Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer changes from Ingo Molnar:
 "Timer enhancements, generalizations and cleanups from Tejun Heo, in
  preparation for workqueue facility enhancements."

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timer: Implement TIMER_IRQSAFE
  timer: Clean up timer initializers
  timer: Relocate declarations of init_timer_on_stack_key()
  timer: Generalize timer->base flags handling

1 files changed, 65 insertions, 100 deletions

diff --git a/include/linux/timer.h b/include/linux/timer.h
index 6abd9138beda..8c5a197e1587 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -49,147 +49,112 @@ extern struct tvec_base boot_tvec_bases;
 #endif
 
 /*
- * Note that all tvec_bases are 2 byte aligned and lower bit of
- * base in timer_list is guaranteed to be zero. Use the LSB to
- * indicate whether the timer is deferrable.
+ * Note that all tvec_bases are at least 4 byte aligned and lower two bits
+ * of base in timer_list is guaranteed to be zero. Use them for flags.
  *
  * A deferrable timer will work normally when the system is busy, but
  * will not cause a CPU to come out of idle just to service it; instead,
  * the timer will be serviced when the CPU eventually wakes up with a
  * subsequent non-deferrable timer.
+ *
+ * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
+ * the completion of the running instance from IRQ handlers, for example,
+ * by calling del_timer_sync().
+ *
+ * Note: The irq disabled callback execution is a special case for
+ * workqueue locking issues. It's not meant for executing random crap
+ * with interrupts disabled. Abuse is monitored!
  */
-#define TBASE_DEFERRABLE_FLAG		(0x1)
+#define TIMER_DEFERRABLE		0x1LU
+#define TIMER_IRQSAFE			0x2LU
 
-#define TIMER_INITIALIZER(_function, _expires, _data) {		\
+#define TIMER_FLAG_MASK			0x3LU
+
+#define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
 		.entry = { .prev = TIMER_ENTRY_STATIC },	\
 		.function = (_function),			\
 		.expires = (_expires),				\
 		.data = (_data),				\
-		.base = &boot_tvec_bases,			\
+		.base = (void *)((unsigned long)&boot_tvec_bases + (_flags)), \
 		.slack = -1,					\
 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
 			__FILE__ ":" __stringify(__LINE__))	\
 	}
 
-#define TBASE_MAKE_DEFERRED(ptr) ((struct tvec_base *)		\
-		  ((unsigned char *)(ptr) + TBASE_DEFERRABLE_FLAG))
+#define TIMER_INITIALIZER(_function, _expires, _data)		\
+	__TIMER_INITIALIZER((_function), (_expires), (_data), 0)
 
-#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) {\
-		.entry = { .prev = TIMER_ENTRY_STATIC },	\
-		.function = (_function),			\
-		.expires = (_expires),				\
-		.data = (_data),				\
-		.base = TBASE_MAKE_DEFERRED(&boot_tvec_bases),	\
-		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
-			__FILE__ ":" __stringify(__LINE__))	\
-	}
+#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)	\
+	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
 
 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
 	struct timer_list _name =				\
 		TIMER_INITIALIZER(_function, _expires, _data)
 
-void init_timer_key(struct timer_list *timer,
-		    const char *name,
-		    struct lock_class_key *key);
-void init_timer_deferrable_key(struct timer_list *timer,
-			       const char *name,
-			       struct lock_class_key *key);
+void init_timer_key(struct timer_list *timer, unsigned int flags,
+		    const char *name, struct lock_class_key *key);
+
+#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
+extern void init_timer_on_stack_key(struct timer_list *timer,
+				    unsigned int flags, const char *name,
+				    struct lock_class_key *key);
+extern void destroy_timer_on_stack(struct timer_list *timer);
+#else
+static inline void destroy_timer_on_stack(struct timer_list *timer) { }
+static inline void init_timer_on_stack_key(struct timer_list *timer,
+					   unsigned int flags, const char *name,
+					   struct lock_class_key *key)
+{
+	init_timer_key(timer, flags, name, key);
+}
+#endif
 
 #ifdef CONFIG_LOCKDEP
-#define init_timer(timer)						\
+#define __init_timer(_timer, _flags)					\
 	do {								\
 		static struct lock_class_key __key;			\
-		init_timer_key((timer), #timer, &__key);		\
+		init_timer_key((_timer), (_flags), #_timer, &__key);	\
 	} while (0)
 
