Merge tag 'driver-core-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is a small set of changes for 5.6-rc1 for the driver core and
  some firmware subsystem changes.

  Included in here are:
   - device.h splitup like you asked for months ago
   - devtmpfs minor cleanups
   - firmware core minor changes
   - debugfs fix for lockdown mode
   - kernfs cleanup fix
   - cpu topology minor fix

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

* tag 'driver-core-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (22 commits)
  firmware: Rename FW_OPT_NOFALLBACK to FW_OPT_NOFALLBACK_SYSFS
  devtmpfs: factor out common tail of devtmpfs_{create,delete}_node
  devtmpfs: initify a bit
  devtmpfs: simplify initialization of mount_dev
  devtmpfs: factor out setup part of devtmpfsd()
  devtmpfs: fix theoretical stale pointer deref in devtmpfsd()
  driver core: platform: fix u32 greater or equal to zero comparison
  cpu-topology: Don't error on more than CONFIG_NR_CPUS CPUs in device tree
  debugfs: Return -EPERM when locked down
  driver core: Print device when resources present in really_probe()
  driver core: Fix test_async_driver_probe if NUMA is disabled
  driver core: platform: Prevent resouce overflow from causing infinite loops
  fs/kernfs/dir.c: Clean code by removing always true condition
  component: do not dereference opaque pointer in debugfs
  drivers/component: remove modular code
  debugfs: Fix warnings when building documentation
  device.h: move 'struct driver' stuff out to device/driver.h
  device.h: move 'struct class' stuff out to device/class.h
  device.h: move 'struct bus' stuff out to device/bus.h
  device.h: move dev_printk()-like functions to dev_printk.h
  ...

drivers/base/arch_topology.c

@@ -248,6 +248,16 @@ core_initcall(free_raw_capacity);
 #endif
 
 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
+/*
+ * This function returns the logic cpu number of the node.
+ * There are basically three kinds of return values:
+ * (1) logic cpu number which is > 0.
+ * (2) -ENODEV when the device tree(DT) node is valid and found in the DT but
+ * there is no possible logical CPU in the kernel to match. This happens
+ * when CONFIG_NR_CPUS is configure to be smaller than the number of
+ * CPU nodes in DT. We need to just ignore this case.
+ * (3) -1 if the node does not exist in the device tree
+ */
 static int __init get_cpu_for_node(struct device_node *node)
 {
 	struct device_node *cpu_node;
@@ -261,7 +271,8 @@ static int __init get_cpu_for_node(struct device_node *node)
 	if (cpu >= 0)
 		topology_parse_cpu_capacity(cpu_node, cpu);
 	else
-		pr_crit("Unable to find CPU node for %pOF\n", cpu_node);
+		pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",
+			cpu_node, cpumask_pr_args(cpu_possible_mask));
 
 	of_node_put(cpu_node);
 	return cpu;
@@ -286,9 +297,8 @@ static int __init parse_core(struct device_node *core, int package_id,
 				cpu_topology[cpu].package_id = package_id;
 				cpu_topology[cpu].core_id = core_id;
 				cpu_topology[cpu].thread_id = i;
-			} else {
-				pr_err("%pOF: Can't get CPU for thread\n",
-				       t);
+			} else if (cpu != -ENODEV) {
+				pr_err("%pOF: Can't get CPU for thread\n", t);
 				of_node_put(t);
 				return -EINVAL;
 			}
@@ -307,7 +317,7 @@ static int __init parse_core(struct device_node *core, int package_id,
 
 		cpu_topology[cpu].package_id = package_id;
 		cpu_topology[cpu].core_id = core_id;
-	} else if (leaf) {
+	} else if (leaf && cpu != -ENODEV) {
 		pr_err("%pOF: Can't get CPU for leaf core\n", core);
 		return -EINVAL;
 	}

drivers/base/base.h

 /* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
+ * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2008-2012 Novell Inc.
+ * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (c) 2012-2019 Linux Foundation
+ *
+ * Core driver model functions and structures that should not be
+ * shared outside of the drivers/base/ directory.
+ *
+ */
 #include <linux/notifier.h>
 
 /**
@@ -175,3 +186,11 @@ extern void device_links_unbind_consumers(struct device *dev);
 
