Merge 7ac1161c27 ("Merge tag 'driver-core-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core") into android-mainline

Steps on the way to 5.12-rc1.

Resolves conflicts in:
	drivers/base/core.c

Note, this merge sets the fw_devlink_flags to FW_DEVLINK_FLAGS_ON as it
should be in the Android kernel tree.

Cc: Saravana Kannan <saravanak@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I54f6cade1b3365c4427f2a6ed53b3f9d8170c620

Documentation/admin-guide/kernel-parameters.txt

@@ -1434,6 +1434,11 @@
 				to enforce probe and suspend/resume ordering.
 			rpm --	Like "on", but also use to order runtime PM.
 
+	fw_devlink.strict=<bool>
+			[KNL] Treat all inferred dependencies as mandatory
+			dependencies. This only applies for fw_devlink=on|rpm.
+			Format: <bool>
+
 	gamecon.map[2|3]=
 			[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
 			support via parallel port (up to 5 devices per port)

drivers/base/Kconfig

@@ -161,7 +161,7 @@ config HMEM_REPORTING
 	default n
 	depends on NUMA
 	help
-	  Enable reporting for heterogenous memory access attributes under
+	  Enable reporting for heterogeneous memory access attributes under
 	  their non-uniform memory nodes.
 
 source "drivers/base/test/Kconfig"

drivers/base/auxiliary.c

@@ -15,6 +15,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/string.h>
 #include <linux/auxiliary_bus.h>
+#include "base.h"
 
 static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id,
 							    const struct auxiliary_device *auxdev)
@@ -260,19 +261,11 @@ void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv)
 }
 EXPORT_SYMBOL_GPL(auxiliary_driver_unregister);
 
-static int __init auxiliary_bus_init(void)
+void __init auxiliary_bus_init(void)
 {
-	return bus_register(&auxiliary_bus_type);
+	WARN_ON(bus_register(&auxiliary_bus_type));
 }
 
-static void __exit auxiliary_bus_exit(void)
-{
-	bus_unregister(&auxiliary_bus_type);
-}
-
-module_init(auxiliary_bus_init);
-module_exit(auxiliary_bus_exit);
-
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("Auxiliary Bus");
 MODULE_AUTHOR("David Ertman <david.m.ertman@intel.com>");

drivers/base/base.h

@@ -119,6 +119,11 @@ static inline int hypervisor_init(void) { return 0; }
 extern int platform_bus_init(void);
 extern void cpu_dev_init(void);
 extern void container_dev_init(void);
+#ifdef CONFIG_AUXILIARY_BUS
+extern void auxiliary_bus_init(void);
+#else
+static inline void auxiliary_bus_init(void) { }
+#endif
 
 struct kobject *virtual_device_parent(struct device *dev);
 

drivers/base/bus.c

@@ -633,7 +633,7 @@ int bus_add_driver(struct device_driver *drv)
 	error = driver_add_groups(drv, bus->drv_groups);
 	if (error) {
 		/* How the hell do we get out of this pickle? Give up */
-		printk(KERN_ERR "%s: driver_create_groups(%s) failed\n",
+		printk(KERN_ERR "%s: driver_add_groups(%s) failed\n",
 			__func__, drv->name);
 	}
 
@@ -729,23 +729,6 @@ int device_reprobe(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(device_reprobe);
 
-/**
- * find_bus - locate bus by name.
- * @name: name of bus.
- *
- * Call kset_find_obj() to iterate over list of buses to
- * find a bus by name. Return bus if found.
- *
- * Note that kset_find_obj increments bus' reference count.
- */
-#if 0
-struct bus_type *find_bus(char *name)
-{
-	struct kobject *k = kset_find_obj(bus_kset, name);
-	return k ? to_bus(k) : NULL;
-}
-#endif  /*  0  */
-
 static int bus_add_groups(struct bus_type *bus,
 			  const struct attribute_group **groups)
 {

drivers/base/core.c

@@ -149,6 +149,21 @@ void fwnode_links_purge(struct fwnode_handle *fwnode)
 	fwnode_links_purge_consumers(fwnode);
 }
 
