On Thu, Jan 17, 2019 at 10:38:13AM +0100, Rafael J. Wysocki wrote: >On Thu, Jan 17, 2019 at 6:57 AM Wei Yang <richardw.y...@linux.intel.com> wrote: >> >> As the description of struct device_private says, it stores data which >> is private to driver core. And it already has similar fields like: >> knode_parent, knode_driver, knode_driver and knode_bus. This look it is >> more proper to put knode_class together with those fields to make it >> private to driver core. >> >> This patch move device->knode_class to device_private to make it comply >> with code convention. >> >> Signed-off-by: Wei Yang <richardw.y...@linux.intel.com> > >As a rule, I'm not a big fan of changes like this, because the only >reason for doing it seems to be aesthetics and it may be problematic >for people doing various types of backports, live patching etc, but >this particular one makes sense to me.
Rafael, Thanks for your comment. To be honest, I didn't realized the trouble it will introduce to backport and live patching. :-) > >> --- >> drivers/base/base.h | 4 ++++ >> drivers/base/class.c | 12 ++++++++---- >> drivers/base/core.c | 4 ++-- >> include/linux/device.h | 1 - >> 4 files changed, 14 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/base/base.h b/drivers/base/base.h >> index 7a419a7a6235..37329a668935 100644 >> --- a/drivers/base/base.h >> +++ b/drivers/base/base.h >> @@ -60,6 +60,7 @@ struct driver_private { >> * @knode_parent - node in sibling list >> * @knode_driver - node in driver list >> * @knode_bus - node in bus list >> + * @knode_class - node in class list >> * @deferred_probe - entry in deferred_probe_list which is used to retry the >> * binding of drivers which were unable to get all the resources needed >> by >> * the device; typically because it depends on another driver getting >> @@ -74,6 +75,7 @@ struct device_private { >> struct klist_node knode_parent; >> struct klist_node knode_driver; >> struct klist_node knode_bus; >> + struct klist_node knode_class; >> struct list_head deferred_probe; >> struct device *device; >> }; >> @@ -83,6 +85,8 @@ struct device_private { >> container_of(obj, struct device_private, knode_driver) >> #define to_device_private_bus(obj) \ >> container_of(obj, struct device_private, knode_bus) >> +#define to_device_private_class(obj) \ >> + container_of(obj, struct device_private, knode_class) >> >> /* initialisation functions */ >> extern int devices_init(void); >> diff --git a/drivers/base/class.c b/drivers/base/class.c >> index 54def4e02f00..df7fde599407 100644 >> --- a/drivers/base/class.c >> +++ b/drivers/base/class.c >> @@ -119,14 +119,16 @@ static void class_put(struct class *cls) >> >> static void klist_class_dev_get(struct klist_node *n) >> { >> - struct device *dev = container_of(n, struct device, knode_class); >> + struct device_private *p = to_device_private_class(n); >> + struct device *dev = p->device; > >the > >p = to_device_private_class(n) >dev = p->device > >pattern is repeated below for at least a couple of times. > >Care to add a static helper for this to reduce the code duplication somewhat? > Yep, this is reasonable. Let me put them in a helper. >> >> get_device(dev); >> } >> >> static void klist_class_dev_put(struct klist_node *n) >> { >> - struct device *dev = container_of(n, struct device, knode_class); >> + struct device_private *p = to_device_private_class(n); >> + struct device *dev = p->device; >> >> put_device(dev); >> } >> @@ -277,7 +279,7 @@ void class_dev_iter_init(struct class_dev_iter *iter, >> struct class *class, >> struct klist_node *start_knode = NULL; >> >> if (start) >> - start_knode = &start->knode_class; >> + start_knode = &start->p->knode_class; >> klist_iter_init_node(&class->p->klist_devices, &iter->ki, >> start_knode); >> iter->type = type; >> } >> @@ -298,13 +300,15 @@ EXPORT_SYMBOL_GPL(class_dev_iter_init); >> struct device *class_dev_iter_next(struct class_dev_iter *iter) >> { >> struct klist_node *knode; >> + struct device_private *p; >> struct device *dev; >> >> while (1) { >> knode = klist_next(&iter->ki); >> if (!knode) >> return NULL; >> - dev = container_of(knode, struct device, knode_class); >> + p = to_device_private_class(knode); >> + dev = p->device; >> if (!iter->type || iter->type == dev->type) >> return dev; >> } >> diff --git a/drivers/base/core.c b/drivers/base/core.c >> index 04bbcd779e11..a624d27d11c0 100644 >> --- a/drivers/base/core.c >> +++ b/drivers/base/core.c >> @@ -1932,7 +1932,7 @@ int device_add(struct device *dev) >> if (dev->class) { >> mutex_lock(&dev->class->p->mutex); >> /* tie the class to the device */ >> - klist_add_tail(&dev->knode_class, >> + klist_add_tail(&dev->p->knode_class, >> &dev->class->p->klist_devices); >> >> /* notify any interfaces that the device is here */ >> @@ -2069,7 +2069,7 @@ void device_del(struct device *dev) >> if (class_intf->remove_dev) >> class_intf->remove_dev(dev, class_intf); >> /* remove the device from the class list */ >> - klist_del(&dev->knode_class); >> + klist_del(&dev->p->knode_class); >> mutex_unlock(&dev->class->p->mutex); >> } >> device_remove_file(dev, &dev_attr_uevent); >> diff --git a/include/linux/device.h b/include/linux/device.h >> index 1b25c7a43f4c..040e97669f94 100644 >> --- a/include/linux/device.h >> +++ b/include/linux/device.h >> @@ -1035,7 +1035,6 @@ struct device { >> spinlock_t devres_lock; >> struct list_head devres_head; >> >> - struct klist_node knode_class; >> struct class *class; >> const struct attribute_group **groups; /* optional groups */ >> >> -- >> 2.19.1 >> -- Wei Yang Help you, Help me