1 files changed, 67 insertions, 24 deletions

diff --git a/kernel/locking/lglock.c b/kernel/locking/lglock.c
index 951cfcd10b4a..57e0ea72c28a 100644
--- a/kernel/locking/lglock.c
+++ b/kernel/locking/lglock.c
@@ -4,6 +4,15 @@
 #include <linux/cpu.h>
 #include <linux/string.h>
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define lg_lock_ptr		arch_spinlock_t
+# define lg_do_lock(l)		arch_spin_lock(l)
+# define lg_do_unlock(l)	arch_spin_unlock(l)
+#else
+# define lg_lock_ptr		struct rt_mutex
+# define lg_do_lock(l)		__rt_spin_lock__no_mg(l)
+# define lg_do_unlock(l)	__rt_spin_unlock(l)
+#endif
 /*
  * Note there is no uninit, so lglocks cannot be defined in
  * modules (but it's fine to use them from there)
@@ -12,51 +21,60 @@
 
 void lg_lock_init(struct lglock *lg, char *name)
 {
+#ifdef CONFIG_PREEMPT_RT_FULL
+	int i;
+
+	for_each_possible_cpu(i) {
+		struct rt_mutex *lock = per_cpu_ptr(lg->lock, i);
+
+		rt_mutex_init(lock);
+	}
+#endif
 	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;
+	lg_lock_ptr *lock;
 
-	preempt_disable();
+	migrate_disable();
 	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
 	lock = this_cpu_ptr(lg->lock);
-	arch_spin_lock(lock);
+	lg_do_lock(lock);
 }
 EXPORT_SYMBOL(lg_local_lock);
 
 void lg_local_unlock(struct lglock *lg)
 {
-	arch_spinlock_t *lock;
+	lg_lock_ptr *lock;
 
 	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
 	lock = this_cpu_ptr(lg->lock);
-	arch_spin_unlock(lock);
-	preempt_enable();
+	lg_do_unlock(lock);
+	migrate_enable();
 }
 EXPORT_SYMBOL(lg_local_unlock);
 
 void lg_local_lock_cpu(struct lglock *lg, int cpu)
 {
-	arch_spinlock_t *lock;
+	lg_lock_ptr *lock;
 
-	preempt_disable();
+	preempt_disable_nort();
 	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
 	lock = per_cpu_ptr(lg->lock, cpu);
-	arch_spin_lock(lock);
+	lg_do_lock(lock);
 }
 EXPORT_SYMBOL(lg_local_lock_cpu);
 
 void lg_local_unlock_cpu(struct lglock *lg, int cpu)
 {
-	arch_spinlock_t *lock;
+	lg_lock_ptr *lock;
 
 	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
 	lock = per_cpu_ptr(lg->lock, cpu);
-	arch_spin_unlock(lock);
-	preempt_enable();
+	lg_do_unlock(lock);
+	preempt_enable_nort();
 }
 EXPORT_SYMBOL(lg_local_unlock_cpu);
 
@@ -68,30 +86,30 @@ void lg_double_lock(struct lglock *lg, int cpu1, int cpu2)
 	if (cpu2 < cpu1)
 		swap(cpu1, cpu2);
 
-	preempt_disable();
+	preempt_disable_nort();
 	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));
+	lg_do_lock(per_cpu_ptr(lg->lock, cpu1));
+	lg_do_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();
+	lg_do_unlock(per_cpu_ptr(lg->lock, cpu1));
+	lg_do_unlock(per_cpu_ptr(lg->lock, cpu2));
+	preempt_enable_nort();
 }
 
 void lg_global_lock(struct lglock *lg)
 {
 	int i;
 
-	preempt_disable();
+	preempt_disable_nort();
 	lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
 	for_each_possible_cpu(i) {
-		arch_spinlock_t *lock;
+		lg_lock_ptr *lock;
 		lock = per_cpu_ptr(lg->lock, i);
-		arch_spin_lock(lock);
+		lg_do_lock(lock);
 	}
 }
 EXPORT_SYMBOL(lg_global_lock);
@@ -102,10 +120,35 @@ void lg_global_unlock(struct lglock *lg)
 
 	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
 	for_each_possible_cpu(i) {
-		arch_spinlock_t *lock;
+		lg_lock_ptr *lock;
 		lock = per_cpu_ptr(lg->lock, i);
-		arch_spin_unlock(lock);
+		lg_do_unlock(lock);
 	}
-	preempt_enable();
+	preempt_enable_nort();
 }
 EXPORT_SYMBOL(lg_global_unlock);
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * HACK: If you use this, you get to keep the pieces.
+ * Used in queue_stop_cpus_work() when stop machinery
+ * is called from inactive CPU, so we can't schedule.
+ */
+# define lg_do_trylock_relax(l)			\
+	do {					\
+		while (!__rt_spin_trylock(l))	\
+			cpu_relax();		\
+	} while (0)
+
+void lg_global_trylock_relax(struct lglock *lg)
+{
+	int i;
+
+	lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+	for_each_possible_cpu(i) {
+		lg_lock_ptr *lock;
+		lock = per_cpu_ptr(lg->lock, i);
+		lg_do_trylock_relax(lock);
+	}
+}
+#endif