 /* device pm support */
 void device_pm_move_to_tail(struct device *dev);
+
+#ifdef CONFIG_DEVTMPFS
+int devtmpfs_create_node(struct device *dev);
+int devtmpfs_delete_node(struct device *dev);
+#else
+static inline int devtmpfs_create_node(struct device *dev) { return 0; }
+static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
+#endif

drivers/base/bus.c

@@ -9,6 +9,7 @@
  */
 
 #include <linux/async.h>
+#include <linux/device/bus.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/errno.h>

drivers/base/class.c

@@ -8,6 +8,7 @@
  * Copyright (c) 2003-2004 IBM Corp.
  */
 
+#include <linux/device/class.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/init.h>

drivers/base/component.c

@@ -11,7 +11,6 @@
 #include <linux/device.h>
 #include <linux/kref.h>
 #include <linux/list.h>
-#include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/debugfs.h>
@@ -102,11 +101,11 @@ static int component_devices_show(struct seq_file *s, void *data)
 	seq_printf(s, "%-40s %20s\n", "device name", "status");
 	seq_puts(s, "-------------------------------------------------------------\n");
 	for (i = 0; i < match->num; i++) {
-		struct device *d = (struct device *)match->compare[i].data;
+		struct component *component = match->compare[i].component;
 
-		seq_printf(s, "%-40s %20s\n", dev_name(d),
-			   match->compare[i].component ?
-			   "registered" : "not registered");
+		seq_printf(s, "%-40s %20s\n",
+			   component ? dev_name(component->dev) : "(unknown)",
+			   component ? (component->bound ? "bound" : "not bound") : "not registered");
 	}
 	mutex_unlock(&component_mutex);
 
@@ -775,5 +774,3 @@ void component_del(struct device *dev, const struct component_ops *ops)
 	kfree(component);
 }
 EXPORT_SYMBOL_GPL(component_del);
-
-MODULE_LICENSE("GPL v2");

drivers/base/dd.c

@@ -516,7 +516,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	atomic_inc(&probe_count);
 	pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
 		 drv->bus->name, __func__, drv->name, dev_name(dev));
-	WARN_ON(!list_empty(&dev->devres_head));
+	if (!list_empty(&dev->devres_head)) {
+		dev_crit(dev, "Resources present before probing\n");
+		return -EBUSY;
+	}
 
 re_probe:
 	dev->driver = drv;

drivers/base/devtmpfs.c

@@ -30,11 +30,7 @@
 
 static struct task_struct *thread;
 
-#if defined CONFIG_DEVTMPFS_MOUNT
-static int mount_dev = 1;
-#else
-static int mount_dev;
-#endif
+static int __initdata mount_dev = IS_ENABLED(CONFIG_DEVTMPFS_MOUNT);
 
 static DEFINE_SPINLOCK(req_lock);
 
@@ -93,6 +89,23 @@ static inline int is_blockdev(struct device *dev)
 static inline int is_blockdev(struct device *dev) { return 0; }
 #endif
 
+static int devtmpfs_submit_req(struct req *req, const char *tmp)
+{
+	init_completion(&req->done);
+
+	spin_lock(&req_lock);
+	req->next = requests;
+	requests = req;
+	spin_unlock(&req_lock);
+
+	wake_up_process(thread);
+	wait_for_completion(&req->done);
+
+	kfree(tmp);
+
+	return req->err;
+}
+
 int devtmpfs_create_node(struct device *dev)
 {
 	const char *tmp = NULL;
@@ -117,19 +130,7 @@ int devtmpfs_create_node(struct device *dev)
 
 	req.dev = dev;
 
-	init_completion(&req.done);
-
-	spin_lock(&req_lock);
-	req.next = requests;
-	requests = &req;
-	spin_unlock(&req_lock);
-
-	wake_up_process(thread);
-	wait_for_completion(&req.done);
-
-	kfree(tmp);
-
-	return req.err;
+	return devtmpfs_submit_req(&req, tmp);
 }
 
 int devtmpfs_delete_node(struct device *dev)
@@ -147,18 +148,7 @@ int devtmpfs_delete_node(struct device *dev)
 	req.mode = 0;
 	req.dev = dev;
 
-	init_completion(&req.done);
-
-	spin_lock(&req_lock);
-	req.next = requests;
-	requests = &req;
-	spin_unlock(&req_lock);
-
-	wake_up_process(thread);
-	wait_for_completion(&req.done);
-
-	kfree(tmp);
-	return req.err;
+	return devtmpfs_submit_req(&req, tmp);
 }
 
 static int dev_mkdir(const char *name, umode_t mode)
@@ -359,7 +349,7 @@ static int handle_remove(const char *nodename, struct device *dev)
  * If configured, or requested by the commandline, devtmpfs will be
  * auto-mounted after the kernel mounted the root filesystem.
  */
-int devtmpfs_mount(void)
+int __init devtmpfs_mount(void)
 {
 	int err;
 
@@ -388,18 +378,30 @@ static int handle(const char *name, umode_t mode, kuid_t uid, kgid_t gid,
 		return handle_remove(name, dev);
 }
 
