Merge tag 'driver-core-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the "big" set of driver core and kernfs changes for 6.9-rc1.

  Nothing all that crazy here, just some good updates that include:

   - automatic attribute group hiding from Dan Williams (he fixed up my
     horrible attempt at doing this.)

   - kobject lock contention fixes from Eric Dumazet

   - driver core cleanups from Andy

   - kernfs rcu work from Tejun

   - fw_devlink changes to resolve some reported issues

   - other minor changes, all details in the shortlog

  All of these have been in linux-next for a long time with no reported
  issues"

* tag 'driver-core-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (28 commits)
  device: core: Log warning for devices pending deferred probe on timeout
  driver: core: Use dev_* instead of pr_* so device metadata is added
  driver: core: Log probe failure as error and with device metadata
  of: property: fw_devlink: Add support for "post-init-providers" property
  driver core: Add FWLINK_FLAG_IGNORE to completely ignore a fwnode link
  driver core: Adds flags param to fwnode_link_add()
  debugfs: fix wait/cancellation handling during remove
  device property: Don't use "proxy" headers
  device property: Move enum dev_dma_attr to fwnode.h
  driver core: Move fw_devlink stuff to where it belongs
  driver core: Drop unneeded 'extern' keyword in fwnode.h
  firmware_loader: Suppress warning on FW_OPT_NO_WARN flag
  sysfs:Addresses documentation in sysfs_merge_group and sysfs_unmerge_group.
  firmware_loader: introduce __free() cleanup hanler
  platform-msi: Remove usage of the deprecated ida_simple_xx() API
  sysfs: Introduce DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE()
  sysfs: Document new "group visible" helpers
  sysfs: Fix crash on empty group attributes array
  sysfs: Introduce a mechanism to hide static attribute_groups
  sysfs: Introduce a mechanism to hide static attribute_groups
  ...

drivers/base/component.c

@@ -751,7 +751,7 @@ static int __component_add(struct device *dev, const struct component_ops *ops,
  * component_bind_all(). See also &struct component_ops.
  *
  * @subcomponent must be nonzero and is used to differentiate between multiple
- * components registerd on the same device @dev. These components are match
+ * components registered on the same device @dev. These components are match
  * using component_match_add_typed().
  *
  * The component needs to be unregistered at driver unload/disconnect by
@@ -781,7 +781,7 @@ EXPORT_SYMBOL_GPL(component_add_typed);
  * The component needs to be unregistered at driver unload/disconnect by
  * calling component_del().
  *
- * See also component_add_typed() for a variant that allows multipled different
+ * See also component_add_typed() for a variant that allows multiple different
  * components on the same device.
  */
 int component_add(struct device *dev, const struct component_ops *ops)

drivers/base/core.c

@@ -92,12 +92,13 @@ static int __fwnode_link_add(struct fwnode_handle *con,
 	return 0;
 }
 
-int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup)
+int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup,
+		    u8 flags)
 {
 	int ret;
 
 	mutex_lock(&fwnode_link_lock);
-	ret = __fwnode_link_add(con, sup, 0);
+	ret = __fwnode_link_add(con, sup, flags);
 	mutex_unlock(&fwnode_link_lock);
 	return ret;
 }
@@ -1011,7 +1012,8 @@ static struct fwnode_handle *fwnode_links_check_suppliers(
 		return NULL;
 
 	list_for_each_entry(link, &fwnode->suppliers, c_hook)
-		if (!(link->flags & FWLINK_FLAG_CYCLE))
+		if (!(link->flags &
+		      (FWLINK_FLAG_CYCLE | FWLINK_FLAG_IGNORE)))
 			return link->supplier;
 
 	return NULL;
@@ -1871,6 +1873,7 @@ static void fw_devlink_unblock_consumers(struct device *dev)
 	device_links_write_unlock();
 }
 
+#define get_dev_from_fwnode(fwnode)	get_device((fwnode)->dev)
 
 static bool fwnode_init_without_drv(struct fwnode_handle *fwnode)
 {
@@ -1901,6 +1904,63 @@ static bool fwnode_ancestor_init_without_drv(struct fwnode_handle *fwnode)
 	return false;
 }
 
+/**
+ * fwnode_is_ancestor_of - Test if @ancestor is ancestor of @child
+ * @ancestor: Firmware which is tested for being an ancestor
+ * @child: Firmware which is tested for being the child
+ *
+ * A node is considered an ancestor of itself too.
+ *
+ * Return: true if @ancestor is an ancestor of @child. Otherwise, returns false.
+ */
+static bool fwnode_is_ancestor_of(const struct fwnode_handle *ancestor,
+				  const struct fwnode_handle *child)
+{
+	struct fwnode_handle *parent;
+
+	if (IS_ERR_OR_NULL(ancestor))
+		return false;
+
+	if (child == ancestor)
+		return true;
+
+	fwnode_for_each_parent_node(child, parent) {
+		if (parent == ancestor) {
+			fwnode_handle_put(parent);
+			return true;
+		}
+	}
+	return false;
+}
+
+/**
+ * fwnode_get_next_parent_dev - Find device of closest ancestor fwnode
+ * @fwnode: firmware node
+ *
+ * Given a firmware node (@fwnode), this function finds its closest ancestor
+ * firmware node that has a corresponding struct device and returns that struct
+ * device.
+ *
+ * The caller is responsible for calling put_device() on the returned device
+ * pointer.
+ *
+ * Return: a pointer to the device of the @fwnode's closest ancestor.
+ */
+static struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *parent;
+	struct device *dev;
+
+	fwnode_for_each_parent_node(fwnode, parent) {
+		dev = get_dev_from_fwnode(parent);
+		if (dev) {
+			fwnode_handle_put(parent);
+			return dev;
+		}
+	}
+	return NULL;
+}
+
 /**
  * __fw_devlink_relax_cycles - Relax and mark dependency cycles.
  * @con: Potential consumer device.
@@ -1962,6 +2022,9 @@ static bool __fw_devlink_relax_cycles(struct device *con,
 	}
 