+static void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *child;
+
+	/* Don't purge consumer links of an added child */
+	if (fwnode->dev)
+		return;
+
+	fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
+	fwnode_links_purge_consumers(fwnode);
+
+	fwnode_for_each_available_child_node(fwnode, child)
+		fw_devlink_purge_absent_suppliers(child);
+}
+
 #ifdef CONFIG_SRCU
 static DEFINE_MUTEX(device_links_lock);
 DEFINE_STATIC_SRCU(device_links_srcu);
@@ -245,7 +260,8 @@ int device_is_dependent(struct device *dev, void *target)
 		return ret;
 
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
-		if (link->flags == (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
+		if ((link->flags & ~DL_FLAG_INFERRED) ==
+		    (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
 			continue;
 
 		if (link->consumer == target)
@@ -318,7 +334,8 @@ static int device_reorder_to_tail(struct device *dev, void *not_used)
 
 	device_for_each_child(dev, NULL, device_reorder_to_tail);
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
-		if (link->flags == (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
+		if ((link->flags & ~DL_FLAG_INFERRED) ==
+		    (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
 			continue;
 		device_reorder_to_tail(link->consumer, NULL);
 	}
@@ -566,7 +583,8 @@ postcore_initcall(devlink_class_init);
 #define DL_MANAGED_LINK_FLAGS (DL_FLAG_AUTOREMOVE_CONSUMER | \
 			       DL_FLAG_AUTOREMOVE_SUPPLIER | \
 			       DL_FLAG_AUTOPROBE_CONSUMER  | \
-			       DL_FLAG_SYNC_STATE_ONLY)
+			       DL_FLAG_SYNC_STATE_ONLY | \
+			       DL_FLAG_INFERRED)
 
 #define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
 			    DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
@@ -635,7 +653,7 @@ struct device_link *device_link_add(struct device *consumer,
 	if (!consumer || !supplier || flags & ~DL_ADD_VALID_FLAGS ||
 	    (flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
 	    (flags & DL_FLAG_SYNC_STATE_ONLY &&
-	     flags != DL_FLAG_SYNC_STATE_ONLY) ||
+	     (flags & ~DL_FLAG_INFERRED) != DL_FLAG_SYNC_STATE_ONLY) ||
 	    (flags & DL_FLAG_AUTOPROBE_CONSUMER &&
 	     flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
 		      DL_FLAG_AUTOREMOVE_SUPPLIER)))
@@ -691,6 +709,10 @@ struct device_link *device_link_add(struct device *consumer,
 		if (link->consumer != consumer)
 			continue;
 
+		if (link->flags & DL_FLAG_INFERRED &&
+		    !(flags & DL_FLAG_INFERRED))
+			link->flags &= ~DL_FLAG_INFERRED;
+
 		if (flags & DL_FLAG_PM_RUNTIME) {
 			if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
 				pm_runtime_new_link(consumer);
@@ -950,6 +972,10 @@ int device_links_check_suppliers(struct device *dev)
 	mutex_lock(&fwnode_link_lock);
 	if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
 	    !fw_devlink_is_permissive()) {
+		dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n",
+			list_first_entry(&dev->fwnode->suppliers,
+			struct fwnode_link,
+			c_hook)->supplier);
 		mutex_unlock(&fwnode_link_lock);
 		return -EPROBE_DEFER;
 	}
@@ -964,6 +990,8 @@ int device_links_check_suppliers(struct device *dev)
 		if (link->status != DL_STATE_AVAILABLE &&
 		    !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
 			device_links_missing_supplier(dev);
+			dev_dbg(dev, "probe deferral - supplier %s not ready\n",
+				dev_name(link->supplier));
 			ret = -EPROBE_DEFER;
 			break;
 		}
@@ -1142,12 +1170,22 @@ void device_links_driver_bound(struct device *dev)
 	LIST_HEAD(sync_list);
 