-static int devtmpfsd(void *p)
+static int devtmpfs_setup(void *p)
 {
-	int *err = p;
-	*err = ksys_unshare(CLONE_NEWNS);
-	if (*err)
+	int err;
+
+	err = ksys_unshare(CLONE_NEWNS);
+	if (err)
 		goto out;
-	*err = do_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL);
-	if (*err)
+	err = do_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL);
+	if (err)
 		goto out;
 	ksys_chdir("/.."); /* will traverse into overmounted root */
 	ksys_chroot(".");
+out:
+	*(int *)p = err;
 	complete(&setup_done);
+	return err;
+}
+
+static int devtmpfsd(void *p)
+{
+	int err = devtmpfs_setup(p);
+
+	if (err)
+		return err;
 	while (1) {
 		spin_lock(&req_lock);
 		while (requests) {
@@ -420,9 +422,6 @@ static int devtmpfsd(void *p)
 		schedule();
 	}
 	return 0;
-out:
-	complete(&setup_done);
-	return *err;
 }
 
 /*

drivers/base/driver.c

@@ -8,6 +8,7 @@
  * Copyright (c) 2007 Novell Inc.
  */
 
+#include <linux/device/driver.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/errno.h>

drivers/base/firmware_loader/fallback.c

@@ -606,7 +606,7 @@ static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
 		return false;
 	}
 
-	if ((opt_flags & FW_OPT_NOFALLBACK))
+	if ((opt_flags & FW_OPT_NOFALLBACK_SYSFS))
 		return false;
 
 	/* Also permit LSMs and IMA to fail firmware sysfs fallback */
@@ -630,10 +630,11 @@ static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
  * interface. Userspace is in charge of loading the firmware through the sysfs
  * loading interface. This sysfs fallback mechanism may be disabled completely
  * on a system by setting the proc sysctl value ignore_sysfs_fallback to true.
- * If this false we check if the internal API caller set the @FW_OPT_NOFALLBACK
- * flag, if so it would also disable the fallback mechanism. A system may want
- * to enfoce the sysfs fallback mechanism at all times, it can do this by
- * setting ignore_sysfs_fallback to false and force_sysfs_fallback to true.
+ * If this is false we check if the internal API caller set the
+ * @FW_OPT_NOFALLBACK_SYSFS flag, if so it would also disable the fallback
+ * mechanism. A system may want to enforce the sysfs fallback mechanism at all
+ * times, it can do this by setting ignore_sysfs_fallback to false and
+ * force_sysfs_fallback to true.
  * Enabling force_sysfs_fallback is functionally equivalent to build a kernel
  * with CONFIG_FW_LOADER_USER_HELPER_FALLBACK.
  **/

drivers/base/firmware_loader/firmware.h

@@ -27,16 +27,16 @@
  *	firmware file lookup on storage is avoided. Used for calls where the
  *	file may be too big, or where the driver takes charge of its own
  *	firmware caching mechanism.
- * @FW_OPT_NOFALLBACK: Disable the fallback mechanism. Takes precedence over
- *	&FW_OPT_UEVENT and &FW_OPT_USERHELPER.
+ * @FW_OPT_NOFALLBACK_SYSFS: Disable the sysfs fallback mechanism. Takes
+ *	precedence over &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
  */
 enum fw_opt {
-	FW_OPT_UEVENT =         BIT(0),
-	FW_OPT_NOWAIT =         BIT(1),
-	FW_OPT_USERHELPER =     BIT(2),
-	FW_OPT_NO_WARN =        BIT(3),
-	FW_OPT_NOCACHE =        BIT(4),
-	FW_OPT_NOFALLBACK =     BIT(5),
+	FW_OPT_UEVENT			= BIT(0),
+	FW_OPT_NOWAIT			= BIT(1),
+	FW_OPT_USERHELPER		= BIT(2),
+	FW_OPT_NO_WARN			= BIT(3),
+	FW_OPT_NOCACHE			= BIT(4),
+	FW_OPT_NOFALLBACK_SYSFS		= BIT(5),
 };
 
 enum fw_status {

drivers/base/firmware_loader/main.c

@@ -877,7 +877,7 @@ int request_firmware_direct(const struct firmware **firmware_p,
 	__module_get(THIS_MODULE);
 	ret = _request_firmware(firmware_p, name, device, NULL, 0,
 				FW_OPT_UEVENT | FW_OPT_NO_WARN |
-				FW_OPT_NOFALLBACK);
+				FW_OPT_NOFALLBACK_SYSFS);
 	module_put(THIS_MODULE);
 	return ret;
 }

drivers/base/platform.c

@@ -27,6 +27,7 @@
 #include <linux/limits.h>
 #include <linux/property.h>
 #include <linux/kmemleak.h>
+#include <linux/types.h>
 
