intel-iommu: dump mappings but don't die on pte already set

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 14308533b1cb..40ce5a03f18f 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -1673,7 +1673,16 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
                 /* We don't need lock here, nobody else
                  * touches the iova range
                  */
-                BUG_ON(dma_pte_addr(pte));
+                if (unlikely(dma_pte_addr(pte))) {
+                        static int dumps = 5;
+                        printk(KERN_CRIT "ERROR: DMA PTE for vPFN 0x%lx already set (to %llx)\n",
+                               iov_pfn, pte->val);
+                        if (dumps) {
+                                dumps--;
+                                debug_dma_dump_mappings(NULL);
+                        }
+                        WARN_ON(1);
+                }
                 pte->val = pteval;
                 pte++;
                 if (!nr_pages ||