[RFC PATCH 2/6] iommu/arm-smmu-v3: Record IIDR in arm_smmu_device structure

[John Garry]

To allow other devices know the SMMU HW IIDR, record the IIDR contents as
the first member of the arm_smmu_device structure.

In storing as the first member, it saves exposing SMMU APIs, which are
nicely self-contained today.

Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
 drivers/iommu/arm-smmu-v3.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 40f4757096c3..1ed3ef0f1ec3 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -70,6 +70,8 @@
 #define IDR1_SSIDSIZE			GENMASK(10, 6)
 #define IDR1_SIDSIZE			GENMASK(5, 0)
 
+#define ARM_SMMU_IIDR                  0x18
+
 #define ARM_SMMU_IDR5			0x14
 #define IDR5_STALL_MAX			GENMASK(31, 16)
 #define IDR5_GRAN64K			(1 << 6)
@@ -546,6 +548,7 @@ struct arm_smmu_strtab_cfg {
 
 /* An SMMUv3 instance */
 struct arm_smmu_device {
+	u32						iidr; /* must be first member */
 	struct device			*dev;
 	void __iomem			*base;
 
@@ -3153,6 +3156,8 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	iommu_device_set_ops(&smmu->iommu, &arm_smmu_ops);
 	iommu_device_set_fwnode(&smmu->iommu, dev->fwnode);
 
+	smmu->iidr = readl(smmu->base + ARM_SMMU_IIDR);
+
 	ret = iommu_device_register(&smmu->iommu);
 	if (ret) {
 		dev_err(dev, "Failed to register iommu\n");
-- 
2.17.1