---

yaml
---
r: 176891
b: refs/heads/master
c: 6ecbf01
h: refs/heads/master
i:
  176889: 28ea567
  176887: d8a9f73
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2c99220810c1c79322034628b993573b088ff2da
+refs/heads/master: 6ecbf01c7ce4c0f4c3bdfa0e64ac6258328fda6c

trunk/drivers/pci/dmar.c

@@ -613,6 +613,8 @@ int __init dmar_table_init(void)
 	return 0;
 }
 
+static int bios_warned;
+
 int __init check_zero_address(void)
 {
 	struct acpi_table_dmar *dmar;
@@ -643,6 +645,7 @@ int __init check_zero_address(void)
 				     dmi_get_system_info(DMI_BIOS_VENDOR),
 				     dmi_get_system_info(DMI_BIOS_VERSION),
 				     dmi_get_system_info(DMI_PRODUCT_VERSION));
+				bios_warned = 1;
 				goto failed;
 			}
 
@@ -662,6 +665,7 @@ int __init check_zero_address(void)
 				      dmi_get_system_info(DMI_BIOS_VENDOR),
 				      dmi_get_system_info(DMI_BIOS_VERSION),
 				      dmi_get_system_info(DMI_PRODUCT_VERSION));
+				bios_warned = 1;
 				goto failed;
 			}
 		}
@@ -722,6 +726,18 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
 	int agaw = 0;
 	int msagaw = 0;
 
+	if (!drhd->reg_base_addr) {
+		if (!bios_warned) {
+			WARN(1, "Your BIOS is broken; DMAR reported at address zero!\n"
+			     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
+			     dmi_get_system_info(DMI_BIOS_VENDOR),
+			     dmi_get_system_info(DMI_BIOS_VERSION),
+			     dmi_get_system_info(DMI_PRODUCT_VERSION));
+			bios_warned = 1;
+		}
+		return -EINVAL;
+	}
+
 	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
 	if (!iommu)
 		return -ENOMEM;
@@ -738,13 +754,16 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
 	iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
 
 	if (iommu->cap == (uint64_t)-1 && iommu->ecap == (uint64_t)-1) {
-		/* Promote an attitude of violence to a BIOS engineer today */
-		WARN(1, "Your BIOS is broken; DMAR reported at address %llx returns all ones!\n"
-		     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
-		     drhd->reg_base_addr,
-		     dmi_get_system_info(DMI_BIOS_VENDOR),
-		     dmi_get_system_info(DMI_BIOS_VERSION),
-		     dmi_get_system_info(DMI_PRODUCT_VERSION));
+		if (!bios_warned) {
+			/* Promote an attitude of violence to a BIOS engineer today */
+			WARN(1, "Your BIOS is broken; DMAR reported at address %llx returns all ones!\n"
+			     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
+			     drhd->reg_base_addr,
+			     dmi_get_system_info(DMI_BIOS_VENDOR),
+			     dmi_get_system_info(DMI_BIOS_VERSION),
+			     dmi_get_system_info(DMI_PRODUCT_VERSION));
+			bios_warned = 1;
+		}
 		goto err_unmap;
 	}