From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
lglocks and brlocks are currently generated with some complicated macros
in lglock.h. But there's no reason to not just use common utility
functions and put all the data into a common data structure.
Since there are at least two users it makes sense to share this code in a
library. This is also easier maintainable than a macro forest.
This will also make it later possible to dynamically allocate lglocks and
also use them in modules (this would both still need some additional, but
now straightforward, code)
[akpm@xxxxxxxxxxxxxxxxxxxx: checkpatch fixes]
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
fs/file_table.c | 1
fs/internal.h | 2
include/linux/lglock.h | 125 ++++++++++---------------------------------------
kernel/Makefile | 2
kernel/lglock.c | 89 ++++++++++++++++++++++++++++++++++
5 files changed, 117 insertions(+), 102 deletions(-)
diff --git a/fs/file_table.c b/fs/file_table.c
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -34,7 +34,6 @@ struct files_stat_struct files_stat = {
.max_files = NR_FILE
};
-DECLARE_LGLOCK(files_lglock);
DEFINE_LGLOCK(files_lglock);
/* SLAB cache for file structures */
diff --git a/fs/internal.h b/fs/internal.h
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -56,7 +56,7 @@ extern int sb_prepare_remount_readonly(s
extern void __init mnt_init(void);
-DECLARE_BRLOCK(vfsmount_lock);
+extern struct lglock vfsmount_lock;
/*
diff --git a/include/linux/lglock.h b/include/linux/lglock.h
--- a/include/linux/lglock.h
+++ b/include/linux/lglock.h
@@ -23,26 +23,17 @@
#include <linux/lockdep.h>
#include <linux/percpu.h>
#include <linux/cpu.h>
+#include <linux/notifier.h>
/* can make br locks by using local lock for read side, global lock for write */
-#define br_lock_init(name) name##_lock_init()
-#define br_read_lock(name) name##_local_lock()
-#define br_read_unlock(name) name##_local_unlock()
-#define br_write_lock(name) name##_global_lock()
-#define br_write_unlock(name) name##_global_unlock()
+#define br_lock_init(name) lg_lock_init(name, #name)
+#define br_read_lock(name) lg_local_lock(name)
+#define br_read_unlock(name) lg_local_unlock(name)
+#define br_write_lock(name) lg_global_lock(name)
+#define br_write_unlock(name) lg_global_unlock(name)
-#define DECLARE_BRLOCK(name) DECLARE_LGLOCK(name)
#define DEFINE_BRLOCK(name) DEFINE_LGLOCK(name)
-
-#define lg_lock_init(name) name##_lock_init()
-#define lg_local_lock(name) name##_local_lock()
-#define lg_local_unlock(name) name##_local_unlock()
-#define lg_local_lock_cpu(name, cpu) name##_local_lock_cpu(cpu)
-#define lg_local_unlock_cpu(name, cpu) name##_local_unlock_cpu(cpu)
-#define lg_global_lock(name) name##_global_lock()
-#define lg_global_unlock(name) name##_global_unlock()
-
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define LOCKDEP_INIT_MAP lockdep_init_map
@@ -57,90 +48,26 @@
#define DEFINE_LGLOCK_LOCKDEP(name)
#endif
-
-#define DECLARE_LGLOCK(name) \
- extern void name##_lock_init(void); \
- extern void name##_local_lock(void); \
- extern void name##_local_unlock(void); \
- extern void name##_local_lock_cpu(int cpu); \
- extern void name##_local_unlock_cpu(int cpu); \
- extern void name##_global_lock(void); \
- extern void name##_global_unlock(void); \
+struct lglock {
+ arch_spinlock_t __percpu *lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lock_class_key lock_key;
+ struct lockdep_map lock_dep_map;
+#endif
+};
#define DEFINE_LGLOCK(name) \
- \
- DEFINE_SPINLOCK(name##_cpu_lock); \
- DEFINE_PER_CPU(arch_spinlock_t, name##_lock); \
- DEFINE_LGLOCK_LOCKDEP(name); \
- \
- void name##_lock_init(void) { \
- int i; \
- LOCKDEP_INIT_MAP(&name##_lock_dep_map, #name, &name##_lock_key, 0); \
- for_each_possible_cpu(i) { \
- arch_spinlock_t *lock; \
- lock = &per_cpu(name##_lock, i); \
- *lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; \
- } \
- } \
- EXPORT_SYMBOL(name##_lock_init); \
- \
- void name##_local_lock(void) { \
- arch_spinlock_t *lock; \
- preempt_disable(); \
- rwlock_acquire_read(&name##_lock_dep_map, 0, 0, _THIS_IP_); \
- lock = &__get_cpu_var(name##_lock); \
- arch_spin_lock(lock); \
- } \
- EXPORT_SYMBOL(name##_local_lock); \
- \
- void name##_local_unlock(void) { \
- arch_spinlock_t *lock; \
- rwlock_release(&name##_lock_dep_map, 1, _THIS_IP_); \
- lock = &__get_cpu_var(name##_lock); \