 #include "base.h"
 #include "power/power.h"
@@ -48,7 +49,7 @@ EXPORT_SYMBOL_GPL(platform_bus);
 struct resource *platform_get_resource(struct platform_device *dev,
 				       unsigned int type, unsigned int num)
 {
-	int i;
+	u32 i;
 
 	for (i = 0; i < dev->num_resources; i++) {
 		struct resource *r = &dev->resource[i];
@@ -255,7 +256,7 @@ struct resource *platform_get_resource_byname(struct platform_device *dev,
 					      unsigned int type,
 					      const char *name)
 {
-	int i;
+	u32 i;
 
 	for (i = 0; i < dev->num_resources; i++) {
 		struct resource *r = &dev->resource[i];
@@ -501,7 +502,8 @@ EXPORT_SYMBOL_GPL(platform_device_add_properties);
  */
 int platform_device_add(struct platform_device *pdev)
 {
-	int i, ret;
+	u32 i;
+	int ret;
 
 	if (!pdev)
 		return -EINVAL;
@@ -569,7 +571,7 @@ int platform_device_add(struct platform_device *pdev)
 		pdev->id = PLATFORM_DEVID_AUTO;
 	}
 
-	while (--i >= 0) {
+	while (i--) {
 		struct resource *r = &pdev->resource[i];
 		if (r->parent)
 			release_resource(r);
@@ -590,7 +592,7 @@ EXPORT_SYMBOL_GPL(platform_device_add);
  */
 void platform_device_del(struct platform_device *pdev)
 {
-	int i;
+	u32 i;
 
 	if (!IS_ERR_OR_NULL(pdev)) {
 		device_del(&pdev->dev);

drivers/base/test/test_async_driver_probe.c

@@ -44,7 +44,8 @@ static int test_probe(struct platform_device *pdev)
 	 * performing an async init on that node.
 	 */
 	if (dev->driver->probe_type == PROBE_PREFER_ASYNCHRONOUS) {
-		if (dev_to_node(dev) != numa_node_id()) {
+		if (IS_ENABLED(CONFIG_NUMA) &&
+		    dev_to_node(dev) != numa_node_id()) {
 			dev_warn(dev, "NUMA node mismatch %d != %d\n",
 				 dev_to_node(dev), numa_node_id());
 			atomic_inc(&warnings);

fs/debugfs/file.c

@@ -142,18 +142,21 @@ EXPORT_SYMBOL_GPL(debugfs_file_put);
  * We also need to exclude any file that has ways to write or alter it as root
  * can bypass the permissions check.
  */
-static bool debugfs_is_locked_down(struct inode *inode,
-				   struct file *filp,
-				   const struct file_operations *real_fops)
+static int debugfs_locked_down(struct inode *inode,
+			       struct file *filp,
+			       const struct file_operations *real_fops)
 {
 	if ((inode->i_mode & 07777) == 0444 &&
 	    !(filp->f_mode & FMODE_WRITE) &&
 	    !real_fops->unlocked_ioctl &&
 	    !real_fops->compat_ioctl &&
 	    !real_fops->mmap)
-		return false;
+		return 0;
 
-	return security_locked_down(LOCKDOWN_DEBUGFS);
+	if (security_locked_down(LOCKDOWN_DEBUGFS))
+		return -EPERM;
+
+	return 0;
 }
 
 static int open_proxy_open(struct inode *inode, struct file *filp)
@@ -168,7 +171,7 @@ static int open_proxy_open(struct inode *inode, struct file *filp)
 
 	real_fops = debugfs_real_fops(filp);
 
-	r = debugfs_is_locked_down(inode, filp, real_fops);
+	r = debugfs_locked_down(inode, filp, real_fops);
 	if (r)
 		goto out;
 
@@ -298,7 +301,7 @@ static int full_proxy_open(struct inode *inode, struct file *filp)
 
 	real_fops = debugfs_real_fops(filp);
 
-	r = debugfs_is_locked_down(inode, filp, real_fops);
+	r = debugfs_locked_down(inode, filp, real_fops);
 	if (r)
 		goto out;
 
@@ -496,10 +499,10 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
  * returned.
  *
- * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
+ * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
  * be returned.
  */
 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
@@ -581,10 +584,10 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
  * returned.
  *
- * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
+ * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
  * be returned.
  */
 struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
@@ -846,10 +849,10 @@ static const struct file_operations fops_bool_wo = {
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
  * returned.
  *
- * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
+ * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
  * be returned.
  */
 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
@@ -899,10 +902,10 @@ static const struct file_operations fops_blob = {
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
  * returned.
  *
- * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
+ * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
  * be returned.
  */
 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
@@ -1091,10 +1094,10 @@ static const struct file_operations fops_regset32 = {
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
  * returned.
  *
- * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
+ * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
  * be returned.
  */
 struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
@@ -1158,4 +1161,3 @@ struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
 				   &debugfs_devm_entry_ops);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);
-

