1 files changed, 110 insertions, 77 deletions

diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index b85ce6310ddb..ecd41fb03e5a 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -48,6 +48,7 @@ struct viommu_dev {
 	u64				pgsize_bitmap;
 	u32				first_domain;
 	u32				last_domain;
+	u32				identity_domain_id;
 	/* Supported MAP flags */
 	u32				map_flags;
 	u32				probe_size;
@@ -62,7 +63,6 @@ struct viommu_mapping {
 struct viommu_domain {
 	struct iommu_domain		domain;
 	struct viommu_dev		*viommu;
-	struct mutex			mutex; /* protects viommu pointer */
 	unsigned int			id;
 	u32				map_flags;
 
@@ -70,7 +70,6 @@ struct viommu_domain {
 	struct rb_root_cached		mappings;
 
 	unsigned long			nr_endpoints;
-	bool				bypass;
 };
 
 struct viommu_endpoint {
@@ -97,6 +96,8 @@ struct viommu_event {
 	};
 };
 
+static struct viommu_domain viommu_identity_domain;
+
 #define to_viommu_domain(domain)	\
 	container_of(domain, struct viommu_domain, domain)
 
@@ -305,6 +306,22 @@ out_unlock:
 	return ret;
 }
 
+static int viommu_send_attach_req(struct viommu_dev *viommu, struct device *dev,
+				  struct virtio_iommu_req_attach *req)
+{
+	int ret;
+	unsigned int i;
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+	for (i = 0; i < fwspec->num_ids; i++) {
+		req->endpoint = cpu_to_le32(fwspec->ids[i]);
+		ret = viommu_send_req_sync(viommu, req, sizeof(*req));
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
 /*
  * viommu_add_mapping - add a mapping to the internal tree
  *
@@ -637,71 +654,45 @@ static void viommu_event_handler(struct virtqueue *vq)
 
 /* IOMMU API */
 
-static struct iommu_domain *viommu_domain_alloc(unsigned type)
+static struct iommu_domain *viommu_domain_alloc_paging(struct device *dev)
 {
+	struct viommu_endpoint *vdev = dev_iommu_priv_get(dev);
+	struct viommu_dev *viommu = vdev->viommu;
+	unsigned long viommu_page_size;
 	struct viommu_domain *vdomain;
-
-	if (type != IOMMU_DOMAIN_UNMANAGED &&
-	    type != IOMMU_DOMAIN_DMA &&
-	    type != IOMMU_DOMAIN_IDENTITY)
-		return NULL;
-
-	vdomain = kzalloc(sizeof(*vdomain), GFP_KERNEL);
-	if (!vdomain)
-		return NULL;
-
-	mutex_init(&vdomain->mutex);
-	spin_lock_init(&vdomain->mappings_lock);
-	vdomain->mappings = RB_ROOT_CACHED;
-
-	return &vdomain->domain;
-}
-
-static int viommu_domain_finalise(struct viommu_endpoint *vdev,
-				  struct iommu_domain *domain)
-{
 	int ret;
-	unsigned long viommu_page_size;
-	struct viommu_dev *viommu = vdev->viommu;
-	struct viommu_domain *vdomain = to_viommu_domain(domain);
 
 	viommu_page_size = 1UL << __ffs(viommu->pgsize_bitmap);
 	if (viommu_page_size > PAGE_SIZE) {
 		dev_err(vdev->dev,
 			"granule 0x%lx larger than system page size 0x%lx\n",
 			viommu_page_size, PAGE_SIZE);
-		return -ENODEV;
+		return ERR_PTR(-ENODEV);
 	}
 
-	ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
-			      viommu->last_domain, GFP_KERNEL);
-	if (ret < 0)
-		return ret;
+	vdomain = kzalloc(sizeof(*vdomain), GFP_KERNEL);
+	if (!vdomain)
+		return ERR_PTR(-ENOMEM);
 
-	vdomain->id		= (unsigned int)ret;
+	spin_lock_init(&vdomain->mappings_lock);
+	vdomain->mappings = RB_ROOT_CACHED;
 
-	domain->pgsize_bitmap	= viommu->pgsize_bitmap;
-	domain->geometry	= viommu->geometry;
+	ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
+			      viommu->last_domain, GFP_KERNEL);
+	if (ret < 0) {
+		kfree(vdomain);
+		return ERR_PTR(ret);
+	}
 
-	vdomain->map_flags	= viommu->map_flags;
-	vdomain->viommu		= viommu;
+	vdomain->id = (unsigned int)ret;
 
-	if (domain->type == IOMMU_DOMAIN_IDENTITY) {
-		if (virtio_has_feature(viommu->vdev,
-				       VIRTIO_IOMMU_F_BYPASS_CONFIG)) {
-			vdomain->bypass = true;
-			return 0;
-		}
+	vdomain->domain.pgsize_bitmap = viommu->pgsize_bitmap;
+	vdomain->domain.geometry = viommu->geometry;
 
-		ret = viommu_domain_map_identity(vdev, vdomain);
-		if (ret) {
-			ida_free(&viommu->domain_ids, vdomain->id);
-			vdomain->viommu = NULL;
-			return ret;
-		}
-	}
+	vdomain->map_flags = viommu->map_flags;
+	vdomain->viommu = viommu;
 