 	list_for_each_entry(link, &sup_handle->suppliers, c_hook) {
+		if (link->flags & FWLINK_FLAG_IGNORE)
+			continue;
+
 		if (__fw_devlink_relax_cycles(con, link->supplier)) {
 			__fwnode_link_cycle(link);
 			ret = true;
@@ -2040,6 +2103,9 @@ static int fw_devlink_create_devlink(struct device *con,
 	int ret = 0;
 	u32 flags;
 
+	if (link->flags & FWLINK_FLAG_IGNORE)
+		return 0;
+
 	if (con->fwnode == link->consumer)
 		flags = fw_devlink_get_flags(link->flags);
 	else

drivers/base/cpu.c

@@ -366,7 +366,7 @@ static int cpu_uevent(const struct device *dev, struct kobj_uevent_env *env)
 }
 #endif
 
-struct bus_type cpu_subsys = {
+const struct bus_type cpu_subsys = {
 	.name = "cpu",
 	.dev_name = "cpu",
 	.match = cpu_subsys_match,

drivers/base/dd.c

@@ -313,7 +313,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work)
 
 	mutex_lock(&deferred_probe_mutex);
 	list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe)
-		dev_info(p->device, "deferred probe pending: %s", p->deferred_probe_reason ?: "(reason unknown)\n");
+		dev_warn(p->device, "deferred probe pending: %s", p->deferred_probe_reason ?: "(reason unknown)\n");
 	mutex_unlock(&deferred_probe_mutex);
 
 	fw_devlink_probing_done();
@@ -397,13 +397,12 @@ bool device_is_bound(struct device *dev)
 static void driver_bound(struct device *dev)
 {
 	if (device_is_bound(dev)) {
-		pr_warn("%s: device %s already bound\n",
-			__func__, kobject_name(&dev->kobj));
+		dev_warn(dev, "%s: device already bound\n", __func__);
 		return;
 	}
 
-	pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name,
-		 __func__, dev_name(dev));
+	dev_dbg(dev, "driver: '%s': %s: bound to device\n", dev->driver->name,
+		__func__);
 
 	klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
 	device_links_driver_bound(dev);
@@ -587,13 +586,13 @@ static int call_driver_probe(struct device *dev, struct device_driver *drv)
 		break;
 	case -ENODEV:
 	case -ENXIO:
-		pr_debug("%s: probe of %s rejects match %d\n",
-			 drv->name, dev_name(dev), ret);
+		dev_dbg(dev, "probe with driver %s rejects match %d\n",
+			drv->name, ret);
 		break;
 	default:
 		/* driver matched but the probe failed */
-		pr_warn("%s: probe of %s failed with error %d\n",
-			drv->name, dev_name(dev), ret);
+		dev_err(dev, "probe with driver %s failed with error %d\n",
+			drv->name, ret);
 		break;
 	}
 
@@ -620,8 +619,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	if (link_ret == -EPROBE_DEFER)
 		return link_ret;
 
-	pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
-		 drv->bus->name, __func__, drv->name, dev_name(dev));
+	dev_dbg(dev, "bus: '%s': %s: probing driver %s with device\n",
+		drv->bus->name, __func__, drv->name);
 	if (!list_empty(&dev->devres_head)) {
 		dev_crit(dev, "Resources present before probing\n");
 		ret = -EBUSY;
@@ -644,8 +643,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 
 	ret = driver_sysfs_add(dev);
 	if (ret) {
-		pr_err("%s: driver_sysfs_add(%s) failed\n",
-		       __func__, dev_name(dev));
+		dev_err(dev, "%s: driver_sysfs_add failed\n", __func__);
 		goto sysfs_failed;
 	}
 
@@ -706,8 +704,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 		dev->pm_domain->sync(dev);
 
 	driver_bound(dev);
-	pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
-		 drv->bus->name, __func__, dev_name(dev), drv->name);
+	dev_dbg(dev, "bus: '%s': %s: bound device to driver %s\n",
+		drv->bus->name, __func__, drv->name);
 	goto done;
 
 dev_sysfs_state_synced_failed:
@@ -786,8 +784,8 @@ static int __driver_probe_device(struct device_driver *drv, struct device *dev)
 		return -EBUSY;
 
 	dev->can_match = true;
-	pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
-		 drv->bus->name, __func__, dev_name(dev), drv->name);
+	dev_dbg(dev, "bus: '%s': %s: matched device with driver %s\n",
+		drv->bus->name, __func__, drv->name);
 
 	pm_runtime_get_suppliers(dev);
 	if (dev->parent)

drivers/base/firmware_loader/main.c

@@ -551,12 +551,16 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
 						       file_size_ptr,
 						       READING_FIRMWARE);
 		if (rc < 0) {
-			if (rc != -ENOENT)
-				dev_warn(device, "loading %s failed with error %d\n",
-					 path, rc);
-			else
-				dev_dbg(device, "loading %s failed for no such file or directory.\n",
-					 path);
+			if (!(fw_priv->opt_flags & FW_OPT_NO_WARN)) {
+				if (rc != -ENOENT)
+					dev_warn(device,
+						 "loading %s failed with error %d\n",
+						 path, rc);
+				else
+					dev_dbg(device,
+						"loading %s failed for no such file or directory.\n",
+						path);
+			}
 			continue;
 		}
 		size = rc;

drivers/base/platform-msi.c

@@ -174,8 +174,8 @@ static int platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
 	if (!datap)
 		return -ENOMEM;
 
