Merge tag 'driver-core-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the small set of driver core and kernfs changes for 6.10-rc1.

  Nothing major here at all, just a small set of changes for some driver
  core apis, and minor fixups. Included in here are:

   - sysfs_bin_attr_simple_read() helper added and used

   - device_show_string() helper added and used

  All usages of these were acked by the various maintainers. Also in
  here are:

   - kernfs minor cleanup

   - removed unused functions

   - typo fix in documentation

   - pay attention to sysfs_create_link() failures in module.c finally

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

* tag 'driver-core-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  device property: Fix a typo in the description of device_get_child_node_count()
  kernfs: mount: Remove unnecessary ‘NULL’ values from knparent
  scsi: Use device_show_string() helper for sysfs attributes
  platform/x86: Use device_show_string() helper for sysfs attributes
  perf: Use device_show_string() helper for sysfs attributes
  IB/qib: Use device_show_string() helper for sysfs attributes
  hwmon: Use device_show_string() helper for sysfs attributes
  driver core: Add device_show_string() helper for sysfs attributes
  treewide: Use sysfs_bin_attr_simple_read() helper
  sysfs: Add sysfs_bin_attr_simple_read() helper
  module: don't ignore sysfs_create_link() failures
  driver core: Remove unused platform_notify, platform_notify_remove

45 files changed, 188 insertions, 422 deletions

diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index 057ec2e3451d..d400fa391c27 100644
--- a/arch/powerpc/perf/hv-24x7.c
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -425,16 +425,6 @@ static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp)
 	return kasprintf(gfp, "%.*s", max_len, maybe_str);
 }
 
-static ssize_t device_show_string(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct dev_ext_attribute *d;
-
-	d = container_of(attr, struct dev_ext_attribute, attr);
-
-	return sprintf(buf, "%s\n", (char *)d->var);
-}
-
 static ssize_t cpumask_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 45dd77e3ccf6..5d0f35bb917e 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -792,14 +792,6 @@ static int __init opal_sysfs_init(void)
 	return 0;
 }
 
-static ssize_t export_attr_read(struct file *fp, struct kobject *kobj,
-				struct bin_attribute *bin_attr, char *buf,
-				loff_t off, size_t count)
-{
-	return memory_read_from_buffer(buf, count, &off, bin_attr->private,
-				       bin_attr->size);
-}
-
 static int opal_add_one_export(struct kobject *parent, const char *export_name,
 			       struct device_node *np, const char *prop_name)
 {
@@ -826,7 +818,7 @@ static int opal_add_one_export(struct kobject *parent, const char *export_name,
 	sysfs_bin_attr_init(attr);
 	attr->attr.name = name;
 	attr->attr.mode = 0400;
-	attr->read = export_attr_read;
+	attr->read = sysfs_bin_attr_simple_read;
 	attr->private = __va(vals[0]);
 	attr->size = vals[1];
 
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 768d1414897f..38c1b1f1deaa 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -5645,18 +5645,11 @@ lbr_is_visible(struct kobject *kobj, struct attribute *attr, int i)
 
 static char pmu_name_str[30];
 
-static ssize_t pmu_name_show(struct device *cdev,
-			     struct device_attribute *attr,
-			     char *buf)
-{
-	return snprintf(buf, PAGE_SIZE, "%s\n", pmu_name_str);
-}
-
-static DEVICE_ATTR_RO(pmu_name);
+static DEVICE_STRING_ATTR_RO(pmu_name, 0444, pmu_name_str);
 
 static struct attribute *intel_pmu_caps_attrs[] = {
-       &dev_attr_pmu_name.attr,
-       NULL
+	&dev_attr_pmu_name.attr.attr,
+	NULL
 };
 
 static DEVICE_ATTR(allow_tsx_force_abort, 0644,
diff --git a/drivers/acpi/bgrt.c b/drivers/acpi/bgrt.c
index e4fb9e225ddf..d1d9c9289087 100644
--- a/drivers/acpi/bgrt.c
+++ b/drivers/acpi/bgrt.c
@@ -29,14 +29,7 @@ BGRT_SHOW(type, image_type);
 BGRT_SHOW(xoffset, image_offset_x);
 BGRT_SHOW(yoffset, image_offset_y);
 
