1 files changed, 27 insertions, 19 deletions

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 07c47a7088be..771709d1dfff 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -85,6 +85,7 @@ struct iommu_cmd {
 struct kmem_cache *amd_iommu_irq_cache;
 
 static void detach_device(struct device *dev);
+static int domain_enable_v2(struct protection_domain *domain, int pasids);
 
 /****************************************************************************
  *
@@ -2450,11 +2451,10 @@ void amd_iommu_domain_direct_map(struct iommu_domain *dom)
 }
 EXPORT_SYMBOL(amd_iommu_domain_direct_map);
 
-int amd_iommu_domain_enable_v2(struct iommu_domain *dom, int pasids)
+/* Note: This function expects iommu_domain->lock to be held prior calling the function. */
+static int domain_enable_v2(struct protection_domain *domain, int pasids)
 {
-	struct protection_domain *domain = to_pdomain(dom);
-	unsigned long flags;
-	int levels, ret;
+	int levels;
 
 	/* Number of GCR3 table levels required */
 	for (levels = 0; (pasids - 1) & ~0x1ff; pasids >>= 9)
@@ -2463,7 +2463,25 @@ int amd_iommu_domain_enable_v2(struct iommu_domain *dom, int pasids)
 	if (levels > amd_iommu_max_glx_val)
 		return -EINVAL;
 
-	spin_lock_irqsave(&domain->lock, flags);
+	domain->gcr3_tbl = (void *)get_zeroed_page(GFP_ATOMIC);
+	if (domain->gcr3_tbl == NULL)
+		return -ENOMEM;
+
+	domain->glx      = levels;
+	domain->flags   |= PD_IOMMUV2_MASK;
+
+	amd_iommu_domain_update(domain);
+
+	return 0;
+}
+
+int amd_iommu_domain_enable_v2(struct iommu_domain *dom, int pasids)
+{
+	struct protection_domain *pdom = to_pdomain(dom);
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&pdom->lock, flags);
 
 	/*
 	 * Save us all sanity checks whether devices already in the
@@ -2471,24 +2489,14 @@ int amd_iommu_domain_enable_v2(struct iommu_domain *dom, int pasids)
 	 * devices attached when it is switched into IOMMUv2 mode.
 	 */
 	ret = -EBUSY;
-	if (domain->dev_cnt > 0 || domain->flags & PD_IOMMUV2_MASK)
-		goto out;
-
-	ret = -ENOMEM;
-	domain->gcr3_tbl = (void *)get_zeroed_page(GFP_ATOMIC);
-	if (domain->gcr3_tbl == NULL)
+	if (pdom->dev_cnt > 0 || pdom->flags & PD_IOMMUV2_MASK)
 		goto out;
 
-	domain->glx      = levels;
-	domain->flags   |= PD_IOMMUV2_MASK;
-
-	amd_iommu_domain_update(domain);
-
-	ret = 0;
+	if (!pdom->gcr3_tbl)
+		ret = domain_enable_v2(pdom, pasids);
 
 out:
-	spin_unlock_irqrestore(&domain->lock, flags);
-
+	spin_unlock_irqrestore(&pdom->lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(amd_iommu_domain_enable_v2);