iommu/vt-d: Remove BUG_ON on checking valid pfn range

When encountering an unexpected invalid pfn range, the kernel should
attempt recovery and proceed with execution. Therefore, using WARN_ON to
replace BUG_ON to avoid halting the machine.

Besides, one redundant checking is reduced.

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Link: https://lore.kernel.org/r/20230406065944.2773296-3-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

@@ -1005,9 +1005,9 @@ static void dma_pte_clear_range(struct dmar_domain *domain,
 	unsigned int large_page;
 	struct dma_pte *first_pte, *pte;
 
-	BUG_ON(!domain_pfn_supported(domain, start_pfn));
-	BUG_ON(!domain_pfn_supported(domain, last_pfn));
-	BUG_ON(start_pfn > last_pfn);
+	if (WARN_ON(!domain_pfn_supported(domain, last_pfn)) ||
+	    WARN_ON(start_pfn > last_pfn))
+		return;
 
 	/* we don't need lock here; nobody else touches the iova range */
 	do {
@@ -1166,9 +1166,9 @@ static void dma_pte_clear_level(struct dmar_domain *domain, int level,
 static void domain_unmap(struct dmar_domain *domain, unsigned long start_pfn,
 			 unsigned long last_pfn, struct list_head *freelist)
 {
-	BUG_ON(!domain_pfn_supported(domain, start_pfn));
-	BUG_ON(!domain_pfn_supported(domain, last_pfn));
-	BUG_ON(start_pfn > last_pfn);
+	if (WARN_ON(!domain_pfn_supported(domain, last_pfn)) ||
+	    WARN_ON(start_pfn > last_pfn))
+		return;
 
 	/* we don't need lock here; nobody else touches the iova range */
 	dma_pte_clear_level(domain, agaw_to_level(domain->agaw),