| Message ID | 1438009443-55317-6-git-send-email-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Mon, 27 Jul 2015, Andy Shevchenko wrote: > The new function device_for_each_child_reverse() is helpful to traverse the > registered devices in a reversed order, e.g. in the case when an operation on > each device should be done first on the last added device, then on one before > last and so on. > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > --- > drivers/base/core.c | 43 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/device.h | 2 ++ > 2 files changed, 45 insertions(+) Applied, thanks. Pull request to follow. > diff --git a/drivers/base/core.c b/drivers/base/core.c > index dafae6d..7d62795 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -1252,6 +1252,19 @@ void device_unregister(struct device *dev) > } > EXPORT_SYMBOL_GPL(device_unregister); > > +static struct device *prev_device(struct klist_iter *i) > +{ > + struct klist_node *n = klist_prev(i); > + struct device *dev = NULL; > + struct device_private *p; > + > + if (n) { > + p = to_device_private_parent(n); > + dev = p->device; > + } > + return dev; > +} > + > static struct device *next_device(struct klist_iter *i) > { > struct klist_node *n = klist_next(i); > @@ -1341,6 +1354,36 @@ int device_for_each_child(struct device *parent, void *data, > EXPORT_SYMBOL_GPL(device_for_each_child); > > /** > + * device_for_each_child_reverse - device child iterator in reversed order. > + * @parent: parent struct device. > + * @fn: function to be called for each device. > + * @data: data for the callback. > + * > + * Iterate over @parent's child devices, and call @fn for each, > + * passing it @data. > + * > + * We check the return of @fn each time. If it returns anything > + * other than 0, we break out and return that value. > + */ > +int device_for_each_child_reverse(struct device *parent, void *data, > + int (*fn)(struct device *dev, void *data)) > +{ > + struct klist_iter i; > + struct device *child; > + int error = 0; > + > + if (!parent->p) > + return 0; > + > + klist_iter_init(&parent->p->klist_children, &i); > + while ((child = prev_device(&i)) && !error) > + error = fn(child, data); > + klist_iter_exit(&i); > + return error; > +} > +EXPORT_SYMBOL_GPL(device_for_each_child_reverse); > + > +/** > * device_find_child - device iterator for locating a particular device. > * @parent: parent struct device > * @match: Callback function to check device > diff --git a/include/linux/device.h b/include/linux/device.h > index a2b4ea7..9d212fe 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -959,6 +959,8 @@ extern int __must_check device_add(struct device *dev); > extern void device_del(struct device *dev); > extern int device_for_each_child(struct device *dev, void *data, > int (*fn)(struct device *dev, void *data)); > +extern int device_for_each_child_reverse(struct device *dev, void *data, > + int (*fn)(struct device *dev, void *data)); > extern struct device *device_find_child(struct device *dev, void *data, > int (*match)(struct device *dev, void *data)); > extern int device_rename(struct device *dev, const char *new_name);
diff --git a/drivers/base/core.c b/drivers/base/core.c index dafae6d..7d62795 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1252,6 +1252,19 @@ void device_unregister(struct device *dev) } EXPORT_SYMBOL_GPL(device_unregister); +static struct device *prev_device(struct klist_iter *i) +{ + struct klist_node *n = klist_prev(i); + struct device *dev = NULL; + struct device_private *p; + + if (n) { + p = to_device_private_parent(n); + dev = p->device; + } + return dev; +} + static struct device *next_device(struct klist_iter *i) { struct klist_node *n = klist_next(i); @@ -1341,6 +1354,36 @@ int device_for_each_child(struct device *parent, void *data, EXPORT_SYMBOL_GPL(device_for_each_child); /** + * device_for_each_child_reverse - device child iterator in reversed order. + * @parent: parent struct device. + * @fn: function to be called for each device. + * @data: data for the callback. + * + * Iterate over @parent's child devices, and call @fn for each, + * passing it @data. + * + * We check the return of @fn each time. If it returns anything + * other than 0, we break out and return that value. + */ +int device_for_each_child_reverse(struct device *parent, void *data, + int (*fn)(struct device *dev, void *data)) +{ + struct klist_iter i; + struct device *child; + int error = 0; + + if (!parent->p) + return 0; + + klist_iter_init(&parent->p->klist_children, &i); + while ((child = prev_device(&i)) && !error) + error = fn(child, data); + klist_iter_exit(&i); + return error; +} +EXPORT_SYMBOL_GPL(device_for_each_child_reverse); + +/** * device_find_child - device iterator for locating a particular device. * @parent: parent struct device * @match: Callback function to check device diff --git a/include/linux/device.h b/include/linux/device.h index a2b4ea7..9d212fe 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -959,6 +959,8 @@ extern int __must_check device_add(struct device *dev); extern void device_del(struct device *dev); extern int device_for_each_child(struct device *dev, void *data, int (*fn)(struct device *dev, void *data)); +extern int device_for_each_child_reverse(struct device *dev, void *data, + int (*fn)(struct device *dev, void *data)); extern struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); extern int device_rename(struct device *dev, const char *new_name);