ipc: close open coded spin lock calls

[platform/adaptation/renesas_rcar/renesas_kernel.git] / kernel / mutex.c

diff --git a/kernel/mutex.c b/kernel/mutex.c
index fc801aa..e581ada 100644 (file)
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -651,22 +651,60 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
 
 EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
 
+static inline int
+ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+       unsigned tmp;
+
+       if (ctx->deadlock_inject_countdown-- == 0) {
+               tmp = ctx->deadlock_inject_interval;
+               if (tmp > UINT_MAX/4)
+                       tmp = UINT_MAX;
+               else
+                       tmp = tmp*2 + tmp + tmp/2;
+
+               ctx->deadlock_inject_interval = tmp;
+               ctx->deadlock_inject_countdown = tmp;
+               ctx->contending_lock = lock;
+
+               ww_mutex_unlock(lock);
+
+               return -EDEADLK;
+       }
+#endif
+
+       return 0;
+}
 
 int __sched
 __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
+       int ret;
+
        might_sleep();
-       return __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
+       ret =  __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
                                   0, &ctx->dep_map, _RET_IP_, ctx);
+       if (!ret && ctx->acquired > 0)
+               return ww_mutex_deadlock_injection(lock, ctx);
+
+       return ret;
 }
 EXPORT_SYMBOL_GPL(__ww_mutex_lock);
 
 int __sched
 __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
+       int ret;
+
        might_sleep();
-       return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
-                                  0, &ctx->dep_map, _RET_IP_, ctx);
+       ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
+                                 0, &ctx->dep_map, _RET_IP_, ctx);
+
+       if (!ret && ctx->acquired > 0)
+               return ww_mutex_deadlock_injection(lock, ctx);
+
+       return ret;
 }
 EXPORT_SYMBOL_GPL(__ww_mutex_lock_interruptible);