Merge tag 'gpio-updates-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio updates from Bartosz Golaszewski:
 "We have two new drivers, an assortment of updates and cleanups to many
  others, and first part of the big rework of the core GPIOLIB that's
  currently underway.

  Add to that some code shrink in the character device module and
  updates to DT bindings and that's pretty much it.

  Core GPIOLIB:
   - protect the global list of GPIO devices with a read-write semaphore
     as it is rarely modified but can be traversed by multiple readers
     at once
   - remove GPIO devices from the global list when they are
     *unregistered* and not when they are *released* (which only happens
     when the last reference is dropped) as this may lead to a
     successful lookup of an unregistered device
   - remove the unnecessary "extra_checks" switch
   - rename functions that are called with a lock taken
   - remove duplicate includes

  Character device handling:
   - use locking guards to reduce the code size
   - allocate the big linereq structure using the more suitable
     kvzalloc()
   - redulce the size of critical sections
   - improve documentation
   - move the debounce_period_us field out of struct gpio_desc

  New drivers:
   - Nuvoton NPCM SGPIO driver for BMC NPCM7xx/NPCM8xx
   - Realtek DHC (Digital Home Center) SoC GPIO driver

  Driver improvements:
   - replace gpiochip_is_requested() with a safer alternative in the
     form of gpiochip_dup_line_label() as the former returns a pointer
     to a string that can be deleted
   - implement the dbg_show() callback in gpio-sim
   - improve the coding style for local variables by removing
     unnecessary tabs
   - use generic device properties instead of OF variants in gpio-mmio
   - use the preferred coding style for __free() in gpio-mockup
   - reuse PM ops from the gpio-tangier in gpio-elkhartlake
   - rework PM and use cleanup helpers in gpio-tangier
   - fix the EIC configuration in gpio-pmic-eic-sprd
   - remove the unneeded call to platform_set_drvdata() in gpio-sifive
   - use generic GPIO helpers for driver callbacks in gpio-dwapb
   - add clock support on certain pins of gpio-ixp4xx
   - don't use the core-specific DEBUG_GPIO switch in drivers
   - kerneldoc improvements

  DT bindings:
   - add bindings for the new Realtek and Nuvoton devices
   - allow gpio-ranges in gpio-dwapb
   - support GPIO hogs in gpio-rockchip
   - describe the label property in gpio-zynqmp-modepin

  Other:
   - header cleanups
   - forward declarations cleanups"

* tag 'gpio-updates-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (55 commits)
  gpiolib: replace the GPIO device mutex with a read-write semaphore
  gpiolib: remove the GPIO device from the list when it's unregistered
  gpio: nuvoton: Add Nuvoton NPCM sgpio driver
  dt-bindings: gpio: add NPCM sgpio driver bindings
  gpio: rtd: Add support for Realtek DHC(Digital Home Center) RTD SoCs
  dt-bindings: gpio: realtek: Add realtek,rtd-gpio
  gpio: pmic-eic-sprd: Configure the bit corresponding to the EIC through offset
  gpio: dwapb: Use generic request, free and set_config
  gpio: sysfs: drop tabs from local variable declarations
  gpiolib: drop tabs from local variable declarations
  gpiolib: remove extra_checks
  gpio: tps65219: don't use CONFIG_DEBUG_GPIO
  gpiolib: cdev: replace locking wrappers for gpio_device with guards
  gpiolib: cdev: replace locking wrappers for config_mutex with guards
  gpiolib: cdev: allocate linereq using kvzalloc()
  gpiolib: cdev: include overflow.h
  gpiolib: cdev: reduce locking in gpio_desc_to_lineinfo()
  gpiolib: cdev: improve documentation of get/set values
  gpiolib: cdev: fully adopt guard() and scoped_guard()
  gpiolib: remove debounce_period_us from struct gpio_desc
  ...

1 files changed, 328 insertions, 343 deletions

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index f713d1ef7746..2a88736629ef 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -5,6 +5,7 @@
 #include <linux/bitmap.h>
 #include <linux/build_bug.h>
 #include <linux/cdev.h>
+#include <linux/cleanup.h>
 #include <linux/compat.h>
 #include <linux/compiler.h>
 #include <linux/device.h>
@@ -19,8 +20,11 @@
 #include <linux/kfifo.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/overflow.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/poll.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
 #include <linux/seq_file.h>
 #include <linux/spinlock.h>
 #include <linux/timekeeping.h>
@@ -62,45 +66,6 @@ typedef long (*ioctl_fn)(struct file *, unsigned int, unsigned long);
 typedef ssize_t (*read_fn)(struct file *, char __user *,
 			   size_t count, loff_t *);
 
-static __poll_t call_poll_locked(struct file *file,
-				 struct poll_table_struct *wait,
-				 struct gpio_device *gdev, poll_fn func)
-{
-	__poll_t ret;
-
-	down_read(&gdev->sem);
-	ret = func(file, wait);
-	up_read(&gdev->sem);
-
-	return ret;
-}
-
-static long call_ioctl_locked(struct file *file, unsigned int cmd,
-			      unsigned long arg, struct gpio_device *gdev,
-			      ioctl_fn func)
-{
-	long ret;
-
-	down_read(&gdev->sem);
-	ret = func(file, cmd, arg);
-	up_read(&gdev->sem);
-
-	return ret;
-}
-
-static ssize_t call_read_locked(struct file *file, char __user *buf,
-				size_t count, loff_t *f_ps,
-				struct gpio_device *gdev, read_fn func)
-{
-	ssize_t ret;
-
-	down_read(&gdev->sem);
-	ret = func(file, buf, count, f_ps);
-	up_read(&gdev->sem);
-
-	return ret;
-}
-
 /*
  * GPIO line handle management
  */
@@ -235,8 +200,8 @@ static long linehandle_set_config(struct linehandle_state *lh,
 	return 0;
 }
 
