Merge branches 'arm/exynos', 'arm/omap', 'arm/rockchip', 'arm/mediatek', 'arm/smmu...

[karo-tx-linux.git] / drivers / iommu / intel-iommu.c

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index d412a313a37232997d406e53379e1466d10b93e7..90ab0115d78e8dcc4512a6ab2efb27ac45a86c54 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -183,6 +183,7 @@ static int rwbf_quirk;
  * (used when kernel is launched w/ TXT)
  */
 static int force_on = 0;
+int intel_iommu_tboot_noforce;
 
 /*
  * 0: Present
@@ -607,6 +608,10 @@ static int __init intel_iommu_setup(char *str)
                                "Intel-IOMMU: enable pre-production PASID support\n");
                        intel_iommu_pasid28 = 1;
                        iommu_identity_mapping |= IDENTMAP_GFX;
+               } else if (!strncmp(str, "tboot_noforce", 13)) {
+                       printk(KERN_INFO
+                               "Intel-IOMMU: not forcing on after tboot. This could expose security risk for tboot\n");
+                       intel_iommu_tboot_noforce = 1;
                }
 
                str += strcspn(str, ",");
@@ -4730,6 +4735,15 @@ static int intel_iommu_cpu_dead(unsigned int cpu)
        return 0;
 }
 
+static void intel_disable_iommus(void)
+{
+       struct intel_iommu *iommu = NULL;
+       struct dmar_drhd_unit *drhd;
+
+       for_each_iommu(iommu, drhd)
+               iommu_disable_translation(iommu);
+}
+
 static inline struct intel_iommu *dev_to_intel_iommu(struct device *dev)
 {
        return container_of(dev, struct intel_iommu, iommu.dev);
@@ -4840,8 +4854,28 @@ int __init intel_iommu_init(void)
                goto out_free_dmar;
        }
 
-       if (no_iommu || dmar_disabled)
+       if (no_iommu || dmar_disabled) {
+               /*
+                * We exit the function here to ensure IOMMU's remapping and
+                * mempool aren't setup, which means that the IOMMU's PMRs
+                * won't be disabled via the call to init_dmars(). So disable
+                * it explicitly here. The PMRs were setup by tboot prior to
+                * calling SENTER, but the kernel is expected to reset/tear
+                * down the PMRs.
+                */
+               if (intel_iommu_tboot_noforce) {
+                       for_each_iommu(iommu, drhd)
+                               iommu_disable_protect_mem_regions(iommu);
+               }
+
+               /*
+                * Make sure the IOMMUs are switched off, even when we
+                * boot into a kexec kernel and the previous kernel left
+                * them enabled
+                */
+               intel_disable_iommus();
                goto out_free_dmar;
+       }
 
        if (list_empty(&dmar_rmrr_units))
                pr_info("No RMRR found\n");