Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h
index 79b99d6..3998cdf 100644
--- a/include/linux/percpu-rwsem.h
+++ b/include/linux/percpu-rwsem.h
@@ -17,19 +17,23 @@
int readers_block;
};
-#define DEFINE_STATIC_PERCPU_RWSEM(name) \
+#define __DEFINE_PERCPU_RWSEM(name, is_static) \
static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name); \
-static struct percpu_rw_semaphore name = { \
- .rss = __RCU_SYNC_INITIALIZER(name.rss, RCU_SCHED_SYNC), \
+is_static struct percpu_rw_semaphore name = { \
+ .rss = __RCU_SYNC_INITIALIZER(name.rss), \
.read_count = &__percpu_rwsem_rc_##name, \
.rw_sem = __RWSEM_INITIALIZER(name.rw_sem), \
.writer = __RCUWAIT_INITIALIZER(name.writer), \
}
+#define DEFINE_PERCPU_RWSEM(name) \
+ __DEFINE_PERCPU_RWSEM(name, /* not static */)
+#define DEFINE_STATIC_PERCPU_RWSEM(name) \
+ __DEFINE_PERCPU_RWSEM(name, static)
extern int __percpu_down_read(struct percpu_rw_semaphore *, int);
extern void __percpu_up_read(struct percpu_rw_semaphore *);
-static inline void percpu_down_read_preempt_disable(struct percpu_rw_semaphore *sem)
+static inline void percpu_down_read(struct percpu_rw_semaphore *sem)
{
might_sleep();
@@ -41,22 +45,16 @@
* cannot both change sem->state from readers_fast and start checking
* counters while we are here. So if we see !sem->state, we know that
* the writer won't be checking until we're past the preempt_enable()
- * and that one the synchronize_sched() is done, the writer will see
+ * and that once the synchronize_rcu() is done, the writer will see
* anything we did within this RCU-sched read-size critical section.
*/
__this_cpu_inc(*sem->read_count);
if (unlikely(!rcu_sync_is_idle(&sem->rss)))
__percpu_down_read(sem, false); /* Unconditional memory barrier */
- barrier();
/*
- * The barrier() prevents the compiler from
+ * The preempt_enable() prevents the compiler from
* bleeding the critical section out.
*/
-}
-
-static inline void percpu_down_read(struct percpu_rw_semaphore *sem)
-{
- percpu_down_read_preempt_disable(sem);
preempt_enable();
}
@@ -83,13 +81,9 @@
return ret;
}
-static inline void percpu_up_read_preempt_enable(struct percpu_rw_semaphore *sem)
+static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
{
- /*
- * The barrier() prevents the compiler from
- * bleeding the critical section out.
- */
- barrier();
+ preempt_disable();
/*
* Same as in percpu_down_read().
*/
@@ -102,12 +96,6 @@
rwsem_release(&sem->rw_sem.dep_map, 1, _RET_IP_);
}
-static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
-{
- preempt_disable();
- percpu_up_read_preempt_enable(sem);
-}
-
extern void percpu_down_write(struct percpu_rw_semaphore *);
extern void percpu_up_write(struct percpu_rw_semaphore *);
@@ -133,7 +121,7 @@
lock_release(&sem->rw_sem.dep_map, 1, ip);
#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
if (!read)
- sem->rw_sem.owner = RWSEM_OWNER_UNKNOWN;
+ atomic_long_set(&sem->rw_sem.owner, RWSEM_OWNER_UNKNOWN);
#endif
}
@@ -143,7 +131,7 @@
lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip);
#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
if (!read)
- sem->rw_sem.owner = current;
+ atomic_long_set(&sem->rw_sem.owner, (long)current);
#endif
}