, port);
struct uart_port *uport = state->uart_port;
- struct tty_port *port = &state->port;
- unsigned int mctrl;
-
- port->blocked_open++;
- port->count--;
-
- add_wait_queue(&port->open_wait, &wait);
- while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
-
- /*
- * If we have been hung up, tell userspace/restart open.
- */
- if (tty_hung_up_p(filp) || port->tty == NULL)
- break;
-
- /*
- * If the port has been closed, tell userspace/restart open.
- */
- if (!(port->flags & ASYNC_INITIALIZED))
- break;
+ int mctrl;
+ spin_lock_irq(&uport->lock);
+ uport->ops->enable_ms(uport);
+ mctrl = uport->ops->get_mctrl(uport);
+ spin_unlock_irq(&uport->lock);
+ if (mctrl & TIOCM_CAR)
+ return 1;
+ return 0;
+}
- /*
- * If non-blocking mode is set, or CLOCAL mode is set,
- * we don't want to wait for the modem status lines to
- * indicate that the port is ready.
- *
- * Also, if the port is not enabled/configured, we want
- * to allow the open to succeed here. Note that we will
- * have set TTY_IO_ERROR for a non-existant port.
- */
- if ((filp->f_flags & O_NONBLOCK) ||
- (port->tty->termios->c_cflag & CLOCAL) ||
- (port->tty->flags & (1 << TTY_IO_ERROR)))
- break;
+static void uart_dtr_rts(struct tty_port *port, int onoff)
+{
+ struct uart_state *state = container_of(port, struct uart_state, port);
+ struct uart_port *uport = state->uart_port;
- /*
- * Set DTR to allow modem to know we're waiting. Do
- * not set RTS here - we want to make sure we catch
- * the data from the modem.
- */
- if (port->tty->termios->c_cflag & CBAUD)
- uart_set_mctrl(uport, TIOCM_DTR);
+ if (onoff) {
+ uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
/*
- * and wait for the carrier to indicate that the
- * modem is ready for us.
+ * If this is the first open to succeed,
+ * adjust things to suit.
*/
- spin_lock_irq(&uport->lock);
- uport->ops->enable_ms(uport);
- mctrl = uport->ops->get_mctrl(uport);
- spin_unlock_irq(&uport->lock);
- if (mctrl & TIOCM_CAR)
- break;
-
- mutex_unlock(&port->mutex);
- schedule();
- mutex_lock(&port->mutex);
-
- if (signal_pending(current))
- break;
+ if (!test_and_set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags))
+ uart_update_termios(port->tty, state);
}
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&port->open_wait, &wait);
-
- port->count++;
- port->blocked_open--;
-
- if (signal_pending(current))
- return -ERESTARTSYS;
-
- if (!port->tty || tty_hung_up_p(filp))
- return -EAGAIN;
-
- return 0;
+ else
+ uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
}
static struct uart_state *uart_get(struct uart_driver *drv, int line)
@@ -1611,7 +1591,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
struct tty_port *port;
int retval, line = tty->index;
- BUG_ON(!kernel_locked());
+ BUG_ON(!tty_locked());
pr_debug("uart_open(%d) called\n", line);
/*
@@ -1668,23 +1648,14 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
/*
* Start up the serial port.
*/
- retval = uart_startup(state, 0);
+ retval = uart_startup(tty, state, 0);
/*
* If we succeeded, wait until the port is ready.
*/
- if (retval == 0)
- retval = uart_block_til_ready(filp, state);
mutex_unlock(&port->mutex);
-
- /*
- * If this is the first open to succeed, adjust things to suit.
- */
- if (retval == 0 && !(port->flags & ASYNC_NORMAL_ACTIVE)) {
- set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
-
- uart_update_termios(state);
- }
+ if (retval == 0)
+ retval = tty_port_block_til_ready(port, tty, filp);
fail:
return retval;
@@ -2010,9 +1981,13 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
struct tty_port *port = &state->port;
struct device *tty_dev;
struct uart_match match = {uport, drv};
+ struct tty_struct *tty;
mutex_lock(&port->mutex);
+ /* Must be inside the mutex lock until we convert to tty_port */
+ tty = port->tty;
+
tty_dev = device_find_child(uport->dev, &match, serial_match_port);
if (device_may_wakeup(tty_dev)) {
enable_irq_wake(uport->irq);
@@ -2105,9 +2080,12 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
ops->set_mctrl(uport, 0);
spin_unlock_irq(&uport->lock);
if (console_suspend_enabled || !uart_console(uport)) {
+ /* Protected by port mutex for now */
+ struct tty_struct *tty = port->tty;
ret = ops->startup(uport);
if (ret == 0) {
- uart_change_speed(state, NULL);
+ if (tty)
+ uart_change_speed(tty, state, NULL);
spin_lock_irq(&uport->lock);
ops->set_mctrl(uport, uport->mctrl);
ops->start_tx(uport);
@@ -2119,7 +2097,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
* Clear the "initialized" flag so we won't try
* to call the low level drivers shutdown method.
*/
- uart_shutdown(state);
+ uart_shutdown(tty, state);
}
}
@@ -2312,6 +2290,11 @@ static const struct tty_operations uart_ops = {
#endif
};
+static const struct tty_port_operations uart_port_ops = {
+ .carrier_raised = uart_carrier_raised,
+ .dtr_rts = uart_dtr_rts,
+};
+
/**
* uart_register_driver - register a driver with the uart core layer
* @drv: low level driver structure
@@ -2368,6 +2351,7 @@ int uart_register_driver(struct uart_driver *drv)
struct tty_port *port = &state->port;
tty_port_init(port);
+ port->ops = &uart_port_ops;
port->close_delay = 500; /* .5 seconds */
port->closing_wait = 30000; /* 30 seconds */
tasklet_init(&state->tlet, uart_tasklet_action,