[PATCH]iova-lockdep-false-alarm-fix.

[mark gross <mgross@linux.intel.com>]

lockdep goes off on the iova copy_reserved_iova because it and a
function it calls grabs locks in the from, and the to of the copy
operation.

This patch gives the reserved_ioval_list locks special lockdep classes.


--mgross

Signed-off-by: <mgross@linux.intel.com>


Index: linux-2.6.24-mm1/drivers/pci/intel-iommu.c
===================================================================
--- linux-2.6.24-mm1.orig/drivers/pci/intel-iommu.c	2008-02-20 15:52:23.000000000 -0800
+++ linux-2.6.24-mm1/drivers/pci/intel-iommu.c	2008-02-20 16:08:27.000000000 -0800
@@ -1127,6 +1127,8 @@
 }
 
 static struct iova_domain reserved_iova_list;
+static struct lock_class_key reserved_alloc_key;
+static struct lock_class_key reserved_rbtree_key;
 
 static void dmar_init_reserved_ranges(void)
 {
@@ -1137,6 +1139,11 @@
 
 	init_iova_domain(&reserved_iova_list, DMA_32BIT_PFN);
 
+	lockdep_set_class(&reserved_iova_list.iova_alloc_lock,
+		&reserved_alloc_key);
+	lockdep_set_class(&reserved_iova_list.iova_rbtree_lock,
+		&reserved_rbtree_key);
+
 	/* IOAPIC ranges shouldn't be accessed by DMA */
 	iova = reserve_iova(&reserved_iova_list, IOVA_PFN(IOAPIC_RANGE_START),
 		IOVA_PFN(IOAPIC_RANGE_END));