1 files changed, 168 insertions, 26 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index fd034d742447..d02501933467 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -21,7 +21,7 @@
 #include <linux/notifier.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
-#include <linux/genhd.h>
+#include <linux/blkdev.h>
 #include <linux/mutex.h>
 #include <linux/pm_runtime.h>
 #include <linux/netdevice.h>
@@ -32,6 +32,7 @@
 #include <linux/dma-map-ops.h> /* for dma_default_coherent */
 
 #include "base.h"
+#include "physical_location.h"
 #include "power/power.h"
 
 #ifdef CONFIG_SYSFS_DEPRECATED
@@ -53,6 +54,7 @@ static unsigned int defer_sync_state_count = 1;
 static DEFINE_MUTEX(fwnode_link_lock);
 static bool fw_devlink_is_permissive(void);
 static bool fw_devlink_drv_reg_done;
+static bool fw_devlink_best_effort;
 
 /**
  * fwnode_link_add - Create a link between two fwnode_handles.
@@ -485,8 +487,18 @@ static void device_link_release_fn(struct work_struct *work)
 	/* Ensure that all references to the link object have been dropped. */
 	device_link_synchronize_removal();
 
-	while (refcount_dec_not_one(&link->rpm_active))
-		pm_runtime_put(link->supplier);
+	pm_runtime_release_supplier(link);
+	/*
+	 * If supplier_preactivated is set, the link has been dropped between
+	 * the pm_runtime_get_suppliers() and pm_runtime_put_suppliers() calls
+	 * in __driver_probe_device().  In that case, drop the supplier's
+	 * PM-runtime usage counter to remove the reference taken by
+	 * pm_runtime_get_suppliers().
+	 */
+	if (link->supplier_preactivated)
+		pm_runtime_put_noidle(link->supplier);
+
+	pm_request_idle(link->supplier);
 
 	put_device(link->consumer);
 	put_device(link->supplier);
@@ -965,6 +977,12 @@ static void device_links_missing_supplier(struct device *dev)
 	}
 }
 
+static bool dev_is_best_effort(struct device *dev)
+{
+	return (fw_devlink_best_effort && dev->can_match) ||
+		(dev->fwnode && (dev->fwnode->flags & FWNODE_FLAG_BEST_EFFORT));
+}
+
 /**
  * device_links_check_suppliers - Check presence of supplier drivers.
  * @dev: Consumer device.
@@ -984,7 +1002,7 @@ static void device_links_missing_supplier(struct device *dev)
 int device_links_check_suppliers(struct device *dev)
 {
 	struct device_link *link;
-	int ret = 0;
+	int ret = 0, fwnode_ret = 0;
 	struct fwnode_handle *sup_fw;
 
 	/*
@@ -997,12 +1015,17 @@ int device_links_check_suppliers(struct device *dev)
 		sup_fw = list_first_entry(&dev->fwnode->suppliers,
 					  struct fwnode_link,
 					  c_hook)->supplier;
-		dev_err_probe(dev, -EPROBE_DEFER, "wait for supplier %pfwP\n",
-			      sup_fw);
-		mutex_unlock(&fwnode_link_lock);
-		return -EPROBE_DEFER;
+		if (!dev_is_best_effort(dev)) {
+			fwnode_ret = -EPROBE_DEFER;
+			dev_err_probe(dev, -EPROBE_DEFER,
+				    "wait for supplier %pfwP\n", sup_fw);
+		} else {
+			fwnode_ret = -EAGAIN;
+		}
 	}
 	mutex_unlock(&fwnode_link_lock);
+	if (fwnode_ret == -EPROBE_DEFER)
+		return fwnode_ret;
 
 	device_links_write_lock();
 
@@ -1012,6 +1035,14 @@ int device_links_check_suppliers(struct device *dev)
 
 		if (link->status != DL_STATE_AVAILABLE &&
 		    !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
+
+			if (dev_is_best_effort(dev) &&
+			    link->flags & DL_FLAG_INFERRED &&
+			    !link->supplier->can_match) {
+				ret = -EAGAIN;
+				continue;
+			}
+
 			device_links_missing_supplier(dev);
 			dev_err_probe(dev, -EPROBE_DEFER,
 				      "supplier %s not ready\n",
@@ -1024,7 +1055,8 @@ int device_links_check_suppliers(struct device *dev)
 	dev->links.status = DL_DEV_PROBING;
 
 	device_links_write_unlock();
-	return ret;
+
+	return ret ? ret : fwnode_ret;
 }
 
 /**
@@ -1289,6 +1321,18 @@ void device_links_driver_bound(struct device *dev)
 			 * save to drop the managed link completely.
 			 */
 			device_link_drop_managed(link);
+		} else if (dev_is_best_effort(dev) &&
+			   link->flags & DL_FLAG_INFERRED &&
+			   link->status != DL_STATE_CONSUMER_PROBE &&
+			   !link->supplier->can_match) {
+			/*
+			 * When dev_is_best_effort() is true, we ignore device
+			 * links to suppliers that don't have a driver.  If the
+			 * consumer device still managed to probe, there's no
+			 * point in maintaining a device link in a weird state
+			 * (consumer probed before supplier). So delete it.
+			 */
+			device_link_drop_managed(link);
 		} else {
 			WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
 			WRITE_ONCE(link->status, DL_STATE_ACTIVE);
@@ -1655,6 +1699,62 @@ void fw_devlink_drivers_done(void)
 	device_links_write_unlock();
 }
 