 	/*
-	 * If a device probes successfully, it's expected to have created all
+	 * If a device binds successfully, it's expected to have created all
 	 * the device links it needs to or make new device links as it needs
-	 * them. So, it no longer needs to wait on any suppliers.
+	 * them. So, fw_devlink no longer needs to create device links to any
+	 * of the device's suppliers.
+	 *
+	 * Also, if a child firmware node of this bound device is not added as
+	 * a device by now, assume it is never going to be added and make sure
+	 * other devices don't defer probe indefinitely by waiting for such a
+	 * child device.
 	 */
-	if (dev->fwnode && dev->fwnode->dev == dev)
+	if (dev->fwnode && dev->fwnode->dev == dev) {
+		struct fwnode_handle *child;
 		fwnode_links_purge_suppliers(dev->fwnode);
+		fwnode_for_each_available_child_node(dev->fwnode, child)
+			fw_devlink_purge_absent_suppliers(child);
+	}
 	device_remove_file(dev, &dev_attr_waiting_for_supplier);
 
 	device_links_write_lock();
@@ -1458,7 +1496,14 @@ static void device_links_purge(struct device *dev)
 	device_links_write_unlock();
 }
 
-static u32 fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER;
+#define FW_DEVLINK_FLAGS_PERMISSIVE	(DL_FLAG_INFERRED | \
+					 DL_FLAG_SYNC_STATE_ONLY)
+#define FW_DEVLINK_FLAGS_ON		(DL_FLAG_INFERRED | \
+					 DL_FLAG_AUTOPROBE_CONSUMER)
+#define FW_DEVLINK_FLAGS_RPM		(FW_DEVLINK_FLAGS_ON | \
+					 DL_FLAG_PM_RUNTIME)
+
+static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
 static int __init fw_devlink_setup(char *arg)
 {
 	if (!arg)
@@ -1467,17 +1512,23 @@ static int __init fw_devlink_setup(char *arg)
 	if (strcmp(arg, "off") == 0) {
 		fw_devlink_flags = 0;
 	} else if (strcmp(arg, "permissive") == 0) {
-		fw_devlink_flags = DL_FLAG_SYNC_STATE_ONLY;
+		fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
 	} else if (strcmp(arg, "on") == 0) {
-		fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER;
+		fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
 	} else if (strcmp(arg, "rpm") == 0) {
-		fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER |
-				   DL_FLAG_PM_RUNTIME;
+		fw_devlink_flags = FW_DEVLINK_FLAGS_RPM;
 	}
 	return 0;
 }
 early_param("fw_devlink", fw_devlink_setup);
 
+static bool fw_devlink_strict;
+static int __init fw_devlink_strict_setup(char *arg)
+{
+	return strtobool(arg, &fw_devlink_strict);
+}
+early_param("fw_devlink.strict", fw_devlink_strict_setup);
+
 u32 fw_devlink_get_flags(void)
 {
 	return fw_devlink_flags;
@@ -1485,7 +1536,12 @@ u32 fw_devlink_get_flags(void)
 
 static bool fw_devlink_is_permissive(void)
 {
-	return fw_devlink_flags == DL_FLAG_SYNC_STATE_ONLY;
+	return fw_devlink_flags == FW_DEVLINK_FLAGS_PERMISSIVE;
+}
+
+bool fw_devlink_is_strict(void)
+{
+	return fw_devlink_strict && !fw_devlink_is_permissive();
 }
 
 static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode)
@@ -1507,6 +1563,53 @@ static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
 		fw_devlink_parse_fwtree(child);
 }
 
+/**
+ * fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links
+ * @con: Device to check dependencies for.
+ * @sup: Device to check against.
+ *
+ * Check if @sup depends on @con or any device dependent on it (its child or
+ * its consumer etc).  When such a cyclic dependency is found, convert all
+ * device links created solely by fw_devlink into SYNC_STATE_ONLY device links.
+ * This is the equivalent of doing fw_devlink=permissive just between the
+ * devices in the cycle. We need to do this because, at this point, fw_devlink
+ * can't tell which of these dependencies is not a real dependency.
+ *
+ * Return 1 if a cycle is found. Otherwise, return 0.
+ */
+static int fw_devlink_relax_cycle(struct device *con, void *sup)
+{
+	struct device_link *link;
+	int ret;
+
+	if (con == sup)
+		return 1;
+
+	ret = device_for_each_child(con, sup, fw_devlink_relax_cycle);
+	if (ret)
+		return ret;
+
+	list_for_each_entry(link, &con->links.consumers, s_node) {
+		if ((link->flags & ~DL_FLAG_INFERRED) ==
+		    (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
+			continue;
+
+		if (!fw_devlink_relax_cycle(link->consumer, sup))
+			continue;
+
+		ret = 1;
+
+		if (!(link->flags & DL_FLAG_INFERRED))
+			continue;
+
+		pm_runtime_drop_link(link);
+		link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
+		dev_dbg(link->consumer, "Relaxing link with %s\n",
+			dev_name(link->supplier));
+	}
+	return ret;
+}
+
 /**
  * fw_devlink_create_devlink - Create a device link from a consumer to fwnode
  * @con - Consumer device for the device link
@@ -1534,16 +1637,40 @@ static int fw_devlink_create_devlink(struct device *con,
 
