driver core changes for 6.5-rc1

Here are a small set of changes for 6.5-rc1 for some driver core
 changes.  Included in here are:
   - device property cleanups to make it easier to write "agnostic"
     drivers when regards to the firmware layer underneath them (DT vs.
     ACPI)
   - debugfs documentation updates
   - devres additions
   - sysfs documentation and changes to handle empty directory creation
     logic better
   - tiny kernfs optimizations
   - other tiny changes
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here are a small set of changes for 6.5-rc1 for some driver core
  changes. Included in here are:

   - device property cleanups to make it easier to write "agnostic"
     drivers when regards to the firmware layer underneath them (DT vs.
     ACPI)

   - debugfs documentation updates

   - devres additions

   - sysfs documentation and changes to handle empty directory creation
     logic better

   - tiny kernfs optimizations

   - other tiny changes

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

* tag 'driver-core-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  sysfs: Skip empty folders creation
  sysfs: Improve readability by following the kernel coding style
  drivers: fwnode: fix fwnode_irq_get[_byname]()
  ata: ahci_platform: Make code agnostic to OF/ACPI
  device property: Implement device_is_compatible()
  ACPI: Move ACPI_DEVICE_CLASS() to mod_devicetable.h
  base/node: Use 'property' to identify an access parameter
  driver core: device.h: add some missing kerneldocs
  kernfs: fix missing kernfs_idr_lock to remove an ID from the IDR
  isa: Remove unnecessary checks
  MAINTAINERS: add entry for auxiliary bus
  debugfs: Correct the 'debugfs_create_str' docs
  serial: qcom_geni: Comment use of devm_krealloc rather than devm_krealloc_array
  iio: adc: Use devm_krealloc_array
  hwmon: pmbus: Use devm_krealloc_array

MAINTAINERS

@@ -3385,6 +3385,16 @@ F:	include/uapi/linux/audit.h
 F:	kernel/audit*
 F:	lib/*audit.c
 
+AUXILIARY BUS DRIVER
+M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+R:	Dave Ertman <david.m.ertman@intel.com>
+R:	Ira Weiny <ira.weiny@intel.com>
+S:	Supported
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
+F:	Documentation/driver-api/auxiliary_bus.rst
+F:	drivers/base/auxiliary.c
+F:	include/linux/auxiliary_bus.h
+
 AUXILIARY DISPLAY DRIVERS
 M:	Miguel Ojeda <ojeda@kernel.org>
 S:	Maintained

drivers/ata/ahci_platform.c

@@ -9,14 +9,14 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/pm.h>
 #include <linux/device.h>
-#include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/libata.h>
 #include <linux/ahci_platform.h>
-#include <linux/acpi.h>
 #include <linux/pci_ids.h>
 #include "ahci.h"
 
@@ -56,10 +56,10 @@ static int ahci_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
-	if (of_device_is_compatible(dev->of_node, "hisilicon,hisi-ahci"))
+	if (device_is_compatible(dev, "hisilicon,hisi-ahci"))
 		hpriv->flags |= AHCI_HFLAG_NO_FBS | AHCI_HFLAG_NO_NCQ;
 
-	port = acpi_device_get_match_data(dev);
+	port = device_get_match_data(dev);
 	if (!port)
 		port = &ahci_port_info;
 

drivers/base/isa.c

@@ -149,11 +149,8 @@ int isa_register_driver(struct isa_driver *isa_driver, unsigned int ndev)
 			break;
 		}
 
-		if (isa_dev->dev.platform_data) {
-			isa_dev->next = isa_driver->devices;
-			isa_driver->devices = &isa_dev->dev;
-		} else
-			device_unregister(&isa_dev->dev);
+		isa_dev->next = isa_driver->devices;
+		isa_driver->devices = &isa_dev->dev;
 	}
 
 	if (!error && !isa_driver->devices)

drivers/base/node.c

@@ -162,15 +162,15 @@ free:
 }
 
 #ifdef CONFIG_HMEM_REPORTING
-#define ACCESS_ATTR(name)						\
-static ssize_t name##_show(struct device *dev,				\
+#define ACCESS_ATTR(property)						\
+static ssize_t property##_show(struct device *dev,			\
 			   struct device_attribute *attr,		\
 			   char *buf)					\
 {									\
 	return sysfs_emit(buf, "%u\n",					\
-			  to_access_nodes(dev)->hmem_attrs.name);	\
+			  to_access_nodes(dev)->hmem_attrs.property);	\
 }									\
-static DEVICE_ATTR_RO(name)
+static DEVICE_ATTR_RO(property)
 
