Commit 793b4501 authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
Browse files

mxser: use guard()s 



Having all the new guards, use them in the mxser code. This improves
readability, makes error handling easier, and marks locked portions of
code explicit.

Signed-off-by: default avatar"Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250814072456.182853-8-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 81600e92

drivers/tty/mxser.c

+74 −123
Original line number Diff line number Diff line
@@ -442,11 +442,8 @@ static void __mxser_start_tx(struct mxser_port *info) 


static void mxser_start_tx(struct mxser_port *info)

{

	unsigned long flags;



	spin_lock_irqsave(&info->slock, flags);

	guard(spinlock_irqsave)(&info->slock);

	__mxser_start_tx(info);

	spin_unlock_irqrestore(&info->slock, flags);

}



static void __mxser_stop_tx(struct mxser_port *info)
@@ -465,17 +462,15 @@ static bool mxser_carrier_raised(struct tty_port *port) 
static void mxser_dtr_rts(struct tty_port *port, bool active)

{

	struct mxser_port *mp = container_of(port, struct mxser_port, port);

	unsigned long flags;

	u8 mcr;



	spin_lock_irqsave(&mp->slock, flags);

	guard(spinlock_irqsave)(&mp->slock);

	mcr = inb(mp->ioaddr + UART_MCR);

	if (active)

		mcr |= UART_MCR_DTR | UART_MCR_RTS;

	else

		mcr &= ~(UART_MCR_DTR | UART_MCR_RTS);

	outb(mcr, mp->ioaddr + UART_MCR);

	spin_unlock_irqrestore(&mp->slock, flags);

}



static int mxser_set_baud(struct tty_struct *tty, speed_t newspd)
@@ -828,10 +823,8 @@ static void mxser_stop_rx(struct mxser_port *info) 
static void mxser_shutdown_port(struct tty_port *port)

{

	struct mxser_port *info = container_of(port, struct mxser_port, port);

	unsigned long flags;



	spin_lock_irqsave(&info->slock, flags);



	scoped_guard(spinlock_irqsave, &info->slock) {

		mxser_stop_rx(info);



		/*
@@ -849,11 +842,9 @@ static void mxser_shutdown_port(struct tty_port *port) 
		/* read data port to reset things */

		(void)inb(info->ioaddr + UART_RX);





		if (info->board->must_hwid)

			mxser_must_no_sw_flow_control(info->ioaddr);



	spin_unlock_irqrestore(&info->slock, flags);

	}



	/* make sure ISR is not running while we free the buffer */

	synchronize_irq(info->board->irq);
@@ -880,15 +871,13 @@ static int mxser_open(struct tty_struct *tty, struct file *filp) 
static void mxser_flush_buffer(struct tty_struct *tty)

{

	struct mxser_port *info = tty->driver_data;

	unsigned long flags;



	spin_lock_irqsave(&info->slock, flags);

	scoped_guard(spinlock_irqsave, &info->slock) {

		kfifo_reset(&info->port.xmit_fifo);



		outb(info->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,

		     info->ioaddr + UART_FCR);



	spin_unlock_irqrestore(&info->slock, flags);

	}



	tty_wakeup(tty);

}
@@ -901,14 +890,13 @@ static void mxser_close(struct tty_struct *tty, struct file *filp) 
static ssize_t mxser_write(struct tty_struct *tty, const u8 *buf, size_t count)

{

	struct mxser_port *info = tty->driver_data;

	unsigned long flags;

	size_t written;

	bool is_empty;



	spin_lock_irqsave(&info->slock, flags);

	scoped_guard(spinlock_irqsave, &info->slock) {

		written = kfifo_in(&info->port.xmit_fifo, buf, count);

		is_empty = kfifo_is_empty(&info->port.xmit_fifo);

	spin_unlock_irqrestore(&info->slock, flags);

	}



	if (!is_empty && !tty->flow.stopped)

		if (!tty->hw_stopped || mxser_16550A_or_MUST(info))
@@ -920,14 +908,9 @@ static ssize_t mxser_write(struct tty_struct *tty, const u8 *buf, size_t count) 
static int mxser_put_char(struct tty_struct *tty, u8 ch)

