[PATCH v1 06/10] iommu/vt-d: Remove DEFER_DEVICE_DOMAIN_INFO

[Lu Baolu]

Allocate and set the per-device iommu private data during iommu device
probe. Add a flag to indicate whether default domain attachment is
deferred. With this refactoring, the dummy DEFER_DEVICE_DOMAIN_INFO
pointer is removed.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel/iommu.c | 122 +++++++++++++++---------------------
 1 file changed, 51 insertions(+), 71 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 185aa38df602..165c890b8304 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -309,19 +309,9 @@ static int iommu_skip_te_disable;
 int intel_iommu_gfx_mapped;
 EXPORT_SYMBOL_GPL(intel_iommu_gfx_mapped);
 
-#define DEFER_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-2))
 struct device_domain_info *get_domain_info(struct device *dev)
 {
-	struct device_domain_info *info;
-
-	if (!dev)
-		return NULL;
-
-	info = dev_iommu_priv_get(dev);
-	if (unlikely(info == DEFER_DEVICE_DOMAIN_INFO))
-		return NULL;
-
-	return info;
+	return dev_iommu_priv_get(dev);
 }
 
 DEFINE_SPINLOCK(device_domain_lock);
@@ -708,11 +698,6 @@ struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
 	return &context[devfn];
 }
 
-static bool attach_deferred(struct device *dev)
-{
-	return dev_iommu_priv_get(dev) == DEFER_DEVICE_DOMAIN_INFO;
-}
-
 /**
  * is_downstream_to_pci_bridge - test if a device belongs to the PCI
  *				 sub-hierarchy of a candidate PCI-PCI bridge
@@ -2426,9 +2411,6 @@ struct dmar_domain *find_domain(struct device *dev)
 	if (unlikely(!dev || !dev->iommu))
 		return NULL;
 
-	if (unlikely(attach_deferred(dev)))
-		return NULL;
-
 	/* No lock here, assumes no domain exit in normal case */
 	info = get_domain_info(dev);
 	if (likely(info))
@@ -2497,66 +2479,20 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 						    struct device *dev,
 						    struct dmar_domain *domain)
 {
-	struct device_domain_info *info;
+	struct device_domain_info *info = get_domain_info(dev);
 	unsigned long flags;
 	int ret;
 
-	info = kzalloc(sizeof(*info), GFP_KERNEL);
-	if (!info)
-		return NULL;
-
-	if (!dev_is_real_dma_subdevice(dev)) {
-		info->bus = bus;
-		info->devfn = devfn;
-		info->segment = iommu->segment;
-	} else {
-		struct pci_dev *pdev = to_pci_dev(dev);
-
-		info->bus = pdev->bus->number;
-		info->devfn = pdev->devfn;
-		info->segment = pci_domain_nr(pdev->bus);
-	}
-
-	info->dev = dev;
-	info->domain = domain;
-	info->iommu = iommu;
-
-	if (dev && dev_is_pci(dev)) {
-		struct pci_dev *pdev = to_pci_dev(info->dev);
-
-		if (ecap_dev_iotlb_support(iommu->ecap) &&
-		    pci_ats_supported(pdev) &&
-		    dmar_find_matched_atsr_unit(pdev))
-			info->ats_supported = 1;
-
-		if (sm_supported(iommu)) {
-			if (pasid_supported(iommu)) {
-				int features = pci_pasid_features(pdev);
-				if (features >= 0)
-					info->pasid_supported = features | 1;
-			}
-
-			if (info->ats_supported && ecap_prs(iommu->ecap) &&
-			    pci_pri_supported(pdev))
-				info->pri_supported = 1;
-		}
-	}
-
 	spin_lock_irqsave(&device_domain_lock, flags);
+	info->domain = domain;
 	spin_lock(&iommu->lock);
 	ret = domain_attach_iommu(domain, iommu);
 	spin_unlock(&iommu->lock);
-
 	if (ret) {
 		spin_unlock_irqrestore(&device_domain_lock, flags);
-		kfree(info);
 		return NULL;
 	}
-
 	list_add(&info->link, &domain->devices);
-	list_add(&info->global, &device_domain_list);
-	if (dev)
-		dev_iommu_priv_set(dev, info);
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 
 	/* PASID table is mandatory for a PCI device in scalable mode. */
@@ -4405,14 +4341,56 @@ static bool intel_iommu_capable(enum iommu_cap cap)
 
 static struct iommu_device *intel_iommu_probe_device(struct device *dev)
 {
+	struct pci_dev *pdev = dev_is_pci(dev) ? to_pci_dev(dev) : NULL;
+	struct device_domain_info *info;
 	struct intel_iommu *iommu;
+	unsigned long flags;
+	u8 bus, devfn;
 
-	iommu = device_to_iommu(dev, NULL, NULL);
+	iommu = device_to_iommu(dev, &bus, &devfn);
 	if (!iommu)
 		return ERR_PTR(-ENODEV);
 
-	if (translation_pre_enabled(iommu))
-		dev_iommu_priv_set(dev, DEFER_DEVICE_DOMAIN_INFO);
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return ERR_PTR(-ENOMEM);
+
+	if (dev_is_real_dma_subdevice(dev)) {
+		info->bus = pdev->bus->number;
+		info->devfn = pdev->devfn;
+		info->segment = pci_domain_nr(pdev->bus);
+	} else {
+		info->bus = bus;
+		info->devfn = devfn;
+		info->segment = iommu->segment;
+	}
+
+	info->dev = dev;
+	info->iommu = iommu;
+	if (dev_is_pci(dev)) {
+		if (ecap_dev_iotlb_support(iommu->ecap) &&
+		    pci_ats_supported(pdev) &&
+		    dmar_find_matched_atsr_unit(pdev))
+			info->ats_supported = 1;
+
+		if (sm_supported(iommu)) {
+			if (pasid_supported(iommu)) {
+				int features = pci_pasid_features(pdev);
+
+				if (features >= 0)
+					info->pasid_supported = features | 1;
+			}
+
+			if (info->ats_supported && ecap_prs(iommu->ecap) &&
+			    pci_pri_supported(pdev))
+				info->pri_supported = 1;
+		}
+	}
+
+	spin_lock_irqsave(&device_domain_lock, flags);
+	list_add(&info->global, &device_domain_list);
+	dev_iommu_priv_set(dev, info);
+	spin_unlock_irqrestore(&device_domain_lock, flags);
 
 	return &iommu->iommu;
 }
@@ -4635,7 +4613,9 @@ intel_iommu_dev_disable_feat(struct device *dev, enum iommu_dev_features feat)
 
 static bool intel_iommu_is_attach_deferred(struct device *dev)
 {
-	return attach_deferred(dev);
+	struct device_domain_info *info = get_domain_info(dev);
+
+	return translation_pre_enabled(info->iommu) && !info->domain;
 }
 
 /*
-- 
2.25.1