+/**
+ * wait_for_init_devices_probe - Try to probe any device needed for init
+ *
+ * Some devices might need to be probed and bound successfully before the kernel
+ * boot sequence can finish and move on to init/userspace. For example, a
+ * network interface might need to be bound to be able to mount a NFS rootfs.
+ *
+ * With fw_devlink=on by default, some of these devices might be blocked from
+ * probing because they are waiting on a optional supplier that doesn't have a
+ * driver. While fw_devlink will eventually identify such devices and unblock
+ * the probing automatically, it might be too late by the time it unblocks the
+ * probing of devices. For example, the IP4 autoconfig might timeout before
+ * fw_devlink unblocks probing of the network interface.
+ *
+ * This function is available to temporarily try and probe all devices that have
+ * a driver even if some of their suppliers haven't been added or don't have
+ * drivers.
+ *
+ * The drivers can then decide which of the suppliers are optional vs mandatory
+ * and probe the device if possible. By the time this function returns, all such
+ * "best effort" probes are guaranteed to be completed. If a device successfully
+ * probes in this mode, we delete all fw_devlink discovered dependencies of that
+ * device where the supplier hasn't yet probed successfully because they have to
+ * be optional dependencies.
+ *
+ * Any devices that didn't successfully probe go back to being treated as if
+ * this function was never called.
+ *
+ * This also means that some devices that aren't needed for init and could have
+ * waited for their optional supplier to probe (when the supplier's module is
+ * loaded later on) would end up probing prematurely with limited functionality.
+ * So call this function only when boot would fail without it.
+ */
+void __init wait_for_init_devices_probe(void)
+{
+	if (!fw_devlink_flags || fw_devlink_is_permissive())
+		return;
+
+	/*
+	 * Wait for all ongoing probes to finish so that the "best effort" is
+	 * only applied to devices that can't probe otherwise.
+	 */
+	wait_for_device_probe();
+
+	pr_info("Trying to probe devices needed for running init ...\n");
+	fw_devlink_best_effort = true;
+	driver_deferred_probe_trigger();
+
+	/*
+	 * Wait for all "best effort" probes to finish before going back to
+	 * normal enforcement.
+	 */
+	wait_for_device_probe();
+	fw_devlink_best_effort = false;
+}
+
 static void fw_devlink_unblock_consumers(struct device *dev)
 {
 	struct device_link *link;
@@ -2261,9 +2361,9 @@ static struct kobj_type device_ktype = {
 };
 
 
-static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
+static int dev_uevent_filter(struct kobject *kobj)
 {
-	struct kobj_type *ktype = get_ktype(kobj);
+	const struct kobj_type *ktype = get_ktype(kobj);
 
 	if (ktype == &device_ktype) {
 		struct device *dev = kobj_to_dev(kobj);
@@ -2275,7 +2375,7 @@ static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 	return 0;
 }
 
-static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
+static const char *dev_uevent_name(struct kobject *kobj)
 {
 	struct device *dev = kobj_to_dev(kobj);
 
@@ -2286,8 +2386,7 @@ static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
 	return NULL;
 }
 
-static int dev_uevent(struct kset *kset, struct kobject *kobj,
-		      struct kobj_uevent_env *env)
+static int dev_uevent(struct kobject *kobj, struct kobj_uevent_env *env)
 {
 	struct device *dev = kobj_to_dev(kobj);
 	int retval = 0;
@@ -2382,7 +2481,7 @@ static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
 
 	/* respect filter */
 	if (kset->uevent_ops && kset->uevent_ops->filter)
-		if (!kset->uevent_ops->filter(kset, &dev->kobj))
+		if (!kset->uevent_ops->filter(&dev->kobj))
 			goto out;
 
 	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
@@ -2390,7 +2489,7 @@ static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
 		return -ENOMEM;
 
 	/* let the kset specific function add its keys */
-	retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
+	retval = kset->uevent_ops->uevent(&dev->kobj, env);
 	if (retval)
 		goto out;
 