-#define init_timer_deferrable(timer)					\
+#define __init_timer_on_stack(_timer, _flags)				\
 	do {								\
 		static struct lock_class_key __key;			\
-		init_timer_deferrable_key((timer), #timer, &__key);	\
+		init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
 	} while (0)
+#else
+#define __init_timer(_timer, _flags)					\
+	init_timer_key((_timer), (_flags), NULL, NULL)
+#define __init_timer_on_stack(_timer, _flags)				\
+	init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
+#endif
 
+#define init_timer(timer)						\
+	__init_timer((timer), 0)
+#define init_timer_deferrable(timer)					\
+	__init_timer((timer), TIMER_DEFERRABLE)
 #define init_timer_on_stack(timer)					\
+	__init_timer_on_stack((timer), 0)
+
+#define __setup_timer(_timer, _fn, _data, _flags)			\
 	do {								\
-		static struct lock_class_key __key;			\
-		init_timer_on_stack_key((timer), #timer, &__key);	\
+		__init_timer((_timer), (_flags));			\
+		(_timer)->function = (_fn);				\
+		(_timer)->data = (_data);				\
 	} while (0)
 
-#define setup_timer(timer, fn, data)					\
+#define __setup_timer_on_stack(_timer, _fn, _data, _flags)		\
 	do {								\
-		static struct lock_class_key __key;			\
-		setup_timer_key((timer), #timer, &__key, (fn), (data));\
+		__init_timer_on_stack((_timer), (_flags));		\
+		(_timer)->function = (_fn);				\
+		(_timer)->data = (_data);				\
 	} while (0)
 
+#define setup_timer(timer, fn, data)					\
+	__setup_timer((timer), (fn), (data), 0)
 #define setup_timer_on_stack(timer, fn, data)				\
-	do {								\
-		static struct lock_class_key __key;			\
-		setup_timer_on_stack_key((timer), #timer, &__key,	\
-					 (fn), (data));			\
-	} while (0)
+	__setup_timer_on_stack((timer), (fn), (data), 0)
 #define setup_deferrable_timer_on_stack(timer, fn, data)		\
-	do {								\
-		static struct lock_class_key __key;			\
-		setup_deferrable_timer_on_stack_key((timer), #timer,	\
-						    &__key, (fn),	\
-						    (data));		\
-	} while (0)
-#else
-#define init_timer(timer)\
-	init_timer_key((timer), NULL, NULL)
-#define init_timer_deferrable(timer)\
-	init_timer_deferrable_key((timer), NULL, NULL)
-#define init_timer_on_stack(timer)\
-	init_timer_on_stack_key((timer), NULL, NULL)
-#define setup_timer(timer, fn, data)\
-	setup_timer_key((timer), NULL, NULL, (fn), (data))
-#define setup_timer_on_stack(timer, fn, data)\
-	setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
-#define setup_deferrable_timer_on_stack(timer, fn, data)\
-	setup_deferrable_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
-#endif
-
-#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
-extern void init_timer_on_stack_key(struct timer_list *timer,
-				    const char *name,
-				    struct lock_class_key *key);
-extern void destroy_timer_on_stack(struct timer_list *timer);
-#else
-static inline void destroy_timer_on_stack(struct timer_list *timer) { }
-static inline void init_timer_on_stack_key(struct timer_list *timer,
-					   const char *name,
-					   struct lock_class_key *key)
-{
-	init_timer_key(timer, name, key);
-}
-#endif
-
-static inline void setup_timer_key(struct timer_list * timer,
-				const char *name,
-				struct lock_class_key *key,
-				void (*function)(unsigned long),
-				unsigned long data)
-{
-	timer->function = function;
-	timer->data = data;
-	init_timer_key(timer, name, key);
-}
-
-static inline void setup_timer_on_stack_key(struct timer_list *timer,
-					const char *name,
-					struct lock_class_key *key,
-					void (*function)(unsigned long),
-					unsigned long data)
-{
-	timer->function = function;
-	timer->data = data;
-	init_timer_on_stack_key(timer, name, key);
-}
-
-extern void setup_deferrable_timer_on_stack_key(struct timer_list *timer,
-						const char *name,
-						struct lock_class_key *key,
-						void (*function)(unsigned long),
-						unsigned long data);
+	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
 
 /**
  * timer_pending - is a timer pending?