 	sup_dev = get_dev_from_fwnode(sup_handle);
 	if (sup_dev) {
+		/*
+		 * If it's one of those drivers that don't actually bind to
+		 * their device using driver core, then don't wait on this
+		 * supplier device indefinitely.
+		 */
+		if (sup_dev->links.status == DL_DEV_NO_DRIVER &&
+		    sup_handle->flags & FWNODE_FLAG_INITIALIZED) {
+			ret = -EINVAL;
+			goto out;
+		}
+
 		/*
 		 * If this fails, it is due to cycles in device links.  Just
 		 * give up on this link and treat it as invalid.
 		 */
-		if (!device_link_add(con, sup_dev, flags))
+		if (!device_link_add(con, sup_dev, flags) &&
+		    !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
+			dev_info(con, "Fixing up cyclic dependency with %s\n",
+				 dev_name(sup_dev));
+			device_links_write_lock();
+			fw_devlink_relax_cycle(con, sup_dev);
+			device_links_write_unlock();
+			device_link_add(con, sup_dev,
+					FW_DEVLINK_FLAGS_PERMISSIVE);
 			ret = -EINVAL;
+		}
 
 		goto out;
 	}
 
+	/* Supplier that's already initialized without a struct device. */
+	if (sup_handle->flags & FWNODE_FLAG_INITIALIZED)
+		return -EINVAL;
+
 	/*
 	 * DL_FLAG_SYNC_STATE_ONLY doesn't block probing and supports
 	 * cycles. So cycle detection isn't necessary and shouldn't be
@@ -1632,7 +1759,7 @@ static void __fw_devlink_link_to_consumers(struct device *dev)
 				con_dev = NULL;
 			} else {
 				own_link = false;
-				dl_flags = DL_FLAG_SYNC_STATE_ONLY;
+				dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
 			}
 		}
 
@@ -1687,7 +1814,7 @@ static void __fw_devlink_link_to_suppliers(struct device *dev,
 	if (own_link)
 		dl_flags = fw_devlink_get_flags();
 	else
-		dl_flags = DL_FLAG_SYNC_STATE_ONLY;
+		dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
 
 	list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
 		int ret;

drivers/base/init.c

@@ -32,6 +32,7 @@ void __init driver_init(void)
 	 */
 	of_core_init();
 	platform_bus_init();
+	auxiliary_bus_init();
 	cpu_dev_init();
 	memory_dev_init();
 	container_dev_init();

drivers/base/platform.c

@@ -1463,13 +1463,16 @@ static int platform_remove(struct device *_dev)
 {
 	struct platform_driver *drv = to_platform_driver(_dev->driver);
 	struct platform_device *dev = to_platform_device(_dev);
-	int ret = 0;
 
-	if (drv->remove)
-		ret = drv->remove(dev);
+	if (drv->remove) {
+		int ret = drv->remove(dev);
+
+		if (ret)
+			dev_warn(_dev, "remove callback returned a non-zero value. This will be ignored.\n");
+	}
 	dev_pm_domain_detach(_dev, true);
 
-	return ret;
+	return 0;
 }
 
 static void platform_shutdown(struct device *_dev)

drivers/base/power/domain.c

@@ -2196,6 +2196,7 @@ static int genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
 	cp->node = of_node_get(np);
 	cp->data = data;
 	cp->xlate = xlate;
+	fwnode_dev_initialized(&np->fwnode, true);
 
 	mutex_lock(&of_genpd_mutex);
 	list_add(&cp->link, &of_genpd_providers);
@@ -2385,6 +2386,7 @@ void of_genpd_del_provider(struct device_node *np)
 				}
 			}
 
