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-rw-r--r--kernel/locking/lglock.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/locking/lglock.c b/kernel/locking/lglock.c
index 86ae2aebf..951cfcd10 100644
--- a/kernel/locking/lglock.c
+++ b/kernel/locking/lglock.c
@@ -60,6 +60,28 @@ void lg_local_unlock_cpu(struct lglock *lg, int cpu)
}
EXPORT_SYMBOL(lg_local_unlock_cpu);
+void lg_double_lock(struct lglock *lg, int cpu1, int cpu2)
+{
+ BUG_ON(cpu1 == cpu2);
+
+ /* lock in cpu order, just like lg_global_lock */
+ if (cpu2 < cpu1)
+ swap(cpu1, cpu2);
+
+ preempt_disable();
+ lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+ arch_spin_lock(per_cpu_ptr(lg->lock, cpu1));
+ arch_spin_lock(per_cpu_ptr(lg->lock, cpu2));
+}
+
+void lg_double_unlock(struct lglock *lg, int cpu1, int cpu2)
+{
+ lock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ arch_spin_unlock(per_cpu_ptr(lg->lock, cpu1));
+ arch_spin_unlock(per_cpu_ptr(lg->lock, cpu2));
+ preempt_enable();
+}
+
void lg_global_lock(struct lglock *lg)
{
int i;