void _raw_write_lock(rwlock_t *lock)
{
debug_write_lock_before(lock);
if (unlikely(!__raw_write_trylock(&lock->raw_lock)))
__write_lock_debug(lock);
debug_write_lock_after(lock);
}
int _raw_write_trylock(rwlock_t *lock)
{
int ret = __raw_write_trylock(&lock->raw_lock);
if (ret)
debug_write_lock_after(lock);
#ifndef CONFIG_SMP
/*
* Must not happen on UP:
*/
RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
#endif
return ret;
}
/*
* Must not happen on UP:
*/
RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
#endif
return ret;
}
void _raw_read_unlock(rwlock_t *lock)
{
RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
__raw_read_unlock(&lock->raw_lock);
}
static inline void debug_write_lock_before(rwlock_t *lock)
{
RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
RWLOCK_BUG_ON(lock->owner == current, lock, "recursion");
RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
lock, "cpu recursion");
}
static inline void debug_write_lock_after(rwlock_t *lock)
{
lock->owner_cpu = raw_smp_processor_id();
lock->owner = current;
}
static inline void debug_write_unlock(rwlock_t *lock)
{
RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner");
RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
lock, "wrong CPU");
lock->owner = SPINLOCK_OWNER_INIT;
lock->owner_cpu = -1;
}
#if 0 /* This can cause lockups */
static void __write_lock_debug(rwlock_t *lock)
{
int print_once = 1;
u64 i;
for (;;) {
for (i = 0; i < loops_per_jiffy * HZ; i++) {
if (__raw_write_trylock(&lock->raw_lock))
return;
}
/* lockup suspected: */
if (print_once) {
print_once = 0;
printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, "
"%s/%d, %p (%s)\n",
raw_smp_processor_id(), current->comm,
current->pid, lock, print_tainted());
dump_stack();
}
}
}
int __lockfunc _raw_write_trylock(rwlock_t *lock)
{
return __raw_write_trylock(lock);
}
