coccinelle: alloc_cast: drop removed allocatorsgrafted

- pci_alloc_consistent() and pci_zalloc_consistent() were removed by
  commit 7968778914e5
  ("PCI: Remove the deprecated "pci-dma-compat.h" API")

- kmem_alloc() was removed by commit f078d4ea8276
  ("xfs: convert kmem_alloc() to kmalloc()")

- kmem_zalloc() was removed by commit 10634530f7ba
  ("xfs: convert kmem_zalloc() to kzalloc()")

- kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit
  bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers")

So drop them from the rules.

No functional change.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

1 files changed, 1109 insertions, 0 deletions

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
new file mode 100644
index 000000000..fc06b0c28
--- /dev/null
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -0,0 +1,1109 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kdev_t.h>
+#include <linux/kstrtox.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/srcu.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+
+#include <uapi/linux/gpio.h>
+
+#include "gpiolib.h"
+#include "gpiolib-sysfs.h"
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+
+struct kernfs_node;
+
+#define GPIO_IRQF_TRIGGER_NONE		0
+#define GPIO_IRQF_TRIGGER_FALLING	BIT(0)
+#define GPIO_IRQF_TRIGGER_RISING	BIT(1)
+#define GPIO_IRQF_TRIGGER_BOTH		(GPIO_IRQF_TRIGGER_FALLING | \
+					 GPIO_IRQF_TRIGGER_RISING)
+
+enum {
+	GPIO_SYSFS_LINE_CLASS_ATTR_DIRECTION = 0,
+	GPIO_SYSFS_LINE_CLASS_ATTR_VALUE,
+	GPIO_SYSFS_LINE_CLASS_ATTR_EDGE,
+	GPIO_SYSFS_LINE_CLASS_ATTR_ACTIVE_LOW,
+	GPIO_SYSFS_LINE_CLASS_ATTR_SENTINEL,
+	GPIO_SYSFS_LINE_CLASS_ATTR_SIZE,
+};
+
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+enum {
+	GPIO_SYSFS_LINE_CHIP_ATTR_DIRECTION = 0,
+	GPIO_SYSFS_LINE_CHIP_ATTR_VALUE,
+	GPIO_SYSFS_LINE_CHIP_ATTR_SENTINEL,
+	GPIO_SYSFS_LINE_CHIP_ATTR_SIZE,
+};
+
+struct gpiod_data {
+	struct list_head list;
+
+	struct gpio_desc *desc;
+	struct device *dev;
+
+	struct mutex mutex;
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	struct kernfs_node *value_kn;
+	int irq;
+	unsigned char irq_flags;
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+	bool direction_can_change;
+
+	struct kobject *parent;
+	struct device_attribute dir_attr;
+	struct device_attribute val_attr;
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	struct device_attribute edge_attr;
+	struct device_attribute active_low_attr;
+
+	struct attribute *class_attrs[GPIO_SYSFS_LINE_CLASS_ATTR_SIZE];
+	struct attribute_group class_attr_group;
+	const struct attribute_group *class_attr_groups[2];
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+	struct attribute *chip_attrs[GPIO_SYSFS_LINE_CHIP_ATTR_SIZE];
+	struct attribute_group chip_attr_group;
+	const struct attribute_group *chip_attr_groups[2];
+};
+
+struct gpiodev_data {
+	struct list_head exported_lines;
+	struct gpio_device *gdev;
+	struct device *cdev_id; /* Class device by GPIO device ID */
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	struct device *cdev_base; /* Class device by GPIO base */
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+};
+
+/*
+ * Lock to serialise gpiod export and unexport, and prevent re-export of
+ * gpiod whose chip is being unregistered.
