[4/5] iommu/arm-smmu: remove support for chained SMMUs

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index f284b99402bc..2d0f7cd867ea 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -42,12 +42,6 @@  conditions.
 
 ** System MMU optional properties:
 
-- smmu-parent   : When multiple SMMUs are chained together, this
-                  property can be used to provide a phandle to the
-                  parent SMMU (that is the next SMMU on the path going
-                  from the mmu-masters towards memory) node for this
-                  SMMU.
-
 - calxeda,smmu-secure-config-access : Enable proper handling of buggy
                   implementations that always use secure access to
                   SMMU configuration registers. In this case non-secure
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 835d01f47302..60986de3ada8 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -333,28 +333,17 @@  struct arm_smmu_smr {
 struct arm_smmu_master_cfg {
 	int				num_streamids;
 	u16				streamids[MAX_MASTER_STREAMIDS];
-
-	/*
-	 * We only need to allocate these on the root SMMU, as we
-	 * configure unmatched streams to bypass translation.
-	 */
 	struct arm_smmu_smr		*smrs;
 };
 
 struct arm_smmu_master {
 	struct device_node		*of_node;
-
-	/*
-	 * The following is specific to the master's position in the
-	 * SMMU chain.
-	 */
 	struct rb_node			node;
 	struct arm_smmu_master_cfg	cfg;
 };
 
 struct arm_smmu_device {
 	struct device			*dev;
-	struct device_node		*parent_of_node;
 
 	void __iomem			*base;
 	unsigned long			size;
@@ -392,7 +381,6 @@  struct arm_smmu_device {
 };
 
 struct arm_smmu_cfg {
-	struct arm_smmu_device		*smmu;
 	u8				cbndx;
 	u8				irptndx;
 	u32				cbar;
@@ -404,15 +392,8 @@  struct arm_smmu_cfg {
 #define ARM_SMMU_CB_VMID(cfg)		((cfg)->cbndx + 1)
 
 struct arm_smmu_domain {
-	/*
-	 * A domain can span across multiple, chained SMMUs and requires
-	 * all devices within the domain to follow the same translation
-	 * path.
-	 */
-	struct arm_smmu_device		*leaf_smmu;
-	struct arm_smmu_cfg		root_cfg;
-	phys_addr_t			output_mask;
-
+	struct arm_smmu_device		*smmu;
+	struct arm_smmu_cfg		cfg;
 	spinlock_t			lock;
 };
 
@@ -546,59 +527,20 @@  static int register_smmu_master(struct arm_smmu_device *smmu,
 	return insert_smmu_master(smmu, master);
 }
 
-static struct arm_smmu_device *find_parent_smmu(struct arm_smmu_device *smmu)
+static struct arm_smmu_device *find_smmu_for_device(struct device *dev)
 {
-	struct arm_smmu_device *parent;
-
-	if (!smmu->parent_of_node)
-		return NULL;
-
-	spin_lock(&arm_smmu_devices_lock);
-	list_for_each_entry(parent, &arm_smmu_devices, list)
-		if (parent->dev->of_node == smmu->parent_of_node)
-			goto out_unlock;
-
-	parent = NULL;
-	dev_warn(smmu->dev,
-		 "Failed to find SMMU parent despite parent in DT\n");
-out_unlock:
-	spin_unlock(&arm_smmu_devices_lock);
-	return parent;
-}
-
-static struct arm_smmu_device *find_parent_smmu_for_device(struct device *dev)
-{
-	struct arm_smmu_device *child, *parent, *smmu;
+	struct arm_smmu_device *smmu;
 	struct arm_smmu_master *master = NULL;
 	struct device_node *dev_node = dev_get_master_dev(dev)->of_node;
 
 	spin_lock(&arm_smmu_devices_lock);
-	list_for_each_entry(parent, &arm_smmu_devices, list) {
-		smmu = parent;
-
-		/* Try to find a child of the current SMMU. */
-		list_for_each_entry(child, &arm_smmu_devices, list) {
-			if (child->parent_of_node == parent->dev->of_node) {
-				/* Does the child sit above our master? */
-				master = find_smmu_master(child, dev_node);
-				if (master) {
-					smmu = NULL;
-					break;
-				}
-			}
-		}
-
-		/* We found some children, so keep searching. */
-		if (!smmu) {
-			master = NULL;
-			continue;
-		}
-
+	list_for_each_entry(smmu, &arm_smmu_devices, list) {
 		master = find_smmu_master(smmu, dev_node);
 		if (master)
 			break;
 	}
 	spin_unlock(&arm_smmu_devices_lock);
+
 	return master ? smmu : NULL;
 }
 