-static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd,
-				      unsigned long arg)
+static long linehandle_ioctl(struct file *file, unsigned int cmd,
+			     unsigned long arg)
 {
 	struct linehandle_state *lh = file->private_data;
 	void __user *ip = (void __user *)arg;
@@ -245,6 +210,8 @@ static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd,
 	unsigned int i;
 	int ret;
 
+	guard(rwsem_read)(&lh->gdev->sem);
+
 	if (!lh->gdev->chip)
 		return -ENODEV;
 
@@ -294,15 +261,6 @@ static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd,
 	}
 }
 
-static long linehandle_ioctl(struct file *file, unsigned int cmd,
-			     unsigned long arg)
-{
-	struct linehandle_state *lh = file->private_data;
-
-	return call_ioctl_locked(file, cmd, arg, lh->gdev,
-				 linehandle_ioctl_unlocked);
-}
-
 #ifdef CONFIG_COMPAT
 static long linehandle_ioctl_compat(struct file *file, unsigned int cmd,
 				    unsigned long arg)
@@ -461,6 +419,7 @@ out_free_lh:
 
 /**
  * struct line - contains the state of a requested line
+ * @node: to store the object in supinfo_tree if supplemental
  * @desc: the GPIO descriptor for this line.
  * @req: the corresponding line request
  * @irq: the interrupt triggered in response to events on this GPIO
@@ -473,6 +432,7 @@ out_free_lh:
  * @line_seqno: the seqno for the current edge event in the sequence of
  * events for this line.
  * @work: the worker that implements software debouncing
+ * @debounce_period_us: the debounce period in microseconds
  * @sw_debounced: flag indicating if the software debouncer is active
  * @level: the current debounced physical level of the line
  * @hdesc: the Hardware Timestamp Engine (HTE) descriptor
@@ -481,6 +441,7 @@ out_free_lh:
  * @last_seqno: the last sequence number before debounce period expires
  */
 struct line {
+	struct rb_node node;
 	struct gpio_desc *desc;
 	/*
 	 * -- edge detector specific fields --
@@ -515,6 +476,15 @@ struct line {
 	 */
 	struct delayed_work work;
 	/*
+	 * debounce_period_us is accessed by debounce_irq_handler() and
+	 * process_hw_ts() which are disabled when modified by
+	 * debounce_setup(), edge_detector_setup() or edge_detector_stop()
+	 * or can live with a stale version when updated by
+	 * edge_detector_update().
+	 * The modifying functions are themselves mutually exclusive.
+	 */
+	unsigned int debounce_period_us;
+	/*
 	 * sw_debounce is accessed by linereq_set_config(), which is the
 	 * only setter, and linereq_get_values(), which can live with a
 	 * slightly stale value.
@@ -546,6 +516,17 @@ struct line {
 #endif /* CONFIG_HTE */
 };
 
+/*
+ * a rbtree of the struct lines containing supplemental info.
+ * Used to populate gpio_v2_line_info with cdev specific fields not contained
+ * in the struct gpio_desc.
+ * A line is determined to contain supplemental information by
+ * line_has_supinfo().
+ */
+static struct rb_root supinfo_tree = RB_ROOT;
+/* covers supinfo_tree */
+static DEFINE_SPINLOCK(supinfo_lock);
+
 /**
  * struct linereq - contains the state of a userspace line request
  * @gdev: the GPIO device the line request pertains to
@@ -559,7 +540,8 @@ struct line {
  * this line request.  Note that this is not used when @num_lines is 1, as
  * the line_seqno is then the same and is cheaper to calculate.
  * @config_mutex: mutex for serializing ioctl() calls to ensure consistency
- * of configuration, particularly multi-step accesses to desc flags.
+ * of configuration, particularly multi-step accesses to desc flags and
+ * changes to supinfo status.
  * @lines: the lines held by this line request, with @num_lines elements.
  */
 struct linereq {
@@ -575,6 +557,103 @@ struct linereq {
 	struct line lines[] __counted_by(num_lines);
 };
 
+static void supinfo_insert(struct line *line)
+{
+	struct rb_node **new = &(supinfo_tree.rb_node), *parent = NULL;
+	struct line *entry;
+
+	guard(spinlock)(&supinfo_lock);
+
+	while (*new) {
+		entry = container_of(*new, struct line, node);
+
+		parent = *new;
+		if (line->desc < entry->desc) {
+			new = &((*new)->rb_left);
+		} else if (line->desc > entry->desc) {
+			new = &((*new)->rb_right);
+		} else {
+			/* this should never happen */
+			WARN(1, "duplicate line inserted");
+			return;
+		}
+	}
+
+	rb_link_node(&line->node, parent, new);
+	rb_insert_color(&line->node, &supinfo_tree);
+}
+
+static void supinfo_erase(struct line *line)
+{
+	guard(spinlock)(&supinfo_lock);
+
+	rb_erase(&line->node, &supinfo_tree);
+}
+
+static struct line *supinfo_find(struct gpio_desc *desc)
+{
+	struct rb_node *node = supinfo_tree.rb_node;
+	struct line *line;
+
+	while (node) {
+		line = container_of(node, struct line, node);
+		if (desc < line->desc)
+			node = node->rb_left;
+		else if (desc > line->desc)
+			node = node->rb_right;
+		else
+			return line;
+	}
+	return NULL;
+}
+
+static void supinfo_to_lineinfo(struct gpio_desc *desc,
+				struct gpio_v2_line_info *info)
+{
+	struct gpio_v2_line_attribute *attr;
+	struct line *line;
+
+	guard(spinlock)(&supinfo_lock);
+
+	line = supinfo_find(desc);
+	if (!line)
+		return;
+
+	attr = &info->attrs[info->num_attrs];
+	attr->id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE;
+	attr->debounce_period_us = READ_ONCE(line->debounce_period_us);
+	info->num_attrs++;
+}
+
+static inline bool line_has_supinfo(struct line *line)
+{
+	return READ_ONCE(line->debounce_period_us);
+}
+
+/*
+ * Checks line_has_supinfo() before and after the change to avoid unnecessary
+ * supinfo_tree access.
+ * Called indirectly by linereq_create() or linereq_set_config() so line
+ * is already protected from concurrent changes.
+ */
+static void line_set_debounce_period(struct line *line,
+				     unsigned int debounce_period_us)
+{
+	bool was_suppl = line_has_supinfo(line);
+
+	WRITE_ONCE(line->debounce_period_us, debounce_period_us);
+
+	/* if supinfo status is unchanged then we're done */
+	if (line_has_supinfo(line) == was_suppl)
+		return;
+
+	/* supinfo status has changed, so update the tree */
+	if (was_suppl)
+		supinfo_erase(line);
+	else
+		supinfo_insert(line);
+}
+
 #define GPIO_V2_LINE_BIAS_FLAGS \
 	(GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \
 	 GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \
@@ -625,13 +704,13 @@ static void linereq_put_event(struct linereq *lr,
 {
 	bool overflow = false;
 
