Merge tag 'driver-core-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here are the set of driver core and kernfs changes for 6.8-rc1.
  Nothing major in here this release cycle, just lots of small cleanups
  and some tweaks on kernfs that in the very end, got reverted and will
  come back in a safer way next release cycle.

  Included in here are:

   - more driver core 'const' cleanups and fixes

   - fw_devlink=rpm is now the default behavior

   - kernfs tiny changes to remove some string functions

   - cpu handling in the driver core is updated to work better on many
     systems that add topologies and cpus after booting

   - other minor changes and cleanups

  All of the cpu handling patches have been acked by the respective
  maintainers and are coming in here in one series. Everything has been
  in linux-next for a while with no reported issues"

* tag 'driver-core-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (51 commits)
  Revert "kernfs: convert kernfs_idr_lock to an irq safe raw spinlock"
  kernfs: convert kernfs_idr_lock to an irq safe raw spinlock
  class: fix use-after-free in class_register()
  PM: clk: make pm_clk_add_notifier() take a const pointer
  EDAC: constantify the struct bus_type usage
  kernfs: fix reference to renamed function
  driver core: device.h: fix Excess kernel-doc description warning
  driver core: class: fix Excess kernel-doc description warning
  driver core: mark remaining local bus_type variables as const
  driver core: container: make container_subsys const
  driver core: bus: constantify subsys_register() calls
  driver core: bus: make bus_sort_breadthfirst() take a const pointer
  kernfs: d_obtain_alias(NULL) will do the right thing...
  driver core: Better advertise dev_err_probe()
  kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy()
  kernfs: Convert kernfs_name_locked() from strlcpy() to strscpy()
  kernfs: Convert kernfs_walk_ns() from strlcpy() to strscpy()
  initramfs: Expose retained initrd as sysfs file
  fs/kernfs/dir: obey S_ISGID
  kernel/cgroup: use kernfs_create_dir_ns()
  ...

24 files changed, 104 insertions, 73 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 6f2bfcf7645c..3c3f8037ebed 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -314,7 +314,6 @@ config ACPI_HOTPLUG_CPU
 	bool
 	depends on ACPI_PROCESSOR && HOTPLUG_CPU
 	select ACPI_CONTAINER
-	default y
 
 config ACPI_PROCESSOR_AGGREGATOR
 	tristate "Processor Aggregator"
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 0f5218e361df..4fe2ef54088c 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -184,24 +184,6 @@ static void __init acpi_pcc_cpufreq_init(void) {}
 
 /* Initialization */
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
-int __weak acpi_map_cpu(acpi_handle handle,
-		phys_cpuid_t physid, u32 acpi_id, int *pcpu)
-{
-	return -ENODEV;
-}
-
-int __weak acpi_unmap_cpu(int cpu)
-{
-	return -ENODEV;
-}
-
-int __weak arch_register_cpu(int cpu)
-{
-	return -ENODEV;
-}
-
-void __weak arch_unregister_cpu(int cpu) {}
-
 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 {
 	unsigned long long sta;
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 07d76fb740b6..a6ead5204046 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -881,6 +881,7 @@ static struct fwnode_handle *acpi_parse_string_ref(const struct fwnode_handle *f
  * @index: Index of the reference to return
  * @num_args: Maximum number of arguments after each reference
  * @args: Location to store the returned reference with optional arguments
+ *	  (may be NULL)
  *
  * Find property with @name, verifify that it is a package containing at least
  * one object reference and if so, store the ACPI device object pointer to the
@@ -938,6 +939,9 @@ int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode,
 		if (!device)
 			return -EINVAL;
 
+		if (!args)
+			return 0;
+
 		args->fwnode = acpi_fwnode_handle(device);
 		args->nargs = 0;
 
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 5aaa0865625d..018ac202de34 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -219,20 +219,34 @@ static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
 
 static DEVICE_ATTR_RO(cpu_capacity);
 
-static int register_cpu_capacity_sysctl(void)
+static int cpu_capacity_sysctl_add(unsigned int cpu)
 {
-	int i;
-	struct device *cpu;
+	struct device *cpu_dev = get_cpu_device(cpu);
 
