mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-31 16:38:12 +00:00
7a2c4cc537
A few drivers which need a work-queue must cancel work at driver detach. Some of those implement remove() solely for this purpose. Help drivers to avoid unnecessary remove and error-branch implementation by adding managed verision of work initialization. This will also help drivers to avoid mixing manual and devm based unwinding when other resources are handled by devm. Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/94ff4175e7f2ff134ed2fa7d6e7641005cc9784b.1623146580.git.matti.vaittinen@fi.rohmeurope.com Signed-off-by: Hans de Goede <hdegoede@redhat.com>
79 lines
2.7 KiB
C
79 lines
2.7 KiB
C
/* 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
|