-static ssize_t image_read(struct file *file, struct kobject *kobj,
-	       struct bin_attribute *attr, char *buf, loff_t off, size_t count)
-{
-	memcpy(buf, attr->private + off, count);
-	return count;
-}
-
-static BIN_ATTR_RO(image, 0);	/* size gets filled in later */
+static BIN_ATTR_SIMPLE_RO(image);
 
 static struct attribute *bgrt_attributes[] = {
 	&bgrt_attr_version.attr,
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 0738ccad08b2..db4f910e8e36 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -192,11 +192,14 @@ extern struct kset *devices_kset;
 void devices_kset_move_last(struct device *dev);
 
 #if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS)
-void module_add_driver(struct module *mod, struct device_driver *drv);
+int module_add_driver(struct module *mod, struct device_driver *drv);
 void module_remove_driver(struct device_driver *drv);
 #else
-static inline void module_add_driver(struct module *mod,
-				     struct device_driver *drv) { }
+static inline int module_add_driver(struct module *mod,
+				    struct device_driver *drv)
+{
+	return 0;
+}
 static inline void module_remove_driver(struct device_driver *drv) { }
 #endif
 
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index daee55c9b2d9..ffea0728b8b2 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -674,7 +674,12 @@ int bus_add_driver(struct device_driver *drv)
 		if (error)
 			goto out_del_list;
 	}
-	module_add_driver(drv->owner, drv);
+	error = module_add_driver(drv->owner, drv);
+	if (error) {
+		printk(KERN_ERR "%s: failed to create module links for %s\n",
+			__func__, drv->name);
+		goto out_detach;
+	}
 
 	error = driver_create_file(drv, &driver_attr_uevent);
 	if (error) {
@@ -699,6 +704,8 @@ int bus_add_driver(struct device_driver *drv)
 
 	return 0;
 
+out_detach:
+	driver_detach(drv);
 out_del_list:
 	klist_del(&priv->knode_bus);
 out_unregister:
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 5f4e03336e68..131d96c6090b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2346,8 +2346,6 @@ static void fw_devlink_link_device(struct device *dev)
 
 /* Device links support end. */
 
-int (*platform_notify)(struct device *dev) = NULL;
-int (*platform_notify_remove)(struct device *dev) = NULL;
 static struct kobject *dev_kobj;
 
 /* /sys/dev/char */
@@ -2395,16 +2393,10 @@ static void device_platform_notify(struct device *dev)
 	acpi_device_notify(dev);
 
 	software_node_notify(dev);
-
-	if (platform_notify)
-		platform_notify(dev);
 }
 
 static void device_platform_notify_remove(struct device *dev)
 {
-	if (platform_notify_remove)
-		platform_notify_remove(dev);
-
 	software_node_notify_remove(dev);
 
 	acpi_device_notify_remove(dev);
@@ -2546,6 +2538,15 @@ ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 }
 EXPORT_SYMBOL_GPL(device_show_bool);
 
+ssize_t device_show_string(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct dev_ext_attribute *ea = to_ext_attr(attr);
+
+	return sysfs_emit(buf, "%s\n", (char *)ea->var);
+}
+EXPORT_SYMBOL_GPL(device_show_string);
+
 /**
  * device_release - free device structure.
  * @kobj: device's kobject.
diff --git a/drivers/base/module.c b/drivers/base/module.c
index 46ad4d636731..a1b55da07127 100644
--- a/drivers/base/module.c
+++ b/drivers/base/module.c
@@ -30,14 +30,14 @@ static void module_create_drivers_dir(struct module_kobject *mk)
 	mutex_unlock(&drivers_dir_mutex);
 }
 
-void module_add_driver(struct module *mod, struct device_driver *drv)
+int module_add_driver(struct module *mod, struct device_driver *drv)
 {
 	char *driver_name;
-	int no_warn;
 	struct module_kobject *mk = NULL;
+	int ret;
 
 	if (!drv)
-		return;
+		return 0;
 
 	if (mod)
 		mk = &mod->mkobj;
@@ -56,17 +56,37 @@ void module_add_driver(struct module *mod, struct device_driver *drv)
 	}
 
 	if (!mk)
-		return;
+		return 0;
+
+	ret = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
+	if (ret)
+		return ret;
 