 ACCESS_ATTR(read_bandwidth);
 ACCESS_ATTR(read_latency);

drivers/base/property.c

@@ -987,12 +987,18 @@ EXPORT_SYMBOL(fwnode_iomap);
  * @fwnode:	Pointer to the firmware node
  * @index:	Zero-based index of the IRQ
  *
- * Return: Linux IRQ number on success. Other values are determined
- * according to acpi_irq_get() or of_irq_get() operation.
+ * Return: Linux IRQ number on success. Negative errno on failure.
  */
 int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index)
 {
-	return fwnode_call_int_op(fwnode, irq_get, index);
+	int ret;
+
+	ret = fwnode_call_int_op(fwnode, irq_get, index);
+	/* We treat mapping errors as invalid case */
+	if (ret == 0)
+		return -EINVAL;
+
+	return ret;
 }
 EXPORT_SYMBOL(fwnode_irq_get);
 

drivers/hwmon/pmbus/pmbus_core.c

@@ -1191,9 +1191,9 @@ static int pmbus_add_attribute(struct pmbus_data *data, struct attribute *attr)
 {
 	if (data->num_attributes >= data->max_attributes - 1) {
 		int new_max_attrs = data->max_attributes + PMBUS_ATTR_ALLOC_SIZE;
-		void *new_attrs = devm_krealloc(data->dev, data->group.attrs,
-						new_max_attrs * sizeof(void *),
-						GFP_KERNEL);
+		void *new_attrs = devm_krealloc_array(data->dev, data->group.attrs,
+						      new_max_attrs, sizeof(void *),
+						      GFP_KERNEL);
 		if (!new_attrs)
 			return -ENOMEM;
 		data->group.attrs = new_attrs;

drivers/iio/adc/xilinx-ams.c

@@ -1263,7 +1263,7 @@ static int ams_parse_firmware(struct iio_dev *indio_dev)
 	struct device *dev = indio_dev->dev.parent;
 	struct fwnode_handle *child = NULL;
 	struct fwnode_handle *fwnode = dev_fwnode(dev);
-	size_t ams_size, dev_size;
+	size_t ams_size;
 	int ret, ch_cnt = 0, i, rising_off, falling_off;
 	unsigned int num_channels = 0;
 
@@ -1320,11 +1320,8 @@ static int ams_parse_firmware(struct iio_dev *indio_dev)
 		}
 	}
 
-	dev_size = array_size(sizeof(*dev_channels), num_channels);
-	if (dev_size == SIZE_MAX)
-		return -ENOMEM;
-
-	dev_channels = devm_krealloc(dev, ams_channels, dev_size, GFP_KERNEL);
+	dev_channels = devm_krealloc_array(dev, ams_channels, num_channels,
+					   sizeof(*dev_channels), GFP_KERNEL);
 	if (!dev_channels)
 		return -ENOMEM;
 

drivers/iio/adc/xilinx-xadc-core.c

@@ -613,20 +613,17 @@ static int xadc_update_scan_mode(struct iio_dev *indio_dev,
 	const unsigned long *mask)
 {
 	struct xadc *xadc = iio_priv(indio_dev);
-	size_t new_size, n;
+	size_t n;
 	void *data;
 
 	n = bitmap_weight(mask, indio_dev->masklength);
 
