x86, AMD IOMMU: initialize device table properly

This patch adds device table initializations which forbids memory accesses
for devices per default and disables all page faults.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 19 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index d9a9da597e79..ceba33811537 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -801,6 +801,21 @@ static int __init init_memory_definitions(struct acpi_table_header *table)
 }
 
 /*
+ * Init the device table to not allow DMA access for devices and
+ * suppress all page faults
+ */
+static void init_device_table(void)
+{
+        u16 devid;
+
+        for (devid = 0; devid <= amd_iommu_last_bdf; ++devid) {
+                set_dev_entry_bit(devid, DEV_ENTRY_VALID);
+                set_dev_entry_bit(devid, DEV_ENTRY_TRANSLATION);
+                set_dev_entry_bit(devid, DEV_ENTRY_NO_PAGE_FAULT);
+        }
+}
+
+/*
  * This function finally enables all IOMMUs found in the system after
  * they have been initialized
  */
@@ -931,6 +946,9 @@ int __init amd_iommu_init(void)
         if (amd_iommu_pd_alloc_bitmap == NULL)
                 goto free;
 
+        /* init the device table */
+        init_device_table();
+
         /*
          * let all alias entries point to itself
          */
diff --git a/include/asm-x86/amd_iommu_types.h b/include/asm-x86/amd_iommu_types.h
index 32543229db76..f0beca73e364 100644
--- a/include/asm-x86/amd_iommu_types.h
+++ b/include/asm-x86/amd_iommu_types.h
@@ -103,6 +103,7 @@
 #define DEV_ENTRY_TRANSLATION   0x01
 #define DEV_ENTRY_IR            0x3d
 #define DEV_ENTRY_IW            0x3e
+#define DEV_ENTRY_NO_PAGE_FAULT 0x62
 #define DEV_ENTRY_EX            0x67
 #define DEV_ENTRY_SYSMGT1       0x68
 #define DEV_ENTRY_SYSMGT2       0x69