-	/* Don't check return codes; these calls are idempotent */
-	no_warn = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
 	driver_name = make_driver_name(drv);
-	if (driver_name) {
-		module_create_drivers_dir(mk);
-		no_warn = sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
-					    driver_name);
-		kfree(driver_name);
+	if (!driver_name) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	module_create_drivers_dir(mk);
+	if (!mk->drivers_dir) {
+		ret = -EINVAL;
+		goto out;
 	}
+
+	ret = sysfs_create_link(mk->drivers_dir, &drv->p->kobj, driver_name);
+	if (ret)
+		goto out;
+
+	kfree(driver_name);
+
+	return 0;
+out:
+	sysfs_remove_link(&drv->p->kobj, "module");
+	sysfs_remove_link(mk->drivers_dir, driver_name);
+	kfree(driver_name);
+
+	return ret;
 }
 
 void module_remove_driver(struct device_driver *drv)
diff --git a/drivers/base/property.c b/drivers/base/property.c
index 7324a704a9a1..89a06fd16a99 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -905,7 +905,7 @@ EXPORT_SYMBOL_GPL(fwnode_device_is_available);
 
 /**
  * device_get_child_node_count - return the number of child nodes for device
- * @dev: Device to cound the child nodes for
+ * @dev: Device to count the child nodes for
  *
  * Return: the number of child nodes for a given device.
  */
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 68231c638c55..23b002e4d4a0 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -761,16 +761,8 @@ static void __init dmi_scan_machine(void)
 	pr_info("DMI not present or invalid.\n");
 }
 
-static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
-			      struct bin_attribute *attr, char *buf,
-			      loff_t pos, size_t count)
-{
-	memcpy(buf, attr->private + pos, count);
-	return count;
-}
-
-static BIN_ATTR(smbios_entry_point, S_IRUSR, raw_table_read, NULL, 0);
-static BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0);
+static BIN_ATTR_SIMPLE_ADMIN_RO(smbios_entry_point);
+static BIN_ATTR_SIMPLE_ADMIN_RO(DMI);
 
 static int __init dmi_init(void)
 {
diff --git a/drivers/firmware/efi/rci2-table.c b/drivers/firmware/efi/rci2-table.c
index de1a9a1f9f14..4fd45d6f69a4 100644
--- a/drivers/firmware/efi/rci2-table.c
+++ b/drivers/firmware/efi/rci2-table.c
@@ -40,15 +40,7 @@ static u8 *rci2_base;
 static u32 rci2_table_len;
 unsigned long rci2_table_phys __ro_after_init = EFI_INVALID_TABLE_ADDR;
 
-static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
-			      struct bin_attribute *attr, char *buf,
-			      loff_t pos, size_t count)
-{
-	memcpy(buf, attr->private + pos, count);
-	return count;
-}
-
-static BIN_ATTR(rci2, S_IRUSR, raw_table_read, NULL, 0);
+static BIN_ATTR_SIMPLE_ADMIN_RO(rci2);
 
 static u16 checksum(void)
 {
diff --git a/drivers/gpu/drm/i915/gvt/firmware.c b/drivers/gpu/drm/i915/gvt/firmware.c
index d800d267f0e9..221a3ae81baf 100644
--- a/drivers/gpu/drm/i915/gvt/firmware.c
+++ b/drivers/gpu/drm/i915/gvt/firmware.c
@@ -51,21 +51,7 @@ struct gvt_firmware_header {
 
 #define dev_to_drm_minor(d) dev_get_drvdata((d))
 
-static ssize_t
-gvt_firmware_read(struct file *filp, struct kobject *kobj,
-	     struct bin_attribute *attr, char *buf,
-	     loff_t offset, size_t count)
-{
-	memcpy(buf, attr->private + offset, count);
-	return count;
-}
-
-static struct bin_attribute firmware_attr = {
-	.attr = {.name = "gvt_firmware", .mode = (S_IRUSR)},
-	.read = gvt_firmware_read,
-	.write = NULL,
-	.mmap = NULL,
-};
+static BIN_ATTR_SIMPLE_ADMIN_RO(gvt_firmware);
 
 static int expose_firmware_sysfs(struct intel_gvt *gvt)
 {
@@ -108,10 +94,10 @@ static int expose_firmware_sysfs(struct intel_gvt *gvt)
 	crc32_start = offsetof(struct gvt_firmware_header, version);
 	h->crc32 = crc32_le(0, firmware + crc32_start, size - crc32_start);
 
-	firmware_attr.size = size;
-	firmware_attr.private = firmware;
+	bin_attr_gvt_firmware.size = size;
+	bin_attr_gvt_firmware.private = firmware;
 
