Guards can help to make the code more readable. So use it wherever they
do so.
On many places labels and 'ret' locals are eliminated completely.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
---
[v2] change also the third goto in uart_suspend_port().
How could this only slip through?
---
drivers/tty/serial/serial_core.c | 113 +++++++++++++------------------
1 file changed, 47 insertions(+), 66 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 61fbc730c01b..d94d73e45fb6 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1104,21 +1104,19 @@ static int uart_tiocmget(struct tty_struct *tty)
struct uart_state *state = tty->driver_data;
struct tty_port *port = &state->port;
struct uart_port *uport;
- int result = -EIO;
+ int result;
+
+ guard(mutex)(&port->mutex);
- mutex_lock(&port->mutex);
uport = uart_port_check(state);
- if (!uport)
- goto out;
+ if (!uport || tty_io_error(tty))
+ return -EIO;
+
+ uart_port_lock_irq(uport);
+ result = uport->mctrl;
+ result |= uport->ops->get_mctrl(uport);
+ uart_port_unlock_irq(uport);
- if (!tty_io_error(tty)) {
- uart_port_lock_irq(uport);
- result = uport->mctrl;
- result |= uport->ops->get_mctrl(uport);
- uart_port_unlock_irq(uport);
- }
-out:
- mutex_unlock(&port->mutex);
return result;
}
@@ -1128,20 +1126,16 @@ uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
struct uart_state *state = tty->driver_data;
struct tty_port *port = &state->port;
struct uart_port *uport;
- int ret = -EIO;
- mutex_lock(&port->mutex);
+ guard(mutex)(&port->mutex);
+
uport = uart_port_check(state);
- if (!uport)
- goto out;
+ if (!uport || tty_io_error(tty))
+ return -EIO;
- if (!tty_io_error(tty)) {
- uart_update_mctrl(uport, set, clear);
- ret = 0;
- }
-out:
- mutex_unlock(&port->mutex);
- return ret;
+ uart_update_mctrl(uport, set, clear);
+
+ return 0;
}
static int uart_break_ctl(struct tty_struct *tty, int break_state)
@@ -1149,19 +1143,17 @@ static int uart_break_ctl(struct tty_struct *tty, int break_state)
struct uart_state *state = tty->driver_data;
struct tty_port *port = &state->port;
struct uart_port *uport;
- int ret = -EIO;
- mutex_lock(&port->mutex);
+ guard(mutex)(&port->mutex);
+
uport = uart_port_check(state);
if (!uport)
- goto out;
+ return -EIO;
if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl)
uport->ops->break_ctl(uport, break_state);
- ret = 0;
-out:
- mutex_unlock(&port->mutex);
- return ret;
+
+ return 0;
}
static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
@@ -1178,17 +1170,14 @@ static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
* changing, and hence any extra opens of the port while
* we're auto-configuring.
*/
- if (mutex_lock_interruptible(&port->mutex))
- return -ERESTARTSYS;
+ scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &port->mutex) {
+ uport = uart_port_check(state);
+ if (!uport)
+ return -EIO;
- uport = uart_port_check(state);
- if (!uport) {
- ret = -EIO;
- goto out;
- }
+ if (tty_port_users(port) != 1)
+ return -EBUSY;
- ret = -EBUSY;
- if (tty_port_users(port) == 1) {
uart_shutdown(tty, state);
/*
@@ -1209,14 +1198,15 @@ static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
uport->ops->config_port(uport, flags);
ret = uart_startup(tty, state, true);
- if (ret == 0)
- tty_port_set_initialized(port, true);
+ if (ret < 0)
+ return ret;
if (ret > 0)
- ret = 0;
+ return 0;
+
+ tty_port_set_initialized(port, true);
}
-out:
- mutex_unlock(&port->mutex);
- return ret;
+
+ return 0;
}
static void uart_enable_ms(struct uart_port *uport)
@@ -1711,10 +1701,11 @@ static void uart_set_termios(struct tty_struct *tty,
unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
bool sw_changed = false;
- mutex_lock(&state->port.mutex);
+ guard(mutex)(&state->port.mutex);
+
uport = uart_port_check(state);
if (!uport)
- goto out;
+ return;
/*
* Drivers doing software flow control also need to know
@@ -1737,9 +1728,8 @@ static void uart_set_termios(struct tty_struct *tty,
tty->termios.c_ospeed == old_termios->c_ospeed &&
tty->termios.c_ispeed == old_termios->c_ispeed &&
((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
- !sw_changed) {
- goto out;
- }
+ !sw_changed)
+ return;
uart_change_line_settings(tty, state, old_termios);
/* reload cflag from termios; port driver may have overridden flags */
@@ -1756,8 +1746,6 @@ static void uart_set_termios(struct tty_struct *tty,
mask |= TIOCM_RTS;
uart_set_mctrl(uport, mask);
}
-out:
- mutex_unlock(&state->port.mutex);
}
/*
@@ -2051,10 +2039,11 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
unsigned int status;
int mmio;
- mutex_lock(&port->mutex);
+ guard(mutex)(&port->mutex);
+
uport = uart_port_check(state);
if (!uport)
- goto out;
+ return;
mmio = uport->iotype >= UPIO_MEM;
seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
@@ -2066,7 +2055,7 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
if (uport->type == PORT_UNKNOWN) {
seq_putc(m, '\n');
- goto out;
+ return;
}
if (capable(CAP_SYS_ADMIN)) {
@@ -2117,8 +2106,6 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
seq_putc(m, '\n');
#undef STATBIT
#undef INFOBIT
-out:
- mutex_unlock(&port->mutex);
}
static int uart_proc_show(struct seq_file *m, void *v)
@@ -2395,13 +2382,12 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
struct device *tty_dev;
struct uart_match match = {uport, drv};
- mutex_lock(&port->mutex);
+ guard(mutex)(&port->mutex);
tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port);
if (tty_dev && device_may_wakeup(tty_dev)) {
enable_irq_wake(uport->irq);
put_device(tty_dev);
- mutex_unlock(&port->mutex);
return 0;
}
put_device(tty_dev);
@@ -2419,7 +2405,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
uart_port_unlock_irq(uport);
}
device_set_awake_path(uport->dev);
- goto unlock;
+ return 0;
}
uport->suspended = 1;
@@ -2462,8 +2448,6 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
console_stop(uport->cons);
uart_change_pm(state, UART_PM_STATE_OFF);
-unlock:
- mutex_unlock(&port->mutex);
return 0;
}
@@ -2477,14 +2461,13 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
struct uart_match match = {uport, drv};
struct ktermios termios;
- mutex_lock(&port->mutex);
+ guard(mutex)(&port->mutex);
tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port);
if (!uport->suspended && device_may_wakeup(tty_dev)) {
if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
disable_irq_wake(uport->irq);
put_device(tty_dev);
- mutex_unlock(&port->mutex);
return 0;
}
put_device(tty_dev);
@@ -2557,8 +2540,6 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
tty_port_set_suspended(port, false);
}
- mutex_unlock(&port->mutex);
-
return 0;
}
EXPORT_SYMBOL(uart_resume_port);
--
2.46.0
