[PATCH v4 05/13] iommu/vt-d: Prepare intel_iommu_set_dev_pasid() handle replacement

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

To handle domain replacement, the intel_iommu_set_dev_pasid() needs to
keep the old configuration and the prepare for the new setup. This requires
a bit refactoring to prepare for it.

domain_add_dev_pasid() and domain_remove_dev_pasid() are added to add/remove
the dev_pasid_info which represents the association of the pasid/device and
domain. Till now, it's still not ready for replacement yet.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 drivers/iommu/intel/iommu.c | 90 +++++++++++++++++++++++++------------
 1 file changed, 61 insertions(+), 29 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 86000901de46..6bc5ce03c6f5 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4252,8 +4252,8 @@ static int intel_iommu_iotlb_sync_map(struct iommu_domain *domain,
 	return 0;
 }
 
-static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
-					 struct iommu_domain *domain)
+static void domain_remove_dev_pasid(struct iommu_domain *domain,
+				    struct device *dev, ioasid_t pasid)
 {
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
 	struct dev_pasid_info *curr, *dev_pasid = NULL;
@@ -4261,10 +4261,12 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
 	struct dmar_domain *dmar_domain;
 	unsigned long flags;
 
-	if (domain->type == IOMMU_DOMAIN_IDENTITY) {
-		intel_pasid_tear_down_entry(iommu, dev, pasid, false);
+	if (!domain)
+		return;
+
+	/* Identity domain has no meta data for pasid. */
+	if (domain->type == IOMMU_DOMAIN_IDENTITY)
 		return;
-	}
 
 	dmar_domain = to_dmar_domain(domain);
 	spin_lock_irqsave(&dmar_domain->lock, flags);
@@ -4282,8 +4284,54 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
 	domain_detach_iommu(dmar_domain, iommu);
 	intel_iommu_debugfs_remove_dev_pasid(dev_pasid);
 	kfree(dev_pasid);
+}
+
+static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
+					 struct iommu_domain *domain)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct intel_iommu *iommu = info->iommu;
+
 	intel_pasid_tear_down_entry(iommu, dev, pasid, false);
 	intel_drain_pasid_prq(dev, pasid);
+	domain_remove_dev_pasid(domain, dev, pasid);
+}
+
+static struct dev_pasid_info *
+domain_add_dev_pasid(struct iommu_domain *domain,
+		     struct device *dev, ioasid_t pasid)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct intel_iommu *iommu = info->iommu;
+	struct dev_pasid_info *dev_pasid;
+	unsigned long flags;
+	int ret;
+
+	dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
+	if (!dev_pasid)
+		return ERR_PTR(-ENOMEM);
+
+	ret = domain_attach_iommu(dmar_domain, iommu);
+	if (ret)
+		goto out_free;
+
+	ret = cache_tag_assign_domain(dmar_domain, dev, pasid);
+	if (ret)
+		goto out_detach_iommu;
+
+	dev_pasid->dev = dev;
+	dev_pasid->pasid = pasid;
+	spin_lock_irqsave(&dmar_domain->lock, flags);
+	list_add(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
+	spin_unlock_irqrestore(&dmar_domain->lock, flags);
+
+	return dev_pasid;
+out_detach_iommu:
+	domain_detach_iommu(dmar_domain, iommu);
+out_free:
+	kfree(dev_pasid);
+	return ERR_PTR(ret);
 }
 
 static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
@@ -4294,7 +4342,6 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
 	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
 	struct intel_iommu *iommu = info->iommu;
 	struct dev_pasid_info *dev_pasid;
-	unsigned long flags;
 	int ret;
 
 	if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
@@ -4310,17 +4357,9 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
 	if (ret)
 		return ret;
 
-	dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
-	if (!dev_pasid)
-		return -ENOMEM;
-
-	ret = domain_attach_iommu(dmar_domain, iommu);
-	if (ret)
-		goto out_free;
-
-	ret = cache_tag_assign_domain(dmar_domain, dev, pasid);
-	if (ret)
-		goto out_detach_iommu;
+	dev_pasid = domain_add_dev_pasid(domain, dev, pasid);
+	if (IS_ERR(dev_pasid))
+		return PTR_ERR(dev_pasid);
 
 	if (dmar_domain->use_first_level)
 		ret = domain_setup_first_level(iommu, dmar_domain,
@@ -4329,24 +4368,17 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
 		ret = intel_pasid_setup_second_level(iommu, dmar_domain,
 						     dev, pasid);
 	if (ret)
-		goto out_unassign_tag;
+		goto out_remove_dev_pasid;
 
-	dev_pasid->dev = dev;
-	dev_pasid->pasid = pasid;
-	spin_lock_irqsave(&dmar_domain->lock, flags);
-	list_add(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
-	spin_unlock_irqrestore(&dmar_domain->lock, flags);
+	domain_remove_dev_pasid(old, dev, pasid);
 
 	if (domain->type & __IOMMU_DOMAIN_PAGING)
 		intel_iommu_debugfs_create_dev_pasid(dev_pasid);
 
 	return 0;
-out_unassign_tag:
-	cache_tag_unassign_domain(dmar_domain, dev, pasid);
-out_detach_iommu:
-	domain_detach_iommu(dmar_domain, iommu);
-out_free:
-	kfree(dev_pasid);
+
+out_remove_dev_pasid:
+	domain_remove_dev_pasid(domain, dev, pasid);
 	return ret;
 }
 
-- 
2.34.1