-	ret = device_create_bin_file(&pdev->dev, &firmware_attr);
+	ret = device_create_bin_file(&pdev->dev, &bin_attr_gvt_firmware);
 	if (ret) {
 		vfree(firmware);
 		return ret;
@@ -123,8 +109,8 @@ static void clean_firmware_sysfs(struct intel_gvt *gvt)
 {
 	struct pci_dev *pdev = to_pci_dev(gvt->gt->i915->drm.dev);
 
-	device_remove_bin_file(&pdev->dev, &firmware_attr);
-	vfree(firmware_attr.private);
+	device_remove_bin_file(&pdev->dev, &bin_attr_gvt_firmware);
+	vfree(bin_attr_gvt_firmware.private);
 }
 
 /**
diff --git a/drivers/hwmon/i5k_amb.c b/drivers/hwmon/i5k_amb.c
index ff48913fe6bf..02f5d35dd319 100644
--- a/drivers/hwmon/i5k_amb.c
+++ b/drivers/hwmon/i5k_amb.c
@@ -101,14 +101,7 @@ struct i5k_amb_data {
 	unsigned int num_attrs;
 };
 
-static ssize_t name_show(struct device *dev, struct device_attribute *devattr,
-			 char *buf)
-{
-	return sprintf(buf, "%s\n", DRVNAME);
-}
-
-
-static DEVICE_ATTR_RO(name);
+static DEVICE_STRING_ATTR_RO(name, 0444, DRVNAME);
 
 static struct platform_device *amb_pdev;
 
@@ -373,7 +366,7 @@ static int i5k_amb_hwmon_init(struct platform_device *pdev)
 		}
 	}
 
-	res = device_create_file(&pdev->dev, &dev_attr_name);
+	res = device_create_file(&pdev->dev, &dev_attr_name.attr);
 	if (res)
 		goto exit_remove;
 
@@ -386,7 +379,7 @@ static int i5k_amb_hwmon_init(struct platform_device *pdev)
 	return res;
 
 exit_remove:
-	device_remove_file(&pdev->dev, &dev_attr_name);
+	device_remove_file(&pdev->dev, &dev_attr_name.attr);
 	for (i = 0; i < data->num_attrs; i++)
 		device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
 	kfree(data->attrs);
@@ -561,7 +554,7 @@ static void i5k_amb_remove(struct platform_device *pdev)
 	struct i5k_amb_data *data = platform_get_drvdata(pdev);
 
 	hwmon_device_unregister(data->hwmon_dev);
-	device_remove_file(&pdev->dev, &dev_attr_name);
+	device_remove_file(&pdev->dev, &dev_attr_name.attr);
 	for (i = 0; i < data->num_attrs; i++)
 		device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
 	kfree(data->attrs);
diff --git a/drivers/hwmon/ibmpex.c b/drivers/hwmon/ibmpex.c
index db066b368918..228c5f6c6f38 100644
--- a/drivers/hwmon/ibmpex.c
+++ b/drivers/hwmon/ibmpex.c
@@ -256,12 +256,7 @@ static struct ibmpex_bmc_data *get_bmc_data(int iface)
 	return NULL;
 }
 
-static ssize_t name_show(struct device *dev, struct device_attribute *devattr,
-			 char *buf)
-{
-	return sprintf(buf, "%s\n", DRVNAME);
-}
-static SENSOR_DEVICE_ATTR_RO(name, name, 0);
+static DEVICE_STRING_ATTR_RO(name, 0444, DRVNAME);
 
 static ssize_t ibmpex_show_sensor(struct device *dev,
 				  struct device_attribute *devattr,
@@ -415,8 +410,7 @@ static int ibmpex_find_sensors(struct ibmpex_bmc_data *data)
 	if (err)
 		goto exit_remove;
 
-	err = device_create_file(data->bmc_device,
-			&sensor_dev_attr_name.dev_attr);
+	err = device_create_file(data->bmc_device, &dev_attr_name.attr);
 	if (err)
 		goto exit_remove;
 
