Merge tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of changes for the driver core for 5.17-rc1.

  Lots of little things here, including:

   - kobj_type cleanups

   - auxiliary_bus documentation updates

   - auxiliary_device conversions for some drivers (relevant subsystems
     all have provided acks for these)

   - kernfs lock contention reduction for some workloads

   - other tiny cleanups and changes.

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

* tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (43 commits)
  kobject documentation: remove default_attrs information
  drivers/firmware: Add missing platform_device_put() in sysfb_create_simplefb
  debugfs: lockdown: Allow reading debugfs files that are not world readable
  driver core: Make bus notifiers in right order in really_probe()
  driver core: Move driver_sysfs_remove() after driver_sysfs_add()
  firmware: edd: remove empty default_attrs array
  firmware: dmi-sysfs: use default_groups in kobj_type
  qemu_fw_cfg: use default_groups in kobj_type
  firmware: memmap: use default_groups in kobj_type
  sh: sq: use default_groups in kobj_type
  headers/uninline: Uninline single-use function: kobject_has_children()
  devtmpfs: mount with noexec and nosuid
  driver core: Simplify async probe test code by using ktime_ms_delta()
  nilfs2: use default_groups in kobj_type
  kobject: remove kset from struct kset_uevent_ops callbacks
  driver core: make kobj_type constant.
  driver core: platform: document registration-failure requirement
  vdpa/mlx5: Use auxiliary_device driver data helpers
  net/mlx5e: Use auxiliary_device driver data helpers
  soundwire: intel: Use auxiliary_device driver data helpers
  ...

4 files changed, 212 insertions, 27 deletions

diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h
index fc51d45f106b..de21d9d24a95 100644
--- a/include/linux/auxiliary_bus.h
+++ b/include/linux/auxiliary_bus.h
@@ -11,12 +11,172 @@
 #include <linux/device.h>
 #include <linux/mod_devicetable.h>
 