-	spin_lock(&lr->wait.lock);
-	if (kfifo_is_full(&lr->events)) {
-		overflow = true;
-		kfifo_skip(&lr->events);
+	scoped_guard(spinlock, &lr->wait.lock) {
+		if (kfifo_is_full(&lr->events)) {
+			overflow = true;
+			kfifo_skip(&lr->events);
+		}
+		kfifo_in(&lr->events, le, 1);
 	}
-	kfifo_in(&lr->events, le, 1);
-	spin_unlock(&lr->wait.lock);
 	if (!overflow)
 		wake_up_poll(&lr->wait, EPOLLIN);
 	else
@@ -723,7 +802,7 @@ static enum hte_return process_hw_ts(struct hte_ts_data *ts, void *p)
 		line->total_discard_seq++;
 		line->last_seqno = ts->seq;
 		mod_delayed_work(system_wq, &line->work,
-		  usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us)));
+		  usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));
 	} else {
 		if (unlikely(ts->seq < line->line_seqno))
 			return HTE_CB_HANDLED;
@@ -864,7 +943,7 @@ static irqreturn_t debounce_irq_handler(int irq, void *p)
 	struct line *line = p;
 
 	mod_delayed_work(system_wq, &line->work,
-		usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us)));
+		usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));
 
 	return IRQ_HANDLED;
 }
@@ -946,7 +1025,7 @@ static int debounce_setup(struct line *line, unsigned int debounce_period_us)
 	/* try hardware */
 	ret = gpiod_set_debounce(line->desc, debounce_period_us);
 	if (!ret) {
-		WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
+		line_set_debounce_period(line, debounce_period_us);
 		return ret;
 	}
 	if (ret != -ENOTSUPP)
@@ -1025,8 +1104,7 @@ static void edge_detector_stop(struct line *line)
 	cancel_delayed_work_sync(&line->work);
 	WRITE_ONCE(line->sw_debounced, 0);
 	WRITE_ONCE(line->edflags, 0);
-	if (line->desc)
-		WRITE_ONCE(line->desc->debounce_period_us, 0);
+	line_set_debounce_period(line, 0);
 	/* do not change line->level - see comment in debounced_value() */
 }
 
@@ -1051,7 +1129,7 @@ static int edge_detector_setup(struct line *line,
 		ret = debounce_setup(line, debounce_period_us);
 		if (ret)
 			return ret;
-		WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
+		line_set_debounce_period(line, debounce_period_us);
 	}
 
 	/* detection disabled or sw debouncer will provide edge detection */
@@ -1093,12 +1171,12 @@ static int edge_detector_update(struct line *line,
 			gpio_v2_line_config_debounce_period(lc, line_idx);
 
 	if ((active_edflags == edflags) &&
-	    (READ_ONCE(line->desc->debounce_period_us) == debounce_period_us))
+	    (READ_ONCE(line->debounce_period_us) == debounce_period_us))
 		return 0;
 
 	/* sw debounced and still will be...*/
 	if (debounce_period_us && READ_ONCE(line->sw_debounced)) {
-		WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
+		line_set_debounce_period(line, debounce_period_us);
 		return 0;
 	}
 
@@ -1272,9 +1350,18 @@ static long linereq_get_values(struct linereq *lr, void __user *ip)
 	if (copy_from_user(&lv, ip, sizeof(lv)))
 		return -EFAULT;
 
+	/*
+	 * gpiod_get_array_value_complex() requires compacted desc and val
+	 * arrays, rather than the sparse ones in lv.
+	 * Calculation of num_get and construction of the desc array is
+	 * optimized to avoid allocation for the desc array for the common
+	 * num_get == 1 case.
+	 */
+	/* scan requested lines to calculate the subset to get */
 	for (num_get = 0, i = 0; i < lr->num_lines; i++) {
 		if (lv.mask & BIT_ULL(i)) {
 			num_get++;
+			/* capture desc for the num_get == 1 case */
 			descs = &lr->lines[i].desc;
 		}
 	}
@@ -1283,6 +1370,7 @@ static long linereq_get_values(struct linereq *lr, void __user *ip)
 		return -EINVAL;
 
 	if (num_get != 1) {
+		/* build compacted desc array */
 		descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL);
 		if (!descs)
 			return -ENOMEM;
@@ -1303,6 +1391,7 @@ static long linereq_get_values(struct linereq *lr, void __user *ip)
 
 	lv.bits = 0;
 	for (didx = 0, i = 0; i < lr->num_lines; i++) {
+		/* unpack compacted vals for the response */
 		if (lv.mask & BIT_ULL(i)) {
 			if (lr->lines[i].sw_debounced)
 				val = debounced_value(&lr->lines[i]);
@@ -1320,22 +1409,38 @@ static long linereq_get_values(struct linereq *lr, void __user *ip)
 	return 0;
 }
 
