Merge tag 'v3.18.40' into linux-linaro-lsk-v3.18

 This is the 3.18.40 stable release

3 files changed, 21 insertions, 12 deletions

diff --git a/include/linux/i8042.h b/include/linux/i8042.h
index 0f9bafa17a02..d98780ca9604 100644
--- a/include/linux/i8042.h
+++ b/include/linux/i8042.h
@@ -62,7 +62,6 @@ struct serio;
 void i8042_lock_chip(void);
 void i8042_unlock_chip(void);
 int i8042_command(unsigned char *param, int command);
-bool i8042_check_port_owner(const struct serio *);
 int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
 					struct serio *serio));
 int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str,
@@ -83,11 +82,6 @@ static inline int i8042_command(unsigned char *param, int command)
 	return -ENODEV;
 }
 
-static inline bool i8042_check_port_owner(const struct serio *serio)
-{
-	return false;
-}
-
 static inline int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
 					struct serio *serio))
 {
diff --git a/include/linux/lockref.h b/include/linux/lockref.h
index 4bfde0e99ed5..b10b122dd099 100644
--- a/include/linux/lockref.h
+++ b/include/linux/lockref.h
@@ -28,12 +28,13 @@ struct lockref {
 #endif
 		struct {
 			spinlock_t lock;
-			unsigned int count;
+			int count;
 		};
 	};
 };
 
 extern void lockref_get(struct lockref *);
+extern int lockref_put_return(struct lockref *);
 extern int lockref_get_not_zero(struct lockref *);
 extern int lockref_get_or_lock(struct lockref *);
 extern int lockref_put_or_lock(struct lockref *);
diff --git a/include/linux/serio.h b/include/linux/serio.h
index 9f779c7a2da4..27ae809edd70 100644
--- a/include/linux/serio.h
+++ b/include/linux/serio.h
@@ -29,7 +29,8 @@ struct serio {
 
 	struct serio_device_id id;
 
-	spinlock_t lock;		/* protects critical sections from port's interrupt handler */
+	/* Protects critical sections from port's interrupt handler */
+	spinlock_t lock;
 
 	int (*write)(struct serio *, unsigned char);
 	int (*open)(struct serio *);
@@ -38,16 +39,29 @@ struct serio {
 	void (*stop)(struct serio *);
 
 	struct serio *parent;
-	struct list_head child_node;	/* Entry in parent->children list */
+	/* Entry in parent->children list */
+	struct list_head child_node;
 	struct list_head children;
-	unsigned int depth;		/* level of nesting in serio hierarchy */
+	/* Level of nesting in serio hierarchy */
+	unsigned int depth;
 
-	struct serio_driver *drv;	/* accessed from interrupt, must be protected by serio->lock and serio->sem */
-	struct mutex drv_mutex;		/* protects serio->drv so attributes can pin driver */
+	/*
+	 * serio->drv is accessed from interrupt handlers; when modifying
+	 * caller should acquire serio->drv_mutex and serio->lock.
+	 */
+	struct serio_driver *drv;
+	/* Protects serio->drv so attributes can pin current driver */
+	struct mutex drv_mutex;
 
 	struct device dev;
 
 	struct list_head node;
+
+	/*
+	 * For use by PS/2 layer when several ports share hardware and
+	 * may get indigestion when exposed to concurrent access (i8042).
+	 */
+	struct mutex *ps2_cmd_mutex;
 };
 #define to_serio_port(d)	container_of(d, struct serio, dev)