@@ -639,9 +581,10 @@  static void arm_smmu_tlb_sync(struct arm_smmu_device *smmu)
 	}
 }
 
-static void arm_smmu_tlb_inv_context(struct arm_smmu_cfg *cfg)
+static void arm_smmu_tlb_inv_context(struct arm_smmu_domain *smmu_domain)
 {
-	struct arm_smmu_device *smmu = cfg->smmu;
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	void __iomem *base = ARM_SMMU_GR0(smmu);
 	bool stage1 = cfg->cbar != CBAR_TYPE_S2_TRANS;
 
@@ -665,11 +608,11 @@  static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
 	unsigned long iova;
 	struct iommu_domain *domain = dev;
 	struct arm_smmu_domain *smmu_domain = domain->priv;
-	struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-	struct arm_smmu_device *smmu = root_cfg->smmu;
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	void __iomem *cb_base;
 
-	cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, root_cfg->cbndx);
+	cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx);
 	fsr = readl_relaxed(cb_base + ARM_SMMU_CB_FSR);
 
 	if (!(fsr & FSR_FAULT))
@@ -696,7 +639,7 @@  static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
 	} else {
 		dev_err_ratelimited(smmu->dev,
 		    "Unhandled context fault: iova=0x%08lx, fsynr=0x%x, cb=%d\n",
-		    iova, fsynr, root_cfg->cbndx);
+		    iova, fsynr, cfg->cbndx);
 		ret = IRQ_NONE;
 		resume = RESUME_TERMINATE;
 	}
@@ -761,19 +704,19 @@  static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
 {
 	u32 reg;
 	bool stage1;
-	struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-	struct arm_smmu_device *smmu = root_cfg->smmu;
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	void __iomem *cb_base, *gr0_base, *gr1_base;
 
 	gr0_base = ARM_SMMU_GR0(smmu);
 	gr1_base = ARM_SMMU_GR1(smmu);
-	stage1 = root_cfg->cbar != CBAR_TYPE_S2_TRANS;
-	cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, root_cfg->cbndx);
+	stage1 = cfg->cbar != CBAR_TYPE_S2_TRANS;
+	cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx);
 
 	/* CBAR */
-	reg = root_cfg->cbar;
+	reg = cfg->cbar;
 	if (smmu->version == 1)
-	      reg |= root_cfg->irptndx << CBAR_IRPTNDX_SHIFT;
+	      reg |= cfg->irptndx << CBAR_IRPTNDX_SHIFT;
 
 	/*
 	 * Use the weakest shareability/memory types, so they are
@@ -783,9 +726,9 @@  static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
 		reg |= (CBAR_S1_BPSHCFG_NSH << CBAR_S1_BPSHCFG_SHIFT) |
 			(CBAR_S1_MEMATTR_WB << CBAR_S1_MEMATTR_SHIFT);
 	} else {
-		reg |= ARM_SMMU_CB_VMID(root_cfg) << CBAR_VMID_SHIFT;
+		reg |= ARM_SMMU_CB_VMID(cfg) << CBAR_VMID_SHIFT;
 	}
-	writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(root_cfg->cbndx));
+	writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(cfg->cbndx));
 
 	if (smmu->version > 1) {
 		/* CBA2R */
@@ -795,7 +738,7 @@  static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
 		reg = CBA2R_RW64_32BIT;
 #endif
 		writel_relaxed(reg,
-			       gr1_base + ARM_SMMU_GR1_CBA2R(root_cfg->cbndx));
+			       gr1_base + ARM_SMMU_GR1_CBA2R(cfg->cbndx));
 
