#define DMA_32BIT_PFN          IOVA_PFN(DMA_32BIT_MASK)
 #define DMA_64BIT_PFN          IOVA_PFN(DMA_64BIT_MASK)
 
+/* global iommu list, set NULL for ignored DMAR units */
+static struct intel_iommu **g_iommus;
+
 /*
  * 0: Present
  * 1-11: Reserved
        kfree(iommu->domains);
        kfree(iommu->domain_ids);
 
+       g_iommus[iommu->seq_id] = NULL;
+
+       /* if all iommus are freed, free g_iommus */
+       for (i = 0; i < g_num_of_iommus; i++) {
+               if (g_iommus[i])
+                       break;
+       }
+
+       if (i == g_num_of_iommus)
+               kfree(g_iommus);
+
        /* free context mapping */
        free_context_table(iommu);
 }
                 */
        }
 
+       g_iommus = kcalloc(g_num_of_iommus, sizeof(struct intel_iommu *),
+                       GFP_KERNEL);
+       if (!g_iommus) {
+               printk(KERN_ERR "Allocating global iommu array failed\n");
+               ret = -ENOMEM;
+               goto error;
+       }
+
        deferred_flush = kzalloc(g_num_of_iommus *
                sizeof(struct deferred_flush_tables), GFP_KERNEL);
        if (!deferred_flush) {
+               kfree(g_iommus);
                ret = -ENOMEM;
                goto error;
        }
                        continue;
 
                iommu = drhd->iommu;
+               g_iommus[iommu->seq_id] = iommu;
 
                ret = iommu_init_domains(iommu);
                if (ret)
                iommu = drhd->iommu;
                free_iommu(iommu);
        }
+       kfree(g_iommus);
        return ret;
 }