+ */
+static DEFINE_MUTEX(sysfs_lock);
+
+/*
+ * /sys/class/gpio/gpioN... only for GPIOs that are exported
+ *   /direction
+ *      * MAY BE OMITTED if kernel won't allow direction changes
+ *      * is read/write as "in" or "out"
+ *      * may also be written as "high" or "low", initializing
+ *        output value as specified ("out" implies "low")
+ *   /value
+ *      * always readable, subject to hardware behavior
+ *      * may be writable, as zero/nonzero
+ *   /edge
+ *      * configures behavior of poll(2) on /value
+ *      * available only if pin can generate IRQs on input
+ *      * is read/write as "none", "falling", "rising", or "both"
+ *   /active_low
+ *      * configures polarity of /value
+ *      * is read/write as zero/nonzero
+ *      * also affects existing and subsequent "falling" and "rising"
+ *        /edge configuration
+ */
+
+static ssize_t direction_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct gpiod_data *data = container_of(attr, struct gpiod_data,
+					       dir_attr);
+	struct gpio_desc *desc = data->desc;
+	int value;
+
+	scoped_guard(mutex, &data->mutex) {
+		gpiod_get_direction(desc);
+		value = !!test_bit(GPIOD_FLAG_IS_OUT, &desc->flags);
+	}
+
+	return sysfs_emit(buf, "%s\n", value ? "out" : "in");
+}
+
+static ssize_t direction_store(struct device *dev,
+			       struct device_attribute *attr, const char *buf,
+			       size_t size)
+{
+	struct gpiod_data *data = container_of(attr, struct gpiod_data,
+					       dir_attr);
+	struct gpio_desc *desc = data->desc;
+	ssize_t status;
+
+	guard(mutex)(&data->mutex);
+
+	if (sysfs_streq(buf, "high"))
+		status = gpiod_direction_output_raw(desc, 1);
+	else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
+		status = gpiod_direction_output_raw(desc, 0);
+	else if (sysfs_streq(buf, "in"))
+		status = gpiod_direction_input(desc);
+	else
+		status = -EINVAL;
+
+	return status ? : size;
+}
+
+static ssize_t value_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	struct gpiod_data *data = container_of(attr, struct gpiod_data,
+					       val_attr);
+	struct gpio_desc *desc = data->desc;
+	ssize_t status;
+
+	scoped_guard(mutex, &data->mutex)
+		status = gpiod_get_value_cansleep(desc);
+
+	if (status < 0)
+		return status;
+
+	return sysfs_emit(buf, "%zd\n", status);
+}
+
+static ssize_t value_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t size)
+{
+	struct gpiod_data *data = container_of(attr, struct gpiod_data,
+					       val_attr);
+	struct gpio_desc *desc = data->desc;
+	ssize_t status;
+	long value;
+
+	status = kstrtol(buf, 0, &value);
+	if (status)
+		return status;
+
+	guard(mutex)(&data->mutex);
+
+	status = gpiod_set_value_cansleep(desc, value);
+	if (status)
+		return status;
+
+	return size;
+}
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
+{
+	struct gpiod_data *data = priv;
+
+	sysfs_notify_dirent(data->value_kn);
+
+	return IRQ_HANDLED;
+}
+
+/* Caller holds gpiod-data mutex. */
+static int gpio_sysfs_request_irq(struct gpiod_data *data, unsigned char flags)
+{
+	struct gpio_desc *desc = data->desc;
+	unsigned long irq_flags;
+	int ret;
+
+	CLASS(gpio_chip_guard, guard)(desc);
+	if (!guard.gc)
+		return -ENODEV;
+
+	data->irq = gpiod_to_irq(desc);
+	if (data->irq < 0)
+		return -EIO;
+
+	irq_flags = IRQF_SHARED;
+	if (flags & GPIO_IRQF_TRIGGER_FALLING) {
+		irq_flags |= test_bit(GPIOD_FLAG_ACTIVE_LOW, &desc->flags) ?
+				IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
+		set_bit(GPIOD_FLAG_EDGE_FALLING, &desc->flags);
+	}
+	if (flags & GPIO_IRQF_TRIGGER_RISING) {
+		irq_flags |= test_bit(GPIOD_FLAG_ACTIVE_LOW, &desc->flags) ?
+				IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
+		set_bit(GPIOD_FLAG_EDGE_RISING, &desc->flags);
+	}
+
+	/*
+	 * FIXME: This should be done in the irq_request_resources callback
+	 * when the irq is requested, but a few drivers currently fail to do
+	 * so.
+	 *
+	 * Remove this redundant call (along with the corresponding unlock)
+	 * when those drivers have been fixed.
+	 */
+	ret = gpiochip_lock_as_irq(guard.gc, gpiod_hwgpio(desc));
+	if (ret < 0)
+		goto err_clr_bits;
+
+	ret = request_any_context_irq(data->irq, gpio_sysfs_irq, irq_flags,
+				"gpiolib", data);
+	if (ret < 0)
+		goto err_unlock;
+
+	data->irq_flags = flags;
+
+	return 0;
+
+err_unlock:
+	gpiochip_unlock_as_irq(guard.gc, gpiod_hwgpio(desc));
+err_clr_bits:
+	clear_bit(GPIOD_FLAG_EDGE_RISING, &desc->flags);
+	clear_bit(GPIOD_FLAG_EDGE_FALLING, &desc->flags);
+
+	return ret;
+}
+
+/*
+ * Caller holds gpiod-data mutex (unless called after class-device
+ * deregistration).