fs/debugfs/inode.c

@@ -423,7 +423,7 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
  * returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
@@ -502,7 +502,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe);
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
  * returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
@@ -534,7 +534,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_file_size);
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
  * returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
@@ -627,7 +627,7 @@ EXPORT_SYMBOL(debugfs_create_automount);
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the symbolic
  * link is to be removed (no automatic cleanup happens if your module is
- * unloaded, you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR)
+ * unloaded, you are responsible here.)  If an error occurs, ERR_PTR(-ERROR)
  * will be returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
@@ -906,4 +906,3 @@ static int __init debugfs_init(void)
 	return retval;
 }
 core_initcall(debugfs_init);
-

fs/kernfs/dir.c

@@ -1266,7 +1266,7 @@ void kernfs_activate(struct kernfs_node *kn)
 
 	pos = NULL;
 	while ((pos = kernfs_next_descendant_post(pos, kn))) {
-		if (!pos || (pos->flags & KERNFS_ACTIVATED))
+		if (pos->flags & KERNFS_ACTIVATED)
 			continue;
 
 		WARN_ON_ONCE(pos->parent && RB_EMPTY_NODE(&pos->rb));

include/linux/dev_printk.h

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dev_printk.h - printk messages helpers for devices
+ *
+ * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
+ * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2008-2009 Novell Inc.
+ *
+ */
+
+#ifndef _DEVICE_PRINTK_H_
+#define _DEVICE_PRINTK_H_
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <linux/ratelimit.h>
+
+#ifndef dev_fmt
+#define dev_fmt(fmt) fmt
+#endif
+
+struct device;
+
+#ifdef CONFIG_PRINTK
+
+__printf(3, 0) __cold
+int dev_vprintk_emit(int level, const struct device *dev,
+		     const char *fmt, va_list args);
+__printf(3, 4) __cold
+int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...);
+
+__printf(3, 4) __cold
+void dev_printk(const char *level, const struct device *dev,
+		const char *fmt, ...);
+__printf(2, 3) __cold
+void _dev_emerg(const struct device *dev, const char *fmt, ...);
+__printf(2, 3) __cold
+void _dev_alert(const struct device *dev, const char *fmt, ...);
+__printf(2, 3) __cold
+void _dev_crit(const struct device *dev, const char *fmt, ...);
+__printf(2, 3) __cold
+void _dev_err(const struct device *dev, const char *fmt, ...);
+__printf(2, 3) __cold
+void _dev_warn(const struct device *dev, const char *fmt, ...);
+__printf(2, 3) __cold
+void _dev_notice(const struct device *dev, const char *fmt, ...);
+__printf(2, 3) __cold
+void _dev_info(const struct device *dev, const char *fmt, ...);
+
+#else
+
+static inline __printf(3, 0)
+int dev_vprintk_emit(int level, const struct device *dev,
+		     const char *fmt, va_list args)
+{ return 0; }
+static inline __printf(3, 4)
+int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
+{ return 0; }
+
+static inline void __dev_printk(const char *level, const struct device *dev,
+				struct va_format *vaf)
+{}
+static inline __printf(3, 4)
+void dev_printk(const char *level, const struct device *dev,
+		 const char *fmt, ...)
+{}
+
+static inline __printf(2, 3)
+void _dev_emerg(const struct device *dev, const char *fmt, ...)
+{}
+static inline __printf(2, 3)
+void _dev_crit(const struct device *dev, const char *fmt, ...)
+{}
+static inline __printf(2, 3)
+void _dev_alert(const struct device *dev, const char *fmt, ...)
+{}
+static inline __printf(2, 3)
+void _dev_err(const struct device *dev, const char *fmt, ...)
+{}
+static inline __printf(2, 3)
+void _dev_warn(const struct device *dev, const char *fmt, ...)
+{}
+static inline __printf(2, 3)
+void _dev_notice(const struct device *dev, const char *fmt, ...)
+{}
+static inline __printf(2, 3)
+void _dev_info(const struct device *dev, const char *fmt, ...)
+{}
+
+#endif
+
+/*
+ * #defines for all the dev_<level> macros to prefix with whatever
+ * possible use of #define dev_fmt(fmt) ...
+ */
+
+#define dev_emerg(dev, fmt, ...)					\
+	_dev_emerg(dev, dev_fmt(fmt), ##__VA_ARGS__)
+#define dev_crit(dev, fmt, ...)						\
+	_dev_crit(dev, dev_fmt(fmt), ##__VA_ARGS__)
+#define dev_alert(dev, fmt, ...)					\
+	_dev_alert(dev, dev_fmt(fmt), ##__VA_ARGS__)
+#define dev_err(dev, fmt, ...)						\
+	_dev_err(dev, dev_fmt(fmt), ##__VA_ARGS__)
+#define dev_warn(dev, fmt, ...)						\
+	_dev_warn(dev, dev_fmt(fmt), ##__VA_ARGS__)