-	return 0;
+	return &vdomain->domain;
 }
 
 static void viommu_domain_free(struct iommu_domain *domain)
@@ -717,29 +708,37 @@ static void viommu_domain_free(struct iommu_domain *domain)
 	kfree(vdomain);
 }
 
+static struct iommu_domain *viommu_domain_alloc_identity(struct device *dev)
+{
+	struct viommu_endpoint *vdev = dev_iommu_priv_get(dev);
+	struct iommu_domain *domain;
+	int ret;
+
+	if (virtio_has_feature(vdev->viommu->vdev,
+			       VIRTIO_IOMMU_F_BYPASS_CONFIG))
+		return &viommu_identity_domain.domain;
+
+	domain = viommu_domain_alloc_paging(dev);
+	if (IS_ERR(domain))
+		return domain;
+
+	ret = viommu_domain_map_identity(vdev, to_viommu_domain(domain));
+	if (ret) {
+		viommu_domain_free(domain);
+		return ERR_PTR(ret);
+	}
+	return domain;
+}
+
 static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 {
-	int i;
 	int ret = 0;
 	struct virtio_iommu_req_attach req;
-	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 	struct viommu_endpoint *vdev = dev_iommu_priv_get(dev);
 	struct viommu_domain *vdomain = to_viommu_domain(domain);
 
-	mutex_lock(&vdomain->mutex);
-	if (!vdomain->viommu) {
-		/*
-		 * Properly initialize the domain now that we know which viommu
-		 * owns it.
-		 */
-		ret = viommu_domain_finalise(vdev, domain);
-	} else if (vdomain->viommu != vdev->viommu) {
-		ret = -EINVAL;
-	}
-	mutex_unlock(&vdomain->mutex);
-
-	if (ret)
-		return ret;
+	if (vdomain->viommu != vdev->viommu)
+		return -EINVAL;
 
 	/*
 	 * In the virtio-iommu device, when attaching the endpoint to a new
@@ -761,16 +760,9 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		.domain		= cpu_to_le32(vdomain->id),
 	};
 
-	if (vdomain->bypass)
-		req.flags |= cpu_to_le32(VIRTIO_IOMMU_ATTACH_F_BYPASS);
-
-	for (i = 0; i < fwspec->num_ids; i++) {
-		req.endpoint = cpu_to_le32(fwspec->ids[i]);
-
-		ret = viommu_send_req_sync(vdomain->viommu, &req, sizeof(req));
-		if (ret)
-			return ret;
-	}
+	ret = viommu_send_attach_req(vdomain->viommu, dev, &req);
+	if (ret)
+		return ret;
 
 	if (!vdomain->nr_endpoints) {
 		/*
@@ -788,6 +780,40 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	return 0;
 }
 
+static int viommu_attach_identity_domain(struct iommu_domain *domain,
+					 struct device *dev)
+{
+	int ret = 0;
+	struct virtio_iommu_req_attach req;
+	struct viommu_endpoint *vdev = dev_iommu_priv_get(dev);
+	struct viommu_domain *vdomain = to_viommu_domain(domain);
+
+	req = (struct virtio_iommu_req_attach) {
+		.head.type	= VIRTIO_IOMMU_T_ATTACH,
+		.domain		= cpu_to_le32(vdev->viommu->identity_domain_id),
+		.flags          = cpu_to_le32(VIRTIO_IOMMU_ATTACH_F_BYPASS),
+	};
+
+	ret = viommu_send_attach_req(vdev->viommu, dev, &req);
+	if (ret)
+		return ret;
+
+	if (vdev->vdomain)
+		vdev->vdomain->nr_endpoints--;
+	vdomain->nr_endpoints++;
+	vdev->vdomain = vdomain;
+	return 0;
+}
+
+static struct viommu_domain viommu_identity_domain = {
+	.domain = {
+		.type = IOMMU_DOMAIN_IDENTITY,
+		.ops = &(const struct iommu_domain_ops) {
+			.attach_dev = viommu_attach_identity_domain,
+		},
+	},
+};
+
 static void viommu_detach_dev(struct viommu_endpoint *vdev)
 {
 	int i;
@@ -1062,7 +1088,8 @@ static bool viommu_capable(struct device *dev, enum iommu_cap cap)
 
 static struct iommu_ops viommu_ops = {
 	.capable		= viommu_capable,
-	.domain_alloc		= viommu_domain_alloc,
+	.domain_alloc_identity	= viommu_domain_alloc_identity,
+	.domain_alloc_paging	= viommu_domain_alloc_paging,
 	.probe_device		= viommu_probe_device,
 	.release_device		= viommu_release_device,
 	.device_group		= viommu_device_group,
@@ -1184,6 +1211,12 @@ static int viommu_probe(struct virtio_device *vdev)
 	if (virtio_has_feature(vdev, VIRTIO_IOMMU_F_MMIO))
 		viommu->map_flags |= VIRTIO_IOMMU_MAP_F_MMIO;
 
+	/* Reserve an ID to use as the bypass domain */
+	if (virtio_has_feature(viommu->vdev, VIRTIO_IOMMU_F_BYPASS_CONFIG)) {
+		viommu->identity_domain_id = viommu->first_domain;
+		viommu->first_domain++;
+	}
+
 	viommu_ops.pgsize_bitmap = viommu->pgsize_bitmap;
 
 	virtio_device_ready(vdev);