From f299b2c1c7057482c34f44fe41a051ae437adcc7 Mon Sep 17 00:00:00 2001
From: Paul Gortmaker <paul.gortmaker@windriver.com>
Date: Sat, 22 Jan 2011 14:43:36 -0500
Subject: [PATCH] lockdep: add no_validate class

This is one of several extractions from the merge up to 33-rc8.

See it in a git tip repo with:

   git diff 5f854cfc024622e4aae14d7cf422f6ff86278688^2 \
	5f854cfc024622e4aae14d7cf422f6ff86278688 include/linux/lockdep.h

You can find the origin of this change in the tip merge commit:

     commit 5f854cfc024622e4aae14d7cf422f6ff86278688
     Merge: cc24da0 4ec62b2
     Author: Thomas Gleixner <tglx@linutronix.de>
     Date:   Sun Feb 21 20:17:22 2010 +0100

         Forward to 2.6.33-rc8

         Merge branch 'linus' into rt/head with a pile of conflicts.

         Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Normally there are not significant changes/additions in a merge commit that
are not from any other "normal" commit.  But in this case there are, so
break them out into separate explicit commits.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 004302c..5e2950a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -564,6 +564,7 @@ void device_initialize(struct device *dev)
 	kobject_init(&dev->kobj, &device_ktype);
 	INIT_LIST_HEAD(&dev->dma_pools);
 	mutex_init(&dev->mutex);
+	lockdep_set_novalidate_class(&dev->mutex);
 	spin_lock_init(&dev->devres_lock);
 	INIT_LIST_HEAD(&dev->devres_head);
 	device_init_wakeup(dev, 0);
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 9ccf0e2..528620e 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -40,6 +40,8 @@ struct lock_class_key {
 	struct lockdep_subclass_key	subkeys[MAX_LOCKDEP_SUBCLASSES];
 };
 
+extern struct lock_class_key __lockdep_no_validate__;
+
 #define LOCKSTAT_POINTS		4
 
 /*
@@ -266,6 +268,9 @@ extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
 #define lockdep_set_subclass(lock, sub)	\
 		lockdep_init_map(&(lock)->dep_map, #lock, \
 				 (lock)->dep_map.key, sub)
+
+#define lockdep_set_novalidate_class(lock) \
+	lockdep_set_class(lock, &__lockdep_no_validate__)
 /*
  * Compare locking classes
  */
@@ -350,6 +355,9 @@ static inline void lockdep_on(void)
 #define lockdep_set_class_and_subclass(lock, key, sub) \
 		do { (void)(key); } while (0)
 #define lockdep_set_subclass(lock, sub)		do { } while (0)
+
+#define lockdep_set_novalidate_class(lock) do { } while (0)
+
 /*
  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
  * case since the result is not well defined and the caller should rather
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index cf6db46..1199bda 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -805,6 +805,12 @@ out_unlock_set:
 	return class;
 }
 
+#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_TRACE_IRQFLAGS)
+
+/* CHECKME */
+
+#endif /* CONFIG_PROVE_LOCKING || CONFIG_TRACE_IRQFLAGS */
+
 #ifdef CONFIG_PROVE_LOCKING
 /*
  * Allocate a lockdep entry. (assumes the graph_lock held, returns
@@ -2718,6 +2724,8 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
 }
 EXPORT_SYMBOL_GPL(lockdep_init_map);
 
+struct lock_class_key __lockdep_no_validate__;
+
 /*
  * This gets called for every mutex_lock*()/spin_lock*() operation.
  * We maintain the dependency maps and validate the locking attempt:
@@ -2752,6 +2760,9 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 		return 0;
 	}
 
+	if (lock->key == &__lockdep_no_validate__)
+		check = 1;
+
 	if (!subclass)
 		class = lock->class_cache;
 	/*
@@ -3597,6 +3608,9 @@ void lockdep_init(void)
 	for (i = 0; i < CHAINHASH_SIZE; i++)
 		INIT_LIST_HEAD(chainhash_table + i);
 
+	/* Hack alert ! */
+	lockdep_set_novalidate_class(&kernel_sem);
+
 	lockdep_initialized = 1;
 }
 
-- 
1.7.1.1