1 files changed, 94 insertions, 107 deletions

diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
index 2ed5cbe7c8a8..f638219a7c4f 100644
--- a/drivers/gpio/gpio-sim.c
+++ b/drivers/gpio/gpio-sim.c
@@ -7,9 +7,9 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/array_size.h>
 #include <linux/bitmap.h>
 #include <linux/cleanup.h>
-#include <linux/completion.h>
 #include <linux/configfs.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -20,7 +20,6 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irq_sim.h>
-#include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/lockdep.h>
 #include <linux/minmax.h>
@@ -37,6 +36,8 @@
 #include <linux/sysfs.h>
 #include <linux/types.h>
 
+#include "dev-sync-probe.h"
+
 #define GPIO_SIM_NGPIO_MAX	1024
 #define GPIO_SIM_PROP_MAX	4 /* Max 3 properties + sentinel. */
 #define GPIO_SIM_NUM_ATTRS	3 /* value, pull and sentinel */
@@ -119,12 +120,14 @@ static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset)
 	return !!test_bit(offset, chip->value_map);
 }
 
-static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
+static int gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
 {
 	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
 
 	scoped_guard(mutex, &chip->lock)
 		__assign_bit(offset, chip->value_map, value);
+
+	return 0;
 }
 
 static int gpio_sim_get_multiple(struct gpio_chip *gc,
@@ -138,14 +141,16 @@ static int gpio_sim_get_multiple(struct gpio_chip *gc,
 	return 0;
 }
 
-static void gpio_sim_set_multiple(struct gpio_chip *gc,
-				  unsigned long *mask, unsigned long *bits)
+static int gpio_sim_set_multiple(struct gpio_chip *gc,
+				 unsigned long *mask, unsigned long *bits)
 {
 	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
 
 	scoped_guard(mutex, &chip->lock)
 		bitmap_replace(chip->value_map, chip->value_map, bits, mask,
 			       gc->ngpio);
+
+	return 0;
 }
 
 static int gpio_sim_direction_output(struct gpio_chip *gc,
@@ -227,6 +232,27 @@ static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
 	}
 }
 
+static int gpio_sim_irq_requested(struct irq_domain *domain,
+				  irq_hw_number_t hwirq, void *data)
+{
+	struct gpio_sim_chip *chip = data;
+
+	return gpiochip_lock_as_irq(&chip->gc, hwirq);
+}
+
+static void gpio_sim_irq_released(struct irq_domain *domain,
+				  irq_hw_number_t hwirq, void *data)
+{
+	struct gpio_sim_chip *chip = data;
+
+	gpiochip_unlock_as_irq(&chip->gc, hwirq);
+}
+
+static const struct irq_sim_ops gpio_sim_irq_sim_ops = {
+	.irq_sim_irq_requested = gpio_sim_irq_requested,
+	.irq_sim_irq_released = gpio_sim_irq_released,
+};
+
 static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc)
 {
 	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
@@ -308,13 +334,6 @@ static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
 	return len;
 }
 
-static void gpio_sim_mutex_destroy(void *data)
-{
-	struct mutex *lock = data;
-
-	mutex_destroy(lock);
-}
-
 static void gpio_sim_put_device(void *data)
 {
 	struct device *dev = data;
@@ -399,11 +418,6 @@ static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
 	return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);
 }
 
-static int gpio_sim_dev_match_fwnode(struct device *dev, void *data)
-{
-	return device_match_fwnode(dev, data);
-}
-
 static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 {
 	struct gpio_sim_chip *chip;
@@ -450,7 +464,9 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 	if (!chip->pull_map)
 		return -ENOMEM;
 
-	chip->irq_sim = devm_irq_domain_create_sim(dev, swnode, num_lines);
+	chip->irq_sim = devm_irq_domain_create_sim_full(dev, swnode, num_lines,
+							&gpio_sim_irq_sim_ops,
+							chip);
 	if (IS_ERR(chip->irq_sim))
 		return PTR_ERR(chip->irq_sim);
 
@@ -458,9 +474,7 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 	if (ret)
 		return ret;
 
-	mutex_init(&chip->lock);
-	ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy,
-				       &chip->lock);
+	ret = devm_mutex_init(dev, &chip->lock);
 	if (ret)
 		return ret;
 