-	datap->devid = ida_simple_get(&platform_msi_devid_ida,
-				      0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
+	datap->devid = ida_alloc_max(&platform_msi_devid_ida,
+				     (1 << DEV_ID_SHIFT) - 1, GFP_KERNEL);
 	if (datap->devid < 0) {
 		err = datap->devid;
 		kfree(datap);
@@ -193,7 +193,7 @@ static void platform_msi_free_priv_data(struct device *dev)
 	struct platform_msi_priv_data *data = dev->msi.data->platform_data;
 
 	dev->msi.data->platform_data = NULL;
-	ida_simple_remove(&platform_msi_devid_ida, data->devid);
+	ida_free(&platform_msi_devid_ida, data->devid);
 	kfree(data);
 }
 

drivers/base/property.c

@@ -7,15 +7,16 @@
  *          Mika Westerberg <mika.westerberg@linux.intel.com>
  */
 
-#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/err.h>
 #include <linux/export.h>
-#include <linux/kernel.h>
+#include <linux/kconfig.h>
 #include <linux/of.h>
-#include <linux/of_address.h>
-#include <linux/of_graph.h>
-#include <linux/of_irq.h>
 #include <linux/property.h>
 #include <linux/phy.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
 
 struct fwnode_handle *__dev_fwnode(struct device *dev)
 {
@@ -699,34 +700,6 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode)
 }
 EXPORT_SYMBOL_GPL(fwnode_get_next_parent);
 
-/**
- * fwnode_get_next_parent_dev - Find device of closest ancestor fwnode
- * @fwnode: firmware node
- *
- * Given a firmware node (@fwnode), this function finds its closest ancestor
- * firmware node that has a corresponding struct device and returns that struct
- * device.
- *
- * The caller is responsible for calling put_device() on the returned device
- * pointer.
- *
- * Return: a pointer to the device of the @fwnode's closest ancestor.
- */
-struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwnode)
-{
-	struct fwnode_handle *parent;
-	struct device *dev;
-
-	fwnode_for_each_parent_node(fwnode, parent) {
-		dev = get_dev_from_fwnode(parent);
-		if (dev) {
-			fwnode_handle_put(parent);
-			return dev;
-		}
-	}
-	return NULL;
-}
-
 /**
  * fwnode_count_parents - Return the number of parents a node has
  * @fwnode: The node the parents of which are to be counted
@@ -773,34 +746,6 @@ struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode,
 }
 EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
 
-/**
- * fwnode_is_ancestor_of - Test if @ancestor is ancestor of @child
- * @ancestor: Firmware which is tested for being an ancestor
- * @child: Firmware which is tested for being the child
- *
- * A node is considered an ancestor of itself too.
- *
- * Return: true if @ancestor is an ancestor of @child. Otherwise, returns false.
- */
-bool fwnode_is_ancestor_of(const struct fwnode_handle *ancestor, const struct fwnode_handle *child)
-{
-	struct fwnode_handle *parent;
-
-	if (IS_ERR_OR_NULL(ancestor))
-		return false;
-
-	if (child == ancestor)
-		return true;
-
-	fwnode_for_each_parent_node(child, parent) {
-		if (parent == ancestor) {
-			fwnode_handle_put(parent);
-			return true;
-		}
-	}
-	return false;
-}
-
 /**
  * fwnode_get_next_child_node - Return the next child node handle for a node
  * @fwnode: Firmware node to find the next child node for.

drivers/base/swnode.c

@@ -6,10 +6,21 @@
  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
  */
 
+#include <linux/container_of.h>
 #include <linux/device.h>
-#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/kobject.h>
+#include <linux/kstrtox.h>
+#include <linux/list.h>
 #include <linux/property.h>
 #include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
 
 #include "base.h"
 

drivers/firmware/efi/sysfb_efi.c

@@ -336,7 +336,7 @@ static int efifb_add_links(struct fwnode_handle *fwnode)
 	if (!sup_np)
 		return 0;
 
-	fwnode_link_add(fwnode, of_fwnode_handle(sup_np));
+	fwnode_link_add(fwnode, of_fwnode_handle(sup_np), 0);
 	of_node_put(sup_np);
 
 	return 0;

drivers/of/property.c

@@ -1072,7 +1072,8 @@ of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
 }
 
 static void of_link_to_phandle(struct device_node *con_np,
-			      struct device_node *sup_np)
+			      struct device_node *sup_np,
+			      u8 flags)
 {
 	struct device_node *tmp_np = of_node_get(sup_np);
 
@@ -1091,7 +1092,7 @@ static void of_link_to_phandle(struct device_node *con_np,
 		tmp_np = of_get_next_parent(tmp_np);
 	}
 
-	fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np));
+	fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np), flags);
 }
 
 /**
@@ -1204,6 +1205,8 @@ static struct device_node *parse_##fname(struct device_node *np,	     \
  *		 to a struct device, implement this ops so fw_devlink can use it
  *		 to find the true consumer.
  * @optional: Describes whether a supplier is mandatory or not
+ * @fwlink_flags: Optional fwnode link flags to use when creating a fwnode link
+ *		  for this property.
  *
  * Returns:
  * parse_prop() return values are
@@ -1216,6 +1219,7 @@ struct supplier_bindings {
 					  const char *prop_name, int index);
 	struct device_node *(*get_con_dev)(struct device_node *np);
 	bool optional;
+	u8 fwlink_flags;
 };
 
 DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
@@ -1247,6 +1251,7 @@ DEFINE_SIMPLE_PROP(leds, "leds", NULL)
 DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
 DEFINE_SIMPLE_PROP(panel, "panel", NULL)
 DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
+DEFINE_SIMPLE_PROP(post_init_providers, "post-init-providers", NULL)
 DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
 DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
 
@@ -1357,6 +1362,10 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_regulators, },
 	{ .parse_prop = parse_gpio, },
 	{ .parse_prop = parse_gpios, },
+	{
+		.parse_prop = parse_post_init_providers,
+		.fwlink_flags = FWLINK_FLAG_IGNORE,
+	},
 	{}
 };
 
@@ -1401,7 +1410,7 @@ static int of_link_property(struct device_node *con_np, const char *prop_name)
 					: of_node_get(con_np);
 			matched = true;
 			i++;
-			of_link_to_phandle(con_dev_np, phandle);
+			of_link_to_phandle(con_dev_np, phandle, s->fwlink_flags);
 			of_node_put(phandle);
 			of_node_put(con_dev_np);
 		}

fs/debugfs/inode.c

@@ -751,13 +751,28 @@ static void __debugfs_file_removed(struct dentry *dentry)
 	if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)
 		return;
 
-	/* if we hit zero, just wait for all to finish */
-	if (!refcount_dec_and_test(&fsd->active_users)) {
-		wait_for_completion(&fsd->active_users_drained);
+	/* if this was the last reference, we're done */
+	if (refcount_dec_and_test(&fsd->active_users))
 		return;
-	}
 
-	/* if we didn't hit zero, try to cancel any we can */
+	/*
+	 * If there's still a reference, the code that obtained it can
+	 * be in different states:
+	 *  - The common case of not using cancellations, or already
+	 *    after debugfs_leave_cancellation(), where we just need
+	 *    to wait for debugfs_file_put() which signals the completion;
+	 *  - inside a cancellation section, i.e. between
+	 *    debugfs_enter_cancellation() and debugfs_leave_cancellation(),
+	 *    in which case we need to trigger the ->cancel() function,
+	 *    and then wait for debugfs_file_put() just like in the
+	 *    previous case;
+	 *  - before debugfs_enter_cancellation() (but obviously after
+	 *    debugfs_file_get()), in which case we may not see the
+	 *    cancellation in the list on the first round of the loop,
+	 *    but debugfs_enter_cancellation() signals the completion
+	 *    after adding it, so this code gets woken up to call the
+	 *    ->cancel() function.
+	 */
 	while (refcount_read(&fsd->active_users)) {
 		struct debugfs_cancellation *c;
 

fs/kernfs/dir.c

@@ -529,6 +529,20 @@ void kernfs_get(struct kernfs_node *kn)
 }
 EXPORT_SYMBOL_GPL(kernfs_get);
 
+static void kernfs_free_rcu(struct rcu_head *rcu)
+{
+	struct kernfs_node *kn = container_of(rcu, struct kernfs_node, rcu);
+
+	kfree_const(kn->name);
+
+	if (kn->iattr) {
+		simple_xattrs_free(&kn->iattr->xattrs, NULL);
+		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
+	}
+
+	kmem_cache_free(kernfs_node_cache, kn);
+}
+
 /**
  * kernfs_put - put a reference count on a kernfs_node
  * @kn: the target kernfs_node
@@ -557,16 +571,11 @@ void kernfs_put(struct kernfs_node *kn)
 	if (kernfs_type(kn) == KERNFS_LINK)
 		kernfs_put(kn->symlink.target_kn);
 
-	kfree_const(kn->name);
-
-	if (kn->iattr) {
-		simple_xattrs_free(&kn->iattr->xattrs, NULL);
-		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
-	}
 	spin_lock(&kernfs_idr_lock);
 	idr_remove(&root->ino_idr, (u32)kernfs_ino(kn));
 	spin_unlock(&kernfs_idr_lock);
-	kmem_cache_free(kernfs_node_cache, kn);
+
+	call_rcu(&kn->rcu, kernfs_free_rcu);
 
 	kn = parent;
 	if (kn) {
@@ -575,7 +584,7 @@ void kernfs_put(struct kernfs_node *kn)
 	} else {
 		/* just released the root kn, free @root too */
 		idr_destroy(&root->ino_idr);
-		kfree(root);
+		kfree_rcu(root, rcu);
 	}
 }
 EXPORT_SYMBOL_GPL(kernfs_put);
@@ -715,7 +724,7 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root,
 	ino_t ino = kernfs_id_ino(id);
 	u32 gen = kernfs_id_gen(id);
 
-	spin_lock(&kernfs_idr_lock);
+	rcu_read_lock();
 
 	kn = idr_find(&root->ino_idr, (u32)ino);
 	if (!kn)
@@ -739,10 +748,10 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root,
 	if (unlikely(!__kernfs_active(kn) || !atomic_inc_not_zero(&kn->count)))
 		goto err_unlock;
 
