From 9c80172b902db58233346adbb139cfdcb9229f0f Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Fri, 25 May 2018 12:19:57 +0200 Subject: [PATCH] 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 Tested-by: Paul E. McKenney Reviewed-by: Paul E. McKenney Signed-off-by: Rafael J. Wysocki --- include/linux/notifier.h | 34 +++++++++++++++++++++++++++++----- include/linux/srcutiny.h | 6 +++--- include/linux/srcutree.h | 6 +++--- 3 files changed, 35 insertions(+), 11 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, diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h index 261471f407a5..f41d2fb09f87 100644 --- a/include/linux/srcutiny.h +++ b/include/linux/srcutiny.h @@ -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); diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 4eda108abee0..745d4ca4dd50 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -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) -- GitLab