-static long linereq_set_values_unlocked(struct linereq *lr,
-					struct gpio_v2_line_values *lv)
+static long linereq_set_values(struct linereq *lr, void __user *ip)
 {
 	DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
+	struct gpio_v2_line_values lv;
 	struct gpio_desc **descs;
 	unsigned int i, didx, num_set;
 	int ret;
 
+	if (copy_from_user(&lv, ip, sizeof(lv)))
+		return -EFAULT;
+
+	guard(mutex)(&lr->config_mutex);
+
+	/*
+	 * gpiod_set_array_value_complex() requires compacted desc and val
+	 * arrays, rather than the sparse ones in lv.
+	 * Calculation of num_set and construction of the descs and vals arrays
+	 * is optimized to minimize scanning the lv->mask, and to avoid
+	 * allocation for the desc array for the common num_set == 1 case.
+	 */
 	bitmap_zero(vals, GPIO_V2_LINES_MAX);
+	/* scan requested lines to determine the subset to be set */
 	for (num_set = 0, i = 0; i < lr->num_lines; i++) {
-		if (lv->mask & BIT_ULL(i)) {
+		if (lv.mask & BIT_ULL(i)) {
+			/* setting inputs is not allowed */
 			if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags))
 				return -EPERM;
-			if (lv->bits & BIT_ULL(i))
+			/* add to compacted values */
+			if (lv.bits & BIT_ULL(i))
 				__set_bit(num_set, vals);
 			num_set++;
+			/* capture desc for the num_set == 1 case */
 			descs = &lr->lines[i].desc;
 		}
 	}
@@ -1343,12 +1448,12 @@ static long linereq_set_values_unlocked(struct linereq *lr,
 		return -EINVAL;
 
 	if (num_set != 1) {
-		/* build compacted desc array and values */
+		/* build compacted desc array */
 		descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL);
 		if (!descs)
 			return -ENOMEM;
 		for (didx = 0, i = 0; i < lr->num_lines; i++) {
-			if (lv->mask & BIT_ULL(i)) {
+			if (lv.mask & BIT_ULL(i)) {
 				descs[didx] = lr->lines[i].desc;
 				didx++;
 			}
@@ -1362,36 +1467,28 @@ static long linereq_set_values_unlocked(struct linereq *lr,
 	return ret;
 }
 
-static long linereq_set_values(struct linereq *lr, void __user *ip)
-{
-	struct gpio_v2_line_values lv;
-	int ret;
-
-	if (copy_from_user(&lv, ip, sizeof(lv)))
-		return -EFAULT;
-
-	mutex_lock(&lr->config_mutex);
-
-	ret = linereq_set_values_unlocked(lr, &lv);
-
-	mutex_unlock(&lr->config_mutex);
-
-	return ret;
-}
-
-static long linereq_set_config_unlocked(struct linereq *lr,
-					struct gpio_v2_line_config *lc)
+static long linereq_set_config(struct linereq *lr, void __user *ip)
 {
+	struct gpio_v2_line_config lc;
 	struct gpio_desc *desc;
 	struct line *line;
 	unsigned int i;
 	u64 flags, edflags;
 	int ret;
 
+	if (copy_from_user(&lc, ip, sizeof(lc)))
+		return -EFAULT;
+
+	ret = gpio_v2_line_config_validate(&lc, lr->num_lines);
+	if (ret)
+		return ret;
+
+	guard(mutex)(&lr->config_mutex);
+
 	for (i = 0; i < lr->num_lines; i++) {
 		line = &lr->lines[i];
 		desc = lr->lines[i].desc;
-		flags = gpio_v2_line_config_flags(lc, i);
+		flags = gpio_v2_line_config_flags(&lc, i);
 		gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
 		edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS;
 		/*
@@ -1399,7 +1496,7 @@ static long linereq_set_config_unlocked(struct linereq *lr,
 		 * or output, else the line will be treated "as is".
 		 */
 		if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
-			int val = gpio_v2_line_config_output_value(lc, i);
+			int val = gpio_v2_line_config_output_value(&lc, i);
 
 			edge_detector_stop(line);
 			ret = gpiod_direction_output(desc, val);
@@ -1410,7 +1507,7 @@ static long linereq_set_config_unlocked(struct linereq *lr,
 			if (ret)
 				return ret;
 
-			ret = edge_detector_update(line, lc, i, edflags);
+			ret = edge_detector_update(line, &lc, i, edflags);
 			if (ret)
 				return ret;
 		}
@@ -1422,33 +1519,14 @@ static long linereq_set_config_unlocked(struct linereq *lr,
 	return 0;
 }
 
