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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>
This commit is contained in:
Sebastian Andrzej Siewior 2013-03-19 14:44:30 +01:00 committed by Alibek Omarov
parent 49022ede1e
commit 8f52ff829d
2 changed files with 30 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
include/linux/notifier.h
View File

@ -6,7 +6,7 @@
*
* Alan Cox <Alan.Cox@linux.org>
*/
#ifndef _LINUX_NOTIFIER_H
#define _LINUX_NOTIFIER_H
#include <linux/errno.h>
@ -42,9 +42,7 @@
* 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.
*/
typedef int (*notifier_fn_t)(struct notifier_block *nb,
@ -88,7 +86,7 @@ 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);
@ -101,7 +99,13 @@ 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 = \
@ -113,6 +117,18 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
struct raw_notifier_head name = \
RAW_NOTIFIER_INIT(name)
#define _SRCU_NOTIFIER_HEAD(name, mod) \
static DEFINE_PER_CPU(struct srcu_struct_array, \
name##_head_srcu_array); \
mod struct srcu_notifier_head name = \
SRCU_NOTIFIER_INIT(name, name##_head_srcu_array)
#define SRCU_NOTIFIER_HEAD(name) \
_SRCU_NOTIFIER_HEAD(name, )
#define SRCU_NOTIFIER_HEAD_STATIC(name) \
_SRCU_NOTIFIER_HEAD(name, static)
#ifdef __KERNEL__
extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
@ -182,12 +198,12 @@ static inline int notifier_to_errno(int ret)
/*
* Declared notifiers so far. I can imagine quite a few more chains
* over time (eg laptop power reset chains, reboot chain (to clean
* over time (eg laptop power reset chains, reboot chain (to clean
* device units up), device [un]mount chain, module load/unload chain,
* low memory chain, screenblank chain (for plug in modular screenblankers)
* low memory chain, screenblank chain (for plug in modular screenblankers)
* VC switch chains (for loadable kernel svgalib VC switch helpers) etc...
*/
/* CPU notfiers are defined in include/linux/cpu.h. */
/* netdevice notifiers are defined in include/linux/netdevice.h */

9
include/linux/srcu.h
View File

@ -84,10 +84,10 @@ int init_srcu_struct(struct srcu_struct *sp);
void process_srcu(struct work_struct *work);
#define __SRCU_STRUCT_INIT(name) \
#define __SRCU_STRUCT_INIT(name, pcpu_name) \
{ \
.completed = -300, \
.per_cpu_ref = &name##_srcu_array, \
.per_cpu_ref = &pcpu_name, \
.queue_lock = __SPIN_LOCK_UNLOCKED(name.queue_lock), \
.running = false, \
.batch_queue = RCU_BATCH_INIT(name.batch_queue), \
@ -104,11 +104,12 @@ void process_srcu(struct work_struct *work);
*/
#define DEFINE_SRCU(name) \
static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
struct srcu_struct name = __SRCU_STRUCT_INIT(name);
struct srcu_struct name = __SRCU_STRUCT_INIT(name, name##_srcu_array);
#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);
static struct srcu_struct name = __SRCU_STRUCT_INIT(\
name, name##_srcu_array);
/**
* call_srcu() - Queue a callback for invocation after an SRCU grace period