Re: [PATCH v7 05/10] arm-smmu-v3/sva: Add SVA domain support

Jean-Philippe Brucker
2022-05-19T16:38:02Z

On Thu, May 19, 2022 at 03:20:42PM +0800, Lu Baolu wrote:
> Add support for domain ops callbacks for an SVA domain.
>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

(I'll try to take some time next cycle to clean up the driver following
this change)

> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 4 ++
> .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 46 +++++++++++++++++++
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 6 +++
> 3 files changed, 56 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..ec77f6a51ff9 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 +758,10 @@ 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)
> {
> 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..6969974ca89e 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 +549,49 @@ 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 mm_struct *mm;
> + struct iommu_sva *handle;
> +
> + if (domain->type != IOMMU_DOMAIN_SVA)
> + return -EINVAL;
> +
> + mm = domain_to_mm(domain);
> + if (WARN_ON(!mm))
> + return -ENODEV;
> +
> + 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 = domain_to_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 6e2cd082c670..4ad3ca70cf89 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2858,6 +2858,12 @@ static struct iommu_ops arm_smmu_ops = {
> .page_response = arm_smmu_page_response,
> .pgsize_bitmap = -1UL, /* Restricted during device attach */
> .owner = THIS_MODULE,
> +#ifdef CONFIG_ARM_SMMU_V3_SVA
> + .sva_domain_ops = &(const struct iommu_domain_ops) {
> + .set_dev_pasid = arm_smmu_sva_attach_dev_pasid,
> + .block_dev_pasid = arm_smmu_sva_detach_dev_pasid,
> + },
> +#endif
> .default_domain_ops = &(const struct iommu_domain_ops) {
> .attach_dev = arm_smmu_attach_dev,
> .map_pages = arm_smmu_map_pages,
> --
> 2.25.1
>