-	if (check_mul_overflow(n, sizeof(*xadc->data), &new_size))
-		return -ENOMEM;
-
-	data = devm_krealloc(indio_dev->dev.parent, xadc->data,
-			     new_size, GFP_KERNEL);
+	data = devm_krealloc_array(indio_dev->dev.parent, xadc->data,
+				   n, sizeof(*xadc->data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
-	memset(data, 0, new_size);
+	memset(data, 0, n * sizeof(*xadc->data));
 	xadc->data = data;
 
 	return 0;
@@ -1281,9 +1278,9 @@ static int xadc_parse_dt(struct iio_dev *indio_dev, unsigned int *conf, int irq)
 	}
 
 	indio_dev->num_channels = num_channels;
-	indio_dev->channels = devm_krealloc(dev, channels,
-					    sizeof(*channels) * num_channels,
-					    GFP_KERNEL);
+	indio_dev->channels = devm_krealloc_array(dev, channels,
+						  num_channels, sizeof(*channels),
+						  GFP_KERNEL);
 	/* If we can't resize the channels array, just use the original */
 	if (!indio_dev->channels)
 		indio_dev->channels = channels;

drivers/tty/serial/qcom_geni_serial.c

@@ -1053,6 +1053,11 @@ static int setup_fifos(struct qcom_geni_serial_port *port)
 		(port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
 
 	if (port->rx_buf && (old_rx_fifo_depth != port->rx_fifo_depth) && port->rx_fifo_depth) {
+		/*
+		 * Use krealloc rather than krealloc_array because rx_buf is
+		 * accessed as 1 byte entries as well as 4 byte entries so it's
+		 * not necessarily an array.
+		 */
 		port->rx_buf = devm_krealloc(uport->dev, port->rx_buf,
 					     port->rx_fifo_depth * sizeof(u32),
 					     GFP_KERNEL);

fs/debugfs/file.c

@@ -940,15 +940,6 @@ static const struct file_operations fops_str_wo = {
  * This function creates a file in debugfs with the given name that
  * contains the value of the variable @value.  If the @mode variable is so
  * set, it can be read from, and written to.
- *
- * 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
- * returned.
- *
- * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
- * be returned.
  */
 void debugfs_create_str(const char *name, umode_t mode,
 			struct dentry *parent, char **value)

fs/kernfs/dir.c

@@ -655,7 +655,9 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
 	return kn;
 
  err_out3:
+	spin_lock(&kernfs_idr_lock);
 	idr_remove(&root->ino_idr, (u32)kernfs_ino(kn));
+	spin_unlock(&kernfs_idr_lock);
  err_out2:
 	kmem_cache_free(kernfs_node_cache, kn);
  err_out1:

fs/sysfs/group.c

@@ -118,11 +118,13 @@ static int internal_create_group(struct kobject *kobj, int update,
 	/* Updates may happen before the object has been instantiated */
 	if (unlikely(update && !kobj->sd))
 		return -EINVAL;
+
 	if (!grp->attrs && !grp->bin_attrs) {
-		WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
-			kobj->name, grp->name ?: "");
-		return -EINVAL;
+		pr_debug("sysfs: (bin_)attrs not set by subsystem for group: %s/%s, skipping\n",
+			 kobj->name, grp->name ?: "");
+		return 0;
 	}
+
 	kobject_get_ownership(kobj, &uid, &gid);
 	if (grp->name) {
 		if (update) {
@@ -142,8 +144,10 @@ static int internal_create_group(struct kobject *kobj, int update,
 				return PTR_ERR(kn);
 			}
 		}
-	} else
+	} else {
 		kn = kobj->sd;
+	}
+
 	kernfs_get(kn);
 	error = create_files(kn, kobj, uid, gid, grp, update);
 	if (error) {

include/linux/acpi.h

@@ -70,19 +70,6 @@ static inline void acpi_free_fwnode_static(struct fwnode_handle *fwnode)
 	kfree(fwnode);
 }
 