+ */
+static void gpio_sysfs_free_irq(struct gpiod_data *data)
+{
+	struct gpio_desc *desc = data->desc;
+
+	CLASS(gpio_chip_guard, guard)(desc);
+	if (!guard.gc)
+		return;
+
+	data->irq_flags = 0;
+	free_irq(data->irq, data);
+	gpiochip_unlock_as_irq(guard.gc, gpiod_hwgpio(desc));
+	clear_bit(GPIOD_FLAG_EDGE_RISING, &desc->flags);
+	clear_bit(GPIOD_FLAG_EDGE_FALLING, &desc->flags);
+}
+
+static const char *const trigger_names[] = {
+	[GPIO_IRQF_TRIGGER_NONE]	= "none",
+	[GPIO_IRQF_TRIGGER_FALLING]	= "falling",
+	[GPIO_IRQF_TRIGGER_RISING]	= "rising",
+	[GPIO_IRQF_TRIGGER_BOTH]	= "both",
+};
+
+static ssize_t edge_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct gpiod_data *data = container_of(attr, struct gpiod_data,
+					       edge_attr);
+	int flags;
+
+	scoped_guard(mutex, &data->mutex)
+		flags = data->irq_flags;
+
+	if (flags >= ARRAY_SIZE(trigger_names))
+		return 0;
+
+	return sysfs_emit(buf, "%s\n", trigger_names[flags]);
+}
+
+static ssize_t edge_store(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t size)
+{
+	struct gpiod_data *data = container_of(attr, struct gpiod_data,
+					       edge_attr);
+	ssize_t status = size;
+	int flags;
+
+	flags = sysfs_match_string(trigger_names, buf);
+	if (flags < 0)
+		return flags;
+
+	guard(mutex)(&data->mutex);
+
+	if (flags == data->irq_flags)
+		return size;
+
+	if (data->irq_flags)
+		gpio_sysfs_free_irq(data);
+
+	if (!flags)
+		return size;
+
+	status = gpio_sysfs_request_irq(data, flags);
+	if (status)
+		return status;
+
+	gpiod_line_state_notify(data->desc, GPIO_V2_LINE_CHANGED_CONFIG);
+
+	return size;
+}
+
+/* Caller holds gpiod-data mutex. */
+static int gpio_sysfs_set_active_low(struct gpiod_data *data, int value)
+{
+	unsigned int flags = data->irq_flags;
+	struct gpio_desc *desc = data->desc;
+	int status = 0;
+
+	if (!!test_bit(GPIOD_FLAG_ACTIVE_LOW, &desc->flags) == !!value)
+		return 0;
+
+	assign_bit(GPIOD_FLAG_ACTIVE_LOW, &desc->flags, value);
+
+	/* reconfigure poll(2) support if enabled on one edge only */
+	if (flags == GPIO_IRQF_TRIGGER_FALLING ||
+	    flags == GPIO_IRQF_TRIGGER_RISING) {
+		gpio_sysfs_free_irq(data);
+		status = gpio_sysfs_request_irq(data, flags);
+	}
+
+	gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
+
+	return status;
+}
+
+static ssize_t active_low_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct gpiod_data *data = container_of(attr, struct gpiod_data,
+					       active_low_attr);
+	struct gpio_desc *desc = data->desc;
+	int value;
+
+	scoped_guard(mutex, &data->mutex)
+		value = !!test_bit(GPIOD_FLAG_ACTIVE_LOW, &desc->flags);
+
+	return sysfs_emit(buf, "%d\n", value);
+}
+
+static ssize_t active_low_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t size)
+{
+	struct gpiod_data *data = container_of(attr, struct gpiod_data,
+					       active_low_attr);
+	ssize_t status;
+	long value;
+
+	status = kstrtol(buf, 0, &value);
+	if (status)
+		return status;
+
+	guard(mutex)(&data->mutex);
+
+	return gpio_sysfs_set_active_low(data, value) ?: size;
+}
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+static umode_t gpio_is_visible(struct kobject *kobj, struct attribute *attr,
