[RFC PATCH 1/7] drivers: base: Add resource managed version of delayed work init
From: Matti Vaittinen <hidden>
Date: 2021-02-13 12:00:18
Also in:
linux-arm-msm, linux-hwmon, linux-watchdog, lkml, platform-driver-x86
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
A few drivers which need a delayed work-queue must cancel work at exit. Some of those implement remove solely for this purpose. Help drivers to avoid unnecessary remove and error-branch implementation by adding managed verision of delayed work initialization Signed-off-by: Matti Vaittinen <redacted> --- drivers/base/devres.c | 33 +++++++++++++++++++++++++++++++++ include/linux/device.h | 5 +++++ 2 files changed, 38 insertions(+)
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index fb9d5289a620..2879595bb5a4 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c@@ -1231,3 +1231,36 @@ void devm_free_percpu(struct device *dev, void __percpu *pdata) (void *)pdata)); } EXPORT_SYMBOL_GPL(devm_free_percpu); + +static void dev_delayed_work_drop(struct device *dev, void *res) +{ + cancel_delayed_work_sync(*(struct delayed_work **)res); +} + +/** + * devm_delayed_work_autocancel - Resource-managed work allocation + * @dev: Device which lifetime work is bound to + * @pdata: work to be cancelled when device exits + * + * Initialize work which is automatically cancelled when device exits. + * A few drivers need delayed work which must be cancelled before driver + * is unload to avoid accessing removed resources. + * devm_delayed_work_autocancel() can be used to omit the explicit + * cancelleation when driver is unload. + */ +int devm_delayed_work_autocancel(struct device *dev, struct delayed_work *w, + void (*worker)(struct work_struct *work)) +{ + struct delayed_work **ptr; + + ptr = devres_alloc(dev_delayed_work_drop, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + INIT_DELAYED_WORK(w, worker); + *ptr = w; + devres_add(dev, ptr); + + return 0; +} +EXPORT_SYMBOL_GPL(devm_delayed_work_autocancel);
diff --git a/include/linux/device.h b/include/linux/device.h
index 1779f90eeb4c..192456198de7 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h@@ -27,6 +27,7 @@ #include <linux/uidgid.h> #include <linux/gfp.h> #include <linux/overflow.h> +#include <linux/workqueue.h> #include <linux/device/bus.h> #include <linux/device/class.h> #include <linux/device/driver.h>
@@ -249,6 +250,10 @@ void __iomem *devm_of_iomap(struct device *dev, struct device_node *node, int index, resource_size_t *size); +/* delayed work which is cancelled when driver exits */ +int devm_delayed_work_autocancel(struct device *dev, struct delayed_work *w, + void (*worker)(struct work_struct *work)); + /* allows to add/remove a custom action to devres stack */ int devm_add_action(struct device *dev, void (*action)(void *), void *data); void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
--
2.25.4
--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND
~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]