[PATCH v12 12/17] arm-smmu-v3/sva: Add SVA domain support

[Lu Baolu]

Add support for SVA domain allocation and provide an SVA-specific
iommu_domain_ops. This implementation is based on the existing SVA
code. Possible cleanup and refactoring are left for incremental
changes later.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
Tested-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   | 13 ++++
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 61 +++++++++++++++++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 21 ++++++-
 3 files changed, 94 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index d2ba86470c42..c9544b656756 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -758,6 +758,9 @@ struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm);
 void arm_smmu_sva_unbind(struct iommu_sva *handle);
 u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle);
 void arm_smmu_sva_notifier_synchronize(void);
+struct iommu_domain *arm_smmu_sva_domain_alloc(void);
+void arm_smmu_sva_block_dev_pasid(struct iommu_domain *domain,
+				  struct device *dev, ioasid_t id);
 #else /* CONFIG_ARM_SMMU_V3_SVA */
 static inline bool arm_smmu_sva_supported(struct arm_smmu_device *smmu)
 {
@@ -803,5 +806,15 @@ static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
 }
 
 static inline void arm_smmu_sva_notifier_synchronize(void) {}
+
+static inline struct iommu_domain *arm_smmu_sva_domain_alloc(void)
+{
+	return NULL;
+}
+
+static inline void arm_smmu_sva_block_dev_pasid(struct iommu_domain *domain,
+						struct device *dev, ioasid_t id)
+{
+}
 #endif /* CONFIG_ARM_SMMU_V3_SVA */
 #endif /* _ARM_SMMU_V3_H */
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index f155d406c5d5..953ba19a1af8 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -549,3 +549,64 @@ void arm_smmu_sva_notifier_synchronize(void)
 	 */
 	mmu_notifier_synchronize();
 }
+
+void arm_smmu_sva_block_dev_pasid(struct iommu_domain *domain,
+				  struct device *dev, ioasid_t id)
+{
+	struct mm_struct *mm = domain->mm;
+	struct arm_smmu_bond *bond = NULL, *t;
+	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+
+	mutex_lock(&sva_lock);
+	list_for_each_entry(t, &master->bonds, list) {
+		if (t->mm == mm) {
+			bond = t;
+			break;
+		}
+	}
+
+	if (!WARN_ON(!bond) && refcount_dec_and_test(&bond->refs)) {
+		list_del(&bond->list);
+		arm_smmu_mmu_notifier_put(bond->smmu_mn);
+		kfree(bond);
+	}
+	mutex_unlock(&sva_lock);
+}
+
+static int arm_smmu_sva_set_dev_pasid(struct iommu_domain *domain,
+				      struct device *dev, ioasid_t id)
+{
+	int ret = 0;
+	struct iommu_sva *handle;
+	struct mm_struct *mm = domain->mm;
+
+	mutex_lock(&sva_lock);
+	handle = __arm_smmu_sva_bind(dev, mm);
+	if (IS_ERR(handle))
+		ret = PTR_ERR(handle);
+	mutex_unlock(&sva_lock);
+
+	return ret;
+}
+
+static void arm_smmu_sva_domain_free(struct iommu_domain *domain)
+{
+	kfree(domain);
+}
+
+static const struct iommu_domain_ops arm_smmu_sva_domain_ops = {
+	.set_dev_pasid		= arm_smmu_sva_set_dev_pasid,
+	.free			= arm_smmu_sva_domain_free
+};
+
+struct iommu_domain *arm_smmu_sva_domain_alloc(void)
+{
+	struct iommu_domain *domain;
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain)
+		return NULL;
+	domain->ops = &arm_smmu_sva_domain_ops;
+
+	return domain;
+}
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 5520a9607758..a27ce693cc65 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2015,9 +2015,25 @@ static int blocking_domain_attach_dev(struct iommu_domain *domain,
 	return 0;
 }
 
+static int blocking_domain_set_dev_pasid(struct iommu_domain *_domain,
+					 struct device *dev, ioasid_t pasid)
+{
+	struct iommu_domain *domain;
+
+	domain = iommu_get_domain_for_dev_pasid(dev, pasid, IOMMU_DOMAIN_SVA);
+	if (IS_ERR(domain))
+		return PTR_ERR(domain);
+
+	if (domain)
+		arm_smmu_sva_block_dev_pasid(domain, dev, pasid);
+
+	return 0;
+}
+
 static struct iommu_domain blocking_domain = {
 	.ops = &(const struct iommu_domain_ops) {
-		.attach_dev	= blocking_domain_attach_dev
+		.attach_dev	= blocking_domain_attach_dev,
+		.set_dev_pasid	= blocking_domain_set_dev_pasid
 	}
 };
 
@@ -2028,6 +2044,9 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 	if (type == IOMMU_DOMAIN_BLOCKED)
 		return &blocking_domain;
 
+	if (type == IOMMU_DOMAIN_SVA)
+		return arm_smmu_sva_domain_alloc();
+
 	if (type != IOMMU_DOMAIN_UNMANAGED &&
 	    type != IOMMU_DOMAIN_DMA &&
 	    type != IOMMU_DOMAIN_DMA_FQ &&
-- 
2.25.1