iommu/arm-smmu: Convert to domain_alloc_paging()

Now that the BLOCKED and IDENTITY behaviors are managed with their own
domains change to the domain_alloc_paging() op.

The check for using_legacy_binding is now redundant,
arm_smmu_def_domain_type() always returns IOMMU_DOMAIN_IDENTITY for this
mode, so the core code will never attempt to create a DMA domain in the
first place.

Since commit a4fdd97 ("iommu: Use flush queue capability") the core
code only passes in IDENTITY/BLOCKED/UNMANAGED/DMA domain types. It will
not pass in IDENTITY or BLOCKED if the global statics exist, so the test
for DMA is also redundant now too.

Call arm_smmu_init_domain_context() early if a dev is available.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v2-c86cc8c2230e+160bb-smmu_newapi_jgg@nvidia.com
[will: Simplify arm_smmu_domain_alloc_paging() since 'cfg' cannot be NULL]
Signed-off-by: Will Deacon <will@kernel.org>

Author: jgunthorpe

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

@@ -859,14 +859,10 @@ static void arm_smmu_destroy_domain_context(struct arm_smmu_domain *smmu_domain)
 	arm_smmu_rpm_put(smmu);
 }
 
-static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
+static struct iommu_domain *arm_smmu_domain_alloc_paging(struct device *dev)
 {
 	struct arm_smmu_domain *smmu_domain;
 
-	if (type != IOMMU_DOMAIN_UNMANAGED) {
-		if (using_legacy_binding || type != IOMMU_DOMAIN_DMA)
-			return NULL;
-	}
 	/*
 	 * Allocate the domain and initialise some of its data structures.
 	 * We can't really do anything meaningful until we've added a
@@ -879,6 +875,15 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 	mutex_init(&smmu_domain->init_mutex);
 	spin_lock_init(&smmu_domain->cb_lock);
 
+	if (dev) {
+		struct arm_smmu_master_cfg *cfg = dev_iommu_priv_get(dev);
+
+		if (arm_smmu_init_domain_context(smmu_domain, cfg->smmu, dev)) {
+			kfree(smmu_domain);
+			return NULL;
+		}
+	}
+
 	return &smmu_domain->domain;
 }
 
@@ -1603,7 +1608,7 @@ static struct iommu_ops arm_smmu_ops = {
 	.identity_domain	= &arm_smmu_identity_domain,
 	.blocked_domain		= &arm_smmu_blocked_domain,
 	.capable		= arm_smmu_capable,
-	.domain_alloc		= arm_smmu_domain_alloc,
+	.domain_alloc_paging	= arm_smmu_domain_alloc_paging,
 	.probe_device		= arm_smmu_probe_device,
 	.release_device		= arm_smmu_release_device,
 	.probe_finalize		= arm_smmu_probe_finalize,