- arch_spin_unlock(lock); \
- preempt_enable(); \
- } \
- EXPORT_SYMBOL(name##_local_unlock); \
- \
- void name##_local_lock_cpu(int cpu) { \
- arch_spinlock_t *lock; \
- preempt_disable(); \
- rwlock_acquire_read(&name##_lock_dep_map, 0, 0, _THIS_IP_); \
- lock = &per_cpu(name##_lock, cpu); \
- arch_spin_lock(lock); \
- } \
- EXPORT_SYMBOL(name##_local_lock_cpu); \
- \
- void name##_local_unlock_cpu(int cpu) { \
- arch_spinlock_t *lock; \
- rwlock_release(&name##_lock_dep_map, 1, _THIS_IP_); \
- lock = &per_cpu(name##_lock, cpu); \
- arch_spin_unlock(lock); \
- preempt_enable(); \
- } \
- EXPORT_SYMBOL(name##_local_unlock_cpu); \
- \
- void name##_global_lock(void) { \
- int i; \
- preempt_disable(); \
- rwlock_acquire(&name##_lock_dep_map, 0, 0, _RET_IP_); \
- for_each_possible_cpu(i) { \
- arch_spinlock_t *lock; \
- lock = &per_cpu(name##_lock, i); \
- arch_spin_lock(lock); \
- } \
- } \
- EXPORT_SYMBOL(name##_global_lock); \
- \
- void name##_global_unlock(void) { \
- int i; \
- rwlock_release(&name##_lock_dep_map, 1, _RET_IP_); \
- for_each_possible_cpu(i) { \
- arch_spinlock_t *lock; \
- lock = &per_cpu(name##_lock, i); \
- arch_spin_unlock(lock); \
- } \
- preempt_enable(); \
- } \
- EXPORT_SYMBOL(name##_global_unlock);
+ DEFINE_LGLOCK_LOCKDEP(name); \
+ DEFINE_PER_CPU(arch_spinlock_t, name ## _lock) \
+ = __ARCH_SPIN_LOCK_UNLOCKED; \
+ struct lglock name = { .lock = &name ## _lock }
+
+void lg_lock_init(struct lglock *lg, char *name);
+void lg_local_lock(struct lglock *lg);
+void lg_local_unlock(struct lglock *lg);
+void lg_local_lock_cpu(struct lglock *lg, int cpu);
+void lg_local_unlock_cpu(struct lglock *lg, int cpu);
+void lg_global_lock(struct lglock *lg);
+void lg_global_unlock(struct lglock *lg);
+
#endif
diff --git a/kernel/Makefile b/kernel/Makefile
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -10,7 +10,7 @@ obj-y = fork.o exec_domain.o panic.o
kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
notifier.o ksysfs.o cred.o \
- async.o range.o groups.o
+ async.o range.o groups.o lglock.o
ifdef CONFIG_FUNCTION_TRACER
# Do not trace debug files and internal ftrace files
diff --git a/kernel/lglock.c b/kernel/lglock.c
new file mode 100644
--- /dev/null
+++ b/kernel/lglock.c
@@ -0,0 +1,89 @@
+/* See include/linux/lglock.h for description */
+#include <linux/module.h>
+#include <linux/lglock.h>
+#include <linux/cpu.h>
+#include <linux/string.h>
+
+/*
+ * Note there is no uninit, so lglocks cannot be defined in
+ * modules (but it's fine to use them from there)
+ * Could be added though, just undo lg_lock_init
+ */
+
+void lg_lock_init(struct lglock *lg, char *name)
+{
+ LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
+}
+EXPORT_SYMBOL(lg_lock_init);
+
+void lg_local_lock(struct lglock *lg)
+{
+ arch_spinlock_t *lock;
+
+ preempt_disable();
+ rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_);
+ lock = this_cpu_ptr(lg->lock);
+ arch_spin_lock(lock);
+}
+EXPORT_SYMBOL(lg_local_lock);
+
+void lg_local_unlock(struct lglock *lg)
+{
+ arch_spinlock_t *lock;
+
+ rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ lock = this_cpu_ptr(lg->lock);
+ arch_spin_unlock(lock);
+ preempt_enable();
+}
+EXPORT_SYMBOL(lg_local_unlock);
+
+void lg_local_lock_cpu(struct lglock *lg, int cpu)
+{
+ arch_spinlock_t *lock;
+
+ preempt_disable();
+ rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_);
+ lock = per_cpu_ptr(lg->lock, cpu);
+ arch_spin_lock(lock);
+}
+EXPORT_SYMBOL(lg_local_lock_cpu);
+
+void lg_local_unlock_cpu(struct lglock *lg, int cpu)
+{
+ arch_spinlock_t *lock;
+
+ rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ lock = per_cpu_ptr(lg->lock, cpu);
+ arch_spin_unlock(lock);
+ preempt_enable();
+}
+EXPORT_SYMBOL(lg_local_unlock_cpu);
+
+void lg_global_lock(struct lglock *lg)
+{
+ int i;
+
+ preempt_disable();
+ rwlock_acquire(&lg->lock_dep_map, 0, 0, _RET_IP_);
+ for_each_possible_cpu(i) {
+ arch_spinlock_t *lock;
+ lock = per_cpu_ptr(lg->lock, i);
+ arch_spin_lock(lock);
+ }
+}
+EXPORT_SYMBOL(lg_global_lock);
+
+void lg_global_unlock(struct lglock *lg)
+{
+ int i;
+
+ rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ for_each_possible_cpu(i) {
+ arch_spinlock_t *lock;
+ lock = per_cpu_ptr(lg->lock, i);
+ arch_spin_unlock(lock);
+ }
+ preempt_enable();
+}
+EXPORT_SYMBOL(lg_global_unlock);
--
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