-static long linereq_set_config(struct linereq *lr, void __user *ip)
-{
-	struct gpio_v2_line_config lc;
-	int ret;
-
-	if (copy_from_user(&lc, ip, sizeof(lc)))
-		return -EFAULT;
-
-	ret = gpio_v2_line_config_validate(&lc, lr->num_lines);
-	if (ret)
-		return ret;
-
-	mutex_lock(&lr->config_mutex);
-
-	ret = linereq_set_config_unlocked(lr, &lc);
-
-	mutex_unlock(&lr->config_mutex);
-
-	return ret;
-}
-
-static long linereq_ioctl_unlocked(struct file *file, unsigned int cmd,
-				   unsigned long arg)
+static long linereq_ioctl(struct file *file, unsigned int cmd,
+			  unsigned long arg)
 {
 	struct linereq *lr = file->private_data;
 	void __user *ip = (void __user *)arg;
 
+	guard(rwsem_read)(&lr->gdev->sem);
+
 	if (!lr->gdev->chip)
 		return -ENODEV;
 
@@ -1464,15 +1542,6 @@ static long linereq_ioctl_unlocked(struct file *file, unsigned int cmd,
 	}
 }
 
-static long linereq_ioctl(struct file *file, unsigned int cmd,
-			  unsigned long arg)
-{
-	struct linereq *lr = file->private_data;
-
-	return call_ioctl_locked(file, cmd, arg, lr->gdev,
-				 linereq_ioctl_unlocked);
-}
-
 #ifdef CONFIG_COMPAT
 static long linereq_ioctl_compat(struct file *file, unsigned int cmd,
 				 unsigned long arg)
@@ -1481,12 +1550,14 @@ static long linereq_ioctl_compat(struct file *file, unsigned int cmd,
 }
 #endif
 
-static __poll_t linereq_poll_unlocked(struct file *file,
-				      struct poll_table_struct *wait)
+static __poll_t linereq_poll(struct file *file,
+			     struct poll_table_struct *wait)
 {
 	struct linereq *lr = file->private_data;
 	__poll_t events = 0;
 
+	guard(rwsem_read)(&lr->gdev->sem);
+
 	if (!lr->gdev->chip)
 		return EPOLLHUP | EPOLLERR;
 
@@ -1499,22 +1570,16 @@ static __poll_t linereq_poll_unlocked(struct file *file,
 	return events;
 }
 
-static __poll_t linereq_poll(struct file *file,
-			     struct poll_table_struct *wait)
-{
-	struct linereq *lr = file->private_data;
-
-	return call_poll_locked(file, wait, lr->gdev, linereq_poll_unlocked);
-}
-
-static ssize_t linereq_read_unlocked(struct file *file, char __user *buf,
-				     size_t count, loff_t *f_ps)
+static ssize_t linereq_read(struct file *file, char __user *buf,
+			    size_t count, loff_t *f_ps)
 {
 	struct linereq *lr = file->private_data;
 	struct gpio_v2_line_event le;
 	ssize_t bytes_read = 0;
 	int ret;
 
+	guard(rwsem_read)(&lr->gdev->sem);
+
 	if (!lr->gdev->chip)
 		return -ENODEV;
 
@@ -1522,28 +1587,22 @@ static ssize_t linereq_read_unlocked(struct file *file, char __user *buf,
 		return -EINVAL;
 
 	do {
-		spin_lock(&lr->wait.lock);
-		if (kfifo_is_empty(&lr->events)) {
-			if (bytes_read) {
-				spin_unlock(&lr->wait.lock);
-				return bytes_read;
+		scoped_guard(spinlock, &lr->wait.lock) {
+			if (kfifo_is_empty(&lr->events)) {
+				if (bytes_read)
+					return bytes_read;
+
+				if (file->f_flags & O_NONBLOCK)
+					return -EAGAIN;
+
+				ret = wait_event_interruptible_locked(lr->wait,
+						!kfifo_is_empty(&lr->events));
+				if (ret)
+					return ret;
 			}
 
-			if (file->f_flags & O_NONBLOCK) {
-				spin_unlock(&lr->wait.lock);
-				return -EAGAIN;
-			}
-
-			ret = wait_event_interruptible_locked(lr->wait,
-					!kfifo_is_empty(&lr->events));
-			if (ret) {
-				spin_unlock(&lr->wait.lock);
-				return ret;
-			}
+			ret = kfifo_out(&lr->events, &le, 1);
 		}
-
-		ret = kfifo_out(&lr->events, &le, 1);
-		spin_unlock(&lr->wait.lock);
 		if (ret != 1) {
 			/*
 			 * This should never happen - we were holding the
@@ -1562,17 +1621,9 @@ static ssize_t linereq_read_unlocked(struct file *file, char __user *buf,
 	return bytes_read;
 }
 
-static ssize_t linereq_read(struct file *file, char __user *buf,
-			    size_t count, loff_t *f_ps)
-{
-	struct linereq *lr = file->private_data;
-
-	return call_read_locked(file, buf, count, f_ps, lr->gdev,
-				linereq_read_unlocked);
-}
-
 static void linereq_free(struct linereq *lr)
 {
+	struct line *line;
 	unsigned int i;
 
 	if (lr->device_unregistered_nb.notifier_call)
@@ -1580,15 +1631,19 @@ static void linereq_free(struct linereq *lr)
 						   &lr->device_unregistered_nb);
 
 	for (i = 0; i < lr->num_lines; i++) {
-		if (lr->lines[i].desc) {
-			edge_detector_stop(&lr->lines[i]);
-			gpiod_free(lr->lines[i].desc);
-		}
+		line = &lr->lines[i];
+		if (!line->desc)
+			continue;
+
+		edge_detector_stop(line);
+		if (line_has_supinfo(line))
+			supinfo_erase(line);
+		gpiod_free(line->desc);
 	}
 	kfifo_free(&lr->events);
 	kfree(lr->label);
 	gpio_device_put(lr->gdev);
-	kfree(lr);
+	kvfree(lr);
 }
 
 static int linereq_release(struct inode *inode, struct file *file)
@@ -1653,7 +1708,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
 	if (ret)
 		return ret;
 
