iommu/amd: Detect pre enabled translation
Add functions to check whether translation is already enabled in IOMMU.
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 3723037..3f72f44 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -258,6 +258,25 @@ static int amd_iommu_enable_interrupts(void);
static int __init iommu_go_to_state(enum iommu_init_state state);
static void init_device_table_dma(void);
+bool translation_pre_enabled(struct amd_iommu *iommu)
+{
+ return (iommu->flags & AMD_IOMMU_FLAG_TRANS_PRE_ENABLED);
+}
+
+static void clear_translation_pre_enabled(struct amd_iommu *iommu)
+{
+ iommu->flags &= ~AMD_IOMMU_FLAG_TRANS_PRE_ENABLED;
+}
+
+static void init_translation_status(struct amd_iommu *iommu)
+{
+ u32 ctrl;
+
+ ctrl = readl(iommu->mmio_base + MMIO_CONTROL_OFFSET);
+ if (ctrl & (1<<CONTROL_IOMMU_EN))
+ iommu->flags |= AMD_IOMMU_FLAG_TRANS_PRE_ENABLED;
+}
+
static inline void update_last_devid(u16 devid)
{
if (devid > amd_iommu_last_bdf)
@@ -1399,6 +1418,11 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
iommu->int_enabled = false;
+ init_translation_status(iommu);
+
+ if (translation_pre_enabled(iommu))
+ pr_warn("Translation is already enabled - trying to copy translation structures\n");
+
ret = init_iommu_from_acpi(iommu, h);
if (ret)
return ret;