1 files changed, 75 insertions, 123 deletions

diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index 2e1fb0649260..2b5ddc5dac19 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  The Serio abstraction module
  *
@@ -6,24 +7,9 @@
  *  Copyright (c) 2003 Daniele Bellucci
  */
 
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/export.h>
 #include <linux/stddef.h>
 #include <linux/module.h>
 #include <linux/serio.h>
@@ -53,33 +39,27 @@ static void serio_attach_driver(struct serio_driver *drv);
 
 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
 {
-	int retval;
+	guard(mutex)(&serio->drv_mutex);
 
-	mutex_lock(&serio->drv_mutex);
-	retval = drv->connect(serio, drv);
-	mutex_unlock(&serio->drv_mutex);
-
-	return retval;
+	return drv->connect(serio, drv);
 }
 
 static int serio_reconnect_driver(struct serio *serio)
 {
-	int retval = -1;
+	guard(mutex)(&serio->drv_mutex);
 
-	mutex_lock(&serio->drv_mutex);
 	if (serio->drv && serio->drv->reconnect)
-		retval = serio->drv->reconnect(serio);
-	mutex_unlock(&serio->drv_mutex);
+		return serio->drv->reconnect(serio);
 
-	return retval;
+	return -1;
 }
 
 static void serio_disconnect_driver(struct serio *serio)
 {
-	mutex_lock(&serio->drv_mutex);
+	guard(mutex)(&serio->drv_mutex);
+
 	if (serio->drv)
 		serio->drv->disconnect(serio);
-	mutex_unlock(&serio->drv_mutex);
 }
 
 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
@@ -162,9 +142,8 @@ static LIST_HEAD(serio_event_list);
 static struct serio_event *serio_get_event(void)
 {
 	struct serio_event *event = NULL;
-	unsigned long flags;
 
-	spin_lock_irqsave(&serio_event_lock, flags);
+	guard(spinlock_irqsave)(&serio_event_lock);
 
 	if (!list_empty(&serio_event_list)) {
 		event = list_first_entry(&serio_event_list,
@@ -172,7 +151,6 @@ static struct serio_event *serio_get_event(void)
 		list_del_init(&event->node);
 	}
 
-	spin_unlock_irqrestore(&serio_event_lock, flags);
 	return event;
 }
 
@@ -186,9 +164,8 @@ static void serio_remove_duplicate_events(void *object,
 					  enum serio_event_type type)
 {
 	struct serio_event *e, *next;
-	unsigned long flags;
 
-	spin_lock_irqsave(&serio_event_lock, flags);
+	guard(spinlock_irqsave)(&serio_event_lock);
 
 	list_for_each_entry_safe(e, next, &serio_event_list, node) {
 		if (object == e->object) {
@@ -204,15 +181,13 @@ static void serio_remove_duplicate_events(void *object,
 			serio_free_event(e);
 		}
 	}
-
-	spin_unlock_irqrestore(&serio_event_lock, flags);
 }
 
 static void serio_handle_event(struct work_struct *work)
 {
 	struct serio_event *event;
 
-	mutex_lock(&serio_mutex);
+	guard(mutex)(&serio_mutex);
 
 	while ((event = serio_get_event())) {
 
@@ -243,8 +218,6 @@ static void serio_handle_event(struct work_struct *work)
 		serio_remove_duplicate_events(event->object, event->type);
 		serio_free_event(event);
 	}
-
-	mutex_unlock(&serio_mutex);
 }
 
 static DECLARE_WORK(serio_event_work, serio_handle_event);
@@ -252,11 +225,9 @@ static DECLARE_WORK(serio_event_work, serio_handle_event);
 static int serio_queue_event(void *object, struct module *owner,
 			     enum serio_event_type event_type)
 {
-	unsigned long flags;
 	struct serio_event *event;
-	int retval = 0;
 
-	spin_lock_irqsave(&serio_event_lock, flags);
+	guard(spinlock_irqsave)(&serio_event_lock);
 
 	/*
 	 * Scan event list for the other events for the same serio port,
@@ -268,24 +239,22 @@ static int serio_queue_event(void *object, struct module *owner,
 	list_for_each_entry_reverse(event, &serio_event_list, node) {
 		if (event->object == object) {
 			if (event->type == event_type)
-				goto out;
+				return 0;
 			break;
 		}
 	}
 
-	event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
+	event = kmalloc(sizeof(*event), GFP_ATOMIC);
 	if (!event) {
 		pr_err("Not enough memory to queue event %d\n", event_type);
-		retval = -ENOMEM;
-		goto out;
+		return -ENOMEM;
 	}
 
 	if (!try_module_get(owner)) {
 		pr_warn("Can't get module reference, dropping event %d\n",
 			event_type);
 		kfree(event);
-		retval = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
 	event->type = event_type;
@@ -295,9 +264,7 @@ static int serio_queue_event(void *object, struct module *owner,
 	list_add_tail(&event->node, &serio_event_list);
 	queue_work(system_long_wq, &serio_event_work);
 