 		/* TTBCR2 */
 		switch (smmu->input_size) {
@@ -845,13 +788,13 @@  static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
 	}
 
 	/* TTBR0 */
-	arm_smmu_flush_pgtable(smmu, root_cfg->pgd,
+	arm_smmu_flush_pgtable(smmu, cfg->pgd,
 			       PTRS_PER_PGD * sizeof(pgd_t));
-	reg = __pa(root_cfg->pgd);
+	reg = __pa(cfg->pgd);
 	writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBR0_LO);
-	reg = (phys_addr_t)__pa(root_cfg->pgd) >> 32;
+	reg = (phys_addr_t)__pa(cfg->pgd) >> 32;
 	if (stage1)
-		reg |= ARM_SMMU_CB_ASID(root_cfg) << TTBRn_HI_ASID_SHIFT;
+		reg |= ARM_SMMU_CB_ASID(cfg) << TTBRn_HI_ASID_SHIFT;
 	writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBR0_HI);
 
 	/*
@@ -920,44 +863,24 @@  static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
 }
 
 static int arm_smmu_init_domain_context(struct iommu_domain *domain,
-					struct device *dev,
-					struct arm_smmu_device *device_smmu)
+					struct arm_smmu_device *smmu)
 {
 	int irq, ret, start;
 	struct arm_smmu_domain *smmu_domain = domain->priv;
-	struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-	struct arm_smmu_device *smmu, *parent;
-
-	/*
-	 * Walk the SMMU chain to find the root device for this chain.
-	 * We assume that no masters have translations which terminate
-	 * early, and therefore check that the root SMMU does indeed have
-	 * a StreamID for the master in question.
-	 */
-	parent = device_smmu;
-	smmu_domain->output_mask = -1;
-	do {
-		smmu = parent;
-		smmu_domain->output_mask &= (1ULL << smmu->s2_output_size) - 1;
-	} while ((parent = find_parent_smmu(smmu)));
-
-	if (!find_smmu_master_cfg(smmu, dev)) {
-		dev_err(dev, "unable to find root SMMU config for device\n");
-		return -ENODEV;
-	}
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 
 	if (smmu->features & ARM_SMMU_FEAT_TRANS_NESTED) {
 		/*
 		 * We will likely want to change this if/when KVM gets
 		 * involved.
 		 */
-		root_cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
+		cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
 		start = smmu->num_s2_context_banks;
 	} else if (smmu->features & ARM_SMMU_FEAT_TRANS_S2) {
-		root_cfg->cbar = CBAR_TYPE_S2_TRANS;
+		cfg->cbar = CBAR_TYPE_S2_TRANS;
 		start = 0;
 	} else {
-		root_cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
+		cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
 		start = smmu->num_s2_context_banks;
 	}
 
@@ -966,39 +889,38 @@  static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 	if (IS_ERR_VALUE(ret))
 		return ret;
 
-	root_cfg->cbndx = ret;
+	cfg->cbndx = ret;
 	if (smmu->version == 1) {
-		root_cfg->irptndx = atomic_inc_return(&smmu->irptndx);
-		root_cfg->irptndx %= smmu->num_context_irqs;
+		cfg->irptndx = atomic_inc_return(&smmu->irptndx);
+		cfg->irptndx %= smmu->num_context_irqs;
 	} else {
-		root_cfg->irptndx = root_cfg->cbndx;
+		cfg->irptndx = cfg->cbndx;
 	}
 
-	irq = smmu->irqs[smmu->num_global_irqs + root_cfg->irptndx];
+	irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx];
 	ret = request_irq(irq, arm_smmu_context_fault, IRQF_SHARED,
 			  "arm-smmu-context-fault", domain);
 	if (IS_ERR_VALUE(ret)) {
 		dev_err(smmu->dev, "failed to request context IRQ %d (%u)\n",
-			root_cfg->irptndx, irq);
-		root_cfg->irptndx = INVALID_IRPTNDX;
+			cfg->irptndx, irq);
+		cfg->irptndx = INVALID_IRPTNDX;
 		goto out_free_context;
 	}
 
