iommu/arm-smmu: Reorganize arm_smmu_domain_add_master()

Make arm_smmu_domain_add_master() not use the smmu_domain to detect the
s2cr configuration, instead pass it in as a parameter. It always returns
zero so make it return void.

Since it no longer really does anything to do with a domain call it
arm_smmu_master_install_s2crs().

This is done to make the next two patches able to re-use this code without
forcing the creation of a struct arm_smmu_domain.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v2-c86cc8c2230e+160bb-smmu_newapi_jgg@nvidia.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/iommu/arm/arm-smmu/arm-smmu.c

@@ -1081,21 +1081,14 @@ static void arm_smmu_master_free_smes(struct arm_smmu_master_cfg *cfg,
 	mutex_unlock(&smmu->stream_map_mutex);
 }
 
-static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
-				      struct arm_smmu_master_cfg *cfg,
-				      struct iommu_fwspec *fwspec)
+static void arm_smmu_master_install_s2crs(struct arm_smmu_master_cfg *cfg,
+					  enum arm_smmu_s2cr_type type,
+					  u8 cbndx, struct iommu_fwspec *fwspec)
 {
-	struct arm_smmu_device *smmu = smmu_domain->smmu;
+	struct arm_smmu_device *smmu = cfg->smmu;
 	struct arm_smmu_s2cr *s2cr = smmu->s2crs;
-	u8 cbndx = smmu_domain->cfg.cbndx;
-	enum arm_smmu_s2cr_type type;
 	int i, idx;
 
-	if (smmu_domain->stage == ARM_SMMU_DOMAIN_BYPASS)
-		type = S2CR_TYPE_BYPASS;
-	else
-		type = S2CR_TYPE_TRANS;
-
 	for_each_cfg_sme(cfg, fwspec, i, idx) {
 		if (type == s2cr[idx].type && cbndx == s2cr[idx].cbndx)
 			continue;
@@ -1105,7 +1098,6 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 		s2cr[idx].cbndx = cbndx;
 		arm_smmu_write_s2cr(smmu, idx);
 	}
-	return 0;
 }
 
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
@@ -1153,7 +1145,12 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	}
 
 	/* Looks ok, so add the device to the domain */
-	ret = arm_smmu_domain_add_master(smmu_domain, cfg, fwspec);
+	arm_smmu_master_install_s2crs(cfg,
+				      smmu_domain->stage ==
+						      ARM_SMMU_DOMAIN_BYPASS ?
+					      S2CR_TYPE_BYPASS :
+					      S2CR_TYPE_TRANS,
+				      smmu_domain->cfg.cbndx, fwspec);
 
 	/*
 	 * Setup an autosuspend delay to avoid bouncing runpm state.