srcu: Add DEFINE_SRCU()
In old days, we had two different API sets for dynamic-allocated per-CPU
data and DEFINE_PER_CPU()-defined per_cpu data, and because SRCU used
dynamic-allocated per-CPU data, its srcu_struct structures cannot be
declared statically. This commit therefore introduces DEFINE_SRCU()
and DEFINE_STATIC_SRCU() to allow statically declared SRCU structures,
using the new static per-CPU interfaces.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Updated for __DELAYED_WORK_INITIALIZER() added argument,
fixed whitespace issue. ]
diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index 5cce128..6eb691b 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -42,6 +42,8 @@
struct rcu_head *head, **tail;
};
+#define RCU_BATCH_INIT(name) { NULL, &(name.head) }
+
struct srcu_struct {
unsigned completed;
struct srcu_struct_array __percpu *per_cpu_ref;
@@ -72,14 +74,42 @@
__init_srcu_struct((sp), #sp, &__srcu_key); \
})
+#define __SRCU_DEP_MAP_INIT(srcu_name) .dep_map = { .name = #srcu_name },
#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
int init_srcu_struct(struct srcu_struct *sp);
+#define __SRCU_DEP_MAP_INIT(srcu_name)
#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
void process_srcu(struct work_struct *work);
+#define __SRCU_STRUCT_INIT(name) \
+ { \
+ .completed = -300, \
+ .per_cpu_ref = &name##_srcu_array, \
+ .queue_lock = __SPIN_LOCK_UNLOCKED(name.queue_lock), \
+ .running = false, \
+ .batch_queue = RCU_BATCH_INIT(name.batch_queue), \
+ .batch_check0 = RCU_BATCH_INIT(name.batch_check0), \
+ .batch_check1 = RCU_BATCH_INIT(name.batch_check1), \
+ .batch_done = RCU_BATCH_INIT(name.batch_done), \
+ .work = __DELAYED_WORK_INITIALIZER(name.work, process_srcu, 0),\
+ __SRCU_DEP_MAP_INIT(name) \
+ }
+
+/*
+ * define and init a srcu struct at build time.
+ * dont't call init_srcu_struct() nor cleanup_srcu_struct() on it.
+ */
+#define DEFINE_SRCU(name) \
+ static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
+ struct srcu_struct name = __SRCU_STRUCT_INIT(name);
+
+#define DEFINE_STATIC_SRCU(name) \
+ static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
+ static struct srcu_struct name = __SRCU_STRUCT_INIT(name);
+
/**
* call_srcu() - Queue a callback for invocation after an SRCU grace period
* @sp: srcu_struct in queue the callback