{

	struct mxser_port *info = tty->driver_data;

	unsigned long flags;

	int ret;



	spin_lock_irqsave(&info->slock, flags);

	ret = kfifo_put(&info->port.xmit_fifo, ch);

	spin_unlock_irqrestore(&info->slock, flags);



	return ret;

	guard(spinlock_irqsave)(&info->slock);

	return kfifo_put(&info->port.xmit_fifo, ch);

}
@@ -968,7 +951,7 @@ static int mxser_get_serial_info(struct tty_struct *tty, 
	struct tty_port *port = &info->port;

	unsigned int closing_wait, close_delay;



	mutex_lock(&port->mutex);

	guard(mutex)(&port->mutex);



	close_delay = jiffies_to_msecs(info->port.close_delay) / 10;

	closing_wait = info->port.closing_wait;
@@ -984,7 +967,7 @@ static int mxser_get_serial_info(struct tty_struct *tty, 
	ss->close_delay = close_delay;

	ss->closing_wait = closing_wait;

	ss->custom_divisor = MXSER_CUSTOM_DIVISOR;

	mutex_unlock(&port->mutex);



	return 0;

}
@@ -994,20 +977,15 @@ static int mxser_set_serial_info(struct tty_struct *tty, 
	struct mxser_port *info = tty->driver_data;

	struct tty_port *port = &info->port;

	speed_t baud;

	unsigned long sl_flags;

	unsigned int old_speed, close_delay, closing_wait;

	int retval = 0;



	if (tty_io_error(tty))

		return -EIO;



	mutex_lock(&port->mutex);

	guard(mutex)(&port->mutex);



	if (ss->irq != info->board->irq ||

			ss->port != info->ioaddr) {

		mutex_unlock(&port->mutex);

	if (ss->irq != info->board->irq || ss->port != info->ioaddr)

		return -EINVAL;

	}



	old_speed = port->flags & ASYNC_SPD_MASK;
@@ -1020,10 +998,9 @@ static int mxser_set_serial_info(struct tty_struct *tty, 
		if ((ss->baud_base != MXSER_BAUD_BASE) ||

				(close_delay != port->close_delay) ||

				(closing_wait != port->closing_wait) ||

				((ss->flags & ~ASYNC_USR_MASK) != (port->flags & ~ASYNC_USR_MASK))) {

			mutex_unlock(&port->mutex);

				((ss->flags & ~ASYNC_USR_MASK) != (port->flags & ~ASYNC_USR_MASK)))

			return -EPERM;

		}



		port->flags = (port->flags & ~ASYNC_USR_MASK) |

				(ss->flags & ASYNC_USR_MASK);

	} else {
@@ -1039,10 +1016,9 @@ static int mxser_set_serial_info(struct tty_struct *tty, 
				(ss->baud_base != MXSER_BAUD_BASE ||

				ss->custom_divisor !=

				MXSER_CUSTOM_DIVISOR)) {

			if (ss->custom_divisor == 0) {

				mutex_unlock(&port->mutex);

			if (ss->custom_divisor == 0)

				return -EINVAL;

			}



			baud = ss->baud_base / ss->custom_divisor;

			tty_encode_baud_rate(tty, baud, baud);

		}
@@ -1054,16 +1030,17 @@ static int mxser_set_serial_info(struct tty_struct *tty, 


	if (tty_port_initialized(port)) {

		if (old_speed != (port->flags & ASYNC_SPD_MASK)) {

			spin_lock_irqsave(&info->slock, sl_flags);

			guard(spinlock_irqsave)(&info->slock);

			mxser_change_speed(tty, NULL);

			spin_unlock_irqrestore(&info->slock, sl_flags);

		}

	} else {

		retval = mxser_activate(port, tty);



		return 0;

	}



	int retval = mxser_activate(port, tty);

	if (retval == 0)

		tty_port_set_initialized(port, true);

	}

	mutex_unlock(&port->mutex);



	return retval;

}
@@ -1080,13 +1057,11 @@ static int mxser_set_serial_info(struct tty_struct *tty, 
static int mxser_get_lsr_info(struct mxser_port *info,

		unsigned int __user *value)