+			       int n)
+{
+	struct device_attribute *dev_attr = container_of(attr,
+						struct device_attribute, attr);
+	umode_t mode = attr->mode;
+	struct gpiod_data *data;
+
+	if (strcmp(attr->name, "direction") == 0) {
+		data = container_of(dev_attr, struct gpiod_data, dir_attr);
+
+		if (!data->direction_can_change)
+			mode = 0;
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	} else if (strcmp(attr->name, "edge") == 0) {
+		data = container_of(dev_attr, struct gpiod_data, edge_attr);
+
+		if (gpiod_to_irq(data->desc) < 0)
+			mode = 0;
+
+		if (!data->direction_can_change &&
+		    test_bit(GPIOD_FLAG_IS_OUT, &data->desc->flags))
+			mode = 0;
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+	}
+
+	return mode;
+}
+
+/*
+ * /sys/class/gpio/gpiochipN/
+ *   /base ... matching gpio_chip.base (N)
+ *   /label ... matching gpio_chip.label
+ *   /ngpio ... matching gpio_chip.ngpio
+ *
+ * AND
+ *
+ * /sys/class/gpio/chipX/
+ *   /export ... export GPIO at given offset
+ *   /unexport ... unexport GPIO at given offset
+ *   /label ... matching gpio_chip.label
+ *   /ngpio ... matching gpio_chip.ngpio
+ */
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+static ssize_t base_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	const struct gpiodev_data *data = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n", data->gdev->base);
+}
+static DEVICE_ATTR_RO(base);
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+static ssize_t label_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	const struct gpiodev_data *data = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", data->gdev->label);
+}
+static DEVICE_ATTR_RO(label);
+
+static ssize_t ngpio_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	const struct gpiodev_data *data = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n", data->gdev->ngpio);
+}
+static DEVICE_ATTR_RO(ngpio);
+
+static int export_gpio_desc(struct gpio_desc *desc)
+{
+	int offset, ret;
+
+	CLASS(gpio_chip_guard, guard)(desc);
+	if (!guard.gc)
+		return -ENODEV;
+
+	offset = gpiod_hwgpio(desc);
+	if (!gpiochip_line_is_valid(guard.gc, offset)) {
+		pr_debug_ratelimited("%s: GPIO %d masked\n", __func__,
+				     gpiod_hwgpio(desc));
+		return -EINVAL;
+	}
+
+	/*
+	 * No extra locking here; GPIOD_FLAG_SYSFS just signifies that the
+	 * request and export were done by on behalf of userspace, so
+	 * they may be undone on its behalf too.
+	 */
+
+	ret = gpiod_request_user(desc, "sysfs");
+	if (ret)
+		return ret;
+
+	ret = gpiod_set_transitory(desc, false);
+	if (ret) {
+		gpiod_free(desc);
+		return ret;
+	}
+
+	ret = gpiod_export(desc, true);
+	if (ret < 0) {
+		gpiod_free(desc);
+	} else {
+		set_bit(GPIOD_FLAG_SYSFS, &desc->flags);
+		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
+	}
+
+	return ret;
+}
+
+static int unexport_gpio_desc(struct gpio_desc *desc)
+{
+	/*
+	 * No extra locking here; GPIOD_FLAG_SYSFS just signifies that the
+	 * request and export were done by on behalf of userspace, so
+	 * they may be undone on its behalf too.
