gpiolib: switch the line state notifier to atomic

With everything else ready, we can now switch to using the atomic
notifier for line state events which will allow us to notify user-space
about direction changes from atomic context.

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241018-gpio-notify-in-kernel-events-v5-7-c79135e58a1c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 7759dca92f8bb381b701660bcd403cb3e7415575..cb4fb55e2696a1f1df47679b65be9823e2ce57cb 100644 (file)
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2729,8 +2729,8 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
        cdev->gdev = gpio_device_get(gdev);
 
        cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify;
-       ret = blocking_notifier_chain_register(&gdev->line_state_notifier,
-                                              &cdev->lineinfo_changed_nb);
+       ret = atomic_notifier_chain_register(&gdev->line_state_notifier,
+                                            &cdev->lineinfo_changed_nb);
        if (ret)
                goto out_free_bitmap;
 
@@ -2754,8 +2754,8 @@ out_unregister_device_notifier:
        blocking_notifier_chain_unregister(&gdev->device_notifier,
                                           &cdev->device_unregistered_nb);
 out_unregister_line_notifier:
-       blocking_notifier_chain_unregister(&gdev->line_state_notifier,
-                                          &cdev->lineinfo_changed_nb);
+       atomic_notifier_chain_unregister(&gdev->line_state_notifier,
+                                        &cdev->lineinfo_changed_nb);
 out_free_bitmap:
        gpio_device_put(gdev);
        bitmap_free(cdev->watched_lines);
@@ -2779,8 +2779,8 @@ static int gpio_chrdev_release(struct inode *inode, struct file *file)
 
        blocking_notifier_chain_unregister(&gdev->device_notifier,
                                           &cdev->device_unregistered_nb);
-       blocking_notifier_chain_unregister(&gdev->line_state_notifier,
-                                          &cdev->lineinfo_changed_nb);
+       atomic_notifier_chain_unregister(&gdev->line_state_notifier,
+                                        &cdev->lineinfo_changed_nb);
        bitmap_free(cdev->watched_lines);
        gpio_device_put(gdev);
        kfree(cdev);

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 807bee86afd5eb754bc68999760ff1c823db8595..83e85dbfdeed9dfc04144adeee56f886914e853f 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1026,7 +1026,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
                }
        }
 
-       BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
+       ATOMIC_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
        BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
 
        ret = init_srcu_struct(&gdev->srcu);
@@ -4098,8 +4098,8 @@ EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
 
 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
 {
-       blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
-                                    action, desc);
+       atomic_notifier_call_chain(&desc->gdev->line_state_notifier,
+                                  action, desc);
 }
 
 /**

diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 8737e164127837ba6dc0455561250750d3d6872f..a54be597d21a2843c6288585496df49e0584cad0 100644 (file)
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -72,7 +72,7 @@ struct gpio_device {
        const char              *label;
        void                    *data;
        struct list_head        list;
-       struct blocking_notifier_head line_state_notifier;
+       struct atomic_notifier_head line_state_notifier;
        struct workqueue_struct *line_state_wq;
        struct blocking_notifier_head device_notifier;
        struct srcu_struct      srcu;