Commit 47d8b4c1 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpio: add SRCU infrastructure to struct gpio_device 



Add the SRCU struct to GPIO device. It will be used to serialize access
to the GPIO chip pointer. Initialize and clean it up where applicable.

Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Acked-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent 8a5b477b

drivers/gpio/gpiolib.c

+10 −3
Original line number Diff line number Diff line
@@ -680,6 +680,7 @@ static void gpiodev_release(struct device *dev) 
	ida_free(&gpio_ida, gdev->id);

	kfree_const(gdev->label);

	kfree(gdev->descs);

	cleanup_srcu_struct(&gdev->srcu);

	kfree(gdev);

}
@@ -948,6 +949,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, 
	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);

	init_rwsem(&gdev->sem);



	ret = init_srcu_struct(&gdev->srcu);

	if (ret)

		goto err_remove_from_list;



#ifdef CONFIG_PINCTRL

	INIT_LIST_HEAD(&gdev->pin_ranges);

#endif
@@ -955,15 +960,15 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, 
	if (gc->names) {

		ret = gpiochip_set_desc_names(gc);

		if (ret)

			goto err_remove_from_list;

			goto err_cleanup_gdev_srcu;

	}

	ret = gpiochip_set_names(gc);

	if (ret)

		goto err_remove_from_list;

		goto err_cleanup_gdev_srcu;



	ret = gpiochip_init_valid_mask(gc);

	if (ret)

		goto err_remove_from_list;

		goto err_cleanup_gdev_srcu;



	ret = of_gpiochip_add(gc);

	if (ret)
@@ -1038,6 +1043,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, 
err_free_gpiochip_mask:

	gpiochip_remove_pin_ranges(gc);

	gpiochip_free_valid_mask(gc);

err_cleanup_gdev_srcu:

	cleanup_srcu_struct(&gdev->srcu);

err_remove_from_list:

	scoped_guard(mutex, &gpio_devices_lock)

		list_del_rcu(&gdev->list);

drivers/gpio/gpiolib.h

+2 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ 
 * @sem: protects the structure from a NULL-pointer dereference of @chip by

 *       user-space operations when the device gets unregistered during

 *       a hot-unplug event

 * @srcu: protects the pointer to the underlying GPIO chip

 * @pin_ranges: range of pins served by the GPIO driver

 *

 * This state container holds most of the runtime variable data
@@ -73,6 +74,7 @@ struct gpio_device { 
	struct blocking_notifier_head line_state_notifier;

	struct blocking_notifier_head device_notifier;

	struct rw_semaphore	sem;

	struct srcu_struct	srcu;



#ifdef CONFIG_PINCTRL

	/*