[PATCH v14 08/13] arm-smmu-v3/sva: Add SVA domain support

From: Lu Baolu
Date: Fri Sep 23 2022 - 20:19:38 EST


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>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Tested-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 14 +++++
.../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 61 +++++++++++++++++++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 +++++
3 files changed, 90 insertions(+)

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..5aa853e98d38 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_remove_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 +806,16 @@ 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_remove_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..503f2b79d11a 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_remove_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 625fb21577ed..373ea910ad2f 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2009,6 +2009,9 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
{
struct arm_smmu_domain *smmu_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 &&
@@ -2818,6 +2821,17 @@ static int arm_smmu_dev_disable_feature(struct device *dev,
}
}

+static void arm_smmu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+{
+ struct iommu_domain *domain;
+
+ domain = iommu_get_domain_for_dev_pasid(dev, pasid, IOMMU_DOMAIN_SVA);
+ if (WARN_ON(IS_ERR(domain)) || !domain)
+ return;
+
+ arm_smmu_sva_remove_dev_pasid(domain, dev, pasid);
+}
+
static struct iommu_ops arm_smmu_ops = {
.capable = arm_smmu_capable,
.domain_alloc = arm_smmu_domain_alloc,
@@ -2826,6 +2840,7 @@ static struct iommu_ops arm_smmu_ops = {
.device_group = arm_smmu_device_group,
.of_xlate = arm_smmu_of_xlate,
.get_resv_regions = arm_smmu_get_resv_regions,
+ .remove_dev_pasid = arm_smmu_remove_dev_pasid,
.dev_enable_feat = arm_smmu_dev_enable_feature,
.dev_disable_feat = arm_smmu_dev_disable_feature,
.sva_bind = arm_smmu_sva_bind,
--
2.34.1