+#define dev_notice(dev, fmt, ...)					\
+	_dev_notice(dev, dev_fmt(fmt), ##__VA_ARGS__)
+#define dev_info(dev, fmt, ...)						\
+	_dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
+
+#if defined(CONFIG_DYNAMIC_DEBUG)
+#define dev_dbg(dev, fmt, ...)						\
+	dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
+#elif defined(DEBUG)
+#define dev_dbg(dev, fmt, ...)						\
+	dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__)
+#else
+#define dev_dbg(dev, fmt, ...)						\
+({									\
+	if (0)								\
+		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
+})
+#endif
+
+#ifdef CONFIG_PRINTK
+#define dev_level_once(dev_level, dev, fmt, ...)			\
+do {									\
+	static bool __print_once __read_mostly;				\
+									\
+	if (!__print_once) {						\
+		__print_once = true;					\
+		dev_level(dev, fmt, ##__VA_ARGS__);			\
+	}								\
+} while (0)
+#else
+#define dev_level_once(dev_level, dev, fmt, ...)			\
+do {									\
+	if (0)								\
+		dev_level(dev, fmt, ##__VA_ARGS__);			\
+} while (0)
+#endif
+
+#define dev_emerg_once(dev, fmt, ...)					\
+	dev_level_once(dev_emerg, dev, fmt, ##__VA_ARGS__)
+#define dev_alert_once(dev, fmt, ...)					\
+	dev_level_once(dev_alert, dev, fmt, ##__VA_ARGS__)
+#define dev_crit_once(dev, fmt, ...)					\
+	dev_level_once(dev_crit, dev, fmt, ##__VA_ARGS__)
+#define dev_err_once(dev, fmt, ...)					\
+	dev_level_once(dev_err, dev, fmt, ##__VA_ARGS__)
+#define dev_warn_once(dev, fmt, ...)					\
+	dev_level_once(dev_warn, dev, fmt, ##__VA_ARGS__)
+#define dev_notice_once(dev, fmt, ...)					\
+	dev_level_once(dev_notice, dev, fmt, ##__VA_ARGS__)
+#define dev_info_once(dev, fmt, ...)					\
+	dev_level_once(dev_info, dev, fmt, ##__VA_ARGS__)
+#define dev_dbg_once(dev, fmt, ...)					\
+	dev_level_once(dev_dbg, dev, fmt, ##__VA_ARGS__)
+
+#define dev_level_ratelimited(dev_level, dev, fmt, ...)			\
+do {									\
+	static DEFINE_RATELIMIT_STATE(_rs,				\
+				      DEFAULT_RATELIMIT_INTERVAL,	\
+				      DEFAULT_RATELIMIT_BURST);		\
+	if (__ratelimit(&_rs))						\
+		dev_level(dev, fmt, ##__VA_ARGS__);			\
+} while (0)
+
+#define dev_emerg_ratelimited(dev, fmt, ...)				\
+	dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__)
+#define dev_alert_ratelimited(dev, fmt, ...)				\
+	dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__)
+#define dev_crit_ratelimited(dev, fmt, ...)				\
+	dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__)
+#define dev_err_ratelimited(dev, fmt, ...)				\
+	dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__)
+#define dev_warn_ratelimited(dev, fmt, ...)				\
+	dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__)
+#define dev_notice_ratelimited(dev, fmt, ...)				\
+	dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
+#define dev_info_ratelimited(dev, fmt, ...)				\
+	dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
+#if defined(CONFIG_DYNAMIC_DEBUG)
+/* descriptor check is first to prevent flooding with "callbacks suppressed" */
+#define dev_dbg_ratelimited(dev, fmt, ...)				\
+do {									\
+	static DEFINE_RATELIMIT_STATE(_rs,				\
+				      DEFAULT_RATELIMIT_INTERVAL,	\
+				      DEFAULT_RATELIMIT_BURST);		\
+	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
+	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
+	    __ratelimit(&_rs))						\
+		__dynamic_dev_dbg(&descriptor, dev, dev_fmt(fmt),	\
+				  ##__VA_ARGS__);			\
+} while (0)
+#elif defined(DEBUG)
+#define dev_dbg_ratelimited(dev, fmt, ...)				\
+do {									\
+	static DEFINE_RATELIMIT_STATE(_rs,				\
+				      DEFAULT_RATELIMIT_INTERVAL,	\
+				      DEFAULT_RATELIMIT_BURST);		\
+	if (__ratelimit(&_rs))						\
+		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
+} while (0)
+#else
+#define dev_dbg_ratelimited(dev, fmt, ...)				\
+do {									\
+	if (0)								\
+		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
+} while (0)
+#endif
+
+#ifdef VERBOSE_DEBUG
+#define dev_vdbg	dev_dbg
+#else
+#define dev_vdbg(dev, fmt, ...)						\
+({									\
+	if (0)								\
+		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
+})
+#endif
+
+/*
+ * dev_WARN*() acts like dev_printk(), but with the key difference of
+ * using WARN/WARN_ONCE to include file/line information and a backtrace.
+ */
+#define dev_WARN(dev, format, arg...) \
+	WARN(1, "%s %s: " format, dev_driver_string(dev), dev_name(dev), ## arg);
+
+#define dev_WARN_ONCE(dev, condition, format, arg...) \
+	WARN_ONCE(condition, "%s %s: " format, \
+			dev_driver_string(dev), dev_name(dev), ## arg)
+
+#endif /* _DEVICE_PRINTK_H_ */