-out:
-	spin_unlock_irqrestore(&serio_event_lock, flags);
-	return retval;
+	return 0;
 }
 
 /*
@@ -307,9 +274,8 @@ out:
 static void serio_remove_pending_events(void *object)
 {
 	struct serio_event *event, *next;
-	unsigned long flags;
 
-	spin_lock_irqsave(&serio_event_lock, flags);
+	guard(spinlock_irqsave)(&serio_event_lock);
 
 	list_for_each_entry_safe(event, next, &serio_event_list, node) {
 		if (event->object == object) {
@@ -317,8 +283,6 @@ static void serio_remove_pending_events(void *object)
 			serio_free_event(event);
 		}
 	}
-
-	spin_unlock_irqrestore(&serio_event_lock, flags);
 }
 
 /*
@@ -330,23 +294,19 @@ static void serio_remove_pending_events(void *object)
 static struct serio *serio_get_pending_child(struct serio *parent)
 {
 	struct serio_event *event;
-	struct serio *serio, *child = NULL;
-	unsigned long flags;
+	struct serio *serio;
 
-	spin_lock_irqsave(&serio_event_lock, flags);
+	guard(spinlock_irqsave)(&serio_event_lock);
 
 	list_for_each_entry(event, &serio_event_list, node) {
 		if (event->type == SERIO_REGISTER_PORT) {
 			serio = event->object;
-			if (serio->parent == parent) {
-				child = serio;
-				break;
-			}
+			if (serio->parent == parent)
+				return serio;
 		}
 	}
 
-	spin_unlock_irqrestore(&serio_event_lock, flags);
-	return child;
+	return NULL;
 }
 
 /*
@@ -397,29 +357,27 @@ static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, c
 	struct device_driver *drv;
 	int error;
 
-	error = mutex_lock_interruptible(&serio_mutex);
-	if (error)
-		return error;
-
-	if (!strncmp(buf, "none", count)) {
-		serio_disconnect_port(serio);
-	} else if (!strncmp(buf, "reconnect", count)) {
-		serio_reconnect_subtree(serio);
-	} else if (!strncmp(buf, "rescan", count)) {
-		serio_disconnect_port(serio);
-		serio_find_driver(serio);
-		serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
-	} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
-		serio_disconnect_port(serio);
-		error = serio_bind_driver(serio, to_serio_driver(drv));
-		serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
-	} else {
-		error = -EINVAL;
+	scoped_cond_guard(mutex_intr, return -EINTR, &serio_mutex) {
+		if (!strncmp(buf, "none", count)) {
+			serio_disconnect_port(serio);
+		} else if (!strncmp(buf, "reconnect", count)) {
+			serio_reconnect_subtree(serio);
+		} else if (!strncmp(buf, "rescan", count)) {
+			serio_disconnect_port(serio);
+			serio_find_driver(serio);
+			serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
+		} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
+			serio_disconnect_port(serio);
+			error = serio_bind_driver(serio, to_serio_driver(drv));
+			serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
+			if (error)
+				return error;
+		} else {
+			return -EINVAL;
+		}
 	}
 
-	mutex_unlock(&serio_mutex);
-
-	return error ? error : count;
+	return count;
 }
 
 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
@@ -541,9 +499,9 @@ static void serio_add_port(struct serio *serio)
 	int error;
 
 	if (parent) {
-		serio_pause_rx(parent);
+		guard(serio_pause_rx)(parent);
+
 		list_add_tail(&serio->child_node, &parent->children);
-		serio_continue_rx(parent);
 	}
 
 	list_add_tail(&serio->node, &serio_list);
@@ -575,9 +533,9 @@ static void serio_destroy_port(struct serio *serio)
 		serio->stop(serio);
 
 	if (serio->parent) {
-		serio_pause_rx(serio->parent);
+		guard(serio_pause_rx)(serio->parent);
+
 		list_del_init(&serio->child_node);
-		serio_continue_rx(serio->parent);
 		serio->parent = NULL;
 	}
 
@@ -716,10 +674,10 @@ EXPORT_SYMBOL(__serio_register_port);
  */
 void serio_unregister_port(struct serio *serio)
 {
-	mutex_lock(&serio_mutex);
+	guard(mutex)(&serio_mutex);
+
 	serio_disconnect_port(serio);
 	serio_destroy_port(serio);
-	mutex_unlock(&serio_mutex);
 }
 EXPORT_SYMBOL(serio_unregister_port);
 
@@ -730,12 +688,12 @@ void serio_unregister_child_port(struct serio *serio)
 {
 	struct serio *s, *next;
 
