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

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

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
>