Merge branch 'pci/devtree-create'

- Add device_add_of_node() to set dev->of_node and dev->fwnode only if they
  haven't been set already (Herve Codina)

- Allow of_pci_set_address() to set the DT address property for root bus
  nodes, where there is no PCI bridge to supply the PCI bus/device/function
  part of the property (Herve Codina)

- Create DT nodes for PCI host bridges to enable loading device tree
  overlays to create platform devices for PCI devices that have several
  features that require multiple drivers (Herve Codina)

* pci/devtree-create:
  PCI: of: Create device tree PCI host bridge node
  PCI: of_property: Constify parameter in of_pci_get_addr_flags()
  PCI: of_property: Add support for NULL pdev in of_pci_set_address()
  PCI: of: Use device_{add,remove}_of_node() to attach of_node to existing device
  driver core: Introduce device_{add,remove}_of_node()

7 files changed, 300 insertions, 7 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 5a1f05198114..49eb5aaf19cc 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -5171,6 +5171,67 @@ 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
  * @dev2: device whose device-tree node is being reused
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 7a806f5c0d20..762d4e3fde3c 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -653,8 +653,8 @@ 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);
 	of_node_put(np);
@@ -711,11 +711,18 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
 		goto out_free_node;
 
 	np->data = cset;
-	pdev->dev.of_node = np;
+
+	ret = device_add_of_node(&pdev->dev, np);
+	if (ret)
+		goto out_revert_cset;
+
 	kfree(name);
 
 	return;
 
+out_revert_cset:
+	np->data = NULL;
+	of_changeset_revert(cset);
 out_free_node:
 	of_node_put(np);
 out_destroy_cset:
@@ -724,7 +731,112 @@ out_destroy_cset:
 out_free_name:
 	kfree(name);
 }
-#endif
+
+void of_pci_remove_host_bridge_node(struct pci_host_bridge *bridge)
+{
+	struct device_node *np;
+
+	np = pci_bus_to_OF_node(bridge->bus);
+	if (!np || !of_node_check_flag(np, OF_DYNAMIC))
+		return;
+
+	device_remove_of_node(&bridge->bus->dev);
+	device_remove_of_node(&bridge->dev);
+	of_changeset_revert(np->data);
+	of_changeset_destroy(np->data);
+	of_node_put(np);
+}
+
+void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge)
+{
+	struct device_node *np = NULL;
+	struct of_changeset *cset;
+	const char *name;
+	int ret;
+
+	/*
+	 * If there is already a device tree node linked to the PCI bus handled
+	 * by this bridge (i.e. the PCI root bus), nothing to do.
+	 */
+	if (pci_bus_to_OF_node(bridge->bus))
+		return;
+
+	/*
+	 * The root bus has no node. Check that the host bridge has no node
+	 * too
+	 */
+	if (bridge->dev.of_node) {
+		dev_err(&bridge->dev, "PCI host bridge of_node already set");
+		return;
+	}
+
+	/* Check if there is a DT root node to attach the created node */
+	if (!of_root) {
+		pr_err("of_root node is NULL, cannot create PCI host bridge node\n");
+		return;
+	}
+
+	name = kasprintf(GFP_KERNEL, "pci@%x,%x", pci_domain_nr(bridge->bus),
+			 bridge->bus->number);
+	if (!name)
+		return;
+
+	cset = kmalloc(sizeof(*cset), GFP_KERNEL);
+	if (!cset)
+		goto out_free_name;
+	of_changeset_init(cset);
+
+	np = of_changeset_create_node(cset, of_root, name);
+	if (!np)
+		goto out_destroy_cset;
+
+	ret = of_pci_add_host_bridge_properties(bridge, cset, np);
+	if (ret)
+		goto out_free_node;
+
+	/*
+	 * This of_node will be added to an existing device. The of_node parent
+	 * is the root OF node and so this node will be handled by the platform
+	 * bus. Avoid any new device creation.
+	 */
+	of_node_set_flag(np, OF_POPULATED);
+	np->fwnode.dev = &bridge->dev;
+	fwnode_dev_initialized(&np->fwnode, true);
+
+	ret = of_changeset_apply(cset);
+	if (ret)
+		goto out_free_node;
+
+	np->data = cset;
+
+	/* Add the of_node to host bridge and the root bus */
+	ret = device_add_of_node(&bridge->dev, np);
+	if (ret)
+		goto out_revert_cset;
+
+	ret = device_add_of_node(&bridge->bus->dev, np);
+	if (ret)
+		goto out_remove_bridge_dev_of_node;
+
+	kfree(name);
+
+	return;
+
+out_remove_bridge_dev_of_node:
+	device_remove_of_node(&bridge->dev);
+out_revert_cset:
+	np->data = NULL;
+	of_changeset_revert(cset);
+out_free_node:
+	of_node_put(np);
+out_destroy_cset:
+	of_changeset_destroy(cset);
+	kfree(cset);
+out_free_name:
+	kfree(name);
+}
+
+#endif /* CONFIG_PCI_DYNAMIC_OF_NODES */
 