{

	unsigned char status;

	unsigned int result;

	unsigned long flags;

	u8 status;



	spin_lock_irqsave(&info->slock, flags);

	scoped_guard(spinlock_irqsave, &info->slock)

		status = inb(info->ioaddr + UART_LSR);

	spin_unlock_irqrestore(&info->slock, flags);

	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);

	return put_user(result, value);

}
@@ -1095,16 +1070,15 @@ static int mxser_tiocmget(struct tty_struct *tty) 
{

	struct mxser_port *info = tty->driver_data;

	unsigned char control;

	unsigned long flags;

	u8 msr;



	if (tty_io_error(tty))

		return -EIO;



	spin_lock_irqsave(&info->slock, flags);

	scoped_guard(spinlock_irqsave, &info->slock) {

		control = info->MCR;

		msr = mxser_check_modem_status(tty, info);

	spin_unlock_irqrestore(&info->slock, flags);

	}



	return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) |

		    ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) |
@@ -1118,12 +1092,11 @@ static int mxser_tiocmset(struct tty_struct *tty, 
		unsigned int set, unsigned int clear)

{

	struct mxser_port *info = tty->driver_data;

	unsigned long flags;



	if (tty_io_error(tty))

		return -EIO;



	spin_lock_irqsave(&info->slock, flags);

	guard(spinlock_irqsave)(&info->slock);



	if (set & TIOCM_RTS)

		info->MCR |= UART_MCR_RTS;
@@ -1136,7 +1109,7 @@ static int mxser_tiocmset(struct tty_struct *tty, 
		info->MCR &= ~UART_MCR_DTR;



	outb(info->MCR, info->ioaddr + UART_MCR);

	spin_unlock_irqrestore(&info->slock, flags);



	return 0;

}
@@ -1144,12 +1117,11 @@ static int mxser_cflags_changed(struct mxser_port *info, unsigned long arg, 
		struct async_icount *cprev)

{

	struct async_icount cnow;

	unsigned long flags;

	int ret;



	spin_lock_irqsave(&info->slock, flags);

	cnow = info->icount;	/* atomic copy */

	spin_unlock_irqrestore(&info->slock, flags);

	/* atomic copy */

	scoped_guard(spinlock_irqsave, &info->slock)

		cnow = info->icount;



	ret =	((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||

		((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
@@ -1179,19 +1151,17 @@ static int mxser_ioctl_op_mode(struct mxser_port *port, int index, bool set, 
		if (opmode & ~OP_MODE_MASK)

			return -EINVAL;



		spin_lock_irq(&port->slock);

		guard(spinlock_irq)(&port->slock);

		val = inb(port->opmode_ioaddr);

		val &= ~(OP_MODE_MASK << shiftbit);

		val |= (opmode << shiftbit);

		outb(val, port->opmode_ioaddr);

		spin_unlock_irq(&port->slock);



		return 0;

	}



	spin_lock_irq(&port->slock);

	scoped_guard(spinlock_irq, &port->slock)

		opmode = inb(port->opmode_ioaddr) >> shiftbit;

	spin_unlock_irq(&port->slock);



	return put_user(opmode & OP_MODE_MASK, u_opmode);

}
@@ -1201,7 +1171,6 @@ static int mxser_ioctl(struct tty_struct *tty, 
{

	struct mxser_port *info = tty->driver_data;

	struct async_icount cnow;

	unsigned long flags;

	void __user *argp = (void __user *)arg;



	if (cmd == MOXA_SET_OP_MODE || cmd == MOXA_GET_OP_MODE)
@@ -1221,9 +1190,9 @@ static int mxser_ioctl(struct tty_struct *tty, 
		 * Caller should use TIOCGICOUNT to see which one it was

		 */

	case TIOCMIWAIT:

		spin_lock_irqsave(&info->slock, flags);

		cnow = info->icount;	/* note the counters on entry */

		spin_unlock_irqrestore(&info->slock, flags);

