iommu/mediatek: Use gather to achieve the tlb range flush

Use the iommu_gather mechanism to achieve the tlb range flush.
Gather the iova range in the "tlb_add_page", then flush the merged iova
range in iotlb_sync.

Suggested-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/mtk_iommu.c

@@ -245,11 +245,9 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
 					    void *cookie)
 {
 	struct mtk_iommu_data *data = cookie;
-	unsigned long flags;
+	struct iommu_domain *domain = &data->m4u_dom->domain;
 
-	spin_lock_irqsave(&data->tlb_lock, flags);
+	iommu_iotlb_gather_add_page(domain, gather, iova, granule);
-	mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie);
-	spin_unlock_irqrestore(&data->tlb_lock, flags);
 }
 
 static const struct iommu_flush_ops mtk_iommu_flush_ops = {
@@ -469,9 +467,15 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
 				 struct iommu_iotlb_gather *gather)
 {
 	struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
+	size_t length = gather->end - gather->start;
 	unsigned long flags;
 
+	if (gather->start == ULONG_MAX)
+		return;
+
 	spin_lock_irqsave(&data->tlb_lock, flags);
+	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
+				       false, data);
 	mtk_iommu_tlb_sync(data);
 	spin_unlock_irqrestore(&data->tlb_lock, flags);
 }