Add functions to check whether translation is already enabled in IOMMU.
Maybe it need be checked per IOMMU. Currently for debugging I didn't do
like that.
Signed-off-by: Baoquan He <b...@redhat.com>
---
drivers/iommu/amd_iommu_init.c | 26 ++++++++++++++++++++++++++
drivers/iommu/amd_iommu_proto.h | 4 ++++
2 files changed, 30 insertions(+)
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 5845918..1fc369e 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -229,6 +229,27 @@ 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);
+static u8 g_pre_enabled;
+
+bool translation_pre_enabled(void)
+{
+ return !!g_pre_enabled;
+}
+
+void clear_translation_pre_enabled(void)
+{
+ g_pre_enabled = 0;
+}
+
+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))
+ g_pre_enabled = 1;
+}
+
static inline void update_last_devid(u16 devid)
{
if (devid > amd_iommu_last_bdf)
@@ -1142,6 +1163,11 @@ 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())
+ pr_warn("Translation is already enabled - trying to copy
translation structures\n");
+
ret = init_iommu_from_acpi(iommu, h);
if (ret)
return ret;
diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index 0bd9eb3..743e209 100644
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -98,4 +98,8 @@ static inline bool iommu_feature(struct amd_iommu *iommu, u64
f)
return !!(iommu->features & f);
}
+/* kdump checking */
+extern bool translation_pre_enabled(void);
+extern void clear_translation_pre_enabled(void);
+
#endif /* _ASM_X86_AMD_IOMMU_PROTO_H */
--
2.4.0
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