@@ -425,7 +419,7 @@ static int ibmpex_find_sensors(struct ibmpex_bmc_data *data)
 exit_remove:
 	device_remove_file(data->bmc_device,
 			   &sensor_dev_attr_reset_high_low.dev_attr);
-	device_remove_file(data->bmc_device, &sensor_dev_attr_name.dev_attr);
+	device_remove_file(data->bmc_device, &dev_attr_name.attr);
 	for (i = 0; i < data->num_sensors; i++)
 		for (j = 0; j < PEX_NUM_SENSOR_FUNCS; j++) {
 			if (!data->sensors[i].attr[j].dev_attr.attr.name)
@@ -516,7 +510,7 @@ static void ibmpex_bmc_delete(struct ibmpex_bmc_data *data)
 
 	device_remove_file(data->bmc_device,
 			   &sensor_dev_attr_reset_high_low.dev_attr);
-	device_remove_file(data->bmc_device, &sensor_dev_attr_name.dev_attr);
+	device_remove_file(data->bmc_device, &dev_attr_name.attr);
 	for (i = 0; i < data->num_sensors; i++)
 		for (j = 0; j < PEX_NUM_SENSOR_FUNCS; j++) {
 			if (!data->sensors[i].attr[j].dev_attr.attr.name)
diff --git a/drivers/infiniband/hw/qib/qib.h b/drivers/infiniband/hw/qib/qib.h
index 26c615772be3..8ee4edd7883c 100644
--- a/drivers/infiniband/hw/qib/qib.h
+++ b/drivers/infiniband/hw/qib/qib.h
@@ -1359,7 +1359,6 @@ static inline u32 qib_get_rcvhdrtail(const struct qib_ctxtdata *rcd)
  * sysfs interface.
  */
 
-extern const char ib_qib_version[];
 extern const struct attribute_group qib_attr_group;
 extern const struct attribute_group *qib_attr_port_groups[];
 
diff --git a/drivers/infiniband/hw/qib/qib_driver.c b/drivers/infiniband/hw/qib/qib_driver.c
index bf3fa12fe935..4fcbef99e400 100644
--- a/drivers/infiniband/hw/qib/qib_driver.c
+++ b/drivers/infiniband/hw/qib/qib_driver.c
@@ -44,12 +44,6 @@
 
 #include "qib.h"
 
-/*
- * The size has to be longer than this string, so we can append
- * board/chip information to it in the init code.
- */
-const char ib_qib_version[] = QIB_DRIVER_VERSION "\n";
-
 DEFINE_MUTEX(qib_mutex);	/* general driver use */
 
 unsigned qib_ibmtu;
diff --git a/drivers/infiniband/hw/qib/qib_sysfs.c b/drivers/infiniband/hw/qib/qib_sysfs.c
index 41c272980f91..53ec7510e4eb 100644
--- a/drivers/infiniband/hw/qib/qib_sysfs.c
+++ b/drivers/infiniband/hw/qib/qib_sysfs.c
@@ -585,13 +585,7 @@ static ssize_t hca_type_show(struct device *device,
 static DEVICE_ATTR_RO(hca_type);
 static DEVICE_ATTR(board_id, 0444, hca_type_show, NULL);
 
-static ssize_t version_show(struct device *device,
-			    struct device_attribute *attr, char *buf)
-{
-	/* The string printed here is already newline-terminated. */
-	return sysfs_emit(buf, "%s", (char *)ib_qib_version);
-}
-static DEVICE_ATTR_RO(version);
+static DEVICE_STRING_ATTR_RO(version, 0444, QIB_DRIVER_VERSION);
 
 static ssize_t boardversion_show(struct device *device,
 				 struct device_attribute *attr, char *buf)
@@ -721,7 +715,7 @@ static struct attribute *qib_attributes[] = {
 	&dev_attr_hw_rev.attr,
 	&dev_attr_hca_type.attr,
 	&dev_attr_board_id.attr,
-	&dev_attr_version.attr,
+	&dev_attr_version.attr.attr,
 	&dev_attr_nctxts.attr,
 	&dev_attr_nfreectxts.attr,
 	&dev_attr_serial.attr,
diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_uncore_drw_pmu.c
index 89dd38343f93..38a2947ae813 100644
--- a/drivers/perf/alibaba_uncore_drw_pmu.c
+++ b/drivers/perf/alibaba_uncore_drw_pmu.c
@@ -236,24 +236,16 @@ static const struct attribute_group ali_drw_pmu_cpumask_attr_group = {
 	.attrs = ali_drw_pmu_cpumask_attrs,
 };
 
-static ssize_t ali_drw_pmu_identifier_show(struct device *dev,
-					struct device_attribute *attr,
-					char *page)
-{
-	return sysfs_emit(page, "%s\n", "ali_drw_pmu");
-}
-
 static umode_t ali_drw_pmu_identifier_attr_visible(struct kobject *kobj,
 						struct attribute *attr, int n)
 {
 	return attr->mode;
 }
 
