-#include <asm/swiotlb.h>
-
-/*
- * History lesson:
- * The execution chain of IOMMUs in 2.6.36 looks as so:
- *
- *            [xen-swiotlb]
- *                 |
- *         +----[swiotlb *]--+
- *        /         |         \
- *       /          |          \
- *    [GART]     [Calgary]  [Intel VT-d]
- *     /
- *    /
- * [AMD-Vi]

.. snip..

- *
 void __init pci_iommu_alloc(void)
 {
-	struct iommu_table_entry *p;
-
-	sort_iommu_table(__iommu_table, __iommu_table_end);
-	check_iommu_entries(__iommu_table, __iommu_table_end);
-
-	for (p = __iommu_table; p < __iommu_table_end; p++) {
-		if (p && p->detect && p->detect() > 0) {
-			p->flags |= IOMMU_DETECTED;
-			if (p->early_init)
-				p->early_init();
-			if (p->flags & IOMMU_FINISH_IF_DETECTED)
-				break;
-		}
+	if (xen_pv_domain()) {
+		pci_xen_swiotlb_init();
+		return;
 	}
+	pci_swiotlb_detect_4gb();

I think you also need to check for IBM Calgary?

+	gart_iommu_hole_init();
+	amd_iommu_detect();
+	detect_intel_iommu();
+	if (x86_swiotlb_enable)
+		swiotlb_init(0);