1 files changed, 109 insertions, 59 deletions

diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
index c4106e37e6db..b6c230fab840 100644
--- a/drivers/gpio/gpio-sim.c
+++ b/drivers/gpio/gpio-sim.c
@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/array_size.h>
 #include <linux/bitmap.h>
 #include <linux/cleanup.h>
 #include <linux/completion.h>
@@ -20,8 +21,8 @@
 #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>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
@@ -226,6 +227,27 @@ 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);
@@ -234,10 +256,10 @@ static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc)
 
 	guard(mutex)(&chip->lock);
 
-	for_each_requested_gpio(gc, i, label)
+	for_each_hwgpio(gc, i, label)
 		seq_printf(seq, " gpio-%-3d (%s) %s,%s\n",
 			   gc->base + i,
-			   label,
+			   label ?: "<unused>",
 			   test_bit(i, chip->direction_map) ? "input" :
 				test_bit(i, chip->value_map) ? "output-high" :
 							       "output-low",
@@ -307,13 +329,6 @@ 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;
@@ -398,11 +413,6 @@ 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;
@@ -420,7 +430,7 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 
 	ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
 	if (ret) {
-		label = devm_kasprintf(dev, GFP_KERNEL, "%s-%pfwP",
+		label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP",
 				       dev_name(dev), swnode);
 		if (!label)
 			return -ENOMEM;
@@ -449,7 +459,9 @@ 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);
 
@@ -457,9 +469,7 @@ 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;
 
@@ -488,7 +498,7 @@ 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;
 
@@ -505,15 +515,12 @@ 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;
@@ -580,19 +587,19 @@ static int gpio_sim_bus_notifier_call(struct notifier_block *nb,
 
 	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;
+	if (!device_match_name(dev, devname))
+		return NOTIFY_DONE;
 
-		complete(&simdev->probe_completion);
-		return NOTIFY_OK;
-	}
+	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_DONE;
+	return NOTIFY_OK;
 }
 
 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item)
@@ -697,8 +704,10 @@ static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog)
 	return gpio_sim_line_get_device(line);
 }
 
-static bool gpio_sim_device_is_live_unlocked(struct gpio_sim_device *dev)
+static bool gpio_sim_device_is_live(struct gpio_sim_device *dev)
 {
+	lockdep_assert_held(&dev->lock);
+
 	return !!dev->pdev;
 }
 
@@ -737,7 +746,7 @@ gpio_sim_device_config_live_show(struct config_item *item, char *page)
 	bool live;
 
 	scoped_guard(mutex, &dev->lock)
-		live = gpio_sim_device_is_live_unlocked(dev);
+		live = gpio_sim_device_is_live(dev);
 
 	return sprintf(page, "%c\n", live ? '1' : '0');
 }
@@ -833,7 +842,7 @@ static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
 							  GFP_KERNEL);
 			else
 				hog->chip_label = kasprintf(GFP_KERNEL,
-							"gpio-sim.%u-%pfwP",
+							"gpio-sim.%u:%pfwP",
 							dev->id,
 							bank->swnode);
 			if (!hog->chip_label) {
@@ -926,7 +935,7 @@ static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev)
 	return false;
 }
 
-static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev)
+static int gpio_sim_device_activate(struct gpio_sim_device *dev)
 {
 	struct platform_device_info pdevinfo;
 	struct fwnode_handle *swnode;
@@ -934,6 +943,8 @@ static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev)
 	struct gpio_sim_bank *bank;
 	int ret;
 
+	lockdep_assert_held(&dev->lock);
+
 	if (list_empty(&dev->bank_list))
 		return -ENODATA;
 
@@ -998,10 +1009,12 @@ static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev)
 	return 0;
 }
 
-static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev)
+static void gpio_sim_device_deactivate(struct gpio_sim_device *dev)
 {
 	struct fwnode_handle *swnode;
 
+	lockdep_assert_held(&dev->lock);
+
 	swnode = dev_fwnode(&dev->pdev->dev);
 	platform_device_unregister(dev->pdev);
 	gpio_sim_remove_hogs(dev);
@@ -1009,6 +1022,33 @@ static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev)
 	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
 gpio_sim_device_config_live_store(struct config_item *item,
 				  const char *page, size_t count)
@@ -1021,14 +1061,24 @@ 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_unlocked(dev))
-		ret = -EPERM;
-	else if (live)
-		ret = gpio_sim_device_activate_unlocked(dev);
-	else
-		gpio_sim_device_deactivate_unlocked(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;
 }
@@ -1069,7 +1119,7 @@ static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return device_for_each_child(&dev->pdev->dev, &ctx,
 					     gpio_sim_emit_chip_name);
 
@@ -1098,7 +1148,7 @@ static ssize_t gpio_sim_bank_config_label_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	trimmed = gpio_sim_strdup_trimmed(page, count);
@@ -1142,7 +1192,7 @@ gpio_sim_bank_config_num_lines_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	bank->num_lines = num_lines;
@@ -1179,7 +1229,7 @@ static ssize_t gpio_sim_line_config_name_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	trimmed = gpio_sim_strdup_trimmed(page, count);
@@ -1219,7 +1269,7 @@ static ssize_t gpio_sim_hog_config_name_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	trimmed = gpio_sim_strdup_trimmed(page, count);
@@ -1274,7 +1324,7 @@ gpio_sim_hog_config_direction_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	if (sysfs_streq(page, "input"))
@@ -1392,7 +1442,7 @@ gpio_sim_bank_config_make_line_group(struct config_group *group,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return ERR_PTR(-EBUSY);
 
 	line = kzalloc(sizeof(*line), GFP_KERNEL);
@@ -1445,7 +1495,7 @@ gpio_sim_device_config_make_bank_group(struct config_group *group,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return ERR_PTR(-EBUSY);
 
 	bank = kzalloc(sizeof(*bank), GFP_KERNEL);
@@ -1467,8 +1517,8 @@ static void gpio_sim_device_config_group_release(struct config_item *item)
 	struct gpio_sim_device *dev = to_gpio_sim_device(item);
 
 	scoped_guard(mutex, &dev->lock) {
-		if (gpio_sim_device_is_live_unlocked(dev))
-			gpio_sim_device_deactivate_unlocked(dev);
+		if (gpio_sim_device_is_live(dev))
+			gpio_sim_device_deactivate(dev);
 	}
 
 	mutex_destroy(&dev->lock);