		/* note the counters on entry */

		scoped_guard(spinlock_irqsave, &info->slock)

			cnow = info->icount;



		return wait_event_interruptible(info->port.delta_msr_wait,

				mxser_cflags_changed(info, arg, &cnow));
@@ -1246,11 +1215,9 @@ static int mxser_get_icount(struct tty_struct *tty, 
{

	struct mxser_port *info = tty->driver_data;

	struct async_icount cnow;

	unsigned long flags;



	spin_lock_irqsave(&info->slock, flags);

	scoped_guard(spinlock_irqsave, &info->slock)

		cnow = info->icount;

	spin_unlock_irqrestore(&info->slock, flags);



	icount->frame = cnow.frame;

	icount->brk = cnow.brk;
@@ -1328,34 +1295,28 @@ static void mxser_unthrottle(struct tty_struct *tty) 
static void mxser_stop(struct tty_struct *tty)

{

	struct mxser_port *info = tty->driver_data;

	unsigned long flags;



	spin_lock_irqsave(&info->slock, flags);

	guard(spinlock_irqsave)(&info->slock);

	if (info->IER & UART_IER_THRI)

		__mxser_stop_tx(info);

	spin_unlock_irqrestore(&info->slock, flags);

}



static void mxser_start(struct tty_struct *tty)

{

	struct mxser_port *info = tty->driver_data;

	unsigned long flags;



	spin_lock_irqsave(&info->slock, flags);

	guard(spinlock_irqsave)(&info->slock);

	if (!kfifo_is_empty(&info->port.xmit_fifo))

		__mxser_start_tx(info);

	spin_unlock_irqrestore(&info->slock, flags);

}



static void mxser_set_termios(struct tty_struct *tty,

			      const struct ktermios *old_termios)

{

	struct mxser_port *info = tty->driver_data;

	unsigned long flags;



	spin_lock_irqsave(&info->slock, flags);

	scoped_guard(spinlock_irqsave, &info->slock)

		mxser_change_speed(tty, old_termios);

	spin_unlock_irqrestore(&info->slock, flags);



	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {

		tty->hw_stopped = false;
@@ -1367,9 +1328,8 @@ static void mxser_set_termios(struct tty_struct *tty, 
		tty->flow.stopped = 0;



		if (info->board->must_hwid) {

			spin_lock_irqsave(&info->slock, flags);

			guard(spinlock_irqsave)(&info->slock);

			mxser_must_set_rx_sw_flow_control(info->ioaddr, false);

			spin_unlock_irqrestore(&info->slock, flags);

		}



		mxser_start(tty);
@@ -1378,14 +1338,8 @@ static void mxser_set_termios(struct tty_struct *tty, 


static bool mxser_tx_empty(struct mxser_port *info)

{

	unsigned long flags;

	u8 lsr;



	spin_lock_irqsave(&info->slock, flags);

	lsr = inb(info->ioaddr + UART_LSR);

	spin_unlock_irqrestore(&info->slock, flags);



	return !(lsr & UART_LSR_TEMT);

	guard(spinlock_irqsave)(&info->slock);

	return !(inb(info->ioaddr + UART_LSR) & UART_LSR_TEMT);

}



/*
@@ -1459,17 +1413,15 @@ static void mxser_hangup(struct tty_struct *tty) 
static int mxser_rs_break(struct tty_struct *tty, int break_state)

{

	struct mxser_port *info = tty->driver_data;

	unsigned long flags;

	u8 lcr;



	spin_lock_irqsave(&info->slock, flags);

	guard(spinlock_irqsave)(&info->slock);

	lcr = inb(info->ioaddr + UART_LCR);

	if (break_state == -1)

		lcr |= UART_LCR_SBC;

	else

		lcr &= ~UART_LCR_SBC;

	outb(lcr, info->ioaddr + UART_LCR);

	spin_unlock_irqrestore(&info->slock, flags);



	return 0;

}
@@ -1672,12 +1624,11 @@ static irqreturn_t mxser_interrupt(int irq, void *dev_id) 
			port = &brd->ports[i];



			int_cnt = 0;

			spin_lock(&port->slock);

			guard(spinlock)(&port->slock);

			do {

				if (mxser_port_isr(port))

					break;

			} while (int_cnt++ < MXSER_ISR_PASS_LIMIT);

			spin_unlock(&port->slock);

		}

	}