+			fwnode_dev_initialized(&cp->node->fwnode, false);
 			list_del(&cp->link);
 			of_node_put(cp->node);
 			kfree(cp);

drivers/base/test/Makefile

@@ -2,3 +2,4 @@
 obj-$(CONFIG_TEST_ASYNC_DRIVER_PROBE)	+= test_async_driver_probe.o
 
 obj-$(CONFIG_KUNIT_DRIVER_PE_TEST) += property-entry-test.o
+CFLAGS_REMOVE_property-entry-test.o += -fplugin-arg-structleak_plugin-byref -fplugin-arg-structleak_plugin-byref-all

drivers/clk/clk.c

@@ -4659,6 +4659,8 @@ int of_clk_add_provider(struct device_node *np,
 	if (ret < 0)
 		of_clk_del_provider(np);
 
+	fwnode_dev_initialized(&np->fwnode, true);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(of_clk_add_provider);
@@ -4776,6 +4778,7 @@ void of_clk_del_provider(struct device_node *np)
 	list_for_each_entry(cp, &of_clk_providers, link) {
 		if (cp->node == np) {
 			list_del(&cp->link);
+			fwnode_dev_initialized(&np->fwnode, false);
 			of_node_put(cp->node);
 			kfree(cp);
 			break;

drivers/gpio/gpiolib-of.c

@@ -1039,3 +1039,14 @@ void of_gpiochip_remove(struct gpio_chip *chip)
 {
 	of_node_put(chip->of_node);
 }
+
+void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev)
+{
+	/* If the gpiochip has an assigned OF node this takes precedence */
+	if (gc->of_node)
+		gdev->dev.of_node = gc->of_node;
+	else
+		gc->of_node = gdev->dev.of_node;
+	if (gdev->dev.of_node)
+		gdev->dev.fwnode = of_fwnode_handle(gdev->dev.of_node);
+}

drivers/gpio/gpiolib-of.h

@@ -15,6 +15,7 @@ int of_gpiochip_add(struct gpio_chip *gc);
 void of_gpiochip_remove(struct gpio_chip *gc);
 int of_gpio_get_count(struct device *dev, const char *con_id);
 bool of_gpio_need_valid_mask(const struct gpio_chip *gc);
+void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev);
 #else
 static inline struct gpio_desc *of_find_gpio(struct device *dev,
 					     const char *con_id,
@@ -33,6 +34,10 @@ static inline bool of_gpio_need_valid_mask(const struct gpio_chip *gc)
 {
 	return false;
 }
+static inline void of_gpio_dev_init(struct gpio_chip *gc,
+				    struct gpio_device *gdev)
+{
+}
 #endif /* CONFIG_OF_GPIO */
 
 extern struct notifier_block gpio_of_notifier;

drivers/gpio/gpiolib.c

@@ -56,8 +56,10 @@
 static DEFINE_IDA(gpio_ida);
 static dev_t gpio_devt;
 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
+static int gpio_bus_match(struct device *dev, struct device_driver *drv);
 static struct bus_type gpio_bus_type = {
 	.name = "gpio",
+	.match = gpio_bus_match,
 };
 
 /*
@@ -590,13 +592,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 		gdev->dev.of_node = gc->parent->of_node;
 	}
 
-#ifdef CONFIG_OF_GPIO
-	/* If the gpiochip has an assigned OF node this takes precedence */
-	if (gc->of_node)
-		gdev->dev.of_node = gc->of_node;
-	else
-		gc->of_node = gdev->dev.of_node;
-#endif
+	of_gpio_dev_init(gc, gdev);
 
 	gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
 	if (gdev->id < 0) {
@@ -4215,6 +4211,41 @@ void gpiod_put_array(struct gpio_descs *descs)
 }
 EXPORT_SYMBOL_GPL(gpiod_put_array);
 