-	spin_unlock(&kernfs_idr_lock);
+	rcu_read_unlock();
 	return kn;
 err_unlock:
-	spin_unlock(&kernfs_idr_lock);
+	rcu_read_unlock();
 	return NULL;
 }
 

fs/kernfs/file.c

@@ -483,9 +483,11 @@ static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma)
 		goto out_put;
 
 	rc = 0;
-	of->mmapped = true;
-	of_on(of)->nr_mmapped++;
-	of->vm_ops = vma->vm_ops;
+	if (!of->mmapped) {
+		of->mmapped = true;
+		of_on(of)->nr_mmapped++;
+		of->vm_ops = vma->vm_ops;
+	}
 	vma->vm_ops = &kernfs_vm_ops;
 out_put:
 	kernfs_put_active(of->kn);

fs/kernfs/kernfs-internal.h

@@ -49,6 +49,8 @@ struct kernfs_root {
 	struct rw_semaphore	kernfs_rwsem;
 	struct rw_semaphore	kernfs_iattr_rwsem;
 	struct rw_semaphore	kernfs_supers_rwsem;
+
+	struct rcu_head		rcu;
 };
 
 /* +1 to avoid triggering overflow warning when negating it */

fs/sysfs/group.c

@@ -31,6 +31,17 @@ static void remove_files(struct kernfs_node *parent,
 			kernfs_remove_by_name(parent, (*bin_attr)->attr.name);
 }
 
+static umode_t __first_visible(const struct attribute_group *grp, struct kobject *kobj)
+{
+	if (grp->attrs && grp->attrs[0] && grp->is_visible)
+		return grp->is_visible(kobj, grp->attrs[0], 0);
+
+	if (grp->bin_attrs && grp->bin_attrs[0] && grp->is_bin_visible)
+		return grp->is_bin_visible(kobj, grp->bin_attrs[0], 0);
+
+	return 0;
+}
+
 static int create_files(struct kernfs_node *parent, struct kobject *kobj,
 			kuid_t uid, kgid_t gid,
 			const struct attribute_group *grp, int update)
@@ -52,6 +63,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
 				kernfs_remove_by_name(parent, (*attr)->name);
 			if (grp->is_visible) {
 				mode = grp->is_visible(kobj, *attr, i);
+				mode &= ~SYSFS_GROUP_INVISIBLE;
 				if (!mode)
 					continue;
 			}
@@ -81,6 +93,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
 						(*bin_attr)->attr.name);
 			if (grp->is_bin_visible) {
 				mode = grp->is_bin_visible(kobj, *bin_attr, i);
+				mode &= ~SYSFS_GROUP_INVISIBLE;
 				if (!mode)
 					continue;
 			}
@@ -127,16 +140,31 @@ static int internal_create_group(struct kobject *kobj, int update,
 
 	kobject_get_ownership(kobj, &uid, &gid);
 	if (grp->name) {
+		umode_t mode = __first_visible(grp, kobj);
+
+		if (mode & SYSFS_GROUP_INVISIBLE)
+			mode = 0;
+		else
+			mode = S_IRWXU | S_IRUGO | S_IXUGO;
+
 		if (update) {
 			kn = kernfs_find_and_get(kobj->sd, grp->name);
 			if (!kn) {
-				pr_warn("Can't update unknown attr grp name: %s/%s\n",
-					kobj->name, grp->name);
-				return -EINVAL;
+				pr_debug("attr grp %s/%s not created yet\n",
+					 kobj->name, grp->name);
+				/* may have been invisible prior to this update */
+				update = 0;
+			} else if (!mode) {
+				sysfs_remove_group(kobj, grp);
+				kernfs_put(kn);
+				return 0;
 			}
-		} else {
-			kn = kernfs_create_dir_ns(kobj->sd, grp->name,
-						  S_IRWXU | S_IRUGO | S_IXUGO,
+		}
+
+		if (!update) {
+			if (!mode)
+				return 0;
+			kn = kernfs_create_dir_ns(kobj->sd, grp->name, mode,
 						  uid, gid, kobj, NULL);
 			if (IS_ERR(kn)) {
 				if (PTR_ERR(kn) == -EEXIST)
@@ -279,9 +307,8 @@ void sysfs_remove_group(struct kobject *kobj,
 	if (grp->name) {
 		kn = kernfs_find_and_get(parent, grp->name);
 		if (!kn) {
-			WARN(!kn, KERN_WARNING
-			     "sysfs group '%s' not found for kobject '%s'\n",
-			     grp->name, kobject_name(kobj));
+			pr_debug("sysfs group '%s' not found for kobject '%s'\n",
+				 grp->name, kobject_name(kobj));
 			return;
 		}
 	} else {
@@ -318,13 +345,13 @@ void sysfs_remove_groups(struct kobject *kobj,
 EXPORT_SYMBOL_GPL(sysfs_remove_groups);
 
 /**
- * sysfs_merge_group - merge files into a pre-existing attribute group.
+ * sysfs_merge_group - merge files into a pre-existing named attribute group.
  * @kobj:	The kobject containing the group.
  * @grp:	The files to create and the attribute group they belong to.
  *
- * This function returns an error if the group doesn't exist or any of the
- * files already exist in that group, in which case none of the new files
- * are created.
+ * This function returns an error if the group doesn't exist, the .name field is
+ * NULL or any of the files already exist in that group, in which case none of
+ * the new files are created.
  */
 int sysfs_merge_group(struct kobject *kobj,
 		       const struct attribute_group *grp)
@@ -356,7 +383,7 @@ int sysfs_merge_group(struct kobject *kobj,
 EXPORT_SYMBOL_GPL(sysfs_merge_group);
 