-static struct device_attribute ali_drw_pmu_identifier_attr =
-	__ATTR(identifier, 0444, ali_drw_pmu_identifier_show, NULL);
+static DEVICE_STRING_ATTR_RO(ali_drw_pmu_identifier, 0444, "ali_drw_pmu");
 
 static struct attribute *ali_drw_pmu_identifier_attrs[] = {
-	&ali_drw_pmu_identifier_attr.attr,
+	&dev_attr_ali_drw_pmu_identifier.attr.attr,
 	NULL
 };
 
diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c
index a7fd80677919..c76bac668dea 100644
--- a/drivers/perf/arm-cci.c
+++ b/drivers/perf/arm-cci.c
@@ -127,8 +127,6 @@ enum cci_models {
 
 static void pmu_write_counters(struct cci_pmu *cci_pmu,
 				 unsigned long *mask);
-static ssize_t __maybe_unused cci_pmu_format_show(struct device *dev,
-			struct device_attribute *attr, char *buf);
 static ssize_t __maybe_unused cci_pmu_event_show(struct device *dev,
 			struct device_attribute *attr, char *buf);
 
@@ -138,7 +136,7 @@ static ssize_t __maybe_unused cci_pmu_event_show(struct device *dev,
 	})[0].attr.attr
 
 #define CCI_FORMAT_EXT_ATTR_ENTRY(_name, _config) \
-	CCI_EXT_ATTR_ENTRY(_name, cci_pmu_format_show, (char *)_config)
+	CCI_EXT_ATTR_ENTRY(_name, device_show_string, _config)
 #define CCI_EVENT_EXT_ATTR_ENTRY(_name, _config) \
 	CCI_EXT_ATTR_ENTRY(_name, cci_pmu_event_show, (unsigned long)_config)
 
@@ -688,14 +686,6 @@ static void __cci_pmu_disable(struct cci_pmu *cci_pmu)
 	writel(val, cci_pmu->ctrl_base + CCI_PMCR);
 }
 
-static ssize_t cci_pmu_format_show(struct device *dev,
-			struct device_attribute *attr, char *buf)
-{
-	struct dev_ext_attribute *eattr = container_of(attr,
-				struct dev_ext_attribute, attr);
-	return sysfs_emit(buf, "%s\n", (char *)eattr->var);
-}
-
 static ssize_t cci_pmu_event_show(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
diff --git a/drivers/perf/arm-ccn.c b/drivers/perf/arm-ccn.c
index f4495ff6525f..86ef31ac7503 100644
--- a/drivers/perf/arm-ccn.c
+++ b/drivers/perf/arm-ccn.c
@@ -215,18 +215,9 @@ static void arm_ccn_pmu_config_set(u64 *config, u32 node_xp, u32 type, u32 port)
 	*config |= (node_xp << 0) | (type << 8) | (port << 24);
 }
 
-static ssize_t arm_ccn_pmu_format_show(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct dev_ext_attribute *ea = container_of(attr,
-			struct dev_ext_attribute, attr);
-
-	return sysfs_emit(buf, "%s\n", (char *)ea->var);
-}
-
 #define CCN_FORMAT_ATTR(_name, _config) \
 	struct dev_ext_attribute arm_ccn_pmu_format_attr_##_name = \
-			{ __ATTR(_name, S_IRUGO, arm_ccn_pmu_format_show, \
+			{ __ATTR(_name, S_IRUGO, device_show_string, \
 			NULL), _config }
 
 static CCN_FORMAT_ATTR(node, "config:0-7");
diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
index ba0cf2f466ef..c318dc909767 100644
--- a/drivers/perf/arm_cspmu/arm_cspmu.c
+++ b/drivers/perf/arm_cspmu/arm_cspmu.c
@@ -223,16 +223,6 @@ arm_cspmu_event_attr_is_visible(struct kobject *kobj,
 	return attr->mode;
 }
 
-ssize_t arm_cspmu_sysfs_format_show(struct device *dev,
-				struct device_attribute *attr,
-				char *buf)
-{
-	struct dev_ext_attribute *eattr =
-		container_of(attr, struct dev_ext_attribute, attr);
-	return sysfs_emit(buf, "%s\n", (char *)eattr->var);
-}
-EXPORT_SYMBOL_GPL(arm_cspmu_sysfs_format_show);
-
 static struct attribute *arm_cspmu_format_attrs[] = {