iommu/exynos: Fix warnings from DMA-debug

Add a simple checks for dma_map_single() return value to make DMA-debug
checker happly. Exynos IOMMU on Samsung Exynos SoCs always use device,
which has linear DMA mapping ops (dma address is equal to physical memory
address), so no failures are returned from dma_map_single().

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/exynos-iommu.c

@@ -744,6 +744,8 @@ static struct iommu_domain *exynos_iommu_domain_alloc(unsigned type)
 				DMA_TO_DEVICE);
 	/* For mapping page table entries we rely on dma == phys */
 	BUG_ON(handle != virt_to_phys(domain->pgtable));
+	if (dma_mapping_error(dma_dev, handle))
+		goto err_lv2ent;
 
 	spin_lock_init(&domain->lock);
 	spin_lock_init(&domain->pgtablelock);
@@ -755,6 +757,8 @@ static struct iommu_domain *exynos_iommu_domain_alloc(unsigned type)
 
 	return &domain->domain;
 
+err_lv2ent:
+	free_pages((unsigned long)domain->lv2entcnt, 1);
 err_counter:
 	free_pages((unsigned long)domain->pgtable, 2);
 err_dma_cookie:
@@ -898,6 +902,7 @@ static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
 	}
 
 	if (lv1ent_fault(sent)) {
+		dma_addr_t handle;
 		sysmmu_pte_t *pent;
 		bool need_flush_flpd_cache = lv1ent_zero(sent);
 
@@ -909,7 +914,12 @@ static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
 		update_pte(sent, mk_lv1ent_page(virt_to_phys(pent)));
 		kmemleak_ignore(pent);
 		*pgcounter = NUM_LV2ENTRIES;
-		dma_map_single(dma_dev, pent, LV2TABLE_SIZE, DMA_TO_DEVICE);
+		handle = dma_map_single(dma_dev, pent, LV2TABLE_SIZE,
+					DMA_TO_DEVICE);
+		if (dma_mapping_error(dma_dev, handle)) {
+			kmem_cache_free(lv2table_kmem_cache, pent);
+			return ERR_PTR(-EADDRINUSE);
+		}
 
 		/*
 		 * If pre-fetched SLPD is a faulty SLPD in zero_l2_table,