+	 */
+	if (!test_and_clear_bit(GPIOD_FLAG_SYSFS, &desc->flags))
+		return -EINVAL;
+
+	gpiod_unexport(desc);
+	gpiod_free(desc);
+
+	return 0;
+}
+
+static ssize_t do_chip_export_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, ssize_t size,
+				    int (*handler)(struct gpio_desc *desc))
+{
+	struct gpiodev_data *data = dev_get_drvdata(dev);
+	struct gpio_device *gdev = data->gdev;
+	struct gpio_desc *desc;
+	unsigned int gpio;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &gpio);
+	if (ret)
+		return ret;
+
+	desc = gpio_device_get_desc(gdev, gpio);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	ret = handler(desc);
+	if (ret)
+		return ret;
+
+	return size;
+}
+
+static ssize_t chip_export_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t size)
+{
+	return do_chip_export_store(dev, attr, buf, size, export_gpio_desc);
+}
+
+static struct device_attribute dev_attr_export = __ATTR(export, 0200, NULL,
+							chip_export_store);
+
+static ssize_t chip_unexport_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t size)
+{
+	return do_chip_export_store(dev, attr, buf, size, unexport_gpio_desc);
+}
+
+static struct device_attribute dev_attr_unexport = __ATTR(unexport, 0200,
+							  NULL,
+							  chip_unexport_store);
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+static struct attribute *gpiochip_attrs[] = {
+	&dev_attr_base.attr,
+	&dev_attr_label.attr,
+	&dev_attr_ngpio.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(gpiochip);
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+static struct attribute *gpiochip_ext_attrs[] = {
+	&dev_attr_label.attr,
+	&dev_attr_ngpio.attr,
+	&dev_attr_export.attr,
+	&dev_attr_unexport.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(gpiochip_ext);
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+/*
+ * /sys/class/gpio/export ... write-only
+ *	integer N ... number of GPIO to export (full access)
+ * /sys/class/gpio/unexport ... write-only
+ *	integer N ... number of GPIO to unexport
+ */
+static ssize_t export_store(const struct class *class,
+			    const struct class_attribute *attr,
+			    const char *buf, size_t len)
+{
+	struct gpio_desc *desc;
+	int status;
+	long gpio;
+
+	status = kstrtol(buf, 0, &gpio);
+	if (status)
+		return status;
+
+	desc = gpio_to_desc(gpio);
+	/* reject invalid GPIOs */
+	if (!desc) {
+		pr_debug_ratelimited("%s: invalid GPIO %ld\n", __func__, gpio);
+		return -EINVAL;
+	}
+
+	status = export_gpio_desc(desc);
+	if (status)
+		pr_debug("%s: status %d\n", __func__, status);
+	return status ? : len;
+}
+static CLASS_ATTR_WO(export);
+
+static ssize_t unexport_store(const struct class *class,
+			      const struct class_attribute *attr,
+			      const char *buf, size_t len)
+{
+	struct gpio_desc *desc;
+	int status;
+	long gpio;
+
+	status = kstrtol(buf, 0, &gpio);
+	if (status < 0)
+		return status;
+
+	desc = gpio_to_desc(gpio);
+	/* reject bogus commands (gpiod_unexport() ignores them) */
+	if (!desc) {
+		pr_debug_ratelimited("%s: invalid GPIO %ld\n", __func__, gpio);
+		return -EINVAL;
+	}
+
+	status = unexport_gpio_desc(desc);
+	if (status)
+		pr_debug("%s: status %d\n", __func__, status);
+	return status ? : len;
+}
+static CLASS_ATTR_WO(unexport);
+
+static struct attribute *gpio_class_attrs[] = {
+	&class_attr_export.attr,
+	&class_attr_unexport.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(gpio_class);
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+static const struct class gpio_class = {
+	.name =		"gpio",
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	.class_groups =	gpio_class_groups,
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+};
+
+static int match_gdev(struct device *dev, const void *desc)
+{
+	struct gpiodev_data *data = dev_get_drvdata(dev);
+	const struct gpio_device *gdev = desc;
+
+	return data && data->gdev == gdev;
+}
+
+static struct gpiodev_data *
+gdev_get_data(struct gpio_device *gdev) __must_hold(&sysfs_lock)
+{
+	/*
+	 * Find the first device in GPIO class that matches. Whether that's
+	 * the one indexed by GPIO base or device ID doesn't matter, it has
+	 * the same address set as driver data.
