| Message ID | 20250204073501.278248-2-herve.codina@bootlin.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | Add support for the PCI host bridge device-tree node creation. | expand |
On Tue, Feb 04, 2025 at 08:34:56AM +0100, Herve Codina wrote: > An of_node can be set to a device using device_set_node(). > This function cannot prevent any of_node and/or fwnode overwrites. > > When adding an of_node on an already present device, the following > operations need to be done: > - Attach the of_node if no of_node were already attached > - Attach the of_node as a fwnode if no fwnode were already attached > > This is the purpose of device_add_of_node(). > device_remove_of_node() reverts the operations done by > device_add_of_node(). > > Signed-off-by: Herve Codina <herve.codina@bootlin.com> > --- > drivers/base/core.c | 61 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/device.h | 2 ++ > 2 files changed, 63 insertions(+) > Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On Tue, 4 Feb 2025 08:34:56 +0100 Herve Codina <herve.codina@bootlin.com> wrote: > An of_node can be set to a device using device_set_node(). > This function cannot prevent any of_node and/or fwnode overwrites. > > When adding an of_node on an already present device, the following > operations need to be done: > - Attach the of_node if no of_node were already attached > - Attach the of_node as a fwnode if no fwnode were already attached > > This is the purpose of device_add_of_node(). > device_remove_of_node() reverts the operations done by > device_add_of_node(). > > Signed-off-by: Herve Codina <herve.codina@bootlin.com> A few passing comments. Not suggestions to actually change anything at this stage though. Maybe a potential follow up if you think it's a good idea. > --- > drivers/base/core.c | 61 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/device.h | 2 ++ > 2 files changed, 63 insertions(+) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 5a1f05198114..d1b044af64de 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -5170,6 +5170,67 @@ void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode) > } > EXPORT_SYMBOL_GPL(set_secondary_fwnode); > > +/** > + * device_remove_of_node - Remove an of_node from a device > + * @dev: device whose device-tree node is being removed > + */ > +void device_remove_of_node(struct device *dev) > +{ > + dev = get_device(dev); > + if (!dev) > + return; Maybe use struct device *d __free(put_device) = get_device(dev); if (!d->of_node); return; Not a reason to respin though! > + > + if (!dev->of_node) > + goto end; > + > + if (dev->fwnode == of_fwnode_handle(dev->of_node)) > + dev->fwnode = NULL; > + > + of_node_put(dev->of_node); > + dev->of_node = NULL; > + > +end: > + put_device(dev); > +} > +EXPORT_SYMBOL_GPL(device_remove_of_node); > + > +/** > + * device_add_of_node - Add an of_node to an existing device > + * @dev: device whose device-tree node is being added > + * @of_node: of_node to add > + * > + * Return: 0 on success or error code on failure. > + */ > +int device_add_of_node(struct device *dev, struct device_node *of_node) > +{ > + int ret; > + > + if (!of_node) > + return -EINVAL; > + > + dev = get_device(dev); Likewise could use __free() magic here as well for slight simpliciations. > + if (!dev) > + return -EINVAL; > + > + if (dev->of_node) { > + dev_err(dev, "Cannot replace node %pOF with %pOF\n", > + dev->of_node, of_node); > + ret = -EBUSY; > + goto end; > + } > + > + dev->of_node = of_node_get(of_node); > + > + if (!dev->fwnode) > + dev->fwnode = of_fwnode_handle(of_node); > + > + ret = 0; > +end: > + put_device(dev); > + return ret; > +} > +EXPORT_SYMBOL_GPL(device_add_of_node); > + > /** > * device_set_of_node_from_dev - reuse device-tree node of another device > * @dev: device whose device-tree node is being set > diff --git a/include/linux/device.h b/include/linux/device.h > index 80a5b3268986..1244e5892292 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -1191,6 +1191,8 @@ int device_online(struct device *dev); > void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode); > void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode); > void device_set_node(struct device *dev, struct fwnode_handle *fwnode); > +int device_add_of_node(struct device *dev, struct device_node *of_node); > +void device_remove_of_node(struct device *dev); > void device_set_of_node_from_dev(struct device *dev, const struct device *dev2); > > static inline struct device_node *dev_of_node(struct device *dev)