-	lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL);
+	lr = kvzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL);
 	if (!lr)
 		return -ENOMEM;
 	lr->num_lines = ulr.num_lines;
@@ -1818,12 +1873,14 @@ struct lineevent_state {
 	(GPIOEVENT_REQUEST_RISING_EDGE | \
 	GPIOEVENT_REQUEST_FALLING_EDGE)
 
-static __poll_t lineevent_poll_unlocked(struct file *file,
-					struct poll_table_struct *wait)
+static __poll_t lineevent_poll(struct file *file,
+			       struct poll_table_struct *wait)
 {
 	struct lineevent_state *le = file->private_data;
 	__poll_t events = 0;
 
+	guard(rwsem_read)(&le->gdev->sem);
+
 	if (!le->gdev->chip)
 		return EPOLLHUP | EPOLLERR;
 
@@ -1835,14 +1892,6 @@ static __poll_t lineevent_poll_unlocked(struct file *file,
 	return events;
 }
 
-static __poll_t lineevent_poll(struct file *file,
-			       struct poll_table_struct *wait)
-{
-	struct lineevent_state *le = file->private_data;
-
-	return call_poll_locked(file, wait, le->gdev, lineevent_poll_unlocked);
-}
-
 static int lineevent_unregistered_notify(struct notifier_block *nb,
 					 unsigned long action, void *data)
 {
@@ -1859,8 +1908,8 @@ struct compat_gpioeevent_data {
 	u32		id;
 };
 
-static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf,
-				       size_t count, loff_t *f_ps)
+static ssize_t lineevent_read(struct file *file, char __user *buf,
+			      size_t count, loff_t *f_ps)
 {
 	struct lineevent_state *le = file->private_data;
 	struct gpioevent_data ge;
@@ -1868,6 +1917,8 @@ static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf,
 	ssize_t ge_size;
 	int ret;
 
+	guard(rwsem_read)(&le->gdev->sem);
+
 	if (!le->gdev->chip)
 		return -ENODEV;
 
@@ -1888,28 +1939,22 @@ static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf,
 		return -EINVAL;
 
 	do {
-		spin_lock(&le->wait.lock);
-		if (kfifo_is_empty(&le->events)) {
-			if (bytes_read) {
-				spin_unlock(&le->wait.lock);
-				return bytes_read;
+		scoped_guard(spinlock, &le->wait.lock) {
+			if (kfifo_is_empty(&le->events)) {
+				if (bytes_read)
+					return bytes_read;
+
+				if (file->f_flags & O_NONBLOCK)
+					return -EAGAIN;
+
+				ret = wait_event_interruptible_locked(le->wait,
+						!kfifo_is_empty(&le->events));
+				if (ret)
+					return ret;
 			}
 
-			if (file->f_flags & O_NONBLOCK) {
-				spin_unlock(&le->wait.lock);
-				return -EAGAIN;
-			}
-
-			ret = wait_event_interruptible_locked(le->wait,
-					!kfifo_is_empty(&le->events));
-			if (ret) {
-				spin_unlock(&le->wait.lock);
-				return ret;
-			}
+			ret = kfifo_out(&le->events, &ge, 1);
 		}
-
-		ret = kfifo_out(&le->events, &ge, 1);
-		spin_unlock(&le->wait.lock);
 		if (ret != 1) {
 			/*
 			 * This should never happen - we were holding the lock
@@ -1928,15 +1973,6 @@ static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf,
 	return bytes_read;
 }
 
-static ssize_t lineevent_read(struct file *file, char __user *buf,
-			      size_t count, loff_t *f_ps)
-{
-	struct lineevent_state *le = file->private_data;
-
-	return call_read_locked(file, buf, count, f_ps, le->gdev,
-				lineevent_read_unlocked);
-}
-
 static void lineevent_free(struct lineevent_state *le)
 {
 	if (le->device_unregistered_nb.notifier_call)
@@ -1957,13 +1993,15 @@ static int lineevent_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static long lineevent_ioctl_unlocked(struct file *file, unsigned int cmd,
-				     unsigned long arg)
+static long lineevent_ioctl(struct file *file, unsigned int cmd,
+			    unsigned long arg)
 {
 	struct lineevent_state *le = file->private_data;
 	void __user *ip = (void __user *)arg;
 	struct gpiohandle_data ghd;
 
+	guard(rwsem_read)(&le->gdev->sem);
+
 	if (!le->gdev->chip)
 		return -ENODEV;
 
@@ -1989,15 +2027,6 @@ static long lineevent_ioctl_unlocked(struct file *file, unsigned int cmd,
 	return -EINVAL;
 }
 
-static long lineevent_ioctl(struct file *file, unsigned int cmd,
-			    unsigned long arg)
-{
-	struct lineevent_state *le = file->private_data;
-
-	return call_ioctl_locked(file, cmd, arg, le->gdev,
-				 lineevent_ioctl_unlocked);
-}
-
 #ifdef CONFIG_COMPAT
 static long lineevent_ioctl_compat(struct file *file, unsigned int cmd,
 				   unsigned long arg)
@@ -2272,84 +2301,72 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
 				  struct gpio_v2_line_info *info)
 {
 	struct gpio_chip *gc = desc->gdev->chip;
-	bool ok_for_pinctrl;
-	unsigned long flags;
-	u32 debounce_period_us;
-	unsigned int num_attrs = 0;
+	unsigned long dflags;
 
 	memset(info, 0, sizeof(*info));
 	info->offset = gpio_chip_hwgpio(desc);
 
