Genericizing iova.[ch]

I would like to potentially move the sparc64 IOMMU code over to using
the nice new drivers/pci/iova.[ch] code for free area management..

In order to do that we have to detach the IOMMU page size assumptions
which only really need to exist in the intel-iommu.[ch] code.

This patch attempts to implement that.

[akpm@linux-foundation.org: build fix]
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/pci/iova.c b/drivers/pci/iova.c
index a84571c..8de7ab6 100644
--- a/drivers/pci/iova.c
+++ b/drivers/pci/iova.c
@@ -9,19 +9,19 @@
 #include "iova.h"
 
 void
-init_iova_domain(struct iova_domain *iovad)
+init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit)
 {
 	spin_lock_init(&iovad->iova_alloc_lock);
 	spin_lock_init(&iovad->iova_rbtree_lock);
 	iovad->rbroot = RB_ROOT;
 	iovad->cached32_node = NULL;
-
+	iovad->dma_32bit_pfn = pfn_32bit;
 }
 
 static struct rb_node *
 __get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
 {
-	if ((*limit_pfn != DMA_32BIT_PFN) ||
+	if ((*limit_pfn != iovad->dma_32bit_pfn) ||
 		(iovad->cached32_node == NULL))
 		return rb_last(&iovad->rbroot);
 	else {
@@ -37,7 +37,7 @@
 __cached_rbnode_insert_update(struct iova_domain *iovad,
 	unsigned long limit_pfn, struct iova *new)
 {
-	if (limit_pfn != DMA_32BIT_PFN)
+	if (limit_pfn != iovad->dma_32bit_pfn)
 		return;
 	iovad->cached32_node = &new->node;
 }