-	root_cfg->smmu = smmu;
+	smmu_domain->smmu = smmu;
 	arm_smmu_init_context_bank(smmu_domain);
-	smmu_domain->leaf_smmu = device_smmu;
 	return 0;
 
 out_free_context:
-	__arm_smmu_free_bitmap(smmu->context_map, root_cfg->cbndx);
+	__arm_smmu_free_bitmap(smmu->context_map, cfg->cbndx);
 	return ret;
 }
 
 static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
 {
 	struct arm_smmu_domain *smmu_domain = domain->priv;
-	struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-	struct arm_smmu_device *smmu = root_cfg->smmu;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 	void __iomem *cb_base;
 	int irq;
 
@@ -1006,16 +928,16 @@  static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
 		return;
 
 	/* Disable the context bank and nuke the TLB before freeing it. */
-	cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, root_cfg->cbndx);
+	cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx);
 	writel_relaxed(0, cb_base + ARM_SMMU_CB_SCTLR);
-	arm_smmu_tlb_inv_context(root_cfg);
+	arm_smmu_tlb_inv_context(smmu_domain);
 
-	if (root_cfg->irptndx != INVALID_IRPTNDX) {
-		irq = smmu->irqs[smmu->num_global_irqs + root_cfg->irptndx];
+	if (cfg->irptndx != INVALID_IRPTNDX) {
+		irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx];
 		free_irq(irq, domain);
 	}
 
-	__arm_smmu_free_bitmap(smmu->context_map, root_cfg->cbndx);
+	__arm_smmu_free_bitmap(smmu->context_map, cfg->cbndx);
 }
 
 static int arm_smmu_domain_init(struct iommu_domain *domain)
@@ -1035,7 +957,7 @@  static int arm_smmu_domain_init(struct iommu_domain *domain)
 	pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
 	if (!pgd)
 		goto out_free_domain;
-	smmu_domain->root_cfg.pgd = pgd;
+	smmu_domain->cfg.pgd = pgd;
 
 	spin_lock_init(&smmu_domain->lock);
 	domain->priv = smmu_domain;
@@ -1090,8 +1012,8 @@  static void arm_smmu_free_puds(pgd_t *pgd)
 static void arm_smmu_free_pgtables(struct arm_smmu_domain *smmu_domain)
 {
 	int i;
-	struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-	pgd_t *pgd, *pgd_base = root_cfg->pgd;
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+	pgd_t *pgd, *pgd_base = cfg->pgd;
 
 	/*
 	 * Recursively free the page tables for this domain. We don't
@@ -1142,7 +1064,7 @@  static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu,
 		return -ENOMEM;
 	}
 
-	/* Allocate the SMRs on the root SMMU */
+	/* Allocate the SMRs on the SMMU */
 	for (i = 0; i < cfg->num_streamids; ++i) {
 		int idx = __arm_smmu_alloc_bitmap(smmu->smr_map, 0,
 						  smmu->num_mapping_groups);
@@ -1210,34 +1132,18 @@  static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 				      struct arm_smmu_master_cfg *cfg)
 {
 	int i, ret;
-	struct arm_smmu_device *parent, *smmu = smmu_domain->root_cfg.smmu;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
 
 	ret = arm_smmu_master_configure_smrs(smmu, cfg);
 	if (ret)
 		return ret;
 
-	/* Bypass the leaves */
-	smmu = smmu_domain->leaf_smmu;
-	while ((parent = find_parent_smmu(smmu))) {
-		/*
-		 * We won't have a StreamID match for anything but the root
-		 * smmu, so we only need to worry about StreamID indexing,
-		 * where we must install bypass entries in the S2CRs.
-		 */
-		if (smmu->features & ARM_SMMU_FEAT_STREAM_MATCH)
-			continue;
-
-		arm_smmu_bypass_stream_mapping(smmu, cfg);
-		smmu = parent;
-	}
-
-	/* Now we're at the root, time to point at our context bank */
 	for (i = 0; i < cfg->num_streamids; ++i) {
 		u32 idx, s2cr;
 		idx = cfg->smrs ? cfg->smrs[i].idx : cfg->streamids[i];
 		s2cr = S2CR_TYPE_TRANS |
-		       (smmu_domain->root_cfg.cbndx << S2CR_CBNDX_SHIFT);
+		       (smmu_domain->cfg.cbndx << S2CR_CBNDX_SHIFT);
 		writel_relaxed(s2cr, gr0_base + ARM_SMMU_GR0_S2CR(idx));
 	}
 