-	for_each_possible_cpu(i) {
-		cpu = get_cpu_device(i);
-		if (!cpu) {
-			pr_err("%s: too early to get CPU%d device!\n",
-			       __func__, i);
-			continue;
-		}
-		device_create_file(cpu, &dev_attr_cpu_capacity);
-	}
+	if (!cpu_dev)
+		return -ENOENT;
+
+	device_create_file(cpu_dev, &dev_attr_cpu_capacity);
+
+	return 0;
+}
+
+static int cpu_capacity_sysctl_remove(unsigned int cpu)
+{
+	struct device *cpu_dev = get_cpu_device(cpu);
+
+	if (!cpu_dev)
+		return -ENOENT;
+
+	device_remove_file(cpu_dev, &dev_attr_cpu_capacity);
+
+	return 0;
+}
+
+static int register_cpu_capacity_sysctl(void)
+{
+	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "topology/cpu-capacity",
+			  cpu_capacity_sysctl_add, cpu_capacity_sysctl_remove);
 
 	return 0;
 }
diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c
index 4d4c2c8d26c4..d3a2c40c2f12 100644
--- a/drivers/base/auxiliary.c
+++ b/drivers/base/auxiliary.c
@@ -244,7 +244,7 @@ static void auxiliary_bus_shutdown(struct device *dev)
 		auxdrv->shutdown(auxdev);
 }
 
-static struct bus_type auxiliary_bus_type = {
+static const struct bus_type auxiliary_bus_type = {
 	.name = "auxiliary",
 	.probe = auxiliary_bus_probe,
 	.remove = auxiliary_bus_remove,
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 84a21084d67d..daee55c9b2d9 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -1030,7 +1030,7 @@ static void device_insertion_sort_klist(struct device *a, struct list_head *list
 	list_move_tail(&a->p->knode_bus.n_node, list);
 }
 
-void bus_sort_breadthfirst(struct bus_type *bus,
+void bus_sort_breadthfirst(const struct bus_type *bus,
 			   int (*compare)(const struct device *a,
 					  const struct device *b))
 {
@@ -1194,7 +1194,7 @@ static void system_root_device_release(struct device *dev)
 	kfree(dev);
 }
 
-static int subsys_register(struct bus_type *subsys,
+static int subsys_register(const struct bus_type *subsys,
 			   const struct attribute_group **groups,
 			   struct kobject *parent_of_root)
 {
@@ -1264,7 +1264,7 @@ err_sp:
  * directory itself and not some create fake root-device placed in
  * /sys/devices/system/<name>.
  */
-int subsys_system_register(struct bus_type *subsys,
+int subsys_system_register(const struct bus_type *subsys,
 			   const struct attribute_group **groups)
 {
 	return subsys_register(subsys, groups, &system_kset->kobj);
@@ -1282,7 +1282,7 @@ EXPORT_SYMBOL_GPL(subsys_system_register);
  * There's no restriction on device naming.  This is for kernel software
  * constructs which need sysfs interface.
  */
-int subsys_virtual_register(struct bus_type *subsys,
+int subsys_virtual_register(const struct bus_type *subsys,
 			    const struct attribute_group **groups)
 {
 	struct kobject *virtual_dir;
diff --git a/drivers/base/class.c b/drivers/base/class.c
index 7e78aee0fd6c..7b38fdf8e1d7 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -213,6 +213,7 @@ int class_register(const struct class *cls)
 	return 0;
 
 err_out:
+	lockdep_unregister_key(key);
 	kfree(cp);
 	return error;
 }
diff --git a/drivers/base/container.c b/drivers/base/container.c
index 1ba42d2d3532..f40588ebc3f5 100644
--- a/drivers/base/container.c
+++ b/drivers/base/container.c
@@ -24,7 +24,7 @@ static int container_offline(struct device *dev)
 	return cdev->offline ? cdev->offline(cdev) : 0;
 }
 