include/linux/device/class.h

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The class-specific portions of the driver model
+ *
+ * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
+ * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2008-2009 Novell Inc.
+ * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (c) 2012-2019 Linux Foundation
+ *
+ * See Documentation/driver-api/driver-model/ for more information.
+ */
+
+#ifndef _DEVICE_CLASS_H_
+#define _DEVICE_CLASS_H_
+
+#include <linux/kobject.h>
+#include <linux/klist.h>
+#include <linux/pm.h>
+#include <linux/device/bus.h>
+
+struct device;
+struct fwnode_handle;
+
+/**
+ * struct class - device classes
+ * @name:	Name of the class.
+ * @owner:	The module owner.
+ * @class_groups: Default attributes of this class.
+ * @dev_groups:	Default attributes of the devices that belong to the class.
+ * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
+ * @dev_uevent:	Called when a device is added, removed from this class, or a
+ *		few other things that generate uevents to add the environment
+ *		variables.
+ * @devnode:	Callback to provide the devtmpfs.
+ * @class_release: Called to release this class.
+ * @dev_release: Called to release the device.
+ * @shutdown_pre: Called at shut-down time before driver shutdown.
+ * @ns_type:	Callbacks so sysfs can detemine namespaces.
+ * @namespace:	Namespace of the device belongs to this class.
+ * @get_ownership: Allows class to specify uid/gid of the sysfs directories
+ *		for the devices belonging to the class. Usually tied to
+ *		device's namespace.
+ * @pm:		The default device power management operations of this class.
+ * @p:		The private data of the driver core, no one other than the
+ *		driver core can touch this.
+ *
+ * A class is a higher-level view of a device that abstracts out low-level
+ * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
+ * at the class level, they are all simply disks. Classes allow user space
+ * to work with devices based on what they do, rather than how they are
+ * connected or how they work.
+ */
+struct class {
+	const char		*name;
+	struct module		*owner;
+
+	const struct attribute_group	**class_groups;
+	const struct attribute_group	**dev_groups;
+	struct kobject			*dev_kobj;
+
+	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
+	char *(*devnode)(struct device *dev, umode_t *mode);
+
+	void (*class_release)(struct class *class);
+	void (*dev_release)(struct device *dev);
+
+	int (*shutdown_pre)(struct device *dev);
+
+	const struct kobj_ns_type_operations *ns_type;
+	const void *(*namespace)(struct device *dev);
+
+	void (*get_ownership)(struct device *dev, kuid_t *uid, kgid_t *gid);
+
+	const struct dev_pm_ops *pm;
+
+	struct subsys_private *p;
+};
+
+struct class_dev_iter {
+	struct klist_iter		ki;
+	const struct device_type	*type;
+};
+
+extern struct kobject *sysfs_dev_block_kobj;
+extern struct kobject *sysfs_dev_char_kobj;
+extern int __must_check __class_register(struct class *class,
+					 struct lock_class_key *key);
+extern void class_unregister(struct class *class);
+
+/* This is a #define to keep the compiler from merging different
+ * instances of the __key variable */
+#define class_register(class)			\
+({						\
+	static struct lock_class_key __key;	\
+	__class_register(class, &__key);	\
+})
+
+struct class_compat;
+struct class_compat *class_compat_register(const char *name);
+void class_compat_unregister(struct class_compat *cls);
+int class_compat_create_link(struct class_compat *cls, struct device *dev,
+			     struct device *device_link);
+void class_compat_remove_link(struct class_compat *cls, struct device *dev,
+			      struct device *device_link);
+
+extern void class_dev_iter_init(struct class_dev_iter *iter,
+				struct class *class,
+				struct device *start,
+				const struct device_type *type);
+extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
+extern void class_dev_iter_exit(struct class_dev_iter *iter);
+
+extern int class_for_each_device(struct class *class, struct device *start,
+				 void *data,
+				 int (*fn)(struct device *dev, void *data));
+extern struct device *class_find_device(struct class *class,
+					struct device *start, const void *data,
+					int (*match)(struct device *, const void *));
+
+/**
+ * class_find_device_by_name - device iterator for locating a particular device
+ * of a specific name.
+ * @class: class type
+ * @name: name of the device to match
+ */
+static inline struct device *class_find_device_by_name(struct class *class,
