5 files changed, 73 insertions, 1 deletions

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 7fc01b13be43..971a968831bf 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -94,6 +94,20 @@ extern struct group_info init_groups;
 # define CAP_INIT_BSET  CAP_INIT_EFF_SET
 #endif
 
+#ifdef CONFIG_PREEMPT_RCU
+#define INIT_TASK_RCU_PREEMPT(tsk)                                      \
+        .rcu_read_lock_nesting = 0,                                     \
+        .rcu_flipctr_idx = 0,
+#elif defined(CONFIG_TREE_PREEMPT_RCU)
+#define INIT_TASK_RCU_PREEMPT(tsk)                                      \
+        .rcu_read_lock_nesting = 0,                                     \
+        .rcu_read_unlock_special = 0,                                   \
+        .rcu_blocked_cpu = -1,                                          \
+        .rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry),
+#else
+#define INIT_TASK_RCU_PREEMPT(tsk)
+#endif
+
 extern struct cred init_cred;
 
 #ifdef CONFIG_PERF_COUNTERS
@@ -173,6 +187,7 @@ extern struct cred init_cred;
         INIT_LOCKDEP                                                    \
         INIT_FTRACE_GRAPH                                               \
         INIT_TRACE_RECURSION                                            \
+        INIT_TASK_RCU_PREEMPT(tsk)                                      \
 }
 
 
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 9d85ee19492a..26892f5e7bd8 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -66,7 +66,7 @@ extern void rcu_scheduler_starting(void);
 extern int rcu_needs_cpu(int cpu);
 extern int rcu_scheduler_active;
 
-#if defined(CONFIG_TREE_RCU)
+#if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU)
 #include <linux/rcutree.h>
 #elif defined(CONFIG_PREEMPT_RCU)
 #include <linux/rcupreempt.h>
diff --git a/include/linux/rcupreempt.h b/include/linux/rcupreempt.h
index aff4772fb49e..a42ab88e9210 100644
--- a/include/linux/rcupreempt.h
+++ b/include/linux/rcupreempt.h
@@ -98,6 +98,10 @@ static inline long rcu_batches_completed_bh(void)
         return rcu_batches_completed();
 }
 
+static inline void exit_rcu(void)
+{
+}
+
 #ifdef CONFIG_RCU_TRACE
 struct rcupreempt_trace;
 extern long *rcupreempt_flipctr(int cpu);
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index c739d90f5e68..a89307717825 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -35,14 +35,30 @@ extern void rcu_bh_qs(int cpu);
 
 extern int rcu_needs_cpu(int cpu);
 
+#ifdef CONFIG_TREE_PREEMPT_RCU
+
+extern void __rcu_read_lock(void);
+extern void __rcu_read_unlock(void);
+extern void exit_rcu(void);
+
+#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+
 static inline void __rcu_read_lock(void)
 {
         preempt_disable();
 }
+
 static inline void __rcu_read_unlock(void)
 {
         preempt_enable();
 }
+
+static inline void exit_rcu(void)
+{
+}
+
+#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
+
 static inline void __rcu_read_lock_bh(void)
 {
         local_bh_disable();
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3ab08e4bb6b8..d7f98f637a2a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1210,6 +1210,13 @@ struct task_struct {
         int rcu_flipctr_idx;
 #endif /* #ifdef CONFIG_PREEMPT_RCU */
 
+#ifdef CONFIG_TREE_PREEMPT_RCU
+        int rcu_read_lock_nesting;
+        char rcu_read_unlock_special;
+        int rcu_blocked_cpu;
+        struct list_head rcu_node_entry;
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
         struct sched_info sched_info;
 #endif
@@ -1723,6 +1730,36 @@ extern cputime_t task_gtime(struct task_struct *p);
 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
 #define used_math() tsk_used_math(current)
 
+#ifdef CONFIG_TREE_PREEMPT_RCU
+
+#define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
+#define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
+#define RCU_READ_UNLOCK_GOT_QS  (1 << 2) /* CPU has responded to RCU core. */
+
+static inline void rcu_copy_process(struct task_struct *p)
+{
+        p->rcu_read_lock_nesting = 0;
+        p->rcu_read_unlock_special = 0;
+        p->rcu_blocked_cpu = -1;
+        INIT_LIST_HEAD(&p->rcu_node_entry);
+}
+
+#elif defined(CONFIG_PREEMPT_RCU)
+
+static inline void rcu_copy_process(struct task_struct *p)
+{
+        p->rcu_read_lock_nesting = 0;
+        p->rcu_flipctr_idx = 0;
+}
+
+#else
+
+static inline void rcu_copy_process(struct task_struct *p)
+{
+}
+
+#endif
+
 #ifdef CONFIG_SMP
 extern int set_cpus_allowed_ptr(struct task_struct *p,
                                 const struct cpumask *new_mask);