3 files changed, 19 insertions, 6 deletions
diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index 6938800e9884..f4bdc5ffa9d9 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -915,6 +915,18 @@ dmar_validate_one_drhd(struct acpi_dmar_header *entry, void *arg)
 	return 0;
 }
 
+static bool dmar_required(void)
+{
+	/* tboot supersedes any user/platform opt */
+	if (!intel_iommu_tboot_noforce && tboot_enabled())
+		return true;
+
+	if (!no_iommu && (!dmar_disabled || dmar_platform_optin()))
+		return true;
+
+	return false;
+}
+
 void __init detect_intel_iommu(void)
 {
 	int ret;
@@ -928,8 +940,7 @@ void __init detect_intel_iommu(void)
 	if (!ret)
 		ret = dmar_walk_dmar_table((struct acpi_table_dmar *)dmar_tbl,
 					   &validate_drhd_cb);
-	if (!ret && !no_iommu && !iommu_detected &&
-	    (!dmar_disabled || dmar_platform_optin())) {
+	if (!ret && !iommu_detected && dmar_required()) {
 		iommu_detected = 1;
 		/* Make sure ACS will be enabled */
 		pci_request_acs();
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 8b38c65f403b..aec1a05d48d0 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -64,7 +64,7 @@ static int rwbf_quirk;
  * (used when kernel is launched w/ TXT)
  */
 static int force_on = 0;
-static int intel_iommu_tboot_noforce;
+int intel_iommu_tboot_noforce;
 static int no_platform_optin;
 
 #define ROOT_ENTRY_NR (VTD_PAGE_SIZE/sizeof(struct root_entry))
@@ -2956,10 +2956,11 @@ static bool has_external_pci(void)
 
 static int __init platform_optin_force_iommu(void)
 {
-	if (!dmar_platform_optin() || no_platform_optin || !has_external_pci())
+	if (no_iommu || !dmar_platform_optin() || no_platform_optin ||
+	    !has_external_pci())
 		return 0;
 
-	if (no_iommu || dmar_disabled)
+	if (dmar_disabled)
 		pr_info("Intel-IOMMU force enabled due to platform opt in\n");
 
 	/*
@@ -2970,7 +2971,6 @@ static int __init platform_optin_force_iommu(void)
 		iommu_set_default_passthrough(false);
 
 	dmar_disabled = 0;
-	no_iommu = 0;
 
 	return 1;
 }
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 6b11081e690f..8e2df00e881c 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1434,6 +1434,7 @@ static inline bool ecmd_has_pmu_essential(struct intel_iommu *iommu)
 
 extern int dmar_disabled;
 extern int intel_iommu_enabled;
+extern int intel_iommu_tboot_noforce;
 #else
 static inline int iommu_calculate_agaw(struct intel_iommu *iommu)
 {
@@ -1446,6 +1447,7 @@ static inline int iommu_calculate_max_sagaw(struct intel_iommu *iommu)
 #define dmar_disabled	(1)
 #define intel_iommu_enabled (0)
 #define intel_iommu_sm (0)
+#define intel_iommu_tboot_noforce (0)
 #endif
 
 static inline const char *decode_prq_descriptor(char *str, size_t size,