summaryrefslogtreecommitdiffstats
path: root/drivers/thunderbolt
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/thunderbolt')
-rw-r--r--drivers/thunderbolt/domain.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/thunderbolt/domain.c b/drivers/thunderbolt/domain.c
index 93e562f18d40..7416bdbd8576 100644
--- a/drivers/thunderbolt/domain.c
+++ b/drivers/thunderbolt/domain.c
@@ -7,7 +7,9 @@
*/
#include <linux/device.h>
+#include <linux/dmar.h>
#include <linux/idr.h>
+#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
@@ -236,6 +238,20 @@ err_free_str:
}
static DEVICE_ATTR_RW(boot_acl);
+static ssize_t iommu_dma_protection_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ /*
+ * Kernel DMA protection is a feature where Thunderbolt security is
+ * handled natively using IOMMU. It is enabled when IOMMU is
+ * enabled and ACPI DMAR table has DMAR_PLATFORM_OPT_IN set.
+ */
+ return sprintf(buf, "%d\n",
+ iommu_present(&pci_bus_type) && dmar_platform_optin());
+}
+static DEVICE_ATTR_RO(iommu_dma_protection);
+
static ssize_t security_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -251,6 +267,7 @@ static DEVICE_ATTR_RO(security);
static struct attribute *domain_attrs[] = {
&dev_attr_boot_acl.attr,
+ &dev_attr_iommu_dma_protection.attr,
&dev_attr_security.attr,
NULL,
};