 /**
  * of_pci_supply_present() - Check if the power supply is present for the PCI
diff --git a/drivers/pci/of_property.c b/drivers/pci/of_property.c
index 58fbafac7c6a..506fcd507113 100644
--- a/drivers/pci/of_property.c
+++ b/drivers/pci/of_property.c
@@ -54,9 +54,13 @@ enum of_pci_prop_compatible {
 static void of_pci_set_address(struct pci_dev *pdev, u32 *prop, u64 addr,
 			       u32 reg_num, u32 flags, bool reloc)
 {
-	prop[0] = FIELD_PREP(OF_PCI_ADDR_FIELD_BUS, pdev->bus->number) |
-		FIELD_PREP(OF_PCI_ADDR_FIELD_DEV, PCI_SLOT(pdev->devfn)) |
-		FIELD_PREP(OF_PCI_ADDR_FIELD_FUNC, PCI_FUNC(pdev->devfn));
+	if (pdev) {
+		prop[0] = FIELD_PREP(OF_PCI_ADDR_FIELD_BUS, pdev->bus->number) |
+			  FIELD_PREP(OF_PCI_ADDR_FIELD_DEV, PCI_SLOT(pdev->devfn)) |
+			  FIELD_PREP(OF_PCI_ADDR_FIELD_FUNC, PCI_FUNC(pdev->devfn));
+	} else
+		prop[0] = 0;
+
 	prop[0] |= flags | reg_num;
 	if (!reloc) {
 		prop[0] |= OF_PCI_ADDR_FIELD_NONRELOC;
@@ -65,7 +69,7 @@ static void of_pci_set_address(struct pci_dev *pdev, u32 *prop, u64 addr,
 	}
 }
 
-static int of_pci_get_addr_flags(struct resource *res, u32 *flags)
+static int of_pci_get_addr_flags(const struct resource *res, u32 *flags)
 {
 	u32 ss;
 
@@ -390,3 +394,106 @@ int of_pci_add_properties(struct pci_dev *pdev, struct of_changeset *ocs,
 
