iommu/ipmmu-vmsa: Add utlb_offset_base

Since we will have changed memory mapping of the IPMMU in the future,
this patch adds a utlb_offset_base into struct ipmmu_features
for IMUCTR and IMUASID registers. No behavior change.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/ipmmu-vmsa.c

@@ -52,6 +52,7 @@ struct ipmmu_features {
 	bool cache_snoop;
 	unsigned int ctx_offset_base;
 	unsigned int ctx_offset_stride;
+	unsigned int utlb_offset_base;
 };
 
 struct ipmmu_vmsa_device {
@@ -232,7 +233,7 @@ static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 
 static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
 {
-	return reg;
+	return mmu->features->utlb_offset_base + reg;
 }
 
 static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
@@ -958,6 +959,7 @@ static const struct ipmmu_features ipmmu_features_default = {
 	.cache_snoop = true,
 	.ctx_offset_base = 0,
 	.ctx_offset_stride = 0x40,
+	.utlb_offset_base = 0,
 };
 
 static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
@@ -971,6 +973,7 @@ static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
 	.cache_snoop = false,
 	.ctx_offset_base = 0,
 	.ctx_offset_stride = 0x40,
+	.utlb_offset_base = 0,
 };
 
 static const struct of_device_id ipmmu_of_ids[] = {