iommu/vt-d: Introduce helper function iova_size() to improve code readability

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel-iommu.c

@@ -3101,10 +3101,10 @@ static void flush_unmaps(void)
 			/* On real hardware multiple invalidations are expensive */
 			if (cap_caching_mode(iommu->cap))
 				iommu_flush_iotlb_psi(iommu, domain->id,
-					iova->pfn_lo, iova->pfn_hi - iova->pfn_lo + 1,
+					iova->pfn_lo, iova_size(iova),
 					!deferred_flush[i].freelist[j], 0);
 			else {
-				mask = ilog2(mm_to_dma_pfn(iova->pfn_hi - iova->pfn_lo + 1));
+				mask = ilog2(mm_to_dma_pfn(iova_size(iova)));
 				iommu_flush_dev_iotlb(deferred_flush[i].domain[j],
 						(uint64_t)iova->pfn_lo << PAGE_SHIFT, mask);
 			}
@@ -3905,8 +3905,7 @@ static int intel_iommu_memory_notifier(struct notifier_block *nb,
 			rcu_read_lock();
 			for_each_active_iommu(iommu, drhd)
 				iommu_flush_iotlb_psi(iommu, si_domain->id,
-					iova->pfn_lo,
-					iova->pfn_hi - iova->pfn_lo + 1,
+					iova->pfn_lo, iova_size(iova),
 					!freelist, 0);
 			rcu_read_unlock();
 			dma_free_pagelist(freelist);

include/linux/iova.h

@@ -34,6 +34,11 @@ struct iova_domain {
 	unsigned long	dma_32bit_pfn;
 };
 
+static inline unsigned long iova_size(struct iova *iova)
+{
+	return iova->pfn_hi - iova->pfn_lo + 1;
+}
+
 struct iova *alloc_iova_mem(void);
 void free_iova_mem(struct iova *iova);
 void free_iova(struct iova_domain *iovad, unsigned long pfn);