intel-iommu: intel_iommu_map_range failed at very end of address space

intel_iommu_map_range() doesn't allow allocation at the very end of the
address space; that code has been simplified and corrected.
Signed-off-by: Tom Lyon <pugs@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/pci/intel-iommu.c

@@ -3626,7 +3626,6 @@ static int intel_iommu_map_range(struct iommu_domain *domain,
 {
 	struct dmar_domain *dmar_domain = domain->priv;
 	u64 max_addr;
-	int addr_width;
 	int prot = 0;
 	int ret;
 
@@ -3639,18 +3638,14 @@ static int intel_iommu_map_range(struct iommu_domain *domain,
 
 	max_addr = iova + size;
 	if (dmar_domain->max_addr < max_addr) {
-		int min_agaw;
 		u64 end;
 
 		/* check if minimum agaw is sufficient for mapped address */
-		min_agaw = vm_domain_min_agaw(dmar_domain);
-		addr_width = agaw_to_width(min_agaw);
-		end = DOMAIN_MAX_ADDR(addr_width);
-		end = end & VTD_PAGE_MASK;
+		end = __DOMAIN_MAX_ADDR(dmar_domain->gaw) + 1;
 		if (end < max_addr) {
-			printk(KERN_ERR "%s: iommu agaw (%d) is not "
+			printk(KERN_ERR "%s: iommu width (%d) is not "
 			       "sufficient for the mapped address (%llx)\n",
-			       __func__, min_agaw, max_addr);
+			       __func__, dmar_domain->gaw, max_addr);
 			return -EFAULT;
 		}
 		dmar_domain->max_addr = max_addr;