-	/*
-	 * This function takes a mutex so we must check this before taking
-	 * the spinlock.
-	 *
-	 * FIXME: find a non-racy way to retrieve this information. Maybe a
-	 * lock common to both frameworks?
-	 */
-	ok_for_pinctrl = pinctrl_gpio_can_use_line(gc, info->offset);
-
-	spin_lock_irqsave(&gpio_lock, flags);
+	scoped_guard(spinlock_irqsave, &gpio_lock) {
+		if (desc->name)
+			strscpy(info->name, desc->name, sizeof(info->name));
 
-	if (desc->name)
-		strscpy(info->name, desc->name, sizeof(info->name));
+		if (desc->label)
+			strscpy(info->consumer, desc->label,
+				sizeof(info->consumer));
 
-	if (desc->label)
-		strscpy(info->consumer, desc->label, sizeof(info->consumer));
+		dflags = READ_ONCE(desc->flags);
+	}
 
 	/*
-	 * Userspace only need to know that the kernel is using this GPIO so
-	 * it can't use it.
+	 * Userspace only need know that the kernel is using this GPIO so it
+	 * can't use it.
+	 * The calculation of the used flag is slightly racy, as it may read
+	 * desc, gc and pinctrl state without a lock covering all three at
+	 * once.  Worst case if the line is in transition and the calculation
+	 * is inconsistent then it looks to the user like they performed the
+	 * read on the other side of the transition - but that can always
+	 * happen.
+	 * The definitive test that a line is available to userspace is to
+	 * request it.
 	 */
-	info->flags = 0;
-	if (test_bit(FLAG_REQUESTED, &desc->flags) ||
-	    test_bit(FLAG_IS_HOGGED, &desc->flags) ||
-	    test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
-	    test_bit(FLAG_EXPORT, &desc->flags) ||
-	    test_bit(FLAG_SYSFS, &desc->flags) ||
+	if (test_bit(FLAG_REQUESTED, &dflags) ||
+	    test_bit(FLAG_IS_HOGGED, &dflags) ||
+	    test_bit(FLAG_USED_AS_IRQ, &dflags) ||
+	    test_bit(FLAG_EXPORT, &dflags) ||
+	    test_bit(FLAG_SYSFS, &dflags) ||
 	    !gpiochip_line_is_valid(gc, info->offset) ||
-	    !ok_for_pinctrl)
+	    !pinctrl_gpio_can_use_line(gc, info->offset))
 		info->flags |= GPIO_V2_LINE_FLAG_USED;
 
-	if (test_bit(FLAG_IS_OUT, &desc->flags))
+	if (test_bit(FLAG_IS_OUT, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_OUTPUT;
 	else
 		info->flags |= GPIO_V2_LINE_FLAG_INPUT;
 
-	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+	if (test_bit(FLAG_ACTIVE_LOW, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW;
 
-	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
+	if (test_bit(FLAG_OPEN_DRAIN, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN;
-	if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
+	if (test_bit(FLAG_OPEN_SOURCE, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE;
 
-	if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
+	if (test_bit(FLAG_BIAS_DISABLE, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED;
-	if (test_bit(FLAG_PULL_DOWN, &desc->flags))
+	if (test_bit(FLAG_PULL_DOWN, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN;
-	if (test_bit(FLAG_PULL_UP, &desc->flags))
+	if (test_bit(FLAG_PULL_UP, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP;
 
-	if (test_bit(FLAG_EDGE_RISING, &desc->flags))
+	if (test_bit(FLAG_EDGE_RISING, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING;
-	if (test_bit(FLAG_EDGE_FALLING, &desc->flags))
+	if (test_bit(FLAG_EDGE_FALLING, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING;
 
-	if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &desc->flags))
+	if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME;
-	else if (test_bit(FLAG_EVENT_CLOCK_HTE, &desc->flags))
+	else if (test_bit(FLAG_EVENT_CLOCK_HTE, &dflags))
 		info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE;
-
-	debounce_period_us = READ_ONCE(desc->debounce_period_us);
-	if (debounce_period_us) {
-		info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE;
-		info->attrs[num_attrs].debounce_period_us = debounce_period_us;
-		num_attrs++;
-	}
-	info->num_attrs = num_attrs;
-
-	spin_unlock_irqrestore(&gpio_lock, flags);
 }
 
 struct gpio_chardev_data {
@@ -2455,6 +2472,7 @@ static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
 			return -EBUSY;
 	}
 	gpio_desc_to_lineinfo(desc, &lineinfo);
+	supinfo_to_lineinfo(desc, &lineinfo);
 
 	if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
 		if (watch)
@@ -2481,12 +2499,17 @@ static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip)
 	return 0;
 }
 
-static long gpio_ioctl_unlocked(struct file *file, unsigned int cmd, unsigned long arg)
+/*
+ * gpio_ioctl() - ioctl handler for the GPIO chardev
+ */
+static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct gpio_chardev_data *cdev = file->private_data;
 	struct gpio_device *gdev = cdev->gdev;
 	void __user *ip = (void __user *)arg;
 
+	guard(rwsem_read)(&gdev->sem);
+
 	/* We fail any subsequent ioctl():s when the chip is gone */
 	if (!gdev->chip)
 		return -ENODEV;
@@ -2518,17 +2541,6 @@ static long gpio_ioctl_unlocked(struct file *file, unsigned int cmd, unsigned lo
 	}
 }
 
-/*
- * gpio_ioctl() - ioctl handler for the GPIO chardev
- */
-static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
-	struct gpio_chardev_data *cdev = file->private_data;
-
-	return call_ioctl_locked(file, cmd, arg, cdev->gdev,
-				 gpio_ioctl_unlocked);
-}
-
 #ifdef CONFIG_COMPAT
 static long gpio_ioctl_compat(struct file *file, unsigned int cmd,
 			      unsigned long arg)
@@ -2553,6 +2565,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
 	chg.event_type = action;
 	chg.timestamp_ns = ktime_get_ns();
 	gpio_desc_to_lineinfo(desc, &chg.info);
+	supinfo_to_lineinfo(desc, &chg.info);
 
