[PATCH v9 01/13] iommu/amd: Detect pre enabled translation

Baoquan He
2017-08-01T11:37:40Z

Add functions to check whether translation is already enabled in IOMMU.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
drivers/iommu/amd_iommu_init.c | 24 ++++++++++++++++++++++++
drivers/iommu/amd_iommu_proto.h | 1 +
drivers/iommu/amd_iommu_types.h | 3 +++
3 files changed, 28 insertions(+)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 5cc597b383c7..e39857ce6481 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;
diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index 466260f8a1df..a9666d2005bb 100644
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -87,4 +87,5 @@ static inline bool iommu_feature(struct amd_iommu *iommu, u64 f)
return !!(iommu->features & f);
}

+extern bool translation_pre_enabled(struct amd_iommu *iommu);
#endif /* _ASM_X86_AMD_IOMMU_PROTO_H */
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 294a409e283b..0c98b2cf04cc 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -435,6 +435,8 @@ struct iommu_domain;
struct irq_domain;
struct amd_irte_ops;

+#define AMD_IOMMU_FLAG_TRANS_PRE_ENABLED (1 << 0)
+
/*
* This structure contains generic data for IOMMU protection domains
* independent of their use.
@@ -569,6 +571,7 @@ struct amd_iommu {
struct amd_irte_ops *irte_ops;
#endif

+ u32 flags;
volatile u64 __aligned(8) cmd_sem;
};

--
2.5.5