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- /* SPDX-License-Identifier: GPL-2.0-only */
- #ifndef __LINUX_DEVM_HELPERS_H
- #define __LINUX_DEVM_HELPERS_H
- /*
- * Functions which do automatically cancel operations or release resources upon
- * driver detach.
- *
- * These should be helpful to avoid mixing the manual and devm-based resource
- * management which can be source of annoying, rarely occurring,
- * hard-to-reproduce bugs.
- *
- * Please take into account that devm based cancellation may be performed some
- * time after the remove() is ran.
- *
- * Thus mixing devm and manual resource management can easily cause problems
- * when unwinding operations with dependencies. IRQ scheduling a work in a queue
- * is typical example where IRQs are often devm-managed and WQs are manually
- * cleaned at remove(). If IRQs are not manually freed at remove() (and this is
- * often the case when we use devm for IRQs) we have a period of time after
- * remove() - and before devm managed IRQs are freed - where new IRQ may fire
- * and schedule a work item which won't be cancelled because remove() was
- * already ran.
- */
- #include <linux/device.h>
- #include <linux/workqueue.h>
- static inline void devm_delayed_work_drop(void *res)
- {
- cancel_delayed_work_sync(res);
- }
- /**
- * devm_delayed_work_autocancel - Resource-managed delayed work allocation
- * @dev: Device which lifetime work is bound to
- * @w: Work item to be queued
- * @worker: Worker function
- *
- * Initialize delayed work which is automatically cancelled when driver is
- * detached. A few drivers need delayed work which must be cancelled before
- * driver is detached to avoid accessing removed resources.
- * devm_delayed_work_autocancel() can be used to omit the explicit
- * cancelleation when driver is detached.
- */
- static inline int devm_delayed_work_autocancel(struct device *dev,
- struct delayed_work *w,
- work_func_t worker)
- {
- INIT_DELAYED_WORK(w, worker);
- return devm_add_action(dev, devm_delayed_work_drop, w);
- }
- static inline void devm_work_drop(void *res)
- {
- cancel_work_sync(res);
- }
- /**
- * devm_work_autocancel - Resource-managed work allocation
- * @dev: Device which lifetime work is bound to
- * @w: Work to be added (and automatically cancelled)
- * @worker: Worker function
- *
- * Initialize work which is automatically cancelled when driver is detached.
- * A few drivers need to queue work which must be cancelled before driver
- * is detached to avoid accessing removed resources.
- * devm_work_autocancel() can be used to omit the explicit
- * cancelleation when driver is detached.
- */
- static inline int devm_work_autocancel(struct device *dev,
- struct work_struct *w,
- work_func_t worker)
- {
- INIT_WORK(w, worker);
- return devm_add_action(dev, devm_work_drop, w);
- }
- #endif
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