[PATCH v1 12/14] iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTED type of allocations

[Nicolin Chen <nicolinc@nvidia.com>]

Add domain allocation support for IOMMU_DOMAIN_NESTED type. This includes
the "finalise" part to log in the user space Stream Table Entry info.

Co-developed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 38 +++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 5ff74edfbd68..1f318b5e0921 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2214,6 +2214,19 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain,
 		return 0;
 	}
 
+	if (domain->type == IOMMU_DOMAIN_NESTED) {
+		if (!(smmu->features & ARM_SMMU_FEAT_TRANS_S1) ||
+		    !(smmu->features & ARM_SMMU_FEAT_TRANS_S2)) {
+			dev_dbg(smmu->dev, "does not implement two stages\n");
+			return -EINVAL;
+		}
+		smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
+		smmu_domain->s1_cfg.s1fmt = user_cfg->s1fmt;
+		smmu_domain->s1_cfg.s1cdmax = user_cfg->s1cdmax;
+		smmu_domain->s1_cfg.cdcfg.cdtab_dma = user_cfg->s1ctxptr;
+		return 0;
+	}
+
 	if (user_cfg_s2 && !(smmu->features & ARM_SMMU_FEAT_TRANS_S2))
 		return -EINVAL;
 	if (user_cfg_s2)
@@ -2863,6 +2876,11 @@ static void arm_smmu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
 	arm_smmu_sva_remove_dev_pasid(domain, dev, pasid);
 }
 
+static const struct iommu_domain_ops arm_smmu_nested_domain_ops = {
+	.attach_dev		= arm_smmu_attach_dev,
+	.free			= arm_smmu_domain_free,
+};
+
 static struct iommu_domain *
 __arm_smmu_domain_alloc(unsigned type,
 			struct arm_smmu_domain *s2,
@@ -2877,11 +2895,15 @@ __arm_smmu_domain_alloc(unsigned type,
 		return arm_smmu_sva_domain_alloc();
 
 	if (type != IOMMU_DOMAIN_UNMANAGED &&
+	    type != IOMMU_DOMAIN_NESTED &&
 	    type != IOMMU_DOMAIN_DMA &&
 	    type != IOMMU_DOMAIN_DMA_FQ &&
 	    type != IOMMU_DOMAIN_IDENTITY)
 		return NULL;
 
+	if (s2 && s2->stage != ARM_SMMU_DOMAIN_S2)
+		return NULL;
+
 	/*
 	 * Allocate the domain and initialise some of its data structures.
 	 * We can't really finalise the domain unless a master is given.
@@ -2889,10 +2911,14 @@ __arm_smmu_domain_alloc(unsigned type,
 	smmu_domain = kzalloc(sizeof(*smmu_domain), GFP_KERNEL);
 	if (!smmu_domain)
 		return NULL;
+	smmu_domain->s2 = s2;
 	domain = &smmu_domain->domain;
 
 	domain->type = type;
-	domain->ops = arm_smmu_ops.default_domain_ops;
+	if (s2)
+		domain->ops = &arm_smmu_nested_domain_ops;
+	else
+		domain->ops = arm_smmu_ops.default_domain_ops;
 
 	mutex_init(&smmu_domain->init_mutex);
 	INIT_LIST_HEAD(&smmu_domain->devices);
@@ -2923,8 +2949,16 @@ arm_smmu_domain_alloc_user(struct device *dev, struct iommu_domain *parent,
 	const struct iommu_hwpt_arm_smmuv3 *user_cfg = user_data;
 	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
 	unsigned type = IOMMU_DOMAIN_UNMANAGED;
+	struct arm_smmu_domain *s2 = NULL;
+
+	if (parent) {
+		if (parent->ops != arm_smmu_ops.default_domain_ops)
+			return NULL;
+		type = IOMMU_DOMAIN_NESTED;
+		s2 = to_smmu_domain(parent);
+	}
 
-	return __arm_smmu_domain_alloc(type, NULL, master, user_cfg);
+	return __arm_smmu_domain_alloc(type, s2, master, user_cfg);
 }
 
 static struct iommu_ops arm_smmu_ops = {
-- 
2.39.2