RE: [PATCH v9 07/11] iommu/sva: Refactoring iommu_sva_bind/unbind_device()

[Tian, Kevin]

> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Tuesday, June 21, 2022 10:44 PM
> +struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct
> mm_struct *mm)
> +{
> +	struct iommu_domain *domain;
> +	ioasid_t max_pasids;
> +	int ret = -EINVAL;
> +
> +	/* Allocate mm->pasid if necessary. */

this comment is for iommu_sva_alloc_pasid()

> +	max_pasids = dev->iommu->max_pasids;
> +	if (!max_pasids)
> +		return ERR_PTR(-EOPNOTSUPP);
> +
> +	ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1);
> +	if (ret)
> +		return ERR_PTR(ret);
> +


...
> +void iommu_sva_unbind_device(struct iommu_sva *handle)
> +{
> +	struct device *dev = handle->dev;
> +	struct iommu_domain *domain =
> +			container_of(handle, struct iommu_domain, bond);
> +	ioasid_t pasid = iommu_sva_get_pasid(handle);
> +
> +	mutex_lock(&iommu_sva_lock);
> +	if (refcount_dec_and_test(&domain->bond.users)) {
> +		iommu_detach_device_pasid(domain, dev, pasid);
> +		iommu_domain_free(domain);
> +	}
> +	mutex_unlock(&iommu_sva_lock);
> +}
> +EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
> +
> +u32 iommu_sva_get_pasid(struct iommu_sva *handle)
> +{
> +	struct iommu_domain *domain =
> +			container_of(handle, struct iommu_domain, bond);
> +
> +	return domain->mm->pasid;
> +}
> +EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);

Looks this is only used by unbind_device. Just open code it.