-struct bus_type container_subsys = {
+const struct bus_type container_subsys = {
 	.name = CONTAINER_BUS_NAME,
 	.dev_name = CONTAINER_BUS_NAME,
 	.online = trivial_online,
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 67ba592afc77..14d46af40f9a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -298,7 +298,7 @@ static inline bool device_link_flag_is_sync_state_only(u32 flags)
  * Check if @target depends on @dev or any device dependent on it (its child or
  * its consumer etc).  Return 1 if that is the case or 0 otherwise.
  */
-int device_is_dependent(struct device *dev, void *target)
+static int device_is_dependent(struct device *dev, void *target)
 {
 	struct device_link *link;
 	int ret;
@@ -1641,7 +1641,7 @@ static void device_links_purge(struct device *dev)
 #define FW_DEVLINK_FLAGS_RPM		(FW_DEVLINK_FLAGS_ON | \
 					 DL_FLAG_PM_RUNTIME)
 
-static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
+static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_RPM;
 static int __init fw_devlink_setup(char *arg)
 {
 	if (!arg)
@@ -4944,13 +4944,14 @@ define_dev_printk_level(_dev_info, KERN_INFO);
  *
  * 	return dev_err_probe(dev, err, ...);
  *
- * Note that it is deemed acceptable to use this function for error
- * prints during probe even if the @err is known to never be -EPROBE_DEFER.
+ * Using this helper in your probe function is totally fine even if @err is
+ * known to never be -EPROBE_DEFER.
  * The benefit compared to a normal dev_err() is the standardized format
- * of the error code and the fact that the error code is returned.
+ * of the error code, it being emitted symbolically (i.e. you get "EAGAIN"
+ * instead of "-35") and the fact that the error code is returned which allows
+ * more compact error paths.
  *
  * Returns @err.
- *
  */
 int dev_err_probe(const struct device *dev, int err, const char *fmt, ...)
 {
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 548491de818e..47de0f140ba6 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -525,19 +525,42 @@ bool cpu_is_hotpluggable(unsigned int cpu)
 EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
 
 #ifdef CONFIG_GENERIC_CPU_DEVICES
-static DEFINE_PER_CPU(struct cpu, cpu_devices);
-#endif
+DEFINE_PER_CPU(struct cpu, cpu_devices);
+
+bool __weak arch_cpu_is_hotpluggable(int cpu)
+{
+	return false;
+}
+
+int __weak arch_register_cpu(int cpu)
+{
+	struct cpu *c = &per_cpu(cpu_devices, cpu);
+
+	c->hotpluggable = arch_cpu_is_hotpluggable(cpu);
+
+	return register_cpu(c, cpu);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void __weak arch_unregister_cpu(int num)
+{
+	unregister_cpu(&per_cpu(cpu_devices, num));
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+#endif /* CONFIG_GENERIC_CPU_DEVICES */
 
 static void __init cpu_dev_register_generic(void)
 {
-#ifdef CONFIG_GENERIC_CPU_DEVICES
-	int i;
+	int i, ret;
 
-	for_each_possible_cpu(i) {
-		if (register_cpu(&per_cpu(cpu_devices, i), i))
-			panic("Failed to register CPU device");
+	if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES))
+		return;
+
+	for_each_present_cpu(i) {
+		ret = arch_register_cpu(i);
+		if (ret)
+			pr_warn("register_cpu %d failed (%d)\n", i, ret);
 	}
-#endif
 }
 
 #ifdef CONFIG_GENERIC_CPU_VULNERABILITIES
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 0c3725c3eefa..85152537dbf1 100644
--- a/drivers/base/dd.c
+++ b/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\n");
+		dev_info(p->device, "deferred probe pending: %s", p->deferred_probe_reason ?: "(reason unknown)\n");
 	mutex_unlock(&deferred_probe_mutex);
 
 	fw_devlink_probing_done();
diff --git a/drivers/base/init.c b/drivers/base/init.c
index 397eb9880cec..c4954835128c 100644
--- a/drivers/base/init.c
+++ b/drivers/base/init.c
@@ -35,8 +35,8 @@ void __init driver_init(void)
 	of_core_init();
 	platform_bus_init();
 	auxiliary_bus_init();
-	cpu_dev_init();
 	memory_dev_init();
 	node_dev_init();
+	cpu_dev_init();
 	container_dev_init();
 }
diff --git a/drivers/base/isa.c b/drivers/base/isa.c
index 675ad3139224..e23d0b49a793 100644
--- a/drivers/base/isa.c
+++ b/drivers/base/isa.c
@@ -82,7 +82,7 @@ static int isa_bus_resume(struct device *dev)
 	return 0;
 }
 
