iommu/vt-d: Add get_domain_info() helper

Add a get_domain_info() helper to retrieve the valid per-device
iommu private data.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200516062101.29541-10-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 27 insertions, 13 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 80d0bd561bdd..a13b723ca38d 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -365,6 +365,21 @@ EXPORT_SYMBOL_GPL(intel_iommu_gfx_mapped);
 
 #define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))
 #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->archdata.iommu;
+	if (unlikely(info == DUMMY_DEVICE_DOMAIN_INFO ||
+		     info == DEFER_DEVICE_DOMAIN_INFO))
+		return NULL;
+
+	return info;
+}
+
 DEFINE_SPINLOCK(device_domain_lock);
 static LIST_HEAD(device_domain_list);
 
@@ -2429,7 +2444,7 @@ struct dmar_domain *find_domain(struct device *dev)
 		dev = &pci_real_dma_dev(to_pci_dev(dev))->dev;
 
 	/* No lock here, assumes no domain exit in normal case */
-	info = dev->archdata.iommu;
+	info = get_domain_info(dev);
 	if (likely(info))
 		return info->domain;
 
@@ -5012,9 +5027,8 @@ static void dmar_remove_one_dev_info(struct device *dev)
 	unsigned long flags;
 
 	spin_lock_irqsave(&device_domain_lock, flags);
-	info = dev->archdata.iommu;
-	if (info && info != DEFER_DEVICE_DOMAIN_INFO
-	    && info != DUMMY_DEVICE_DOMAIN_INFO)
+	info = get_domain_info(dev);
+	if (info)
 		__dmar_remove_one_dev_info(info);
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 }
@@ -5104,7 +5118,7 @@ static void intel_iommu_domain_free(struct iommu_domain *domain)
 static inline bool
 is_aux_domain(struct device *dev, struct iommu_domain *domain)
 {
-	struct device_domain_info *info = dev->archdata.iommu;
+	struct device_domain_info *info = get_domain_info(dev);
 
 	return info && info->auxd_enabled &&
 			domain->type == IOMMU_DOMAIN_UNMANAGED;
@@ -5113,7 +5127,7 @@ is_aux_domain(struct device *dev, struct iommu_domain *domain)
 static void auxiliary_link_device(struct dmar_domain *domain,
 				  struct device *dev)
 {
-	struct device_domain_info *info = dev->archdata.iommu;
+	struct device_domain_info *info = get_domain_info(dev);
 
 	assert_spin_locked(&device_domain_lock);
 	if (WARN_ON(!info))
@@ -5126,7 +5140,7 @@ static void auxiliary_link_device(struct dmar_domain *domain,
 static void auxiliary_unlink_device(struct dmar_domain *domain,
 				    struct device *dev)
 {
-	struct device_domain_info *info = dev->archdata.iommu;
+	struct device_domain_info *info = get_domain_info(dev);
 
 	assert_spin_locked(&device_domain_lock);
 	if (WARN_ON(!info))
@@ -5214,7 +5228,7 @@ static void aux_domain_remove_dev(struct dmar_domain *domain,
 		return;
 
 	spin_lock_irqsave(&device_domain_lock, flags);
-	info = dev->archdata.iommu;
+	info = get_domain_info(dev);
 	iommu = info->iommu;
 
 	auxiliary_unlink_device(domain, dev);
@@ -5404,7 +5418,7 @@ intel_iommu_sva_invalidate(struct iommu_domain *domain, struct device *dev,
 
 	spin_lock_irqsave(&device_domain_lock, flags);
 	spin_lock(&iommu->lock);
-	info = dev->archdata.iommu;
+	info = get_domain_info(dev);
 	if (!info) {
 		ret = -EINVAL;
 		goto out_unlock;
@@ -5768,7 +5782,7 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev)
 	spin_lock(&iommu->lock);
 
 	ret = -EINVAL;
-	info = dev->archdata.iommu;
+	info = get_domain_info(dev);
 	if (!info || !info->pasid_supported)
 		goto out;
 
@@ -5864,7 +5878,7 @@ static int intel_iommu_enable_auxd(struct device *dev)
 		return -ENODEV;
 
 	spin_lock_irqsave(&device_domain_lock, flags);
-	info = dev->archdata.iommu;
+	info = get_domain_info(dev);
 	info->auxd_enabled = 1;
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 
@@ -5877,7 +5891,7 @@ static int intel_iommu_disable_auxd(struct device *dev)
 	unsigned long flags;
 
 	spin_lock_irqsave(&device_domain_lock, flags);
-	info = dev->archdata.iommu;
+	info = get_domain_info(dev);
 	if (!WARN_ON(!info))
 		info->auxd_enabled = 0;
 	spin_unlock_irqrestore(&device_domain_lock, flags);
@@ -5954,7 +5968,7 @@ intel_iommu_dev_disable_feat(struct device *dev, enum iommu_dev_features feat)
 static bool
 intel_iommu_dev_feat_enabled(struct device *dev, enum iommu_dev_features feat)
 {
-	struct device_domain_info *info = dev->archdata.iommu;
+	struct device_domain_info *info = get_domain_info(dev);
 
 	if (feat == IOMMU_DEV_FEAT_AUX)
 		return scalable_mode_support() && info && info->auxd_enabled;