+	 */
+	struct device *cdev __free(put_device) = class_find_device(&gpio_class,
+								   NULL, gdev,
+								   match_gdev);
+	if (!cdev)
+		return NULL;
+
+	return dev_get_drvdata(cdev);
+};
+
+static void gpiod_attr_init(struct device_attribute *dev_attr, const char *name,
+			    ssize_t (*show)(struct device *dev,
+					    struct device_attribute *attr,
+					    char *buf),
+			    ssize_t (*store)(struct device *dev,
+					     struct device_attribute *attr,
+					     const char *buf, size_t count))
+{
+	sysfs_attr_init(&dev_attr->attr);
+	dev_attr->attr.name = name;
+	dev_attr->attr.mode = 0644;
+	dev_attr->show = show;
+	dev_attr->store = store;
+}
+
+/**
+ * gpiod_export - export a GPIO through sysfs
+ * @desc: GPIO to make available, already requested
+ * @direction_may_change: true if userspace may change GPIO direction
+ * Context: arch_initcall or later
+ *
+ * When drivers want to make a GPIO accessible to userspace after they
+ * have requested it -- perhaps while debugging, or as part of their
+ * public interface -- they may use this routine.  If the GPIO can
+ * change direction (some can't) and the caller allows it, userspace
+ * will see "direction" sysfs attribute which may be used to change
+ * the gpio's direction.  A "value" attribute will always be provided.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
+ */
+int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
+{
+	char *path __free(kfree) = NULL;
+	struct gpiodev_data *gdev_data;
+	struct gpiod_data *desc_data;
+	struct gpio_device *gdev;
+	struct attribute **attrs;
+	int status;
+
+	/* can't export until sysfs is available ... */
+	if (!class_is_registered(&gpio_class)) {
+		pr_debug("%s: called too early!\n", __func__);
+		return -ENOENT;
+	}
+
+	if (!desc) {
+		pr_debug("%s: invalid gpio descriptor\n", __func__);
+		return -EINVAL;
+	}
+
+	CLASS(gpio_chip_guard, guard)(desc);
+	if (!guard.gc)
+		return -ENODEV;
+
+	if (test_and_set_bit(GPIOD_FLAG_EXPORT, &desc->flags))
+		return -EPERM;
+
+	gdev = desc->gdev;
+
+	guard(mutex)(&sysfs_lock);
+
+	if (!test_bit(GPIOD_FLAG_REQUESTED, &desc->flags)) {
+		gpiod_dbg(desc, "%s: unavailable (not requested)\n", __func__);
+		status = -EPERM;
+		goto err_clear_bit;
+	}
+
+	desc_data = kzalloc_obj(*desc_data);
+	if (!desc_data) {
+		status = -ENOMEM;
+		goto err_clear_bit;
+	}
+
+	desc_data->desc = desc;
+	mutex_init(&desc_data->mutex);
+	if (guard.gc->direction_input && guard.gc->direction_output)
+		desc_data->direction_can_change = direction_may_change;
+	else
+		desc_data->direction_can_change = false;
+
+	gpiod_attr_init(&desc_data->dir_attr, "direction",
+			direction_show, direction_store);
+	gpiod_attr_init(&desc_data->val_attr, "value", value_show, value_store);
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	gpiod_attr_init(&desc_data->edge_attr, "edge", edge_show, edge_store);
+	gpiod_attr_init(&desc_data->active_low_attr, "active_low",
+			active_low_show, active_low_store);
+
+	attrs = desc_data->class_attrs;
+	desc_data->class_attr_group.is_visible = gpio_is_visible;
+	attrs[GPIO_SYSFS_LINE_CLASS_ATTR_DIRECTION] = &desc_data->dir_attr.attr;
+	attrs[GPIO_SYSFS_LINE_CLASS_ATTR_VALUE] = &desc_data->val_attr.attr;
+	attrs[GPIO_SYSFS_LINE_CLASS_ATTR_EDGE] = &desc_data->edge_attr.attr;
+	attrs[GPIO_SYSFS_LINE_CLASS_ATTR_ACTIVE_LOW] = &desc_data->active_low_attr.attr;
+
+	desc_data->class_attr_group.attrs = desc_data->class_attrs;
+	desc_data->class_attr_groups[0] = &desc_data->class_attr_group;
+
+	/*
+	 * Note: we need to continue passing desc_data here as there's still
+	 * at least one known user of gpiod_export_link() in the tree. This
+	 * function still uses class_find_device() internally.
