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

Since we will have changed memory mapping of the IPMMU in the future,
This patch adds helper functions ipmmu_ctx_{reg,read,write}()
for MMU "context" 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

@@ -190,29 +190,43 @@ static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
 	iowrite32(data, mmu->base + offset);
 }
 
+static unsigned int ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu,
+				  unsigned int context_id, unsigned int reg)
+{
+	return context_id * IM_CTX_SIZE + reg;
+}
+
+static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
+			  unsigned int context_id, unsigned int reg)
+{
+	return ipmmu_read(mmu, ipmmu_ctx_reg(mmu, context_id, reg));
+}
+
+static void ipmmu_ctx_write(struct ipmmu_vmsa_device *mmu,
+			    unsigned int context_id, unsigned int reg, u32 data)
+{
+	ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
+}
+
 static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
 			       unsigned int reg)
 {
-	return ipmmu_read(domain->mmu->root,
-			  domain->context_id * IM_CTX_SIZE + reg);
+	return ipmmu_ctx_read(domain->mmu->root, domain->context_id, reg);
 }
 
 static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
 				 unsigned int reg, u32 data)
 {
-	ipmmu_write(domain->mmu->root,
-		    domain->context_id * IM_CTX_SIZE + reg, data);
+	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 }
 
 static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 				unsigned int reg, u32 data)
 {
 	if (domain->mmu != domain->mmu->root)
-		ipmmu_write(domain->mmu,
-			    domain->context_id * IM_CTX_SIZE + reg, data);
+		ipmmu_ctx_write(domain->mmu, domain->context_id, reg, data);
 
-	ipmmu_write(domain->mmu->root,
-		    domain->context_id * IM_CTX_SIZE + reg, data);
+	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 }
 
 /* -----------------------------------------------------------------------------
@@ -913,7 +927,7 @@ static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
 
 	/* Disable all contexts. */
 	for (i = 0; i < mmu->num_ctx; ++i)
-		ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
+		ipmmu_ctx_write(mmu, i, IMCTR, 0);
 }
 
 static const struct ipmmu_features ipmmu_features_default = {