diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 01b6c9d9956f..4eeae9741a6e 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -46,6 +46,7 @@ * often but notifier_blocks will seldom be removed. */ +struct device; struct notifier_block; typedef int (*notifier_fn_t)(struct notifier_block *nb, @@ -145,8 +146,14 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh, struct notifier_block *nb); +int devm_atomic_notifier_chain_register(struct device *dev, + struct atomic_notifier_head *nh, + struct notifier_block *nb); extern int blocking_notifier_chain_register(struct blocking_notifier_head *nh, struct notifier_block *nb); +int devm_blocking_notifier_chain_register(struct device *dev, + struct blocking_notifier_head *nh, + struct notifier_block *nb); extern int raw_notifier_chain_register(struct raw_notifier_head *nh, struct notifier_block *nb); extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh, diff --git a/kernel/notifier.c b/kernel/notifier.c index 2f9fe7c30287..55fbd2be7407 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -1,4 +1,5 @@ // SPDX-License-Identifier: GPL-2.0-only +#include #include #include #include @@ -197,6 +198,58 @@ int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, } EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); +struct atomic_notifier_chain_devres { + struct atomic_notifier_head *nh; + struct notifier_block *nb; +}; + +static void devm_atomic_notifier_chain_unregister(struct device *dev, void *res) +{ + struct atomic_notifier_chain_devres *dr = res; + + atomic_notifier_chain_unregister(dr->nh, dr->nb); +} + +/** + * devm_atomic_notifier_chain_register - Device-managed atomic notifier registration + * @dev: Device to tie the notifier lifetime to + * @nh: Pointer to head of the atomic notifier chain + * @nb: New entry in notifier chain + * + * Adds a notifier to an atomic notifier chain and registers a cleanup + * action to automatically unregister it when @dev is unbound. + * + * Must be called in process context. + * + * Return: + * 0 on success, negative errno on error. + */ +int devm_atomic_notifier_chain_register(struct device *dev, + struct atomic_notifier_head *nh, + struct notifier_block *nb) +{ + struct atomic_notifier_chain_devres *dr; + int ret; + + dr = devres_alloc(devm_atomic_notifier_chain_unregister, + sizeof(*dr), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + ret = atomic_notifier_chain_register(nh, nb); + if (ret) { + devres_free(dr); + return ret; + } + + dr->nh = nh; + dr->nb = nb; + devres_add(dev, dr); + + return 0; +} +EXPORT_SYMBOL_GPL(devm_atomic_notifier_chain_register); + /** * atomic_notifier_call_chain - Call functions in an atomic notifier chain * @nh: Pointer to head of the atomic notifier chain @@ -349,6 +402,58 @@ int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh, } EXPORT_SYMBOL_GPL(blocking_notifier_call_chain_robust); +struct blocking_notifier_chain_devres { + struct blocking_notifier_head *nh; + struct notifier_block *nb; +}; + +static void devm_blocking_notifier_chain_unregister(struct device *dev, + void *res) +{ + struct blocking_notifier_chain_devres *dr = res; + + blocking_notifier_chain_unregister(dr->nh, dr->nb); +} + +/** + * devm_blocking_notifier_chain_register - Device-managed blocking notifier registration + * @dev: Device to tie the notifier lifetime to + * @nh: Pointer to head of the blocking notifier chain + * @nb: New entry in notifier chain + * + * Adds a notifier to a blocking notifier chain and registers a cleanup + * action to automatically unregister it when @dev is unbound. + * Must be called in process context. + * + * Return: + * 0 on success, negative errno on error. + */ +int devm_blocking_notifier_chain_register(struct device *dev, + struct blocking_notifier_head *nh, + struct notifier_block *nb) +{ + struct blocking_notifier_chain_devres *dr; + int ret; + + dr = devres_alloc(devm_blocking_notifier_chain_unregister, + sizeof(*dr), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + ret = blocking_notifier_chain_register(nh, nb); + if (ret) { + devres_free(dr); + return ret; + } + + dr->nh = nh; + dr->nb = nb; + devres_add(dev, dr); + + return 0; +} +EXPORT_SYMBOL_GPL(devm_blocking_notifier_chain_register); + /** * blocking_notifier_call_chain - Call functions in a blocking notifier chain * @nh: Pointer to head of the blocking notifier chain