+
+static int gpio_bus_match(struct device *dev, struct device_driver *drv)
+{
+	/*
+	 * Only match if the fwnode doesn't already have a proper struct device
+	 * created for it.
+	 */
+	if (dev->fwnode && dev->fwnode->dev != dev)
+		return 0;
+	return 1;
+}
+
+static int gpio_stub_drv_probe(struct device *dev)
+{
+	/*
+	 * The DT node of some GPIO chips have a "compatible" property, but
+	 * never have a struct device added and probed by a driver to register
+	 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
+	 * the consumers of the GPIO chip to get probe deferred forever because
+	 * they will be waiting for a device associated with the GPIO chip
+	 * firmware node to get added and bound to a driver.
+	 *
+	 * To allow these consumers to probe, we associate the struct
+	 * gpio_device of the GPIO chip with the firmware node and then simply
+	 * bind it to this stub driver.
+	 */
+	return 0;
+}
+
+static struct device_driver gpio_stub_drv = {
+	.name = "gpio_stub_drv",
+	.bus = &gpio_bus_type,
+	.probe = gpio_stub_drv_probe,
+};
+
 static int __init gpiolib_dev_init(void)
 {
 	int ret;
@@ -4226,9 +4257,16 @@ static int __init gpiolib_dev_init(void)
 		return ret;
 	}
 
+	if (driver_register(&gpio_stub_drv) < 0) {
+		pr_err("gpiolib: could not register GPIO stub driver\n");
+		bus_unregister(&gpio_bus_type);
+		return ret;
+	}
+
 	ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
 	if (ret < 0) {
 		pr_err("gpiolib: failed to allocate char dev region\n");
+		driver_unregister(&gpio_stub_drv);
 		bus_unregister(&gpio_bus_type);
 		return ret;
 	}

drivers/of/property.c

@@ -24,6 +24,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_graph.h>
+#include <linux/of_irq.h>
 #include <linux/string.h>
 #include <linux/moduleparam.h>
 
@@ -1102,7 +1103,9 @@ static int of_link_to_phandle(struct device_node *con_np,
 	 * created for them.
 	 */
 	sup_dev = get_dev_from_fwnode(&sup_np->fwnode);
-	if (!sup_dev && of_node_check_flag(sup_np, OF_POPULATED)) {
+	if (!sup_dev &&
+	    (of_node_check_flag(sup_np, OF_POPULATED) ||
+	     sup_np->fwnode.flags & FWNODE_FLAG_NOT_DEVICE)) {
 		pr_debug("Not linking %pOFP to %pOFP - No struct device\n",
 			 con_np, sup_np);
 		of_node_put(sup_np);
@@ -1232,6 +1235,7 @@ static struct device_node *parse_##fname(struct device_node *np,	     \
 struct supplier_bindings {
 	struct device_node *(*parse_prop)(struct device_node *np,
 					  const char *prop_name, int index);
+	bool optional;
 };
 
 DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
@@ -1244,8 +1248,6 @@ DEFINE_SIMPLE_PROP(dmas, "dmas", "#dma-cells")
 DEFINE_SIMPLE_PROP(power_domains, "power-domains", "#power-domain-cells")
 DEFINE_SIMPLE_PROP(hwlocks, "hwlocks", "#hwlock-cells")
 DEFINE_SIMPLE_PROP(extcon, "extcon", NULL)
-DEFINE_SIMPLE_PROP(interrupts_extended, "interrupts-extended",
-					"#interrupt-cells")
 DEFINE_SIMPLE_PROP(nvmem_cells, "nvmem-cells", NULL)
 DEFINE_SIMPLE_PROP(phys, "phys", "#phy-cells")
 DEFINE_SIMPLE_PROP(wakeup_parent, "wakeup-parent", NULL)
@@ -1271,19 +1273,55 @@ static struct device_node *parse_iommu_maps(struct device_node *np,
 	return of_parse_phandle(np, prop_name, (index * 4) + 1);
 }
 