 /**
- * sysfs_unmerge_group - remove files from a pre-existing attribute group.
+ * sysfs_unmerge_group - remove files from a pre-existing named attribute group.
  * @kobj:	The kobject containing the group.
  * @grp:	The files to remove and the attribute group they belong to.
  */

include/linux/cpu.h

@@ -130,7 +130,7 @@ static inline void cpu_maps_update_done(void)
 static inline int add_cpu(unsigned int cpu) { return 0;}
 
 #endif /* CONFIG_SMP */
-extern struct bus_type cpu_subsys;
+extern const struct bus_type cpu_subsys;
 
 extern int lockdep_is_cpus_held(void);
 

include/linux/firmware.h

@@ -4,6 +4,7 @@
 
 #include <linux/types.h>
 #include <linux/compiler.h>
+#include <linux/cleanup.h>
 #include <linux/gfp.h>
 
 #define FW_ACTION_NOUEVENT 0
@@ -198,4 +199,6 @@ static inline void firmware_upload_unregister(struct fw_upload *fw_upload)
 
 int firmware_request_cache(struct device *device, const char *name);
 
+DEFINE_FREE(firmware, struct firmware *, release_firmware(_T))
+
 #endif

include/linux/fwnode.h

@@ -9,10 +9,16 @@
 #ifndef _LINUX_FWNODE_H_
 #define _LINUX_FWNODE_H_
 
-#include <linux/types.h>
-#include <linux/list.h>
 #include <linux/bits.h>
 #include <linux/err.h>
+#include <linux/list.h>
+#include <linux/types.h>
+
+enum dev_dma_attr {
+	DEV_DMA_NOT_SUPPORTED,
+	DEV_DMA_NON_COHERENT,
+	DEV_DMA_COHERENT,
+};
 
 struct fwnode_operations;
 struct device;
@@ -53,8 +59,10 @@ struct fwnode_handle {
  * fwnode link flags
  *
  * CYCLE:	The fwnode link is part of a cycle. Don't defer probe.
+ * IGNORE:	Completely ignore this link, even during cycle detection.
  */
 #define FWLINK_FLAG_CYCLE			BIT(0)
+#define FWLINK_FLAG_IGNORE			BIT(1)
 
 struct fwnode_link {
 	struct fwnode_handle *supplier;
@@ -187,7 +195,6 @@ struct fwnode_operations {
 		if (fwnode_has_op(fwnode, op))				\
 			(fwnode)->ops->op(fwnode, ## __VA_ARGS__);	\
 	} while (false)
-#define get_dev_from_fwnode(fwnode)	get_device((fwnode)->dev)
 
 static inline void fwnode_init(struct fwnode_handle *fwnode,
 			       const struct fwnode_operations *ops)
@@ -209,9 +216,10 @@ static inline void fwnode_dev_initialized(struct fwnode_handle *fwnode,
 		fwnode->flags &= ~FWNODE_FLAG_INITIALIZED;
 }
 
-extern bool fw_devlink_is_strict(void);
-int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup);
+int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup,
+		    u8 flags);
 void fwnode_links_purge(struct fwnode_handle *fwnode);
 void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode);
+bool fw_devlink_is_strict(void);
 
 #endif

include/linux/kernfs.h

@@ -206,23 +206,25 @@ struct kernfs_node {
 
 	const void		*ns;	/* namespace tag */
 	unsigned int		hash;	/* ns + name hash */
+	unsigned short		flags;
+	umode_t			mode;
+
 	union {
 		struct kernfs_elem_dir		dir;
 		struct kernfs_elem_symlink	symlink;
 		struct kernfs_elem_attr		attr;
 	};
 
-	void			*priv;
-
 	/*
 	 * 64bit unique ID.  On 64bit ino setups, id is the ino.  On 32bit,
 	 * the low 32bits are ino and upper generation.
 	 */
 	u64			id;
 
-	unsigned short		flags;
-	umode_t			mode;
+	void			*priv;
 	struct kernfs_iattrs	*iattr;
+
+	struct rcu_head		rcu;
 };
 
 /*

include/linux/kobject.h

@@ -38,7 +38,7 @@ extern char uevent_helper[];
 #endif
 
 /* counter to tag the uevent, read only except for the kobject core */
-extern u64 uevent_seqnum;
+extern atomic64_t uevent_seqnum;
 
 /*
  * The actions here must match the index to the string array

include/linux/property.h

@@ -11,6 +11,7 @@
 #define _LINUX_PROPERTY_H_
 
 #include <linux/args.h>
+#include <linux/array_size.h>
 #include <linux/bits.h>
 #include <linux/fwnode.h>
 #include <linux/stddef.h>
@@ -27,12 +28,6 @@ enum dev_prop_type {
 	DEV_PROP_REF,
 };
 
-enum dev_dma_attr {
-	DEV_DMA_NOT_SUPPORTED,
-	DEV_DMA_NON_COHERENT,
-	DEV_DMA_COHERENT,
-};
-
 const struct fwnode_handle *__dev_fwnode_const(const struct device *dev);
 struct fwnode_handle *__dev_fwnode(struct device *dev);
 #define dev_fwnode(dev)							\
@@ -156,11 +151,9 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode);
 	for (parent = fwnode_get_parent(fwnode); parent;	\
 	     parent = fwnode_get_next_parent(parent))
 
-struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwnode);
 unsigned int fwnode_count_parents(const struct fwnode_handle *fwn);
 struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwn,
 					    unsigned int depth);
-bool fwnode_is_ancestor_of(const struct fwnode_handle *ancestor, const struct fwnode_handle *child);
 struct fwnode_handle *fwnode_get_next_child_node(
 	const struct fwnode_handle *fwnode, struct fwnode_handle *child);
 struct fwnode_handle *fwnode_get_next_available_child_node(

include/linux/sysfs.h

@@ -61,22 +61,32 @@ do {							\
 /**
  * struct attribute_group - data structure used to declare an attribute group.
  * @name:	Optional: Attribute group name
- *		If specified, the attribute group will be created in
- *		a new subdirectory with this name.
+ *		If specified, the attribute group will be created in a
+ *		new subdirectory with this name. Additionally when a
+ *		group is named, @is_visible and @is_bin_visible may
+ *		return SYSFS_GROUP_INVISIBLE to control visibility of
+ *		the directory itself.
  * @is_visible:	Optional: Function to return permissions associated with an
- *		attribute of the group. Will be called repeatedly for each
- *		non-binary attribute in the group. Only read/write
+ *		attribute of the group. Will be called repeatedly for
+ *		each non-binary attribute in the group. Only read/write
  *		permissions as well as SYSFS_PREALLOC are accepted. Must
- *		return 0 if an attribute is not visible. The returned value
- *		will replace static permissions defined in struct attribute.
+ *		return 0 if an attribute is not visible. The returned
+ *		value will replace static permissions defined in struct
+ *		attribute. Use SYSFS_GROUP_VISIBLE() when assigning this
+ *		callback to specify separate _group_visible() and
+ *		_attr_visible() handlers.
  * @is_bin_visible:
  *		Optional: Function to return permissions associated with a
  *		binary attribute of the group. Will be called repeatedly
  *		for each binary attribute in the group. Only read/write
- *		permissions as well as SYSFS_PREALLOC are accepted. Must
- *		return 0 if a binary attribute is not visible. The returned
- *		value will replace static permissions defined in
- *		struct bin_attribute.
+ *		permissions as well as SYSFS_PREALLOC (and the
+ *		visibility flags for named groups) are accepted. Must
+ *		return 0 if a binary attribute is not visible. The
+ *		returned value will replace static permissions defined
+ *		in struct bin_attribute. If @is_visible is not set, Use
+ *		SYSFS_GROUP_VISIBLE() when assigning this callback to
+ *		specify separate _group_visible() and _attr_visible()
+ *		handlers.
  * @attrs:	Pointer to NULL terminated list of attributes.
  * @bin_attrs:	Pointer to NULL terminated list of binary attributes.
  *		Either attrs or bin_attrs or both must be provided.
@@ -91,13 +101,121 @@ struct attribute_group {
 	struct bin_attribute	**bin_attrs;
 };
 
+#define SYSFS_PREALLOC		010000
+#define SYSFS_GROUP_INVISIBLE	020000
+
+/*
+ * DEFINE_SYSFS_GROUP_VISIBLE(name):
+ *	A helper macro to pair with the assignment of ".is_visible =
+ *	SYSFS_GROUP_VISIBLE(name)", that arranges for the directory
+ *	associated with a named attribute_group to optionally be hidden.
+ *	This allows for static declaration of attribute_groups, and the
+ *	simplification of attribute visibility lifetime that implies,
+ *	without polluting sysfs with empty attribute directories.
+ * Ex.
+ *
+ * static umode_t example_attr_visible(struct kobject *kobj,
+ *                                   struct attribute *attr, int n)
+ * {
+ *       if (example_attr_condition)
+ *               return 0;
+ *       else if (ro_attr_condition)
+ *               return 0444;
+ *       return a->mode;
+ * }
+ *
+ * static bool example_group_visible(struct kobject *kobj)
+ * {
+ *       if (example_group_condition)
+ *               return false;
+ *       return true;
+ * }
+ *
+ * DEFINE_SYSFS_GROUP_VISIBLE(example);
+ *
+ * static struct attribute_group example_group = {
+ *       .name = "example",
+ *       .is_visible = SYSFS_GROUP_VISIBLE(example),
+ *       .attrs = &example_attrs,
+ * };
+ *
+ * Note that it expects <name>_attr_visible and <name>_group_visible to
+ * be defined. For cases where individual attributes do not need
+ * separate visibility consideration, only entire group visibility at
+ * once, see DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE().
+ */
+#define DEFINE_SYSFS_GROUP_VISIBLE(name)                             \
+	static inline umode_t sysfs_group_visible_##name(            \
+		struct kobject *kobj, struct attribute *attr, int n) \
+	{                                                            \
+		if (n == 0 && !name##_group_visible(kobj))           \
+			return SYSFS_GROUP_INVISIBLE;                \
+		return name##_attr_visible(kobj, attr, n);           \
+	}
+
+/*
+ * DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(name):
+ *	A helper macro to pair with SYSFS_GROUP_VISIBLE() that like
+ *	DEFINE_SYSFS_GROUP_VISIBLE() controls group visibility, but does
+ *	not require the implementation of a per-attribute visibility
+ *	callback.
+ * Ex.
+ *
+ * static bool example_group_visible(struct kobject *kobj)
+ * {
+ *       if (example_group_condition)
+ *               return false;
+ *       return true;
+ * }
+ *
+ * DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(example);
+ *
+ * static struct attribute_group example_group = {
+ *       .name = "example",
+ *       .is_visible = SYSFS_GROUP_VISIBLE(example),
+ *       .attrs = &example_attrs,
+ * };
+ */
+#define DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(name)                   \
+	static inline umode_t sysfs_group_visible_##name(         \
+		struct kobject *kobj, struct attribute *a, int n) \
+	{                                                         \
+		if (n == 0 && !name##_group_visible(kobj))        \
+			return SYSFS_GROUP_INVISIBLE;             \
+		return a->mode;                                   \
+	}
+
+/*
+ * Same as DEFINE_SYSFS_GROUP_VISIBLE, but for groups with only binary
+ * attributes. If an attribute_group defines both text and binary
+ * attributes, the group visibility is determined by the function
+ * specified to is_visible() not is_bin_visible()
+ */
+#define DEFINE_SYSFS_BIN_GROUP_VISIBLE(name)                             \
+	static inline umode_t sysfs_group_visible_##name(                \
+		struct kobject *kobj, struct bin_attribute *attr, int n) \
+	{                                                                \
+		if (n == 0 && !name##_group_visible(kobj))               \
+			return SYSFS_GROUP_INVISIBLE;                    \
+		return name##_attr_visible(kobj, attr, n);               \
+	}
+
+#define DEFINE_SIMPLE_SYSFS_BIN_GROUP_VISIBLE(name)                   \
+	static inline umode_t sysfs_group_visible_##name(             \
+		struct kobject *kobj, struct bin_attribute *a, int n) \
+	{                                                             \
+		if (n == 0 && !name##_group_visible(kobj))            \
+			return SYSFS_GROUP_INVISIBLE;                 \
+		return a->mode;                                       \
+	}
+
+#define SYSFS_GROUP_VISIBLE(fn) sysfs_group_visible_##fn
+
 /*
  * Use these macros to make defining attributes easier.
  * See include/linux/device.h for examples..
  */
 
