From ed2b9e1b6d82c729b2757b449097f28f108b023b Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@kernel.org>
Date: Fri, 16 Jun 2023 16:07:24 -0700
Subject: srcu,notifier: Remove #ifdefs in favor of SRCU Tiny srcu_usage
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This commit removes two #ifdef directives from include/linux/notifier.h
by causing SRCU Tiny to provide a dummy srcu_usage structure and a dummy
__SRCU_USAGE_INIT() macro.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Cc: Sachin Sant <sachinp@linux.ibm.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 include/linux/notifier.h | 11 -----------
 include/linux/srcutiny.h |  4 ++++
 2 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index 86544707236a..45702bdcbceb 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -73,9 +73,7 @@ struct raw_notifier_head {
 
 struct srcu_notifier_head {
 	struct mutex mutex;
-#ifdef CONFIG_TREE_SRCU
 	struct srcu_usage srcuu;
-#endif
 	struct srcu_struct srcu;
 	struct notifier_block __rcu *head;
 };
@@ -106,7 +104,6 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
 #define RAW_NOTIFIER_INIT(name)	{				\
 		.head = NULL }
 
-#ifdef CONFIG_TREE_SRCU
 #define SRCU_NOTIFIER_INIT(name, pcpu)				\
 	{							\
 		.mutex = __MUTEX_INITIALIZER(name.mutex),	\
@@ -114,14 +111,6 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
 		.srcuu = __SRCU_USAGE_INIT(name.srcuu),		\
 		.srcu = __SRCU_STRUCT_INIT(name.srcu, name.srcuu, pcpu), \
 	}
-#else
-#define SRCU_NOTIFIER_INIT(name, pcpu)				\
-	{							\
-		.mutex = __MUTEX_INITIALIZER(name.mutex),	\
-		.head = NULL,					\
-		.srcu = __SRCU_STRUCT_INIT(name.srcu, name.srcuu, pcpu), \
-	}
-#endif
 
 #define ATOMIC_NOTIFIER_HEAD(name)				\
 	struct atomic_notifier_head name =			\
diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h
index ebd72491af99..447133171d95 100644
--- a/include/linux/srcutiny.h
+++ b/include/linux/srcutiny.h
@@ -48,6 +48,10 @@ void srcu_drive_gp(struct work_struct *wp);
 #define DEFINE_STATIC_SRCU(name) \
 	static struct srcu_struct name = __SRCU_STRUCT_INIT(name, name, name)
 
+// Dummy structure for srcu_notifier_head.
+struct srcu_usage { };
+#define __SRCU_USAGE_INIT(name) { }
+
 void synchronize_srcu(struct srcu_struct *ssp);
 
 /*
-- 
cgit