Commit 99fc860f authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
Browse files

serial: 8250: extract serial_get_or_create_irq_info() 



This find-or-create-irq part of the serial_link_irq_chain()'s code is
logically bounded and self-standing. For easier-to-follow code flow,
extract the code to a separate function:
serial_get_or_create_irq_info().

This allows for an easier found-an-irq handling -- simple jump to the
'unlock' label and return. That results in one less 'if' levels.

Note when using guard()s in the upcoming patchset, the label can dropped
altogether.

Signed-off-by: default avatar"Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250611100319.186924-28-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 465fd2fc

drivers/tty/serial/8250/8250_core.c

+26 −11
Original line number Diff line number Diff line
@@ -129,11 +129,15 @@ static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up) 
	}

}



static int serial_link_irq_chain(struct uart_8250_port *up)

/*

 * Either:

 * - find the corresponding info in the hashtable and return it, or

 * - allocate a new one, add it to the hashtable and return it.

 */

static struct irq_info *serial_get_or_create_irq_info(const struct uart_8250_port *up)

{

	struct hlist_head *h;

	struct irq_info *i;

	int ret;



	mutex_lock(&hash_mutex);
@@ -141,20 +145,31 @@ static int serial_link_irq_chain(struct uart_8250_port *up) 


	hlist_for_each_entry(i, h, node)

		if (i->irq == up->port.irq)

			break;

			goto unlock;



	i = kzalloc(sizeof(*i), GFP_KERNEL);

	if (i == NULL) {

		i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);

		if (i == NULL) {

			mutex_unlock(&hash_mutex);

			return -ENOMEM;

		i = ERR_PTR(-ENOMEM);

		goto unlock;

	}

	spin_lock_init(&i->lock);

	i->irq = up->port.irq;

	hlist_add_head(&i->node, h);

	}

unlock:

	mutex_unlock(&hash_mutex);



	return i;

}



static int serial_link_irq_chain(struct uart_8250_port *up)

{

	struct irq_info *i;

	int ret;



	i = serial_get_or_create_irq_info(up);

	if (IS_ERR(i))

		return PTR_ERR(i);



	spin_lock_irq(&i->lock);



	if (i->head) {