-#define SYSFS_PREALLOC 010000
-
 #define __ATTR(_name, _mode, _show, _store) {				\
 	.attr = {.name = __stringify(_name),				\
 		 .mode = VERIFY_OCTAL_PERMISSIONS(_mode) },		\

kernel/ksysfs.c

@@ -39,7 +39,7 @@ static struct kobj_attribute _name##_attr = __ATTR_RW(_name)
 static ssize_t uevent_seqnum_show(struct kobject *kobj,
 				  struct kobj_attribute *attr, char *buf)
 {
-	return sysfs_emit(buf, "%llu\n", (unsigned long long)uevent_seqnum);
+	return sysfs_emit(buf, "%llu\n", (u64)atomic64_read(&uevent_seqnum));
 }
 KERNEL_ATTR_RO(uevent_seqnum);
 

kernel/workqueue.c

@@ -7080,7 +7080,7 @@ static struct device_attribute wq_sysfs_unbound_attrs[] = {
 	__ATTR_NULL,
 };
 
-static struct bus_type wq_subsys = {
+static const struct bus_type wq_subsys = {
 	.name				= "workqueue",
 	.dev_groups			= wq_sysfs_groups,
 };

lib/kobject_uevent.c

@@ -30,7 +30,7 @@
 #include <net/net_namespace.h>
 
 
-u64 uevent_seqnum;
+atomic64_t uevent_seqnum;
 #ifdef CONFIG_UEVENT_HELPER
 char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
 #endif
@@ -42,10 +42,9 @@ struct uevent_sock {
 
 #ifdef CONFIG_NET
 static LIST_HEAD(uevent_sock_list);
-#endif
-
-/* This lock protects uevent_seqnum and uevent_sock_list */
+/* This lock protects uevent_sock_list */
 static DEFINE_MUTEX(uevent_sock_mutex);
+#endif
 
 /* the strings here must match the enum in include/linux/kobject.h */
 static const char *kobject_actions[] = {
@@ -315,6 +314,7 @@ static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env,
 	int retval = 0;
 
 	/* send netlink message */
+	mutex_lock(&uevent_sock_mutex);
 	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
 		struct sock *uevent_sock = ue_sk->sk;
 
@@ -334,6 +334,7 @@ static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env,
 		if (retval == -ENOBUFS || retval == -ESRCH)
 			retval = 0;
 	}
+	mutex_unlock(&uevent_sock_mutex);
 	consume_skb(skb);
 
 	return retval;
@@ -583,16 +584,14 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 		break;
 	}
 
-	mutex_lock(&uevent_sock_mutex);
 	/* we will send an event, so request a new sequence number */
-	retval = add_uevent_var(env, "SEQNUM=%llu", ++uevent_seqnum);
-	if (retval) {
-		mutex_unlock(&uevent_sock_mutex);
+	retval = add_uevent_var(env, "SEQNUM=%llu",
+				atomic64_inc_return(&uevent_seqnum));
+	if (retval)
 		goto exit;
-	}
+
 	retval = kobject_uevent_net_broadcast(kobj, env, action_string,
 					      devpath);
-	mutex_unlock(&uevent_sock_mutex);
 
 #ifdef CONFIG_UEVENT_HELPER
 	/* call uevent_helper, usually only enabled during early boot */
@@ -688,7 +687,8 @@ static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb,
 	int ret;
 
 	/* bump and prepare sequence number */
-	ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", ++uevent_seqnum);
+	ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu",
+		       atomic64_inc_return(&uevent_seqnum));
 	if (ret < 0 || (size_t)ret >= sizeof(buf))
 		return -ENOMEM;
 	ret++;
@@ -742,9 +742,7 @@ static int uevent_net_rcv_skb(struct sk_buff *skb, struct nlmsghdr *nlh,
 		return -EPERM;
 	}
 
-	mutex_lock(&uevent_sock_mutex);
 	ret = uevent_net_broadcast(net->uevent_sock->sk, skb, extack);
-	mutex_unlock(&uevent_sock_mutex);
 
 	return ret;
 }