+	 */
+	desc_data->dev = device_create_with_groups(&gpio_class, &gdev->dev,
+						   MKDEV(0, 0), desc_data,
+						   desc_data->class_attr_groups,
+						   "gpio%u",
+						   desc_to_gpio(desc));
+	if (IS_ERR(desc_data->dev)) {
+		status = PTR_ERR(desc_data->dev);
+		goto err_free_data;
+	}
+
+	desc_data->value_kn = sysfs_get_dirent(desc_data->dev->kobj.sd,
+						       "value");
+	if (!desc_data->value_kn) {
+		status = -ENODEV;
+		goto err_unregister_device;
+	}
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+	gdev_data = gdev_get_data(gdev);
+	if (!gdev_data) {
+		status = -ENODEV;
+		goto err_put_dirent;
+	}
+
+	desc_data->chip_attr_group.name = kasprintf(GFP_KERNEL, "gpio%u",
+						    gpiod_hwgpio(desc));
+	if (!desc_data->chip_attr_group.name) {
+		status = -ENOMEM;
+		goto err_put_dirent;
+	}
+
+	attrs = desc_data->chip_attrs;
+	desc_data->chip_attr_group.is_visible = gpio_is_visible;
+	attrs[GPIO_SYSFS_LINE_CHIP_ATTR_DIRECTION] = &desc_data->dir_attr.attr;
+	attrs[GPIO_SYSFS_LINE_CHIP_ATTR_VALUE] = &desc_data->val_attr.attr;
+
+	desc_data->chip_attr_group.attrs = attrs;
+	desc_data->chip_attr_groups[0] = &desc_data->chip_attr_group;
+
+	desc_data->parent = &gdev_data->cdev_id->kobj;
+	status = sysfs_create_groups(desc_data->parent,
+				     desc_data->chip_attr_groups);
+	if (status)
+		goto err_free_name;
+
+	path = kasprintf(GFP_KERNEL, "gpio%u/value", gpiod_hwgpio(desc));
+	if (!path) {
+		status = -ENOMEM;
+		goto err_remove_groups;
+	}
+
+	list_add(&desc_data->list, &gdev_data->exported_lines);
+
+	return 0;
+
+err_remove_groups:
+	sysfs_remove_groups(desc_data->parent, desc_data->chip_attr_groups);
+err_free_name:
+	kfree(desc_data->chip_attr_group.name);
+err_put_dirent:
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	sysfs_put(desc_data->value_kn);
+err_unregister_device:
+	device_unregister(desc_data->dev);
+err_free_data:
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+	kfree(desc_data);
+err_clear_bit:
+	clear_bit(GPIOD_FLAG_EXPORT, &desc->flags);
+	gpiod_dbg(desc, "%s: status %d\n", __func__, status);
+	return status;
+}
+EXPORT_SYMBOL_GPL(gpiod_export);
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+static int match_export(struct device *dev, const void *desc)
+{
+	struct gpiod_data *data = dev_get_drvdata(dev);
+
+	return gpiod_is_equal(data->desc, desc);
+}
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+/**
+ * gpiod_export_link - create a sysfs link to an exported GPIO node
+ * @dev: device under which to create symlink
+ * @name: name of the symlink
+ * @desc: GPIO to create symlink to, already exported
+ *
+ * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
+ * node. Caller is responsible for unlinking.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
+ */
+int gpiod_export_link(struct device *dev, const char *name,
+		      struct gpio_desc *desc)
+{
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	struct device *cdev;
+	int ret;
+
+	if (!desc) {
+		pr_warn("%s: invalid GPIO\n", __func__);
+		return -EINVAL;
+	}
+
+	cdev = class_find_device(&gpio_class, NULL, desc, match_export);
+	if (!cdev)
+		return -ENODEV;
+
+	ret = sysfs_create_link(&dev->kobj, &cdev->kobj, name);
+	put_device(cdev);
+
+	return ret;
+#else
+	return -EOPNOTSUPP;
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+}
+EXPORT_SYMBOL_GPL(gpiod_export_link);
+
+static void gpiod_unexport_unlocked(struct gpio_desc *desc)
+{
+	struct gpiod_data *tmp, *desc_data = NULL;
+	struct gpiodev_data *gdev_data;
+	struct gpio_device *gdev;
+
+	if (!test_bit(GPIOD_FLAG_EXPORT, &desc->flags))
+		return;
+
+	gdev = gpiod_to_gpio_device(desc);
+	gdev_data = gdev_get_data(gdev);
+	if (!gdev_data)
+		return;
+
+	list_for_each_entry(tmp, &gdev_data->exported_lines, list) {
+		if (gpiod_is_equal(desc, tmp->desc)) {
+			desc_data = tmp;
+			break;
+		}
+	}
+
+	if (!desc_data)
+		return;
+
+	list_del(&desc_data->list);
+	clear_bit(GPIOD_FLAG_EXPORT, &desc->flags);
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	sysfs_put(desc_data->value_kn);
+	device_unregister(desc_data->dev);
+
+	/*
+	 * Release irq after deregistration to prevent race with
+	 * edge_store.
