[PATCH v4 3/7] iommu: Detaching pasid by attaching to the blocked_domain

[Yi Liu <yi.l.liu@intel.com>]

The iommu drivers are on the way to detach pasid by attaching to the blocked
domain. However, this cannot be done in one shot. During the transition, iommu
core would select between the remove_dev_pasid op and the blocked domain.

Suggested-by: Kevin Tian <kevin.tian@intel.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 drivers/iommu/iommu.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 819c6e0188d5..6fd4b904f270 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3302,8 +3302,18 @@ static void iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
 				   struct iommu_domain *domain)
 {
 	const struct iommu_ops *ops = dev_iommu_ops(dev);
+	struct iommu_domain *blocked_domain = ops->blocked_domain;
+	int ret = 1;
 
-	ops->remove_dev_pasid(dev, pasid, domain);
+	if (blocked_domain && blocked_domain->ops->set_dev_pasid) {
+		ret = blocked_domain->ops->set_dev_pasid(blocked_domain,
+							 dev, pasid, domain);
+	} else {
+		ops->remove_dev_pasid(dev, pasid, domain);
+		ret = 0;
+	}
+
+	WARN_ON(ret);
 }
 
 static int __iommu_set_group_pasid(struct iommu_domain *domain,
@@ -3361,7 +3371,9 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
 	int ret;
 
 	if (!domain->ops->set_dev_pasid ||
-	    !ops->remove_dev_pasid)
+	    (!ops->remove_dev_pasid &&
+	     (!ops->blocked_domain ||
+	      !ops->blocked_domain->ops->set_dev_pasid)))
 		return -EOPNOTSUPP;
 
 	if (!group)
-- 
2.34.1