kernel/SRCU: provide a static initializer

There are macros for static initializer for the three out of four
possible notifier types, that are:
	ATOMIC_NOTIFIER_HEAD()
	BLOCKING_NOTIFIER_HEAD()
	RAW_NOTIFIER_HEAD()

This patch provides a static initilizer for the forth type to make it
complete.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Sebastian Andrzej Siewior 2018-05-25 12:19:57 +02:00 committed by Rafael J. Wysocki
parent c7d1f119c4
commit 9c80172b90
3 changed files with 35 additions and 11 deletions

View File

@ -43,9 +43,7 @@
* in srcu_notifier_call_chain(): no cache bounces and no memory barriers.
* As compensation, srcu_notifier_chain_unregister() is rather expensive.
* SRCU notifier chains should be used when the chain will be called very
* often but notifier_blocks will seldom be removed. Also, SRCU notifier
* chains are slightly more difficult to use because they require special
* runtime initialization.
* often but notifier_blocks will seldom be removed.
*/
struct notifier_block;
@ -91,7 +89,7 @@ struct srcu_notifier_head {
(name)->head = NULL; \
} while (0)
/* srcu_notifier_heads must be initialized and cleaned up dynamically */
/* srcu_notifier_heads must be cleaned up dynamically */
extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
#define srcu_cleanup_notifier_head(name) \
cleanup_srcu_struct(&(name)->srcu);
@ -104,7 +102,13 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
.head = NULL }
#define RAW_NOTIFIER_INIT(name) { \
.head = NULL }
/* srcu_notifier_heads cannot be initialized statically */
#define SRCU_NOTIFIER_INIT(name, pcpu) \
{ \
.mutex = __MUTEX_INITIALIZER(name.mutex), \
.head = NULL, \
.srcu = __SRCU_STRUCT_INIT(name.srcu, pcpu), \
}
#define ATOMIC_NOTIFIER_HEAD(name) \
struct atomic_notifier_head name = \
@ -116,6 +120,26 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
struct raw_notifier_head name = \
RAW_NOTIFIER_INIT(name)
#ifdef CONFIG_TREE_SRCU
#define _SRCU_NOTIFIER_HEAD(name, mod) \
static DEFINE_PER_CPU(struct srcu_data, \
name##_head_srcu_data); \
mod struct srcu_notifier_head name = \
SRCU_NOTIFIER_INIT(name, name##_head_srcu_data)
#else
#define _SRCU_NOTIFIER_HEAD(name, mod) \
mod struct srcu_notifier_head name = \
SRCU_NOTIFIER_INIT(name, name)
#endif
#define SRCU_NOTIFIER_HEAD(name) \
_SRCU_NOTIFIER_HEAD(name, /* not static */)
#define SRCU_NOTIFIER_HEAD_STATIC(name) \
_SRCU_NOTIFIER_HEAD(name, static)
#ifdef __KERNEL__
extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh,

View File

@ -43,7 +43,7 @@ struct srcu_struct {
void srcu_drive_gp(struct work_struct *wp);
#define __SRCU_STRUCT_INIT(name) \
#define __SRCU_STRUCT_INIT(name, __ignored) \
{ \
.srcu_wq = __SWAIT_QUEUE_HEAD_INITIALIZER(name.srcu_wq), \
.srcu_cb_tail = &name.srcu_cb_head, \
@ -56,9 +56,9 @@ void srcu_drive_gp(struct work_struct *wp);
* Tree SRCU, which needs some per-CPU data.
*/
#define DEFINE_SRCU(name) \
struct srcu_struct name = __SRCU_STRUCT_INIT(name)
struct srcu_struct name = __SRCU_STRUCT_INIT(name, name)
#define DEFINE_STATIC_SRCU(name) \
static struct srcu_struct name = __SRCU_STRUCT_INIT(name)
static struct srcu_struct name = __SRCU_STRUCT_INIT(name, name)
void synchronize_srcu(struct srcu_struct *sp);

View File

@ -104,9 +104,9 @@ struct srcu_struct {
#define SRCU_STATE_SCAN1 1
#define SRCU_STATE_SCAN2 2
#define __SRCU_STRUCT_INIT(name) \
#define __SRCU_STRUCT_INIT(name, pcpu_name) \
{ \
.sda = &name##_srcu_data, \
.sda = &pcpu_name, \
.lock = __SPIN_LOCK_UNLOCKED(name.lock), \
.srcu_gp_seq_needed = 0 - 1, \
__SRCU_DEP_MAP_INIT(name) \
@ -133,7 +133,7 @@ struct srcu_struct {
*/
#define __DEFINE_SRCU(name, is_static) \
static DEFINE_PER_CPU(struct srcu_data, name##_srcu_data);\
is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name)
is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name, name##_srcu_data)
#define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */)
#define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static)