@@ -2410,7 +2509,7 @@ static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
 	rc = kobject_synth_uevent(&dev->kobj, buf, count);
 
 	if (rc) {
-		dev_err(dev, "uevent: failed to send synthetic uevent\n");
+		dev_err(dev, "uevent: failed to send synthetic uevent: %d\n", rc);
 		return rc;
 	}
 
@@ -2651,8 +2750,17 @@ static int device_add_attrs(struct device *dev)
 			goto err_remove_dev_waiting_for_supplier;
 	}
 
+	if (dev_add_physical_location(dev)) {
+		error = device_add_group(dev,
+			&dev_attr_physical_location_group);
+		if (error)
+			goto err_remove_dev_removable;
+	}
+
 	return 0;
 
+ err_remove_dev_removable:
+	device_remove_file(dev, &dev_attr_removable);
  err_remove_dev_waiting_for_supplier:
 	device_remove_file(dev, &dev_attr_waiting_for_supplier);
  err_remove_dev_online:
@@ -2674,6 +2782,11 @@ static void device_remove_attrs(struct device *dev)
 	struct class *class = dev->class;
 	const struct device_type *type = dev->type;
 
+	if (dev->physical_location) {
+		device_remove_group(dev, &dev_attr_physical_location_group);
+		kfree(dev->physical_location);
+	}
+
 	device_remove_file(dev, &dev_attr_removable);
 	device_remove_file(dev, &dev_attr_waiting_for_supplier);
 	device_remove_file(dev, &dev_attr_online);
@@ -2866,18 +2979,11 @@ void device_initialize(struct device *dev)
 	kobject_init(&dev->kobj, &device_ktype);
 	INIT_LIST_HEAD(&dev->dma_pools);
 	mutex_init(&dev->mutex);
-#ifdef CONFIG_PROVE_LOCKING
-	mutex_init(&dev->lockdep_mutex);
-#endif
 	lockdep_set_novalidate_class(&dev->mutex);
 	spin_lock_init(&dev->devres_lock);
 	INIT_LIST_HEAD(&dev->devres_head);
 	device_pm_init(dev);
 	set_dev_node(dev, NUMA_NO_NODE);
-#ifdef CONFIG_GENERIC_MSI_IRQ
-	raw_spin_lock_init(&dev->msi_lock);
-	INIT_LIST_HEAD(&dev->msi_list);
-#endif
 	INIT_LIST_HEAD(&dev->links.consumers);
 	INIT_LIST_HEAD(&dev->links.suppliers);
 	INIT_LIST_HEAD(&dev->links.defer_sync);
@@ -3029,6 +3135,23 @@ static inline struct kobject *get_glue_dir(struct device *dev)
 	return dev->kobj.parent;
 }
 
+/**
+ * kobject_has_children - Returns whether a kobject has children.
+ * @kobj: the object to test
+ *
+ * This will return whether a kobject has other kobjects as children.
+ *
+ * It does NOT account for the presence of attribute files, only sub
+ * directories. It also assumes there is no concurrent addition or
+ * removal of such children, and thus relies on external locking.
+ */
+static inline bool kobject_has_children(struct kobject *kobj)
+{
+	WARN_ON_ONCE(kref_read(&kobj->kref) == 0);
+
+	return kobj->sd && kobj->sd->dir.subdirs;
+}
+
 /*
  * make sure cleaning up dir as the last step, we need to make
  * sure .release handler of kobject is run with holding the
@@ -3582,7 +3705,6 @@ void device_del(struct device *dev)
 	device_pm_remove(dev);
 	driver_deferred_probe_del(dev);
 	device_platform_notify_remove(dev);
-	device_remove_properties(dev);
 	device_links_purge(dev);
 
 	if (dev->bus)
@@ -3810,6 +3932,26 @@ struct device *device_find_child_by_name(struct device *parent,
 }
 EXPORT_SYMBOL_GPL(device_find_child_by_name);
 
+static int match_any(struct device *dev, void *unused)
+{
+	return 1;
+}
+
+/**
+ * device_find_any_child - device iterator for locating a child device, if any.
+ * @parent: parent struct device
+ *
+ * This is similar to the device_find_child() function above, but it
+ * returns a reference to a child device, if any.
+ *
+ * NOTE: you will need to drop the reference with put_device() after use.
+ */
+struct device *device_find_any_child(struct device *parent)
+{
+	return device_find_child(parent, NULL, match_any);
+}
+EXPORT_SYMBOL_GPL(device_find_any_child);
+
 int __init devices_init(void)
 {
 	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
@@ -4028,7 +4170,7 @@ device_create_groups_vargs(struct class *class, struct device *parent,
 	struct device *dev = NULL;
 	int retval = -ENODEV;
 
-	if (class == NULL || IS_ERR(class))
+	if (IS_ERR_OR_NULL(class))
 		goto error;
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);