From 47d8b4c1d868148c8fb51b785a89e58ca2d02c4d Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 5 Jan 2024 20:42:44 +0100 Subject: [PATCH] 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: Bartosz Golaszewski Reviewed-by: Linus Walleij Acked-by: Andy Shevchenko --- drivers/gpio/gpiolib.c | 13 ++++++++++--- drivers/gpio/gpiolib.h | 2 ++ 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 40052de2361c7..4e0c6df4a8803 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -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 @@ err_remove_of_chip: 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); diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 43ff4931e2c36..35d71e30c546c 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -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 /* -- 2.30.2