* [PATCH v2 1/2] driver core: Introduce device_{add,remove}_of_node()
[not found] <20231130165700.685764-1-herve.codina@bootlin.com>
@ 2023-11-30 16:56 ` Herve Codina
2023-11-30 16:56 ` [PATCH v2 2/2] PCI: of: Attach created of_node to existing device Herve Codina
1 sibling, 0 replies; 3+ messages in thread
From: Herve Codina @ 2023-11-30 16:56 UTC (permalink / raw)
To: Greg Kroah-Hartman, Rafael J. Wysocki, Bjorn Helgaas, Lizhi Hou,
Rob Herring
Cc: Max Zhen, Sonal Santan, Stefano Stabellini, Jonathan Cameron,
linux-kernel, linux-pci, Allan Nielsen, Horatiu Vultur,
Steen Hegelund, Thomas Petazzoni, Herve Codina, stable
An of_node can be duplicated from an existing device using
device_set_of_node_from_dev() or initialized using device_set_node()
In both cases, these functions have to be called before the device_add()
call in order to have the of_node link created in the device sysfs
directory. Further more, these 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
- Create the of_node sysfs link if needed
This is the purpose of device_add_of_node().
device_remove_of_node() reverts the operations done by
device_add_of_node().
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
drivers/base/core.c | 74 ++++++++++++++++++++++++++++++++++++++++++
include/linux/device.h | 2 ++
2 files changed, 76 insertions(+)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 2926f3b1f868..ac026187ac6a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -5046,6 +5046,80 @@ 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;
+
+ sysfs_remove_link(&dev->kobj, "of_node");
+
+ 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
+ */
+void device_add_of_node(struct device *dev, struct device_node *of_node)
+{
+ int ret;
+
+ if (!of_node)
+ return;
+
+ dev = get_device(dev);
+ if (!dev)
+ return;
+
+ if (dev->of_node) {
+ dev_warn(dev, "Replace node %pOF with %pOF\n", dev->of_node, of_node);
+ device_remove_of_node(dev);
+ }
+
+ dev->of_node = of_node_get(of_node);
+
+ if (!dev->fwnode)
+ dev->fwnode = of_fwnode_handle(of_node);
+
+ if (!dev->p) {
+ /*
+ * device_add() was not previously called.
+ * The of_node link will be created when device_add() is called.
+ */
+ goto end;
+ }
+
+ /*
+ * device_add() was previously called and so the of_node link was not
+ * created by device_add_class_symlinks().
+ * Create this link now.
+ */
+ ret = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node");
+ if (ret)
+ dev_warn(dev, "Error %d creating of_node link\n", ret);
+
+end:
+ put_device(dev);
+}
+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 d7a72a8749ea..2b093e62907a 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1128,6 +1128,8 @@ int device_offline(struct device *dev);
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_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);
void device_set_node(struct device *dev, struct fwnode_handle *fwnode);
--
2.42.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH v2 2/2] PCI: of: Attach created of_node to existing device
[not found] <20231130165700.685764-1-herve.codina@bootlin.com>
2023-11-30 16:56 ` [PATCH v2 1/2] driver core: Introduce device_{add,remove}_of_node() Herve Codina
@ 2023-11-30 16:56 ` Herve Codina
2023-12-01 22:49 ` Bjorn Helgaas
1 sibling, 1 reply; 3+ messages in thread
From: Herve Codina @ 2023-11-30 16:56 UTC (permalink / raw)
To: Greg Kroah-Hartman, Rafael J. Wysocki, Bjorn Helgaas, Lizhi Hou,
Rob Herring
Cc: Max Zhen, Sonal Santan, Stefano Stabellini, Jonathan Cameron,
linux-kernel, linux-pci, Allan Nielsen, Horatiu Vultur,
Steen Hegelund, Thomas Petazzoni, Herve Codina, stable
The commit 407d1a51921e ("PCI: Create device tree node for bridge")
creates of_node for PCI devices.
During the insertion handling of these new DT nodes done by of_platform,
new devices (struct device) are created.
For each PCI devices a struct device is already present (created and
handled by the PCI core).
Having a second struct device to represent the exact same PCI device is
not correct.
On the of_node creation, tell the of_platform that there is no need to
create a device for this node (OF_POPULATED flag), link this newly
created of_node to the already present device and tell fwnode that the
device attached to this of_node is ready (fwnode_dev_initialized()).
With this fix, the of_node are available in the sysfs device tree:
/sys/devices/platform/soc/d0070000.pcie/
+ of_node -> .../devicetree/base/soc/pcie@d0070000
+ pci0000:00
+ 0000:00:00.0
+ of_node -> .../devicetree/base/soc/pcie@d0070000/pci@0,0
+ 0000:01:00.0
+ of_node -> .../devicetree/base/soc/pcie@d0070000/pci@0,0/dev@0,0
On the of_node removal, revert the operations.
Fixes: 407d1a51921e ("PCI: Create device tree node for bridge")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
drivers/pci/of.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 51e3dd0ea5ab..5afd2731e876 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -615,7 +615,8 @@ void of_pci_remove_node(struct pci_dev *pdev)
np = pci_device_to_OF_node(pdev);
if (!np || !of_node_check_flag(np, OF_DYNAMIC))
return;
- pdev->dev.of_node = NULL;
+
+ device_remove_of_node(&pdev->dev);
of_changeset_revert(np->data);
of_changeset_destroy(np->data);
@@ -668,12 +669,22 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
if (ret)
goto out_free_node;
+ /*
+ * This of_node will be added to an existing device.
+ * Avoid any device creation and use the existing device
+ */
+ of_node_set_flag(np, OF_POPULATED);
+ np->fwnode.dev = &pdev->dev;
+ fwnode_dev_initialized(&np->fwnode, true);
+
ret = of_changeset_apply(cset);
if (ret)
goto out_free_node;
np->data = cset;
- pdev->dev.of_node = np;
+
+ /* Add the of_node to the existing device */
+ device_add_of_node(&pdev->dev, np);
kfree(name);
return;
--
2.42.0
^ permalink raw reply related [flat|nested] 3+ messages in thread