-static struct bus_type isa_bus_type = {
+static const struct bus_type isa_bus_type = {
 	.name		= "isa",
 	.match		= isa_bus_match,
 	.probe		= isa_bus_probe,
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 8a13babd826c..14f964a7719b 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -68,7 +68,7 @@ static inline unsigned long phys_to_block_id(unsigned long phys)
 static int memory_subsys_online(struct device *dev);
 static int memory_subsys_offline(struct device *dev);
 
-static struct bus_type memory_subsys = {
+static const struct bus_type memory_subsys = {
 	.name = MEMORY_CLASS_NAME,
 	.dev_name = MEMORY_CLASS_NAME,
 	.online = memory_subsys_online,
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 493d533f8375..433897eecbdc 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -21,7 +21,7 @@
 #include <linux/swap.h>
 #include <linux/slab.h>
 
-static struct bus_type node_subsys = {
+static const struct bus_type node_subsys = {
 	.name = "node",
 	.dev_name = "node",
 };
@@ -868,11 +868,15 @@ int __register_one_node(int nid)
 {
 	int error;
 	int cpu;
+	struct node *node;
 
-	node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
-	if (!node_devices[nid])
+	node = kzalloc(sizeof(struct node), GFP_KERNEL);
+	if (!node)
 		return -ENOMEM;
 
+	INIT_LIST_HEAD(&node->access_list);
+	node_devices[nid] = node;
+
 	error = register_node(node_devices[nid], nid);
 
 	/* link cpu under this node */
@@ -881,7 +885,6 @@ int __register_one_node(int nid)
 			register_cpu_under_node(cpu, nid);
 	}
 
-	INIT_LIST_HEAD(&node_devices[nid]->access_list);
 	node_init_caches(nid);
 
 	return error;
diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c
index 4110c19c08dc..e18ba676cdf6 100644
--- a/drivers/base/power/clock_ops.c
+++ b/drivers/base/power/clock_ops.c
@@ -793,7 +793,7 @@ static int pm_clk_notify(struct notifier_block *nb,
  * the remaining members of @clknb should be populated prior to calling this
  * routine.
  */
-void pm_clk_add_notifier(struct bus_type *bus,
+void pm_clk_add_notifier(const struct bus_type *bus,
 				 struct pm_clk_notifier_block *clknb)
 {
 	if (!bus || !clknb)
diff --git a/drivers/base/property.c b/drivers/base/property.c
index 6e39db62446d..a1b01ab42052 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -543,6 +543,7 @@ EXPORT_SYMBOL_GPL(fwnode_property_match_property_string);
  * @nargs:	Number of arguments. Ignored if @nargs_prop is non-NULL.
  * @index:	Index of the reference, from zero onwards.
  * @args:	Result structure with reference and integer arguments.
+ *		May be NULL.
  *
  * Obtain a reference based on a named property in an fwnode, with
  * integer arguments.
diff --git a/drivers/base/soc.c b/drivers/base/soc.c
index 8dec5228fde3..282c38aece0d 100644
--- a/drivers/base/soc.c
+++ b/drivers/base/soc.c
@@ -28,7 +28,7 @@ struct soc_device {
 	int soc_dev_num;
 };
 
-static struct bus_type soc_bus_type = {
+static const struct bus_type soc_bus_type = {
 	.name  = "soc",
 };
 static bool soc_bus_registered;
@@ -106,7 +106,7 @@ static void soc_release(struct device *dev)
 {
 	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
 
-	ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);
+	ida_free(&soc_ida, soc_dev->soc_dev_num);
 	kfree(soc_dev->dev.groups);
 	kfree(soc_dev);
 }
@@ -155,7 +155,7 @@ struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr
 	soc_attr_groups[1] = soc_dev_attr->custom_attr_group;
 
 	/* Fetch a unique (reclaimable) SOC ID. */
-	ret = ida_simple_get(&soc_ida, 0, 0, GFP_KERNEL);
+	ret = ida_alloc(&soc_ida, GFP_KERNEL);
 	if (ret < 0)
 		goto out3;
 	soc_dev->soc_dev_num = ret;
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 1886995a0b3a..36512fb75a20 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -541,6 +541,9 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
 	if (nargs > NR_FWNODE_REFERENCE_ARGS)
 		return -EINVAL;
 
