1 files changed, 83 insertions, 30 deletions

diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index 922cd1fe7ec2..6f1010da221c 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -3,38 +3,91 @@
  */
 #include "iommufd_private.h"
 
-struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
-					     size_t size,
-					     enum iommufd_object_type type)
+/* Driver should use a per-structure helper in include/linux/iommufd.h */
+int _iommufd_object_depend(struct iommufd_object *obj_dependent,
+			   struct iommufd_object *obj_depended)
 {
-	struct iommufd_object *obj;
+	/* Reject self dependency that dead locks */
+	if (obj_dependent == obj_depended)
+		return -EINVAL;
+	/* Only support dependency between two objects of the same type */
+	if (obj_dependent->type != obj_depended->type)
+		return -EINVAL;
+
+	refcount_inc(&obj_depended->users);
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(_iommufd_object_depend, "IOMMUFD");
+
+/* Driver should use a per-structure helper in include/linux/iommufd.h */
+void _iommufd_object_undepend(struct iommufd_object *obj_dependent,
+			      struct iommufd_object *obj_depended)
+{
+	if (WARN_ON_ONCE(obj_dependent == obj_depended ||
+			 obj_dependent->type != obj_depended->type))
+		return;
+
+	refcount_dec(&obj_depended->users);
+}
+EXPORT_SYMBOL_NS_GPL(_iommufd_object_undepend, "IOMMUFD");
+
+/*
+ * Allocate an @offset to return to user space to use for an mmap() syscall
+ *
+ * Driver should use a per-structure helper in include/linux/iommufd.h
+ */
+int _iommufd_alloc_mmap(struct iommufd_ctx *ictx, struct iommufd_object *owner,
+			phys_addr_t mmio_addr, size_t length,
+			unsigned long *offset)
+{
+	struct iommufd_mmap *immap;
+	unsigned long startp;
 	int rc;
 
-	obj = kzalloc(size, GFP_KERNEL_ACCOUNT);
-	if (!obj)
-		return ERR_PTR(-ENOMEM);
-	obj->type = type;
-	/* Starts out bias'd by 1 until it is removed from the xarray */
-	refcount_set(&obj->shortterm_users, 1);
-	refcount_set(&obj->users, 1);
+	if (!PAGE_ALIGNED(mmio_addr))
+		return -EINVAL;
+	if (!length || !PAGE_ALIGNED(length))
+		return -EINVAL;
 
-	/*
-	 * Reserve an ID in the xarray but do not publish the pointer yet since
-	 * the caller hasn't initialized it yet. Once the pointer is published
-	 * in the xarray and visible to other threads we can't reliably destroy
-	 * it anymore, so the caller must complete all errorable operations
-	 * before calling iommufd_object_finalize().
-	 */
-	rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY, xa_limit_31b,
-		      GFP_KERNEL_ACCOUNT);
-	if (rc)
-		goto out_free;
-	return obj;
-out_free:
-	kfree(obj);
-	return ERR_PTR(rc);
+	immap = kzalloc(sizeof(*immap), GFP_KERNEL);
+	if (!immap)
+		return -ENOMEM;
+	immap->owner = owner;
+	immap->length = length;
+	immap->mmio_addr = mmio_addr;
+
+	/* Skip the first page to ease caller identifying the returned offset */
+	rc = mtree_alloc_range(&ictx->mt_mmap, &startp, immap, immap->length,
+			       PAGE_SIZE, ULONG_MAX, GFP_KERNEL);
+	if (rc < 0) {
+		kfree(immap);
+		return rc;
+	}
+
+	/* mmap() syscall will right-shift the offset in vma->vm_pgoff too */
+	immap->vm_pgoff = startp >> PAGE_SHIFT;
+	*offset = startp;
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(_iommufd_alloc_mmap, "IOMMUFD");
+
+/* Driver should use a per-structure helper in include/linux/iommufd.h */
+void _iommufd_destroy_mmap(struct iommufd_ctx *ictx,
+			   struct iommufd_object *owner, unsigned long offset)
+{
+	struct iommufd_mmap *immap;
+
+	immap = mtree_erase(&ictx->mt_mmap, offset);
+	WARN_ON_ONCE(!immap || immap->owner != owner);
+	kfree(immap);
+}
+EXPORT_SYMBOL_NS_GPL(_iommufd_destroy_mmap, "IOMMUFD");
+
+struct device *iommufd_vdevice_to_device(struct iommufd_vdevice *vdev)
+{
+	return vdev->idev->dev;
 }
-EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, "IOMMUFD");
+EXPORT_SYMBOL_NS_GPL(iommufd_vdevice_to_device, "IOMMUFD");
 
 /* Caller should xa_lock(&viommu->vdevs) to protect the return value */
 struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
@@ -45,7 +98,7 @@ struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
 	lockdep_assert_held(&viommu->vdevs.xa_lock);
 
 	vdev = xa_load(&viommu->vdevs, vdev_id);
-	return vdev ? vdev->dev : NULL;
+	return vdev ? iommufd_vdevice_to_device(vdev) : NULL;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_viommu_find_dev, "IOMMUFD");
 
@@ -62,8 +115,8 @@ int iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
 
 	xa_lock(&viommu->vdevs);
 	xa_for_each(&viommu->vdevs, index, vdev) {
-		if (vdev->dev == dev) {
-			*vdev_id = vdev->id;
+		if (iommufd_vdevice_to_device(vdev) == dev) {
+			*vdev_id = vdev->virt_id;
 			rc = 0;
 			break;
 		}