Commit abcd8632 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Greg Kroah-Hartman
Browse files

serial: core: Extract uart_alloc_xmit_buf() and uart_free_xmit_buf() 



After conversion to the kfifo, it becomes possible to extract two helper
functions for better maintenance and code deduplication. Do it here.

Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240409174057.1104262-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5f1149d2

drivers/tty/serial/serial_core.c

+54 −44
Original line number Diff line number Diff line
@@ -243,25 +243,12 @@ static void uart_change_line_settings(struct tty_struct *tty, struct uart_state 
	uart_port_unlock_irq(uport);

}



/*

 * Startup the port.  This will be called once per open.  All calls

 * will be serialised by the per-port mutex.

 */

static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,

			     bool init_hw)

static int uart_alloc_xmit_buf(struct tty_port *port)

{

	struct uart_port *uport = uart_port_check(state);

	struct uart_state *state = container_of(port, struct uart_state, port);

	struct uart_port *uport;

	unsigned long flags;

	unsigned long page;

	int retval = 0;



	if (uport->type == PORT_UNKNOWN)

		return 1;



	/*

	 * Make sure the device is in D0 state.

	 */

	uart_change_pm(state, UART_PM_STATE_ON);



	/*

	 * Initialise and allocate the transmit and temporary
@@ -271,7 +258,7 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, 
	if (!page)

		return -ENOMEM;



	uart_port_lock(state, flags);

	uport = uart_port_lock(state, flags);

	if (!state->port.xmit_buf) {

		state->port.xmit_buf = (unsigned char *)page;

		kfifo_init(&state->port.xmit_fifo, state->port.xmit_buf,
@@ -281,11 +268,58 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, 
		uart_port_unlock(uport, flags);

		/*

		 * Do not free() the page under the port lock, see

		 * uart_shutdown().

		 * uart_free_xmit_buf().

		 */

		free_page(page);

	}



	return 0;

}



static void uart_free_xmit_buf(struct tty_port *port)

{

	struct uart_state *state = container_of(port, struct uart_state, port);

	struct uart_port *uport;

	unsigned long flags;

	char *xmit_buf;



	/*

	 * Do not free() the transmit buffer page under the port lock since

	 * this can create various circular locking scenarios. For instance,

	 * console driver may need to allocate/free a debug object, which

	 * can end up in printk() recursion.

	 */

	uport = uart_port_lock(state, flags);

	xmit_buf = port->xmit_buf;

	port->xmit_buf = NULL;

	INIT_KFIFO(port->xmit_fifo);

	uart_port_unlock(uport, flags);



	free_page((unsigned long)xmit_buf);

}



/*

 * Startup the port.  This will be called once per open.  All calls

 * will be serialised by the per-port mutex.

 */

static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,

			     bool init_hw)

{

	struct uart_port *uport = uart_port_check(state);

	int retval;



	if (uport->type == PORT_UNKNOWN)

		return 1;



	/*

	 * Make sure the device is in D0 state.

	 */

	uart_change_pm(state, UART_PM_STATE_ON);



	retval = uart_alloc_xmit_buf(&state->port);

	if (retval)

		return retval;



	retval = uport->ops->startup(uport);

	if (retval == 0) {

		if (uart_console(uport) && uport->cons->cflag) {
@@ -347,8 +381,6 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) 
{

	struct uart_port *uport = uart_port_check(state);

	struct tty_port *port = &state->port;

	unsigned long flags;

	char *xmit_buf = NULL;



	/*

	 * Set the TTY IO error marker
@@ -381,19 +413,7 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) 
	 */

	tty_port_set_suspended(port, false);



	/*

	 * Do not free() the transmit buffer page under the port lock since

	 * this can create various circular locking scenarios. For instance,

	 * console driver may need to allocate/free a debug object, which

	 * can endup in printk() recursion.

	 */

	uart_port_lock(state, flags);

	xmit_buf = port->xmit_buf;

	port->xmit_buf = NULL;

	INIT_KFIFO(port->xmit_fifo);

	uart_port_unlock(uport, flags);



	free_page((unsigned long)xmit_buf);

	uart_free_xmit_buf(port);

}



/**
@@ -1747,7 +1767,6 @@ static void uart_tty_port_shutdown(struct tty_port *port) 
{

	struct uart_state *state = container_of(port, struct uart_state, port);

	struct uart_port *uport = uart_port_check(state);

	char *buf;



	/*

	 * At this point, we stop accepting input.  To do this, we
@@ -1769,16 +1788,7 @@ static void uart_tty_port_shutdown(struct tty_port *port) 
	 */

	tty_port_set_suspended(port, false);



	/*

	 * Free the transmit buffer.

	 */

	uart_port_lock_irq(uport);

	buf = port->xmit_buf;

	port->xmit_buf = NULL;

	INIT_KFIFO(port->xmit_fifo);

	uart_port_unlock_irq(uport);



	free_page((unsigned long)buf);

	uart_free_xmit_buf(port);



	uart_change_pm(state, UART_PM_STATE_OFF);

}