iommu/ipmmu-vmsa: Add helper functions for "uTLB" registers

Since we will have changed memory mapping of the IPMMU in the future,
This patch adds helper functions ipmmu_utlb_reg() and
ipmmu_imu{asid,ctr}_write() for "uTLB" registers. No behavior change.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/ipmmu-vmsa.c

@@ -230,6 +230,23 @@ static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 }
 
+static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
+{
+	return reg;
+}
+
+static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
+				unsigned int utlb, u32 data)
+{
+	ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
+}
+
+static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
+			       unsigned int utlb, u32 data)
+{
+	ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
+}
+
 /* -----------------------------------------------------------------------------
  * TLB and microTLB Management
  */
@@ -275,11 +292,10 @@ static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
 	 */
 
 	/* TODO: What should we set the ASID to ? */
-	ipmmu_write(mmu, IMUASID(utlb), 0);
+	ipmmu_imuasid_write(mmu, utlb, 0);
 	/* TODO: Do we need to flush the microTLB ? */
-	ipmmu_write(mmu, IMUCTR(utlb),
-		    IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_FLUSH |
-		    IMUCTR_MMUEN);
+	ipmmu_imuctr_write(mmu, utlb, IMUCTR_TTSEL_MMU(domain->context_id) |
+				      IMUCTR_FLUSH | IMUCTR_MMUEN);
 	mmu->utlb_ctx[utlb] = domain->context_id;
 }
 
@@ -291,7 +307,7 @@ static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
 {
 	struct ipmmu_vmsa_device *mmu = domain->mmu;
 
-	ipmmu_write(mmu, IMUCTR(utlb), 0);
+	ipmmu_imuctr_write(mmu, utlb, 0);
 	mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
 }