iommu/ipmmu-vmsa: Calculate context registers' offset instead of a macro

Since we will have changed memory mapping of the IPMMU in the future,
this patch uses ipmmu_features values instead of a macro to
calculate context registers offset. 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

@@ -50,6 +50,8 @@ struct ipmmu_features {
 	bool twobit_imttbcr_sl0;
 	bool reserved_context;
 	bool cache_snoop;
+	unsigned int ctx_offset_base;
+	unsigned int ctx_offset_stride;
 };
 
 struct ipmmu_vmsa_device {
@@ -99,8 +101,6 @@ static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
 
 #define IM_NS_ALIAS_OFFSET		0x800
 
-#define IM_CTX_SIZE			0x40
-
 /* MMU "context" registers */
 #define IMCTR				0x0000		/* R-Car Gen2/3 */
 #define IMCTR_INTEN			(1 << 2)	/* R-Car Gen2/3 */
@@ -193,7 +193,8 @@ static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int 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;
+	return mmu->features->ctx_offset_base +
+	       context_id * mmu->features->ctx_offset_stride + reg;
 }
 
 static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
@@ -939,6 +940,8 @@ static const struct ipmmu_features ipmmu_features_default = {
 	.twobit_imttbcr_sl0 = false,
 	.reserved_context = false,
 	.cache_snoop = true,
+	.ctx_offset_base = 0,
+	.ctx_offset_stride = 0x40,
 };
 
 static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
@@ -950,6 +953,8 @@ static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
 	.twobit_imttbcr_sl0 = true,
 	.reserved_context = true,
 	.cache_snoop = false,
+	.ctx_offset_base = 0,
+	.ctx_offset_stride = 0x40,
 };
 
 static const struct of_device_id ipmmu_of_ids[] = {