-	mutex_lock(&serio_mutex);
+	guard(mutex)(&serio_mutex);
+
 	list_for_each_entry_safe(s, next, &serio->children, child_node) {
 		serio_disconnect_port(s);
 		serio_destroy_port(s);
 	}
-	mutex_unlock(&serio_mutex);
 }
 EXPORT_SYMBOL(serio_unregister_child_port);
 
@@ -790,20 +748,19 @@ static int serio_driver_probe(struct device *dev)
 	return serio_connect_driver(serio, drv);
 }
 
-static int serio_driver_remove(struct device *dev)
+static void serio_driver_remove(struct device *dev)
 {
 	struct serio *serio = to_serio_port(dev);
 
 	serio_disconnect_driver(serio);
-	return 0;
 }
 
 static void serio_cleanup(struct serio *serio)
 {
-	mutex_lock(&serio->drv_mutex);
+	guard(mutex)(&serio->drv_mutex);
+
 	if (serio->drv && serio->drv->cleanup)
 		serio->drv->cleanup(serio);
-	mutex_unlock(&serio->drv_mutex);
 }
 
 static void serio_shutdown(struct device *dev)
@@ -866,7 +823,7 @@ void serio_unregister_driver(struct serio_driver *drv)
 {
 	struct serio *serio;
 
-	mutex_lock(&serio_mutex);
+	guard(mutex)(&serio_mutex);
 
 	drv->manual_bind = true;	/* so serio_find_driver ignores it */
 	serio_remove_pending_events(drv);
@@ -882,21 +839,20 @@ start_over:
 	}
 
 	driver_unregister(&drv->driver);
-	mutex_unlock(&serio_mutex);
 }
 EXPORT_SYMBOL(serio_unregister_driver);
 
 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 {
-	serio_pause_rx(serio);
+	guard(serio_pause_rx)(serio);
+
 	serio->drv = drv;
-	serio_continue_rx(serio);
 }
 
-static int serio_bus_match(struct device *dev, struct device_driver *drv)
+static int serio_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct serio *serio = to_serio_port(dev);
-	struct serio_driver *serio_drv = to_serio_driver(drv);
+	const struct serio_driver *serio_drv = to_serio_driver(drv);
 
 	if (serio->manual_bind || serio_drv->manual_bind)
 		return 0;
@@ -911,9 +867,9 @@ static int serio_bus_match(struct device *dev, struct device_driver *drv)
 			return err;					\
 	} while (0)
 
-static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
+static int serio_uevent(const struct device *dev, struct kobj_uevent_env *env)
 {
-	struct serio *serio;
+	const struct serio *serio;
 
 	if (!dev)
 		return -ENODEV;
@@ -951,14 +907,14 @@ static int serio_resume(struct device *dev)
 	struct serio *serio = to_serio_port(dev);
 	int error = -ENOENT;
 
-	mutex_lock(&serio->drv_mutex);
-	if (serio->drv && serio->drv->fast_reconnect) {
-		error = serio->drv->fast_reconnect(serio);
-		if (error && error != -ENOENT)
-			dev_warn(dev, "fast reconnect failed with error %d\n",
-				 error);
+	scoped_guard(mutex, &serio->drv_mutex) {
+		if (serio->drv && serio->drv->fast_reconnect) {
+			error = serio->drv->fast_reconnect(serio);
+			if (error && error != -ENOENT)
+				dev_warn(dev, "fast reconnect failed with error %d\n",
+					 error);
+		}
 	}
-	mutex_unlock(&serio->drv_mutex);
 
 	if (error) {
 		/*
@@ -1005,25 +961,21 @@ EXPORT_SYMBOL(serio_close);
 irqreturn_t serio_interrupt(struct serio *serio,
 		unsigned char data, unsigned int dfl)
 {
-	unsigned long flags;
-	irqreturn_t ret = IRQ_NONE;
+	guard(spinlock_irqsave)(&serio->lock);
 
-	spin_lock_irqsave(&serio->lock, flags);
+	if (likely(serio->drv))
+		return serio->drv->interrupt(serio, data, dfl);
 
-        if (likely(serio->drv)) {
-                ret = serio->drv->interrupt(serio, data, dfl);
-	} else if (!dfl && device_is_registered(&serio->dev)) {
+	if (!dfl && device_is_registered(&serio->dev)) {
 		serio_rescan(serio);
-		ret = IRQ_HANDLED;
+		return IRQ_HANDLED;
 	}
 
-	spin_unlock_irqrestore(&serio->lock, flags);
-
-	return ret;
+	return IRQ_NONE;
 }
 EXPORT_SYMBOL(serio_interrupt);
 
-struct bus_type serio_bus = {
+const struct bus_type serio_bus = {
 	.name		= "serio",
 	.drv_groups	= serio_driver_groups,
 	.match		= serio_bus_match,