-/**
- * ACPI_DEVICE_CLASS - macro used to describe an ACPI device with
- * the PCI-defined class-code information
- *
- * @_cls : the class, subclass, prog-if triple for this device
- * @_msk : the class mask for this device
- *
- * This macro is used to create a struct acpi_device_id that matches a
- * specific PCI class. The .id and .driver_data fields will be left
- * initialized with the default value.
- */
-#define ACPI_DEVICE_CLASS(_cls, _msk)	.cls = (_cls), .cls_msk = (_msk),
-
 static inline bool has_acpi_companion(struct device *dev)
 {
 	return is_acpi_device_node(dev->fwnode);
@@ -782,7 +769,6 @@ const char *acpi_get_subsystem_id(acpi_handle handle);
 #define ACPI_COMPANION_SET(dev, adev)	do { } while (0)
 #define ACPI_HANDLE(dev)		(NULL)
 #define ACPI_HANDLE_FWNODE(fwnode)	(NULL)
-#define ACPI_DEVICE_CLASS(_cls, _msk)	.cls = (0), .cls_msk = (0),
 
 #include <acpi/acpi_numa.h>
 

include/linux/device.h

@@ -96,7 +96,12 @@ struct device_type {
 	const struct dev_pm_ops *pm;
 };
 
-/* interface for exporting device attributes */
+/**
+ * struct device_attribute - Interface for exporting device attributes.
+ * @attr: sysfs attribute definition.
+ * @show: Show handler.
+ * @store: Store handler.
+ */
 struct device_attribute {
 	struct attribute	attr;
 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
@@ -105,6 +110,11 @@ struct device_attribute {
 			 const char *buf, size_t count);
 };
 
+/**
+ * struct dev_ext_attribute - Exported device attribute with extra context.
+ * @attr: Exported device attribute.
+ * @var: Pointer to context.
+ */
 struct dev_ext_attribute {
 	struct device_attribute attr;
 	void *var;
@@ -123,30 +133,124 @@ ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
 			 const char *buf, size_t count);
 
+/**
+ * DEVICE_ATTR - Define a device attribute.
+ * @_name: Attribute name.
+ * @_mode: File mode.
+ * @_show: Show handler. Optional, but mandatory if attribute is readable.
+ * @_store: Store handler. Optional, but mandatory if attribute is writable.
+ *
+ * Convenience macro for defining a struct device_attribute.
+ *
+ * For example, ``DEVICE_ATTR(foo, 0644, foo_show, foo_store);`` expands to:
+ *
+ * .. code-block:: c
+ *
+ *	struct device_attribute dev_attr_foo = {
+ *		.attr	= { .name = "foo", .mode = 0644 },
+ *		.show	= foo_show,
+ *		.store	= foo_store,
+ *	};
+ */
 #define DEVICE_ATTR(_name, _mode, _show, _store) \
 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
+
+/**
+ * DEVICE_ATTR_PREALLOC - Define a preallocated device attribute.
+ * @_name: Attribute name.
+ * @_mode: File mode.
+ * @_show: Show handler. Optional, but mandatory if attribute is readable.
+ * @_store: Store handler. Optional, but mandatory if attribute is writable.
+ *
+ * Like DEVICE_ATTR(), but ``SYSFS_PREALLOC`` is set on @_mode.
+ */
 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
 	struct device_attribute dev_attr_##_name = \
 		__ATTR_PREALLOC(_name, _mode, _show, _store)
+
+/**
+ * DEVICE_ATTR_RW - Define a read-write device attribute.
+ * @_name: Attribute name.
+ *
+ * Like DEVICE_ATTR(), but @_mode is 0644, @_show is <_name>_show,
+ * and @_store is <_name>_store.
+ */
 #define DEVICE_ATTR_RW(_name) \
 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
+
+/**
+ * DEVICE_ATTR_ADMIN_RW - Define an admin-only read-write device attribute.
+ * @_name: Attribute name.
+ *
+ * Like DEVICE_ATTR_RW(), but @_mode is 0600.
+ */
 #define DEVICE_ATTR_ADMIN_RW(_name) \
 	struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
+
+/**
+ * DEVICE_ATTR_RO - Define a readable device attribute.
+ * @_name: Attribute name.
+ *
+ * Like DEVICE_ATTR(), but @_mode is 0444 and @_show is <_name>_show.
+ */
 #define DEVICE_ATTR_RO(_name) \
 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
+
+/**
+ * DEVICE_ATTR_ADMIN_RO - Define an admin-only readable device attribute.
+ * @_name: Attribute name.
+ *
+ * Like DEVICE_ATTR_RO(), but @_mode is 0400.
+ */
 #define DEVICE_ATTR_ADMIN_RO(_name) \
 	struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
+
+/**
+ * DEVICE_ATTR_WO - Define an admin-only writable device attribute.
+ * @_name: Attribute name.
+ *
+ * Like DEVICE_ATTR(), but @_mode is 0200 and @_store is <_name>_store.
+ */
 #define DEVICE_ATTR_WO(_name) \
 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
+
+/**
+ * DEVICE_ULONG_ATTR - Define a device attribute backed by an unsigned long.
+ * @_name: Attribute name.
+ * @_mode: File mode.
+ * @_var: Identifier of unsigned long.
+ *
+ * Like DEVICE_ATTR(), but @_show and @_store are automatically provided
+ * such that reads and writes to the attribute from userspace affect @_var.
+ */
 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
 	struct dev_ext_attribute dev_attr_##_name = \
 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
+
+/**
+ * DEVICE_INT_ATTR - Define a device attribute backed by an int.
+ * @_name: Attribute name.
+ * @_mode: File mode.
+ * @_var: Identifier of int.
+ *
+ * Like DEVICE_ULONG_ATTR(), but @_var is an int.
+ */
 #define DEVICE_INT_ATTR(_name, _mode, _var) \
 	struct dev_ext_attribute dev_attr_##_name = \
 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
+
+/**
+ * DEVICE_BOOL_ATTR - Define a device attribute backed by a bool.
+ * @_name: Attribute name.
+ * @_mode: File mode.
+ * @_var: Identifier of bool.
+ *
+ * Like DEVICE_ULONG_ATTR(), but @_var is a bool.
+ */
 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
 	struct dev_ext_attribute dev_attr_##_name = \
 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
+
 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
 	struct device_attribute dev_attr_##_name =		\
 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
@@ -711,6 +815,11 @@ static inline bool device_iommu_mapped(struct device *dev)
 /* Get the wakeup routines, which depend on struct device */
 #include <linux/pm_wakeup.h>
 