 	ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock);
 	if (ret)
@@ -2575,12 +2588,14 @@ static int gpio_device_unregistered_notify(struct notifier_block *nb,
 	return NOTIFY_OK;
 }
 
-static __poll_t lineinfo_watch_poll_unlocked(struct file *file,
-					     struct poll_table_struct *pollt)
+static __poll_t lineinfo_watch_poll(struct file *file,
+				    struct poll_table_struct *pollt)
 {
 	struct gpio_chardev_data *cdev = file->private_data;
 	__poll_t events = 0;
 
+	guard(rwsem_read)(&cdev->gdev->sem);
+
 	if (!cdev->gdev->chip)
 		return EPOLLHUP | EPOLLERR;
 
@@ -2593,17 +2608,8 @@ static __poll_t lineinfo_watch_poll_unlocked(struct file *file,
 	return events;
 }
 
-static __poll_t lineinfo_watch_poll(struct file *file,
-				    struct poll_table_struct *pollt)
-{
-	struct gpio_chardev_data *cdev = file->private_data;
-
-	return call_poll_locked(file, pollt, cdev->gdev,
-				lineinfo_watch_poll_unlocked);
-}
-
-static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf,
-					    size_t count, loff_t *off)
+static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
+				   size_t count, loff_t *off)
 {
 	struct gpio_chardev_data *cdev = file->private_data;
 	struct gpio_v2_line_info_changed event;
@@ -2611,6 +2617,8 @@ static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf,
 	int ret;
 	size_t event_size;
 
+	guard(rwsem_read)(&cdev->gdev->sem);
+
 	if (!cdev->gdev->chip)
 		return -ENODEV;
 
@@ -2621,38 +2629,30 @@ static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf,
 #endif
 
 	do {
-		spin_lock(&cdev->wait.lock);
-		if (kfifo_is_empty(&cdev->events)) {
-			if (bytes_read) {
-				spin_unlock(&cdev->wait.lock);
-				return bytes_read;
+		scoped_guard(spinlock, &cdev->wait.lock) {
+			if (kfifo_is_empty(&cdev->events)) {
+				if (bytes_read)
+					return bytes_read;
+
+				if (file->f_flags & O_NONBLOCK)
+					return -EAGAIN;
+
+				ret = wait_event_interruptible_locked(cdev->wait,
+						!kfifo_is_empty(&cdev->events));
+				if (ret)
+					return ret;
 			}
-
-			if (file->f_flags & O_NONBLOCK) {
-				spin_unlock(&cdev->wait.lock);
-				return -EAGAIN;
-			}
-
-			ret = wait_event_interruptible_locked(cdev->wait,
-					!kfifo_is_empty(&cdev->events));
-			if (ret) {
-				spin_unlock(&cdev->wait.lock);
-				return ret;
-			}
-		}
 #ifdef CONFIG_GPIO_CDEV_V1
-		/* must be after kfifo check so watch_abi_version is set */
-		if (atomic_read(&cdev->watch_abi_version) == 2)
-			event_size = sizeof(struct gpio_v2_line_info_changed);
-		else
-			event_size = sizeof(struct gpioline_info_changed);
-		if (count < event_size) {
-			spin_unlock(&cdev->wait.lock);
-			return -EINVAL;
-		}
+			/* must be after kfifo check so watch_abi_version is set */
+			if (atomic_read(&cdev->watch_abi_version) == 2)
+				event_size = sizeof(struct gpio_v2_line_info_changed);
+			else
+				event_size = sizeof(struct gpioline_info_changed);
+			if (count < event_size)
+				return -EINVAL;
 #endif
-		ret = kfifo_out(&cdev->events, &event, 1);
-		spin_unlock(&cdev->wait.lock);
+			ret = kfifo_out(&cdev->events, &event, 1);
+		}
 		if (ret != 1) {
 			ret = -EIO;
 			break;
@@ -2681,15 +2681,6 @@ static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf,
 	return bytes_read;
 }
 
-static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
-				   size_t count, loff_t *off)
-{
-	struct gpio_chardev_data *cdev = file->private_data;
-
-	return call_read_locked(file, buf, count, off, cdev->gdev,
-				lineinfo_watch_read_unlocked);
-}
-
 /**
  * gpio_chrdev_open() - open the chardev for ioctl operations
  * @inode: inode for this chardev
@@ -2703,17 +2694,15 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	struct gpio_chardev_data *cdev;
 	int ret = -ENOMEM;
 
-	down_read(&gdev->sem);
+	guard(rwsem_read)(&gdev->sem);
 
 	/* Fail on open if the backing gpiochip is gone */
-	if (!gdev->chip) {
-		ret = -ENODEV;
-		goto out_unlock;
-	}
+	if (!gdev->chip)
+		return -ENODEV;
 
 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 	if (!cdev)
-		goto out_unlock;
+		return -ENODEV;
 
 	cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL);
 	if (!cdev->watched_lines)
@@ -2742,8 +2731,6 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	if (ret)
 		goto out_unregister_device_notifier;
 
-	up_read(&gdev->sem);
-
 	return ret;
 
 out_unregister_device_notifier:
@@ -2757,8 +2744,6 @@ out_free_bitmap:
 	bitmap_free(cdev->watched_lines);
 out_free_cdev:
 	kfree(cdev);
-out_unlock:
-	up_read(&gdev->sem);
 	return ret;
 }