+	if (!args)
+		return 0;
+
 	args->fwnode = software_node_get(refnode);
 	args->nargs = nargs;
 
@@ -747,10 +750,10 @@ static void software_node_release(struct kobject *kobj)
 	struct swnode *swnode = kobj_to_swnode(kobj);
 
 	if (swnode->parent) {
-		ida_simple_remove(&swnode->parent->child_ids, swnode->id);
+		ida_free(&swnode->parent->child_ids, swnode->id);
 		list_del(&swnode->entry);
 	} else {
-		ida_simple_remove(&swnode_root_ids, swnode->id);
+		ida_free(&swnode_root_ids, swnode->id);
 	}
 
 	if (swnode->allocated)
@@ -776,8 +779,8 @@ swnode_register(const struct software_node *node, struct swnode *parent,
 	if (!swnode)
 		return ERR_PTR(-ENOMEM);
 
-	ret = ida_simple_get(parent ? &parent->child_ids : &swnode_root_ids,
-			     0, 0, GFP_KERNEL);
+	ret = ida_alloc(parent ? &parent->child_ids : &swnode_root_ids,
+			GFP_KERNEL);
 	if (ret < 0) {
 		kfree(swnode);
 		return ERR_PTR(ret);
diff --git a/drivers/edac/edac_device.h b/drivers/edac/edac_device.h
index 3f44e6b9d387..7db22a4c83ef 100644
--- a/drivers/edac/edac_device.h
+++ b/drivers/edac/edac_device.h
@@ -176,7 +176,7 @@ struct edac_device_ctl_info {
 	struct edac_dev_sysfs_attribute *sysfs_attributes;
 
 	/* pointer to main 'edac' subsys in sysfs */
-	struct bus_type *edac_subsys;
+	const struct bus_type *edac_subsys;
 
 	/* the internal state of this controller instance */
 	int op_state;
diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c
index 010c26be5846..237a542e045a 100644
--- a/drivers/edac/edac_device_sysfs.c
+++ b/drivers/edac/edac_device_sysfs.c
@@ -229,7 +229,7 @@ static struct kobj_type ktype_device_ctrl = {
 int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
 {
 	struct device *dev_root;
-	struct bus_type *edac_subsys;
+	const struct bus_type *edac_subsys;
 	int err = -ENODEV;
 
 	edac_dbg(1, "\n");
diff --git a/drivers/edac/edac_module.c b/drivers/edac/edac_module.c
index 32a931d0cb71..1c9f62382666 100644
--- a/drivers/edac/edac_module.c
+++ b/drivers/edac/edac_module.c
@@ -67,7 +67,7 @@ char *edac_op_state_to_string(int opstate)
  * sysfs object: /sys/devices/system/edac
  *	need to export to other files
  */
-static struct bus_type edac_subsys = {
+static const struct bus_type edac_subsys = {
 	.name = "edac",
 	.dev_name = "edac",
 };
@@ -90,7 +90,7 @@ static void edac_subsys_exit(void)
 }
 
 /* return pointer to the 'edac' node in sysfs */
-struct bus_type *edac_get_sysfs_subsys(void)
+const struct bus_type *edac_get_sysfs_subsys(void)
 {
 	return &edac_subsys;
 }
diff --git a/drivers/edac/edac_pci_sysfs.c b/drivers/edac/edac_pci_sysfs.c
index 901d4cd3ca38..7b44afcf48db 100644
--- a/drivers/edac/edac_pci_sysfs.c
+++ b/drivers/edac/edac_pci_sysfs.c
@@ -338,7 +338,7 @@ static struct kobj_type ktype_edac_pci_main_kobj = {
 static int edac_pci_main_kobj_setup(void)
 {
 	int err = -ENODEV;
-	struct bus_type *edac_subsys;
+	const struct bus_type *edac_subsys;
 	struct device *dev_root;
 
 	edac_dbg(0, "\n");
diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 9ee1bf2ece10..a1f6cba3ae6c 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -2668,7 +2668,7 @@ static void genpd_release_dev(struct device *dev)
 	kfree(dev);
 }
 
-static struct bus_type genpd_bus_type = {
+static const struct bus_type genpd_bus_type = {
 	.name		= "genpd",
 };