 	return 0;
 }
+
+static bool of_pci_is_range_resource(const struct resource *res, u32 *flags)
+{
+	if (!(resource_type(res) & IORESOURCE_MEM) &&
+	    !(resource_type(res) & IORESOURCE_MEM_64))
+		return false;
+
+	if (of_pci_get_addr_flags(res, flags))
+		return false;
+
+	return true;
+}
+
+static int of_pci_host_bridge_prop_ranges(struct pci_host_bridge *bridge,
+					  struct of_changeset *ocs,
+					  struct device_node *np)
+{
+	struct resource_entry *window;
+	unsigned int ranges_sz = 0;
+	unsigned int n_range = 0;
+	struct resource *res;
+	int n_addr_cells;
+	u32 *ranges;
+	u64 val64;
+	u32 flags;
+	int ret;
+
+	n_addr_cells = of_n_addr_cells(np);
+	if (n_addr_cells <= 0 || n_addr_cells > 2)
+		return -EINVAL;
+
+	resource_list_for_each_entry(window, &bridge->windows) {
+		res = window->res;
+		if (!of_pci_is_range_resource(res, &flags))
+			continue;
+		n_range++;
+	}
+
+	if (!n_range)
+		return 0;
+
+	ranges = kcalloc(n_range,
+			 (OF_PCI_ADDRESS_CELLS + OF_PCI_SIZE_CELLS +
+			  n_addr_cells) * sizeof(*ranges),
+			 GFP_KERNEL);
+	if (!ranges)
+		return -ENOMEM;
+
+	resource_list_for_each_entry(window, &bridge->windows) {
+		res = window->res;
+		if (!of_pci_is_range_resource(res, &flags))
+			continue;
+
+		/* PCI bus address */
+		val64 = res->start;
+		of_pci_set_address(NULL, &ranges[ranges_sz],
+				   val64 - window->offset, 0, flags, false);
+		ranges_sz += OF_PCI_ADDRESS_CELLS;
+
+		/* Host bus address */
+		if (n_addr_cells == 2)
+			ranges[ranges_sz++] = upper_32_bits(val64);
+		ranges[ranges_sz++] = lower_32_bits(val64);
+
+		/* Size */
+		val64 = resource_size(res);
+		ranges[ranges_sz] = upper_32_bits(val64);
+		ranges[ranges_sz + 1] = lower_32_bits(val64);
+		ranges_sz += OF_PCI_SIZE_CELLS;
+	}
+
+	ret = of_changeset_add_prop_u32_array(ocs, np, "ranges", ranges,
+					      ranges_sz);
+	kfree(ranges);
+	return ret;
+}
+
+int of_pci_add_host_bridge_properties(struct pci_host_bridge *bridge,
+				      struct of_changeset *ocs,
+				      struct device_node *np)
+{
+	int ret;
+
+	ret = of_changeset_add_prop_string(ocs, np, "device_type", "pci");
+	if (ret)
+		return ret;
+
+	ret = of_changeset_add_prop_u32(ocs, np, "#address-cells",
+					OF_PCI_ADDRESS_CELLS);
+	if (ret)
+		return ret;
+
+	ret = of_changeset_add_prop_u32(ocs, np, "#size-cells",
+					OF_PCI_SIZE_CELLS);
+	if (ret)
+		return ret;
+
+	ret = of_pci_host_bridge_prop_ranges(bridge, ocs, np);
+	if (ret)
+		return ret;
+
+	return 0;
+}
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index dd7739fc9cc0..b81e99cd4b62 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -944,9 +944,16 @@ void of_pci_make_dev_node(struct pci_dev *pdev);
 void of_pci_remove_node(struct pci_dev *pdev);
 int of_pci_add_properties(struct pci_dev *pdev, struct of_changeset *ocs,
 			  struct device_node *np);
+void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge);
+void of_pci_remove_host_bridge_node(struct pci_host_bridge *bridge);
+int of_pci_add_host_bridge_properties(struct pci_host_bridge *bridge,
+				      struct of_changeset *ocs,
+				      struct device_node *np);
 #else
 static inline void of_pci_make_dev_node(struct pci_dev *pdev) { }
 static inline void of_pci_remove_node(struct pci_dev *pdev) { }
+static inline void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge) { }
+static inline void of_pci_remove_host_bridge_node(struct pci_host_bridge *bridge) { }
 #endif
 
 #ifdef CONFIG_PCIEAER
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 0214f98aea46..e30fd3407d9d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1098,6 +1098,8 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 		dev_info(&bus->dev, "root bus resource %pR%s\n", res, addr);
 	}
 
+	of_pci_make_host_bridge_node(bridge);
+
 	down_write(&pci_bus_sem);
 	list_add_tail(&bus->node, &pci_root_buses);
 	up_write(&pci_bus_sem);
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 368659a97d57..445afdfa6498 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -164,6 +164,8 @@ void pci_stop_root_bus(struct pci_bus *bus)
 					 &bus->devices, bus_list)
 		pci_stop_bus_device(child);
 
+	of_pci_remove_host_bridge_node(host_bridge);
+
 	/* stop the host bridge */
 	device_release_driver(&host_bridge->dev);
 }
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)