[PATCH RFC 12/16] prcu: Add PRCU Kconfig parameter

[lianglihao]

From: Lihao Liang <lianglihao@xxxxxxxxxx>

Signed-off-by: Lihao Liang <lianglihao@xxxxxxxxxx>
---
 include/linux/prcu.h | 14 ++++++--------
 init/Kconfig         |  7 +++++++
 kernel/rcu/Makefile  |  3 ++-
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/include/linux/prcu.h b/include/linux/prcu.h
index cce967fd..bb20fa40 100644
--- a/include/linux/prcu.h
+++ b/include/linux/prcu.h
@@ -7,8 +7,7 @@
 #include <linux/wait.h>
 #include <linux/completion.h>
 
-#define CONFIG_PRCU
-
+#ifdef CONFIG_PRCU
 struct prcu_version_head {
 	unsigned long long version;
 	struct prcu_version_head *next;
@@ -48,7 +47,6 @@ struct prcu_struct {
 	struct completion barrier_completion;
 };
 
-#ifdef CONFIG_PRCU
 void prcu_read_lock(void);
 void prcu_read_unlock(void);
 void synchronize_prcu(void);
@@ -62,11 +60,11 @@ void prcu_check_callbacks(void);
 
 #else /* #ifdef CONFIG_PRCU */
 
-#define prcu_read_lock() do {} while (0)
-#define prcu_read_unlock() do {} while (0)
-#define synchronize_prcu() do {} while (0)
-#define call_prcu() do {} while (0)
-#define prcu_barrier() do {} while (0)
+#define prcu_read_lock rcu_read_lock
+#define prcu_read_unlock rcu_read_unlock
+#define synchronize_prcu synchronize_rcu
+#define call_prcu call_rcu
+#define prcu_barrier rcu_barrier
 #define prcu_init() do {} while (0)
 #define prcu_note_context_switch() do {} while (0)
 #define prcu_pending() 0
diff --git a/init/Kconfig b/init/Kconfig
index 1d3475fc..c1fd80f9 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -565,6 +565,13 @@ config TASKS_RCU
 	  only voluntary context switch (not preemption!), idle, and
 	  user-mode execution as quiescent states.
 
+config PRCU
+	bool
+	default y
+	help
+	  This option selects the PRCU implementation based on a fast
+	  consensus protocol.
+
 config RCU_STALL_COMMON
 	def_bool ( TREE_RCU || PREEMPT_RCU || RCU_TRACE )
 	help
diff --git a/kernel/rcu/Makefile b/kernel/rcu/Makefile
index 8791419c..9074b395 100644
--- a/kernel/rcu/Makefile
+++ b/kernel/rcu/Makefile
@@ -2,7 +2,7 @@
 # and is generally not a function of system call inputs.
 KCOV_INSTRUMENT := n
 
-obj-y += update.o sync.o prcu.o
+obj-y += update.o sync.o
 obj-$(CONFIG_CLASSIC_SRCU) += srcu.o
 obj-$(CONFIG_TREE_SRCU) += srcutree.o
 obj-$(CONFIG_TINY_SRCU) += srcutiny.o
@@ -12,4 +12,5 @@ obj-$(CONFIG_TREE_RCU) += tree.o
 obj-$(CONFIG_PREEMPT_RCU) += tree.o
 obj-$(CONFIG_TREE_RCU_TRACE) += tree_trace.o
 obj-$(CONFIG_TINY_RCU) += tiny.o
+obj-$(CONFIG_PRCU) += prcu.o
 obj-$(CONFIG_RCU_NEED_SEGCBLIST) += rcu_segcblist.o
-- 
2.14.1.729.g59c0ea183