Re: [PATCH v5 07/12] arm-smmu-v3/sva: Add SVA domain support
From: Baolu Lu
Date: Thu May 05 2022 - 03:09:18 EST
On 2022/5/4 02:12, Jean-Philippe Brucker wrote:
On Mon, May 02, 2022 at 09:48:37AM +0800, Lu Baolu wrote:
Add support for SVA domain allocation and provide an SVA-specific
iommu_domain_ops.
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 14 +++++++
.../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 42 +++++++++++++++++++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 21 ++++++++++
3 files changed, 77 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 cd48590ada30..7631c00fdcbd 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -759,6 +759,10 @@ 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);
+int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t id);
+void arm_smmu_sva_detach_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)
{
@@ -804,5 +808,15 @@ static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
}
static inline void arm_smmu_sva_notifier_synchronize(void) {}
+
+static inline int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t id)
+{
+ return -ENODEV;
+}
+
+static inline void arm_smmu_sva_detach_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 c623dae1e115..3b843cd3ed67 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
@@ -541,3 +541,45 @@ void arm_smmu_sva_notifier_synchronize(void)
*/
mmu_notifier_synchronize();
}
+
+int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t id)
+{
+ int ret = 0;
+ struct iommu_sva *handle;
+ struct mm_struct *mm = iommu_sva_domain_mm(domain);
+
+ if (domain->type != IOMMU_DOMAIN_SVA || !mm)
We wouldn't get that far with a non-SVA domain since iommu_sva_domain_mm()
would dereference a NULL pointer. Could you move it after the domain->type
check, and maybe add a WARN_ON()? It could help catch issues in future
API changes.
Sure. I will make it like this,
int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
struct device *dev, ioasid_t id)
{
int ret = 0;
struct mm_struct *mm;
struct iommu_sva *handle;
if (domain->type != IOMMU_DOMAIN_SVA)
return -EINVAL;
mm = iommu_sva_domain_mm(domain);
if (WARN_ON(!mm))
return -ENODEV;
... ...
+ return -EINVAL;
+
+ 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;
+}
+
+void arm_smmu_sva_detach_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t id)
+{
+ struct arm_smmu_bond *bond = NULL, *t;
+ struct mm_struct *mm = iommu_sva_domain_mm(domain);
+ 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);
+}
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 afc63fce6107..bd80de0bad98 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1995,10 +1995,31 @@ static bool arm_smmu_capable(enum iommu_cap cap)
}
}
+static void arm_smmu_sva_domain_free(struct iommu_domain *domain)
+{
+ kfree(domain);
+}
+
+static const struct iommu_domain_ops arm_smmu_sva_domain_ops = {
+ .attach_dev_pasid = arm_smmu_sva_attach_dev_pasid,
+ .detach_dev_pasid = arm_smmu_sva_detach_dev_pasid,
+ .free = arm_smmu_sva_domain_free,
+};
+
static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
{
struct arm_smmu_domain *smmu_domain;
+ if (type == IOMMU_DOMAIN_SVA) {
+ struct iommu_domain *domain;
+
+ domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+ if (domain)
+ domain->ops = &arm_smmu_sva_domain_ops;
+
+ return domain;
+ }
+
I'd prefer moving all of this to arm-smmu-v3-sva.c and just call
arm_smmu_sva_domain_alloc() here
Sure.
Otherwise the patch looks fine. I'll rework the driver when I find some
time, because we can now remove arm_smmu_bond and move smmu_mn to the SVA
domain, maybe also remove sva_lock but I haven't thought it through.
Yes. Intel SVA code also needs further cleanup. It's in my non-urgent
task list.
Thanks,
Jean
if (type != IOMMU_DOMAIN_UNMANAGED &&
type != IOMMU_DOMAIN_DMA &&
type != IOMMU_DOMAIN_DMA_FQ &&
--
2.25.1
Best regards,
baolu