@@ -1247,7 +1153,7 @@  static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 static void arm_smmu_domain_remove_master(struct arm_smmu_domain *smmu_domain,
 					  struct arm_smmu_master_cfg *cfg)
 {
-	struct arm_smmu_device *smmu = smmu_domain->root_cfg.smmu;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
 
 	/*
 	 * We *must* clear the S2CR first, because freeing the SMR means
@@ -1261,37 +1167,37 @@  static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 {
 	int ret = -EINVAL;
 	struct arm_smmu_domain *smmu_domain = domain->priv;
-	struct arm_smmu_device *device_smmu;
+	struct arm_smmu_device *smmu;
 	struct arm_smmu_master_cfg *cfg;
 	unsigned long flags;
 
-	device_smmu = dev_get_master_dev(dev)->archdata.iommu;
-	if (!device_smmu) {
+	smmu = dev_get_master_dev(dev)->archdata.iommu;
+	if (!smmu) {
 		dev_err(dev, "cannot attach to SMMU, is it on the same bus?\n");
 		return -ENXIO;
 	}
 
 	/*
-	 * Sanity check the domain. We don't currently support domains
-	 * that cross between different SMMU chains.
+	 * Sanity check the domain. We don't support domains across
+	 * different SMMUs.
 	 */
 	spin_lock_irqsave(&smmu_domain->lock, flags);
-	if (!smmu_domain->leaf_smmu) {
+	if (!smmu_domain->smmu) {
 		/* Now that we have a master, we can finalise the domain */
-		ret = arm_smmu_init_domain_context(domain, dev, device_smmu);
+		ret = arm_smmu_init_domain_context(domain, smmu);
 		if (IS_ERR_VALUE(ret))
 			goto err_unlock;
-	} else if (smmu_domain->leaf_smmu != device_smmu) {
+	} else if (smmu_domain->smmu != smmu) {
 		dev_err(dev,
 			"cannot attach to SMMU %s whilst already attached to domain on SMMU %s\n",
-			dev_name(smmu_domain->leaf_smmu->dev),
-			dev_name(device_smmu->dev));
+			dev_name(smmu_domain->smmu->dev),
+			dev_name(smmu->dev));
 		goto err_unlock;
 	}
 	spin_unlock_irqrestore(&smmu_domain->lock, flags);
 
 	/* Looks ok, so add the device to the domain */
-	cfg = find_smmu_master_cfg(smmu_domain->leaf_smmu, dev);
+	cfg = find_smmu_master_cfg(smmu_domain->smmu, dev);
 	if (!cfg)
 		return -ENODEV;
 
@@ -1307,7 +1213,7 @@  static void arm_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
 	struct arm_smmu_domain *smmu_domain = domain->priv;
 	struct arm_smmu_master_cfg *cfg;
 
-	cfg = find_smmu_master_cfg(smmu_domain->leaf_smmu, dev);
+	cfg = find_smmu_master_cfg(smmu_domain->smmu, dev);
 	if (cfg)
 		arm_smmu_domain_remove_master(smmu_domain, cfg);
 }
@@ -1497,12 +1403,12 @@  static int arm_smmu_handle_mapping(struct arm_smmu_domain *smmu_domain,
 	int ret, stage;
 	unsigned long end;
 	phys_addr_t input_mask, output_mask;
-	struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-	pgd_t *pgd = root_cfg->pgd;
-	struct arm_smmu_device *smmu = root_cfg->smmu;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+	pgd_t *pgd = cfg->pgd;
 	unsigned long flags;
 