+	 */
+	if (desc_data->irq_flags)
+		gpio_sysfs_free_irq(desc_data);
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+	sysfs_remove_groups(desc_data->parent,
+			    desc_data->chip_attr_groups);
+
+	mutex_destroy(&desc_data->mutex);
+	kfree(desc_data);
+}
+
+/**
+ * gpiod_unexport - reverse effect of gpiod_export()
+ * @desc: GPIO to make unavailable
+ *
+ * This is implicit on gpiod_free().
+ */
+void gpiod_unexport(struct gpio_desc *desc)
+{
+	if (!desc) {
+		pr_warn("%s: invalid GPIO\n", __func__);
+		return;
+	}
+
+	guard(mutex)(&sysfs_lock);
+
+	gpiod_unexport_unlocked(desc);
+}
+EXPORT_SYMBOL_GPL(gpiod_unexport);
+
+int gpiochip_sysfs_register(struct gpio_chip *gc)
+{
+	struct gpio_device *gdev = gc->gpiodev;
+	struct gpiodev_data *data;
+	struct device *parent;
+	int err;
+
+	/*
+	 * Many systems add gpio chips for SOC support very early,
+	 * before driver model support is available.  In those cases we
+	 * register later, in gpiolib_sysfs_init() ... here we just
+	 * verify that _some_ field of gpio_class got initialized.
+	 */
+	if (!class_is_registered(&gpio_class))
+		return 0;
+
+	/*
+	 * For sysfs backward compatibility we need to preserve this
+	 * preferred parenting to the gpio_chip parent field, if set.
+	 */
+	if (gc->parent)
+		parent = gc->parent;
+	else
+		parent = &gdev->dev;
+
+	data = kmalloc_obj(*data);
+	if (!data)
+		return -ENOMEM;
+
+	data->gdev = gdev;
+	INIT_LIST_HEAD(&data->exported_lines);
+
+	guard(mutex)(&sysfs_lock);
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	/* use chip->base for the ID; it's already known to be unique */
+	data->cdev_base = device_create_with_groups(&gpio_class, parent,
+						    MKDEV(0, 0), data,
+						    gpiochip_groups,
+						    GPIOCHIP_NAME "%d",
+						    gc->base);
+	if (IS_ERR(data->cdev_base)) {
+		err = PTR_ERR(data->cdev_base);
+		kfree(data);
+		return err;
+	}
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+
+	data->cdev_id = device_create_with_groups(&gpio_class, parent,
+						  MKDEV(0, 0), data,
+						  gpiochip_ext_groups,
+						  "chip%d", gdev->id);
+	if (IS_ERR(data->cdev_id)) {
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+		device_unregister(data->cdev_base);
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+		err = PTR_ERR(data->cdev_id);
+		kfree(data);
+		return err;
+	}
+
+	return 0;
+}
+
+void gpiochip_sysfs_unregister(struct gpio_chip *gc)
+{
+	struct gpio_device *gdev = gc->gpiodev;
+	struct gpiodev_data *data;
+	struct gpio_desc *desc;
+
+	guard(mutex)(&sysfs_lock);
+
+	data = gdev_get_data(gdev);
+	if (!data)
+		return;
+
+	/* unregister gpiod class devices owned by sysfs */
+	for_each_gpio_desc_with_flag(gc, desc, GPIOD_FLAG_SYSFS) {
+		gpiod_unexport_unlocked(desc);
+		gpiod_free(desc);
+	}
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	device_unregister(data->cdev_base);
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+	device_unregister(data->cdev_id);
+	kfree(data);
+}
+
+/*
+ * We're not really looking for a device - we just want to iterate over the
+ * list and call this callback for each GPIO device. This is why this function
+ * always returns 0.
+ */
+static int gpiofind_sysfs_register(struct gpio_chip *gc, const void *data)
+{
+	int ret;
+
+	ret = gpiochip_sysfs_register(gc);
+	if (ret)
+		gpiochip_err(gc, "failed to register the sysfs entry: %d\n", ret);
+
+	return 0;
+}
+
+static int __init gpiolib_sysfs_init(void)
+{
+	int status;
+
+	status = class_register(&gpio_class);
+	if (status < 0)
+		return status;
+
+	/* Scan and register the gpio_chips which registered very
+	 * early (e.g. before the class_register above was called).
+	 *
+	 * We run before arch_initcall() so chip->dev nodes can have
+	 * registered, and so arch_initcall() can always gpiod_export().
+	 */
+	(void)gpio_device_find(NULL, gpiofind_sysfs_register);
+
+	return 0;
+}
+postcore_initcall(gpiolib_sysfs_init);