lockdep: add lock_class information to lock_chain and output it

It is based on x86/master branch of git-x86 tree, and has been tested
on x86_64 platform.

ChangeLog:

v2:

- Enclosing proc file system related code into CONFIG_PROVE_LOCKING.

- Fix nr_chain_hlocks update code.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 14d052c..9b0e940 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -178,6 +178,7 @@
 	.release	= seq_release,
 };
 
+#ifdef CONFIG_PROVE_LOCKING
 static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	struct lock_chain *chain;
@@ -264,6 +265,7 @@
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
+#endif /* CONFIG_PROVE_LOCKING */
 
 static void lockdep_stats_debug_show(struct seq_file *m)
 {
@@ -382,7 +384,7 @@
 	seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
 			nr_lock_chains, MAX_LOCKDEP_CHAINS);
 	seq_printf(m, " dependency chain hlocks:       %11d [max: %lu]\n",
-			atomic_read(&nr_chain_hlocks), MAX_LOCKDEP_CHAIN_HLOCKS);
+			nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
 #endif
 
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -750,8 +752,10 @@
 static int __init lockdep_proc_init(void)
 {
 	proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
+#ifdef CONFIG_PROVE_LOCKING
 	proc_create("lockdep_chains", S_IRUSR, NULL,
 		    &proc_lockdep_chains_operations);
+#endif
 	proc_create("lockdep_stats", S_IRUSR, NULL,
 		    &proc_lockdep_stats_operations);