@@ -472,9 +486,9 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 	gc->parent = dev;
 	gc->fwnode = swnode;
 	gc->get = gpio_sim_get;
-	gc->set = gpio_sim_set;
+	gc->set_rv = gpio_sim_set;
 	gc->get_multiple = gpio_sim_get_multiple;
-	gc->set_multiple = gpio_sim_set_multiple;
+	gc->set_multiple_rv = gpio_sim_set_multiple;
 	gc->direction_output = gpio_sim_direction_output;
 	gc->direction_input = gpio_sim_direction_input;
 	gc->get_direction = gpio_sim_get_direction;
@@ -489,7 +503,7 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 	if (ret)
 		return ret;
 
-	chip->dev = device_find_child(dev, swnode, gpio_sim_dev_match_fwnode);
+	chip->dev = device_find_child(dev, swnode, device_match_fwnode);
 	if (!chip->dev)
 		return -ENODEV;
 
@@ -506,15 +520,12 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 static int gpio_sim_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct fwnode_handle *swnode;
 	int ret;
 
-	device_for_each_child_node(dev, swnode) {
+	device_for_each_child_node_scoped(dev, swnode) {
 		ret = gpio_sim_add_bank(swnode, dev);
-		if (ret) {
-			fwnode_handle_put(swnode);
+		if (ret)
 			return ret;
-		}
 	}
 
 	return 0;
@@ -535,14 +546,9 @@ static struct platform_driver gpio_sim_driver = {
 };
 
 struct gpio_sim_device {
+	struct dev_sync_probe_data probe_data;
 	struct config_group group;
 
-	/*
-	 * If pdev is NULL, the device is 'pending' (waiting for configuration).
-	 * Once the pointer is assigned, the device has been created and the
-	 * item is 'live'.
-	 */
-	struct platform_device *pdev;
 	int id;
 
 	/*
@@ -556,46 +562,11 @@ struct gpio_sim_device {
 	 */
 	struct mutex lock;
 
-	/*
-	 * This is used to synchronously wait for the driver's probe to complete
-	 * and notify the user-space about any errors.
-	 */
-	struct notifier_block bus_notifier;
-	struct completion probe_completion;
-	bool driver_bound;
-
 	struct gpiod_hog *hogs;
 
 	struct list_head bank_list;
 };
 
-/* This is called with dev->lock already taken. */
-static int gpio_sim_bus_notifier_call(struct notifier_block *nb,
-				      unsigned long action, void *data)
-{
-	struct gpio_sim_device *simdev = container_of(nb,
-						      struct gpio_sim_device,
-						      bus_notifier);
-	struct device *dev = data;
-	char devname[32];
-
-	snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id);
-
-	if (strcmp(dev_name(dev), devname) == 0) {
-		if (action == BUS_NOTIFY_BOUND_DRIVER)
-			simdev->driver_bound = true;
-		else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND)
-			simdev->driver_bound = false;
-		else
-			return NOTIFY_DONE;
-
-		complete(&simdev->probe_completion);
-		return NOTIFY_OK;
-	}
-
-	return NOTIFY_DONE;
-}
-
 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item)
 {
 	struct config_group *group = to_config_group(item);
@@ -702,7 +673,7 @@ static bool gpio_sim_device_is_live(struct gpio_sim_device *dev)
 {
 	lockdep_assert_held(&dev->lock);
 
-	return !!dev->pdev;
+	return !!dev->probe_data.pdev;
 }
 
 static char *gpio_sim_strdup_trimmed(const char *str, size_t count)
@@ -724,7 +695,7 @@ static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	pdev = dev->pdev;
+	pdev = dev->probe_data.pdev;
 	if (pdev)
 		return sprintf(page, "%s\n", dev_name(&pdev->dev));
 
@@ -933,7 +904,6 @@ static int gpio_sim_device_activate(struct gpio_sim_device *dev)
 {
 	struct platform_device_info pdevinfo;
 	struct fwnode_handle *swnode;
-	struct platform_device *pdev;
 	struct gpio_sim_bank *bank;
 	int ret;
 
@@ -975,31 +945,13 @@ static int gpio_sim_device_activate(struct gpio_sim_device *dev)
 	pdevinfo.fwnode = swnode;
 	pdevinfo.id = dev->id;
 