Hi Jonathan, On Wed, 19 Feb 2025 15:59:01 +0000 Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: ... > > Signed-off-by: Herve Codina <herve.codina@bootlin.com> > A few passing comments. Not suggestions to actually change anything > at this stage though. Maybe a potential follow up if you think it's > a good idea. > ... > > +void device_remove_of_node(struct device *dev) > > +{ > > + dev = get_device(dev); > > + if (!dev) > > + return; > Maybe use > struct device *d __free(put_device) = get_device(dev); > > if (!d->of_node); > return; > > Not a reason to respin though! > > ... > > +int device_add_of_node(struct device *dev, struct device_node *of_node) > > +{ > > + int ret; > > + > > + if (!of_node) > > + return -EINVAL; > > + > > + dev = get_device(dev); > > Likewise could use __free() magic here as well for slight simpliciations. > I see. Indeed, the __free(put_device) can be an improvement in core.c I think that this has to be done out of this series in a more globally way because put_device() is used in several place in this file and having a mix between __free(put_device) and put_device() calls in a goto label is not the best solution. For this reason, as you proposed except if someone else pushes in the __free(put_device) direction in functions introduced in this patch, I prefer to keep this patch as it is. Thanks for your feedback, Hervé
diff --git a/drivers/base/core.c b/drivers/base/core.c index 5a1f05198114..d1b044af64de 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -5170,6 +5170,67 @@ void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode) } EXPORT_SYMBOL_GPL(set_secondary_fwnode); +/** + * device_remove_of_node - Remove an of_node from a device + * @dev: device whose device-tree node is being removed + */ +void device_remove_of_node(struct device *dev) +{ + dev = get_device(dev); + if (!dev) + return; + + if (!dev->of_node) + goto end; + + if (dev->fwnode == of_fwnode_handle(dev->of_node)) + dev->fwnode = NULL; + + of_node_put(dev->of_node); + dev->of_node = NULL; + +end: + put_device(dev); +} +EXPORT_SYMBOL_GPL(device_remove_of_node); + +/** + * device_add_of_node - Add an of_node to an existing device + * @dev: device whose device-tree node is being added + * @of_node: of_node to add + * + * Return: 0 on success or error code on failure. + */ +int device_add_of_node(struct device *dev, struct device_node *of_node) +{ + int ret; + + if (!of_node) + return -EINVAL; + + dev = get_device(dev); + if (!dev) + return -EINVAL; + + if (dev->of_node) { + dev_err(dev, "Cannot replace node %pOF with %pOF\n", + dev->of_node, of_node); + ret = -EBUSY; + goto end; + } + + dev->of_node = of_node_get(of_node); + + if (!dev->fwnode) + dev->fwnode = of_fwnode_handle(of_node); + + ret = 0; +end: + put_device(dev); + return ret; +} +EXPORT_SYMBOL_GPL(device_add_of_node); + /** * device_set_of_node_from_dev - reuse device-tree node of another device * @dev: device whose device-tree node is being set diff --git a/include/linux/device.h b/include/linux/device.h index 80a5b3268986..1244e5892292 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1191,6 +1191,8 @@ int device_online(struct device *dev); void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode); void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode); void device_set_node(struct device *dev, struct fwnode_handle *fwnode); +int device_add_of_node(struct device *dev, struct device_node *of_node); +void device_remove_of_node(struct device *dev); void device_set_of_node_from_dev(struct device *dev, const struct device *dev2); static inline struct device_node *dev_of_node(struct device *dev)
An of_node can be set to a device using device_set_node(). This function cannot prevent any of_node and/or fwnode overwrites. When adding an of_node on an already present device, the following operations need to be done: - Attach the of_node if no of_node were already attached - Attach the of_node as a fwnode if no fwnode were already attached This is the purpose of device_add_of_node(). device_remove_of_node() reverts the operations done by device_add_of_node(). Signed-off-by: Herve Codina <herve.codina@bootlin.com> --- drivers/base/core.c | 61 ++++++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 2 ++ 2 files changed, 63 insertions(+)