Hi Jean,
On 2018/2/22 14:23, Jean-Philippe Brucker wrote:
> @@ -129,7 +439,10 @@ int iommu_sva_device_shutdown(struct device *dev)
> int iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, int *pasid,
> unsigned long flags, void *drvdata)
> {
> + int i, ret;
> + struct io_mm *io_mm = NULL;
> struct iommu_domain *domain;
> + struct iommu_bond *bond = NULL, *tmp;
> struct iommu_param *dev_param = dev->iommu_param;
>
> domain = iommu_get_domain_for_dev(dev);
> @@ -145,7 +458,42 @@ int iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, int *pasid,
> if (flags != (IOMMU_SVA_FEAT_PASID | IOMMU_SVA_FEAT_IOPF))
> return -EINVAL;
>
> - return -ENOSYS; /* TODO */
> + /* If an io_mm already exists, use it */
> + spin_lock(&iommu_sva_lock);
> + idr_for_each_entry(&iommu_pasid_idr, io_mm, i) {
> + if (io_mm->mm != mm || !io_mm_get_locked(io_mm))
> + continue;
> +
> + /* Is it already bound to this device? */
> + list_for_each_entry(tmp, &io_mm->devices, mm_head) {
> + if (tmp->dev != dev)
> + continue;
> +
> + bond = tmp;
> + refcount_inc(&bond->refs);
> + io_mm_put_locked(io_mm);
Should io_mm->pasid still be set to *pasid when the device already bond? so driver can
always get the right pasid if it bond to a mm multi-times, without keeping the pasid itself?
Thanks
Yisheng
> + break;
> + }
> + break;
> + }
> + spin_unlock(&iommu_sva_lock);
> +
> + if (bond)
> + return 0;
> +
> + if (!io_mm) {
> + io_mm = io_mm_alloc(domain, dev, mm);
> + if (IS_ERR(io_mm))
> + return PTR_ERR(io_mm);
> + }
> +
> + ret = io_mm_attach(domain, dev, io_mm, drvdata);
> + if (ret)
> + io_mm_put(io_mm);
> + else
> + *pasid = io_mm->pasid;
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
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