iommu/vt-d: Remove BUG_ON in map/unmap()

Domain map/unmap with invalid parameters shouldn't crash the kernel.
Therefore, using if() replaces the BUG_ON.

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Link: https://lore.kernel.org/r/20230406065944.2773296-6-tina.zhang@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: TinaZhangZW

drivers/iommu/intel/iommu.c

@@ -2159,7 +2159,8 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
 	phys_addr_t pteval;
 	u64 attr;
 
-	BUG_ON(!domain_pfn_supported(domain, iov_pfn + nr_pages - 1));
+	if (unlikely(!domain_pfn_supported(domain, iov_pfn + nr_pages - 1)))
+		return -EINVAL;
 
 	if ((prot & (DMA_PTE_READ|DMA_PTE_WRITE)) == 0)
 		return -EINVAL;
@@ -4314,8 +4315,9 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
 
 	/* Cope with horrid API which requires us to unmap more than the
 	   size argument if it happens to be a large-page mapping. */
-	BUG_ON(!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level,
-			       GFP_ATOMIC));
+	if (unlikely(!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT,
+				     &level, GFP_ATOMIC)))
+		return 0;
 
 	if (size < VTD_PAGE_SIZE << level_to_offset_bits(level))
 		size = VTD_PAGE_SIZE << level_to_offset_bits(level);