+/**
+ * DOC: DEVICE_LIFESPAN
+ *
+ * The registering driver is the entity that allocates memory for the
+ * auxiliary_device and registers it on the auxiliary bus.  It is important to
+ * note that, as opposed to the platform bus, the registering driver is wholly
+ * responsible for the management of the memory used for the device object.
+ *
+ * To be clear the memory for the auxiliary_device is freed in the release()
+ * callback defined by the registering driver.  The registering driver should
+ * only call auxiliary_device_delete() and then auxiliary_device_uninit() when
+ * it is done with the device.  The release() function is then automatically
+ * called if and when other code releases their reference to the devices.
+ *
+ * A parent object, defined in the shared header file, contains the
+ * auxiliary_device.  It also contains a pointer to the shared object(s), which
+ * also is defined in the shared header.  Both the parent object and the shared
+ * object(s) are allocated by the registering driver.  This layout allows the
+ * auxiliary_driver's registering module to perform a container_of() call to go
+ * from the pointer to the auxiliary_device, that is passed during the call to
+ * the auxiliary_driver's probe function, up to the parent object, and then
+ * have access to the shared object(s).
+ *
+ * The memory for the shared object(s) must have a lifespan equal to, or
+ * greater than, the lifespan of the memory for the auxiliary_device.  The
+ * auxiliary_driver should only consider that the shared object is valid as
+ * long as the auxiliary_device is still registered on the auxiliary bus.  It
+ * is up to the registering driver to manage (e.g. free or keep available) the
+ * memory for the shared object beyond the life of the auxiliary_device.
+ *
+ * The registering driver must unregister all auxiliary devices before its own
+ * driver.remove() is completed.  An easy way to ensure this is to use the
+ * devm_add_action_or_reset() call to register a function against the parent
+ * device which unregisters the auxiliary device object(s).
+ *
+ * Finally, any operations which operate on the auxiliary devices must continue
+ * to function (if only to return an error) after the registering driver
+ * unregisters the auxiliary device.
+ */
+
+/**
+ * struct auxiliary_device - auxiliary device object.
+ * @dev: Device,
+ *       The release and parent fields of the device structure must be filled
+ *       in
+ * @name: Match name found by the auxiliary device driver,
+ * @id: unique identitier if multiple devices of the same name are exported,
+ *
+ * An auxiliary_device represents a part of its parent device's functionality.
+ * It is given a name that, combined with the registering drivers
+ * KBUILD_MODNAME, creates a match_name that is used for driver binding, and an
+ * id that combined with the match_name provide a unique name to register with
+ * the bus subsystem.  For example, a driver registering an auxiliary device is
+ * named 'foo_mod.ko' and the subdevice is named 'foo_dev'.  The match name is
+ * therefore 'foo_mod.foo_dev'.
+ *
+ * Registering an auxiliary_device is a three-step process.
+ *
+ * First, a 'struct auxiliary_device' needs to be defined or allocated for each
+ * sub-device desired.  The name, id, dev.release, and dev.parent fields of
+ * this structure must be filled in as follows.
+ *
+ * The 'name' field is to be given a name that is recognized by the auxiliary
+ * driver.  If two auxiliary_devices with the same match_name, eg
+ * "foo_mod.foo_dev", are registered onto the bus, they must have unique id
+ * values (e.g. "x" and "y") so that the registered devices names are
+ * "foo_mod.foo_dev.x" and "foo_mod.foo_dev.y".  If match_name + id are not
+ * unique, then the device_add fails and generates an error message.
+ *
+ * The auxiliary_device.dev.type.release or auxiliary_device.dev.release must
+ * be populated with a non-NULL pointer to successfully register the
+ * auxiliary_device.  This release call is where resources associated with the
+ * auxiliary device must be free'ed.  Because once the device is placed on the
+ * bus the parent driver can not tell what other code may have a reference to
+ * this data.
+ *
+ * The auxiliary_device.dev.parent should be set.  Typically to the registering
+ * drivers device.
+ *
+ * Second, call auxiliary_device_init(), which checks several aspects of the
+ * auxiliary_device struct and performs a device_initialize().  After this step
+ * completes, any error state must have a call to auxiliary_device_uninit() in
+ * its resolution path.
+ *
+ * The third and final step in registering an auxiliary_device is to perform a
+ * call to auxiliary_device_add(), which sets the name of the device and adds
+ * the device to the bus.
+ *
+ * .. code-block:: c
+ *
+ *      #define MY_DEVICE_NAME "foo_dev"
+ *
+ *      ...
+ *
+ *	struct auxiliary_device *my_aux_dev = my_aux_dev_alloc(xxx);
+ *
+ *	// Step 1:
+ *	my_aux_dev->name = MY_DEVICE_NAME;
+ *	my_aux_dev->id = my_unique_id_alloc(xxx);
+ *	my_aux_dev->dev.release = my_aux_dev_release;
+ *	my_aux_dev->dev.parent = my_dev;
+ *
+ *	// Step 2:
+ *	if (auxiliary_device_init(my_aux_dev))
+ *		goto fail;
+ *
+ *	// Step 3:
+ *	if (auxiliary_device_add(my_aux_dev)) {
+ *		auxiliary_device_uninit(my_aux_dev);
+ *		goto fail;
+ *	}
+ *
+ *	...
+ *
+ *
+ * Unregistering an auxiliary_device is a two-step process to mirror the
+ * register process.  First call auxiliary_device_delete(), then call
+ * auxiliary_device_uninit().
+ *
+ * .. code-block:: c
+ *
+ *         auxiliary_device_delete(my_dev->my_aux_dev);
+ *         auxiliary_device_uninit(my_dev->my_aux_dev);
+ */
 struct auxiliary_device {
 	struct device dev;
 	const char *name;
 	u32 id;
 };
 