+						       const char *name)
+{
+	return class_find_device(class, NULL, name, device_match_name);
+}
+
+/**
+ * class_find_device_by_of_node : device iterator for locating a particular device
+ * matching the of_node.
+ * @class: class type
+ * @np: of_node of the device to match.
+ */
+static inline struct device *
+class_find_device_by_of_node(struct class *class, const struct device_node *np)
+{
+	return class_find_device(class, NULL, np, device_match_of_node);
+}
+
+/**
+ * class_find_device_by_fwnode : device iterator for locating a particular device
+ * matching the fwnode.
+ * @class: class type
+ * @fwnode: fwnode of the device to match.
+ */
+static inline struct device *
+class_find_device_by_fwnode(struct class *class,
+			    const struct fwnode_handle *fwnode)
+{
+	return class_find_device(class, NULL, fwnode, device_match_fwnode);
+}
+
+/**
+ * class_find_device_by_devt : device iterator for locating a particular device
+ * matching the device type.
+ * @class: class type
+ * @devt: device type of the device to match.
+ */
+static inline struct device *class_find_device_by_devt(struct class *class,
+						       dev_t devt)
+{
+	return class_find_device(class, NULL, &devt, device_match_devt);
+}
+
+#ifdef CONFIG_ACPI
+struct acpi_device;
+/**
+ * class_find_device_by_acpi_dev : device iterator for locating a particular
+ * device matching the ACPI_COMPANION device.
+ * @class: class type
+ * @adev: ACPI_COMPANION device to match.
+ */
+static inline struct device *
+class_find_device_by_acpi_dev(struct class *class, const struct acpi_device *adev)
+{
+	return class_find_device(class, NULL, adev, device_match_acpi_dev);
+}
+#else
+static inline struct device *
+class_find_device_by_acpi_dev(struct class *class, const void *adev)
+{
+	return NULL;
+}
+#endif
+
+struct class_attribute {
+	struct attribute attr;
+	ssize_t (*show)(struct class *class, struct class_attribute *attr,
+			char *buf);
+	ssize_t (*store)(struct class *class, struct class_attribute *attr,
+			const char *buf, size_t count);
+};
+
+#define CLASS_ATTR_RW(_name) \
+	struct class_attribute class_attr_##_name = __ATTR_RW(_name)
+#define CLASS_ATTR_RO(_name) \
+	struct class_attribute class_attr_##_name = __ATTR_RO(_name)
+#define CLASS_ATTR_WO(_name) \
+	struct class_attribute class_attr_##_name = __ATTR_WO(_name)
+
+extern int __must_check class_create_file_ns(struct class *class,
+					     const struct class_attribute *attr,
+					     const void *ns);
+extern void class_remove_file_ns(struct class *class,
+				 const struct class_attribute *attr,
+				 const void *ns);
+
+static inline int __must_check class_create_file(struct class *class,
+					const struct class_attribute *attr)
+{
+	return class_create_file_ns(class, attr, NULL);
+}
+
+static inline void class_remove_file(struct class *class,
+				     const struct class_attribute *attr)
+{
+	return class_remove_file_ns(class, attr, NULL);
+}
+
+/* Simple class attribute that is just a static string */
+struct class_attribute_string {
+	struct class_attribute attr;
+	char *str;
+};
+
+/* Currently read-only only */
+#define _CLASS_ATTR_STRING(_name, _mode, _str) \
+	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
+#define CLASS_ATTR_STRING(_name, _mode, _str) \
+	struct class_attribute_string class_attr_##_name = \
+		_CLASS_ATTR_STRING(_name, _mode, _str)
+
+extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
+                        char *buf);
+
+struct class_interface {
+	struct list_head	node;
+	struct class		*class;
+
+	int (*add_dev)		(struct device *, struct class_interface *);
+	void (*remove_dev)	(struct device *, struct class_interface *);
+};
+
+extern int __must_check class_interface_register(struct class_interface *);
+extern void class_interface_unregister(struct class_interface *);
+
+extern struct class * __must_check __class_create(struct module *owner,
+						  const char *name,
+						  struct lock_class_key *key);
+extern void class_destroy(struct class *cls);
+
+/* This is a #define to keep the compiler from merging different
+ * instances of the __key variable */
+#define class_create(owner, name)		\
+({						\
+	static struct lock_class_key __key;	\
+	__class_create(owner, name, &__key);	\
+})
+
+
+#endif	/* _DEVICE_CLASS_H_ */

init/main.c

@@ -63,7 +63,7 @@
 #include <linux/lockdep.h>
 #include <linux/kmemleak.h>
 #include <linux/pid_namespace.h>
-#include <linux/device.h>
+#include <linux/device/driver.h>
 #include <linux/kthread.h>
 #include <linux/sched.h>
 #include <linux/sched/init.h>