-	reinit_completion(&dev->probe_completion);
-	dev->driver_bound = false;
-	bus_register_notifier(&platform_bus_type, &dev->bus_notifier);
-
-	pdev = platform_device_register_full(&pdevinfo);
-	if (IS_ERR(pdev)) {
-		bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
-		gpio_sim_remove_hogs(dev);
-		gpio_sim_remove_swnode_recursive(swnode);
-		return PTR_ERR(pdev);
-	}
-
-	wait_for_completion(&dev->probe_completion);
-	bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
-
-	if (!dev->driver_bound) {
-		/* Probe failed, check kernel log. */
-		platform_device_unregister(pdev);
+	ret = dev_sync_probe_register(&dev->probe_data, &pdevinfo);
+	if (ret) {
 		gpio_sim_remove_hogs(dev);
 		gpio_sim_remove_swnode_recursive(swnode);
-		return -ENXIO;
+		return ret;
 	}
 
-	dev->pdev = pdev;
-
 	return 0;
 }
 
@@ -1009,11 +961,37 @@ static void gpio_sim_device_deactivate(struct gpio_sim_device *dev)
 
 	lockdep_assert_held(&dev->lock);
 
-	swnode = dev_fwnode(&dev->pdev->dev);
-	platform_device_unregister(dev->pdev);
+	swnode = dev_fwnode(&dev->probe_data.pdev->dev);
+	dev_sync_probe_unregister(&dev->probe_data);
 	gpio_sim_remove_hogs(dev);
 	gpio_sim_remove_swnode_recursive(swnode);
-	dev->pdev = NULL;
+}
+
+static void
+gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock)
+{
+	struct configfs_subsystem *subsys = dev->group.cg_subsys;
+	struct gpio_sim_bank *bank;
+	struct gpio_sim_line *line;
+	struct config_item *item;
+
+	/*
+	 * The device only needs to depend on leaf entries. This is
+	 * sufficient to lock up all the configfs entries that the
+	 * instantiated, alive device depends on.
+	 */
+	list_for_each_entry(bank, &dev->bank_list, siblings) {
+		list_for_each_entry(line, &bank->line_list, siblings) {
+			item = line->hog ? &line->hog->item
+					 : &line->group.cg_item;
+
+			if (lock)
+				WARN_ON(configfs_depend_item_unlocked(subsys,
+								      item));
+			else
+				configfs_undepend_item_unlocked(item);
+		}
+	}
 }
 
 static ssize_t
@@ -1028,14 +1006,24 @@ gpio_sim_device_config_live_store(struct config_item *item,
 	if (ret)
 		return ret;
 
-	guard(mutex)(&dev->lock);
+	if (live)
+		gpio_sim_device_lockup_configfs(dev, true);
 
-	if (live == gpio_sim_device_is_live(dev))
-		ret = -EPERM;
-	else if (live)
-		ret = gpio_sim_device_activate(dev);
-	else
-		gpio_sim_device_deactivate(dev);
+	scoped_guard(mutex, &dev->lock) {
+		if (live == gpio_sim_device_is_live(dev))
+			ret = -EPERM;
+		else if (live)
+			ret = gpio_sim_device_activate(dev);
+		else
+			gpio_sim_device_deactivate(dev);
+	}
+
+	/*
+	 * Undepend is required only if device disablement (live == 0)
+	 * succeeds or if device enablement (live == 1) fails.
+	 */
+	if (live == !!ret)
+		gpio_sim_device_lockup_configfs(dev, false);
 
 	return ret ?: count;
 }
@@ -1077,7 +1065,7 @@ static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
 	guard(mutex)(&dev->lock);
 
 	if (gpio_sim_device_is_live(dev))
-		return device_for_each_child(&dev->pdev->dev, &ctx,
+		return device_for_each_child(&dev->probe_data.pdev->dev, &ctx,
 					     gpio_sim_emit_chip_name);
 
 	return sprintf(page, "none\n");
@@ -1518,8 +1506,7 @@ gpio_sim_config_make_device_group(struct config_group *group, const char *name)
 	mutex_init(&dev->lock);
 	INIT_LIST_HEAD(&dev->bank_list);
 
-	dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call;
-	init_completion(&dev->probe_completion);
+	dev_sync_probe_init(&dev->probe_data);
 
 	return &no_free_ptr(dev)->group;
 }