+/**
+ * struct auxiliary_driver - Definition of an auxiliary bus driver
+ * @probe: Called when a matching device is added to the bus.
+ * @remove: Called when device is removed from the bus.
+ * @shutdown: Called at shut-down time to quiesce the device.
+ * @suspend: Called to put the device to sleep mode. Usually to a power state.
+ * @resume: Called to bring a device from sleep mode.
+ * @name: Driver name.
+ * @driver: Core driver structure.
+ * @id_table: Table of devices this driver should match on the bus.
+ *
+ * Auxiliary drivers follow the standard driver model convention, where
+ * discovery/enumeration is handled by the core, and drivers provide probe()
+ * and remove() methods. They support power management and shutdown
+ * notifications using the standard conventions.
+ *
+ * Auxiliary drivers register themselves with the bus by calling
+ * auxiliary_driver_register(). The id_table contains the match_names of
+ * auxiliary devices that a driver can bind with.
+ *
+ * .. code-block:: c
+ *
+ *         static const struct auxiliary_device_id my_auxiliary_id_table[] = {
+ *		   { .name = "foo_mod.foo_dev" },
+ *                 {},
+ *         };
+ *
+ *         MODULE_DEVICE_TABLE(auxiliary, my_auxiliary_id_table);
+ *
+ *         struct auxiliary_driver my_drv = {
+ *                 .name = "myauxiliarydrv",
+ *                 .id_table = my_auxiliary_id_table,
+ *                 .probe = my_drv_probe,
+ *                 .remove = my_drv_remove
+ *         };
+ */
 struct auxiliary_driver {
 	int (*probe)(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id);
 	void (*remove)(struct auxiliary_device *auxdev);
@@ -28,6 +188,16 @@ struct auxiliary_driver {
 	const struct auxiliary_device_id *id_table;
 };
 
+static inline void *auxiliary_get_drvdata(struct auxiliary_device *auxdev)
+{
+	return dev_get_drvdata(&auxdev->dev);
+}
+
+static inline void auxiliary_set_drvdata(struct auxiliary_device *auxdev, void *data)
+{
+	dev_set_drvdata(&auxdev->dev, data);
+}
+
 static inline struct auxiliary_device *to_auxiliary_dev(struct device *dev)
 {
 	return container_of(dev, struct auxiliary_device, dev);
@@ -66,6 +236,10 @@ void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv);
  * Helper macro for auxiliary drivers which do not do anything special in
  * module init/exit. This eliminates a lot of boilerplate. Each module may only
  * use this macro once, and calling it replaces module_init() and module_exit()
+ *
+ * .. code-block:: c
+ *
+ *	module_auxiliary_driver(my_drv);
  */
 #define module_auxiliary_driver(__auxiliary_driver) \
 	module_driver(__auxiliary_driver, auxiliary_driver_register, auxiliary_driver_unregister)
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 3ccce6f24548..861c4f0f8a29 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -6,7 +6,6 @@
 #ifndef __LINUX_KERNFS_H
 #define __LINUX_KERNFS_H
 
-#include <linux/kernel.h>
 #include <linux/err.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
@@ -14,14 +13,18 @@
 #include <linux/lockdep.h>
 #include <linux/rbtree.h>
 #include <linux/atomic.h>
+#include <linux/bug.h>
+#include <linux/types.h>
 #include <linux/uidgid.h>
 #include <linux/wait.h>
+#include <linux/rwsem.h>
 
 struct file;
 struct dentry;
 struct iattr;
 struct seq_file;
 struct vm_area_struct;
+struct vm_operations_struct;
 struct super_block;
 struct file_system_type;
 struct poll_table_struct;
@@ -197,6 +200,7 @@ struct kernfs_root {
 	struct list_head	supers;
 
 	wait_queue_head_t	deactivate_waitq;
+	struct rw_semaphore	kernfs_rwsem;
 };
 
 struct kernfs_open_file {
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index efd56f990a46..c7b47399b36a 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -19,10 +19,10 @@
 #include <linux/list.h>
 #include <linux/sysfs.h>
 #include <linux/compiler.h>
+#include <linux/container_of.h>
 #include <linux/spinlock.h>
 #include <linux/kref.h>
 #include <linux/kobject_ns.h>
-#include <linux/kernel.h>
 #include <linux/wait.h>
 #include <linux/atomic.h>
 #include <linux/workqueue.h>
@@ -66,7 +66,7 @@ struct kobject {
 	struct list_head	entry;
 	struct kobject		*parent;
 	struct kset		*kset;
-	struct kobj_type	*ktype;
+	const struct kobj_type	*ktype;
 	struct kernfs_node	*sd; /* sysfs directory entry */
 	struct kref		kref;
 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
@@ -90,13 +90,13 @@ static inline const char *kobject_name(const struct kobject *kobj)
 	return kobj->name;
 }
 
-extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
+extern void kobject_init(struct kobject *kobj, const struct kobj_type *ktype);
 extern __printf(3, 4) __must_check
 int kobject_add(struct kobject *kobj, struct kobject *parent,
 		const char *fmt, ...);
 extern __printf(4, 5) __must_check
 int kobject_init_and_add(struct kobject *kobj,
-			 struct kobj_type *ktype, struct kobject *parent,
+			 const struct kobj_type *ktype, struct kobject *parent,
 			 const char *fmt, ...);
 
 extern void kobject_del(struct kobject *kobj);
@@ -117,23 +117,6 @@ extern void kobject_get_ownership(struct kobject *kobj,
 				  kuid_t *uid, kgid_t *gid);
 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 
-/**
- * kobject_has_children - Returns whether a kobject has children.
- * @kobj: the object to test
- *
- * This will return whether a kobject has other kobjects as children.
- *
- * It does NOT account for the presence of attribute files, only sub
- * directories. It also assumes there is no concurrent addition or
- * removal of such children, and thus relies on external locking.
- */
-static inline bool kobject_has_children(struct kobject *kobj)
-{
-	WARN_ON_ONCE(kref_read(&kobj->kref) == 0);
-
-	return kobj->sd && kobj->sd->dir.subdirs;
-}
-
 struct kobj_type {
 	void (*release)(struct kobject *kobj);
 	const struct sysfs_ops *sysfs_ops;
@@ -153,10 +136,9 @@ struct kobj_uevent_env {
 };
 
 struct kset_uevent_ops {
-	int (* const filter)(struct kset *kset, struct kobject *kobj);
-	const char *(* const name)(struct kset *kset, struct kobject *kobj);
-	int (* const uevent)(struct kset *kset, struct kobject *kobj,
-		      struct kobj_uevent_env *env);
+	int (* const filter)(struct kobject *kobj);
+	const char *(* const name)(struct kobject *kobj);
+	int (* const uevent)(struct kobject *kobj, struct kobj_uevent_env *env);
 };
 
 struct kobj_attribute {
@@ -217,7 +199,7 @@ static inline void kset_put(struct kset *k)
 	kobject_put(&k->kobj);
 }
 
-static inline struct kobj_type *get_ktype(struct kobject *kobj)
+static inline const struct kobj_type *get_ktype(struct kobject *kobj)
 {
 	return kobj->ktype;
 }
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 0b3704ad13c8..a6e201758ae9 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -180,6 +180,19 @@ static inline int cpu_to_mem(int cpu)
 
 #endif	/* [!]CONFIG_HAVE_MEMORYLESS_NODES */
 
+#if defined(topology_die_id) && defined(topology_die_cpumask)
+#define TOPOLOGY_DIE_SYSFS
+#endif
+#if defined(topology_cluster_id) && defined(topology_cluster_cpumask)
+#define TOPOLOGY_CLUSTER_SYSFS
+#endif
+#if defined(topology_book_id) && defined(topology_book_cpumask)
+#define TOPOLOGY_BOOK_SYSFS
+#endif
+#if defined(topology_drawer_id) && defined(topology_drawer_cpumask)
+#define TOPOLOGY_DRAWER_SYSFS
+#endif
+
 #ifndef topology_physical_package_id
 #define topology_physical_package_id(cpu)	((void)(cpu), -1)
 #endif
@@ -192,6 +205,12 @@ static inline int cpu_to_mem(int cpu)
 #ifndef topology_core_id
 #define topology_core_id(cpu)			((void)(cpu), 0)
 #endif
+#ifndef topology_book_id
+#define topology_book_id(cpu)			((void)(cpu), -1)
+#endif
+#ifndef topology_drawer_id
+#define topology_drawer_id(cpu)			((void)(cpu), -1)
+#endif
 #ifndef topology_sibling_cpumask
 #define topology_sibling_cpumask(cpu)		cpumask_of(cpu)
 #endif
@@ -204,6 +223,12 @@ static inline int cpu_to_mem(int cpu)
 #ifndef topology_die_cpumask
 #define topology_die_cpumask(cpu)		cpumask_of(cpu)
 #endif
+#ifndef topology_book_cpumask
+#define topology_book_cpumask(cpu)		cpumask_of(cpu)
+#endif
+#ifndef topology_drawer_cpumask
+#define topology_drawer_cpumask(cpu)		cpumask_of(cpu)
+#endif
 
 #if defined(CONFIG_SCHED_SMT) && !defined(cpu_smt_mask)
 static inline const struct cpumask *cpu_smt_mask(int cpu)