+static struct device_node *parse_gpio_compat(struct device_node *np,
+					     const char *prop_name, int index)
+{
+	struct of_phandle_args sup_args;
+
+	if (strcmp(prop_name, "gpio") && strcmp(prop_name, "gpios"))
+		return NULL;
+
+	/*
+	 * Ignore node with gpio-hog property since its gpios are all provided
+	 * by its parent.
+	 */
+	if (of_find_property(np, "gpio-hog", NULL))
+		return NULL;
+
+	if (of_parse_phandle_with_args(np, prop_name, "#gpio-cells", index,
+				       &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
+static struct device_node *parse_interrupts(struct device_node *np,
+					    const char *prop_name, int index)
+{
+	struct of_phandle_args sup_args;
+
+	if (!IS_ENABLED(CONFIG_OF_IRQ) || IS_ENABLED(CONFIG_PPC))
+		return NULL;
+
+	if (strcmp(prop_name, "interrupts") &&
+	    strcmp(prop_name, "interrupts-extended"))
+		return NULL;
+
+	return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
+}
+
 static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_clocks, },
 	{ .parse_prop = parse_interconnects, },
-	{ .parse_prop = parse_iommus, },
-	{ .parse_prop = parse_iommu_maps, },
+	{ .parse_prop = parse_iommus, .optional = true, },
+	{ .parse_prop = parse_iommu_maps, .optional = true, },
 	{ .parse_prop = parse_mboxes, },
 	{ .parse_prop = parse_io_channels, },
 	{ .parse_prop = parse_interrupt_parent, },
-	{ .parse_prop = parse_dmas, },
+	{ .parse_prop = parse_dmas, .optional = true, },
 	{ .parse_prop = parse_power_domains, },
 	{ .parse_prop = parse_hwlocks, },
 	{ .parse_prop = parse_extcon, },
-	{ .parse_prop = parse_interrupts_extended, },
 	{ .parse_prop = parse_nvmem_cells, },
 	{ .parse_prop = parse_phys, },
 	{ .parse_prop = parse_wakeup_parent, },
@@ -1296,6 +1334,8 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_pinctrl6, },
 	{ .parse_prop = parse_pinctrl7, },
 	{ .parse_prop = parse_pinctrl8, },
+	{ .parse_prop = parse_gpio_compat, },
+	{ .parse_prop = parse_interrupts, },
 	{ .parse_prop = parse_regulators, },
 	{ .parse_prop = parse_gpio, },
 	{ .parse_prop = parse_gpios, },
@@ -1332,6 +1372,11 @@ static int of_link_property(struct device_node *con_np, const char *prop_name)
 
 	/* Do not stop at first failed link, link all available suppliers. */
 	while (!matched && s->parse_prop) {
+		if (s->optional && !fw_devlink_is_strict()) {
+			s++;
+			continue;
+		}
+
 		while ((phandle = s->parse_prop(con_np, prop_name, i))) {
 			matched = true;
 			i++;

fs/debugfs/inode.c

@@ -298,7 +298,7 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent)
 {
 	struct dentry *dentry;
 
-	if (IS_ERR(parent))
+	if (!debugfs_initialized() || IS_ERR_OR_NULL(name) || IS_ERR(parent))
 		return NULL;
 
 	if (!parent)
@@ -319,6 +319,9 @@ static struct dentry *start_creating(const char *name, struct dentry *parent)
 	if (!(debugfs_allow & DEBUGFS_ALLOW_API))
 		return ERR_PTR(-EPERM);
 
+	if (!debugfs_initialized())
+		return ERR_PTR(-ENOENT);
+
 	pr_debug("creating file '%s'\n", name);
 
 	if (IS_ERR(parent))

include/linux/device.h

@@ -323,6 +323,7 @@ enum device_link_state {
  * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
  * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
  * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
+ * INFERRED: Inferred from data (eg: firmware) and not from driver actions.
  */
 #define DL_FLAG_STATELESS		BIT(0)
 #define DL_FLAG_AUTOREMOVE_CONSUMER	BIT(1)
@@ -332,6 +333,7 @@ enum device_link_state {
 #define DL_FLAG_AUTOPROBE_CONSUMER	BIT(5)
 #define DL_FLAG_MANAGED			BIT(6)
 #define DL_FLAG_SYNC_STATE_ONLY		BIT(7)
+#define DL_FLAG_INFERRED		BIT(8)
 
 /**
  * enum dl_dev_state - Device driver presence tracking information.

