[PATCH] lockdep: annotate genirq

Teach special (recursive) locking code to the lock validator.  Has no effect
on non-lockdep kernels.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index aeb6e391276c..a7b497ee919e 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -249,3 +249,19 @@ out:
         return 1;
 }
 
+#ifdef CONFIG_TRACE_IRQFLAGS
+
+/*
+ * lockdep: we want to handle all irq_desc locks as a single lock-class:
+ */
+static struct lock_class_key irq_desc_lock_class;
+
+void early_init_irq_lock_class(void)
+{
+        int i;
+
+        for (i = 0; i < NR_IRQS; i++)
+                lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class);
+}
+
+#endif