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| author |   Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-05-25 12:19:57 +0200 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2018-05-30 10:11:34 +0200 |
| commit | 9c80172b902db58233346adbb139cfdcb9229f0f (patch) | |
| tree | 1566556647e5396400f4a5ae110ea77f07efd193 /include/linux/notifier.h | |
| parent | cpufreq: Fix new policy initialization during limits updates via sysfs (diff) | |
| download | linux-dev-9c80172b902db58233346adbb139cfdcb9229f0f.tar.xz linux-dev-9c80172b902db58233346adbb139cfdcb9229f0f.zip | |
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>
Diffstat (limited to 'include/linux/notifier.h')
| -rw-r--r-- | include/linux/notifier.h | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 6d731110e0db..f35c7bf76143 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -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, |