include/linux/device/driver.h

@@ -75,7 +75,7 @@ enum probe_type {
  * @resume:	Called to bring a device from sleep mode.
  * @groups:	Default attributes that get created by the driver core
  *		automatically.
- * @dev_groups:	Additional attributes attached to device instance once the
+ * @dev_groups:	Additional attributes attached to device instance once
  *		it is bound to the driver.
  * @pm:		Power management operations of the device which matched
  *		this driver.

include/linux/fwnode.h

@@ -11,6 +11,7 @@
 
 #include <linux/types.h>
 #include <linux/list.h>
+#include <linux/err.h>
 
 struct fwnode_operations;
 struct device;
@@ -18,9 +19,13 @@ struct device;
 /*
  * fwnode link flags
  *
- * LINKS_ADDED: The fwnode has already be parsed to add fwnode links.
+ * LINKS_ADDED:	The fwnode has already be parsed to add fwnode links.
+ * NOT_DEVICE:	The fwnode will never be populated as a struct device.
+ * INITIALIZED: The hardware corresponding to fwnode has been initialized.
  */
 #define FWNODE_FLAG_LINKS_ADDED		BIT(0)
+#define FWNODE_FLAG_NOT_DEVICE		BIT(1)
+#define FWNODE_FLAG_INITIALIZED		BIT(2)
 
 struct fwnode_handle {
 	struct fwnode_handle *secondary;
@@ -166,7 +171,20 @@ static inline void fwnode_init(struct fwnode_handle *fwnode,
 	INIT_LIST_HEAD(&fwnode->suppliers);
 }
 
+static inline void fwnode_dev_initialized(struct fwnode_handle *fwnode,
+					  bool initialized)
+{
+	if (IS_ERR_OR_NULL(fwnode))
+		return;
+
+	if (initialized)
+		fwnode->flags |= FWNODE_FLAG_INITIALIZED;
+	else
+		fwnode->flags &= ~FWNODE_FLAG_INITIALIZED;
+}
+
 extern u32 fw_devlink_get_flags(void);
+extern bool fw_devlink_is_strict(void);
 int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup);
 void fwnode_links_purge(struct fwnode_handle *fwnode);
 

include/linux/of_irq.h

@@ -33,8 +33,6 @@ static inline int of_irq_parse_oldworld(struct device_node *device, int index,
 #endif /* CONFIG_PPC32 && CONFIG_PPC_PMAC */
 
 extern int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq);
-extern int of_irq_parse_one(struct device_node *device, int index,
-			  struct of_phandle_args *out_irq);
 extern unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data);
 extern int of_irq_to_resource(struct device_node *dev, int index,
 			      struct resource *r);
@@ -42,6 +40,8 @@ extern int of_irq_to_resource(struct device_node *dev, int index,
 extern void of_irq_init(const struct of_device_id *matches);
 
 #ifdef CONFIG_OF_IRQ
+extern int of_irq_parse_one(struct device_node *device, int index,
+			  struct of_phandle_args *out_irq);
 extern int of_irq_count(struct device_node *dev);
 extern int of_irq_get(struct device_node *dev, int index);
 extern int of_irq_get_byname(struct device_node *dev, const char *name);
@@ -57,6 +57,11 @@ extern struct irq_domain *of_msi_map_get_device_domain(struct device *dev,
 extern void of_msi_configure(struct device *dev, struct device_node *np);
 u32 of_msi_map_id(struct device *dev, struct device_node *msi_np, u32 id_in);
 #else
+static inline int of_irq_parse_one(struct device_node *device, int index,
+				   struct of_phandle_args *out_irq)
+{
+	return -EINVAL;
+}
 static inline int of_irq_count(struct device_node *dev)
 {
 	return 0;

kernel/irq/irqdomain.c

@@ -205,6 +205,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
 	}
 
 	fwnode_handle_get(fwnode);
+	fwnode_dev_initialized(fwnode, true);
 
 	/* Fill structure */
 	INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
@@ -253,6 +254,7 @@ void irq_domain_remove(struct irq_domain *domain)
 
 	pr_debug("Removed domain %s\n", domain->name);
 
+	fwnode_dev_initialized(domain->fwnode, false);
 	fwnode_handle_put(domain->fwnode);
 	if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
 		kfree(domain->name);