-	if (root_cfg->cbar == CBAR_TYPE_S2_TRANS) {
+	if (cfg->cbar == CBAR_TYPE_S2_TRANS) {
 		stage = 2;
 		output_mask = (1ULL << smmu->s2_output_size) - 1;
 	} else {
@@ -1552,10 +1458,6 @@  static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
 	if (!smmu_domain)
 		return -ENODEV;
 
-	/* Check for silent address truncation up the SMMU chain. */
-	if ((phys_addr_t)iova & ~smmu_domain->output_mask)
-		return -ERANGE;
-
 	return arm_smmu_handle_mapping(smmu_domain, iova, paddr, size, prot);
 }
 
@@ -1566,7 +1468,7 @@  static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
 	struct arm_smmu_domain *smmu_domain = domain->priv;
 
 	ret = arm_smmu_handle_mapping(smmu_domain, iova, 0, size, 0);
-	arm_smmu_tlb_inv_context(&smmu_domain->root_cfg);
+	arm_smmu_tlb_inv_context(smmu_domain);
 	return ret ? 0 : size;
 }
 
@@ -1578,9 +1480,9 @@  static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain,
 	pmd_t pmd;
 	pte_t pte;
 	struct arm_smmu_domain *smmu_domain = domain->priv;
-	struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 
-	pgdp = root_cfg->pgd;
+	pgdp = cfg->pgd;
 	if (!pgdp)
 		return 0;
 
@@ -1607,7 +1509,7 @@  static int arm_smmu_domain_has_cap(struct iommu_domain *domain,
 				   unsigned long cap)
 {
 	struct arm_smmu_domain *smmu_domain = domain->priv;
-	u32 features = smmu_domain->root_cfg.smmu->features;
+	u32 features = smmu_domain->smmu->features;
 
 	switch (cap) {
 	case IOMMU_CAP_CACHE_COHERENCY:
@@ -1636,7 +1538,7 @@  static int arm_smmu_add_device(struct device *dev)
 		return -EINVAL;
 	}
 
-	smmu = find_parent_smmu_for_device(dev);
+	smmu = find_smmu_for_device(dev);
 	if (!smmu)
 		return -ENODEV;
 
@@ -1914,7 +1816,6 @@  static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 	struct arm_smmu_device *smmu;
-	struct device_node *dev_node;
 	struct device *dev = &pdev->dev;
 	struct rb_node *node;
 	struct of_phandle_args masterspec;
@@ -1984,12 +1885,9 @@  static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 	}
 	dev_notice(dev, "registered %d master devices\n", i);
 
-	if ((dev_node = of_parse_phandle(dev->of_node, "smmu-parent", 0)))
-		smmu->parent_of_node = dev_node;
-
 	err = arm_smmu_device_cfg_probe(smmu);
 	if (err)
-		goto out_put_parent;
+		goto out_put_masters;
 
 	parse_driver_options(smmu);
 
@@ -1999,7 +1897,7 @@  static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 			"found only %d context interrupt(s) but %d required\n",
 			smmu->num_context_irqs, smmu->num_context_banks);
 		err = -ENODEV;
-		goto out_put_parent;
+		goto out_put_masters;
 	}
 
 	for (i = 0; i < smmu->num_global_irqs; ++i) {
@@ -2027,10 +1925,6 @@  out_free_irqs:
 	while (i--)
 		free_irq(smmu->irqs[i], smmu);
 
-out_put_parent:
-	if (smmu->parent_of_node)
-		of_node_put(smmu->parent_of_node);
-
 out_put_masters:
 	for (node = rb_first(&smmu->masters); node; node = rb_next(node)) {
 		struct arm_smmu_master *master;
@@ -2061,9 +1955,6 @@  static int arm_smmu_device_remove(struct platform_device *pdev)
 	if (!smmu)
 		return -ENODEV;
 
-	if (smmu->parent_of_node)
-		of_node_put(smmu->parent_of_node);
-
 	for (node = rb_first(&smmu->masters); node; node = rb_next(node)) {
 		struct arm_smmu_master *master;
 		master = container_of(node, struct arm_smmu_master, node);