3 files changed, 36 insertions, 4 deletions

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 3b6c6332b09f..38509e1019e9 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -46,6 +46,7 @@ extern int amd_iommu_gpt_level;
 extern unsigned long amd_iommu_pgsize_bitmap;
 
 /* Protection domain ops */
+void amd_iommu_init_identity_domain(void);
 struct protection_domain *protection_domain_alloc(unsigned int type, int nid);
 void protection_domain_free(struct protection_domain *domain);
 struct iommu_domain *amd_iommu_domain_alloc_sva(struct device *dev,
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 7c883be22559..45fdba48d54d 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -2164,6 +2164,9 @@ static int __init amd_iommu_init_pci(void)
 	struct amd_iommu_pci_seg *pci_seg;
 	int ret;
 
+	/* Init global identity domain before registering IOMMU */
+	amd_iommu_init_identity_domain();
+
 	for_each_iommu(iommu) {
 		ret = iommu_init_pci(iommu);
 		if (ret) {
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 671131c22d9d..477aaf76b7ad 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -74,6 +74,9 @@ struct kmem_cache *amd_iommu_irq_cache;
 
 static void detach_device(struct device *dev);
 
+static int amd_iommu_attach_device(struct iommu_domain *dom,
+				   struct device *dev);
+
 static void set_dte_entry(struct amd_iommu *iommu,
 			  struct iommu_dev_data *dev_data);
 
@@ -2263,6 +2266,14 @@ void protection_domain_free(struct protection_domain *domain)
 	kfree(domain);
 }
 
+static void protection_domain_init(struct protection_domain *domain, int nid)
+{
+	spin_lock_init(&domain->lock);
+	INIT_LIST_HEAD(&domain->dev_list);
+	INIT_LIST_HEAD(&domain->dev_data_list);
+	domain->iop.pgtbl.cfg.amd.nid = nid;
+}
+
 struct protection_domain *protection_domain_alloc(unsigned int type, int nid)
 {
 	struct protection_domain *domain;
@@ -2277,10 +2288,7 @@ struct protection_domain *protection_domain_alloc(unsigned int type, int nid)
 		return NULL;
 	}
 
-	spin_lock_init(&domain->lock);
-	INIT_LIST_HEAD(&domain->dev_list);
-	INIT_LIST_HEAD(&domain->dev_data_list);
-	domain->iop.pgtbl.cfg.amd.nid = nid;
+	protection_domain_init(domain, nid);
 
 	return domain;
 }
@@ -2471,6 +2479,25 @@ static struct iommu_domain blocked_domain = {
 	}
 };
 
+static struct protection_domain identity_domain;
+
+static const struct iommu_domain_ops identity_domain_ops = {
+	.attach_dev = amd_iommu_attach_device,
+};
+
+void amd_iommu_init_identity_domain(void)
+{
+	struct iommu_domain *domain = &identity_domain.domain;
+
+	domain->type = IOMMU_DOMAIN_IDENTITY;
+	domain->ops = &identity_domain_ops;
+	domain->owner = &amd_iommu_ops;
+
+	identity_domain.id = domain_id_alloc();
+
+	protection_domain_init(&identity_domain, NUMA_NO_NODE);
+}
+
 static int amd_iommu_attach_device(struct iommu_domain *dom,
 				   struct device *dev)
 {
@@ -2869,6 +2896,7 @@ static int amd_iommu_dev_disable_feature(struct device *dev,
 const struct iommu_ops amd_iommu_ops = {
 	.capable = amd_iommu_capable,
 	.blocked_domain = &blocked_domain,
+	.identity_domain = &identity_domain.domain,
 	.domain_alloc = amd_iommu_domain_alloc,
 	.domain_alloc_user = amd_iommu_domain_alloc_user,
 	.domain_alloc_sva = amd_iommu_domain_alloc_sva,