+/**
+ * dev_name - Return a device's name.
+ * @dev: Device with name to get.
+ * Return: The kobject name of the device, or its initial name if unavailable.
+ */
 static inline const char *dev_name(const struct device *dev)
 {
 	/* Use the init name until the kobject becomes available */

include/linux/mod_devicetable.h

@@ -221,6 +221,19 @@ struct acpi_device_id {
 	__u32 cls_msk;
 };
 
+/**
+ * ACPI_DEVICE_CLASS - macro used to describe an ACPI device with
+ * the PCI-defined class-code information
+ *
+ * @_cls : the class, subclass, prog-if triple for this device
+ * @_msk : the class mask for this device
+ *
+ * This macro is used to create a struct acpi_device_id that matches a
+ * specific PCI class. The .id and .driver_data fields will be left
+ * initialized with the default value.
+ */
+#define ACPI_DEVICE_CLASS(_cls, _msk)	.cls = (_cls), .cls_msk = (_msk),
+
 #define PNP_ID_LEN	8
 #define PNP_MAX_DEVICES	8
 

include/linux/property.h

@@ -85,6 +85,18 @@ bool fwnode_device_is_compatible(const struct fwnode_handle *fwnode, const char
 	return fwnode_property_match_string(fwnode, "compatible", compat) >= 0;
 }
 
+/**
+ * device_is_compatible - match 'compatible' property of the device with a given string
+ * @dev: Pointer to the struct device
+ * @compat: The string to match 'compatible' property with
+ *
+ * Returns: true if matches, otherwise false.
+ */
+static inline bool device_is_compatible(const struct device *dev, const char *compat)
+{
+	return fwnode_device_is_compatible(dev_fwnode(dev), compat);
+}
+
 int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
 				       const char *prop, const char *nargs_prop,
 				       unsigned int nargs, unsigned int index,