IB/uverbs: Have the core code create the uverbs_root_spec

There is no reason for drivers to do this, the core code should take of
everything. The drivers will provide their information from rodata to
describe their modifications to the core's base uapi specification.

The core uses this to build up the runtime uapi for each device.

Signed-off-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Michael J. Ruhl <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>

Author: jgunthorpe

drivers/infiniband/core/uverbs_ioctl_merge.c

@@ -556,7 +556,6 @@ void uverbs_free_spec_tree(struct uverbs_root_spec *root)
 
 	kfree(root);
 }
-EXPORT_SYMBOL(uverbs_free_spec_tree);
 
 struct uverbs_root_spec *uverbs_alloc_spec_tree(unsigned int num_trees,
 						const struct uverbs_object_tree_def **trees)
@@ -661,4 +660,3 @@ struct uverbs_root_spec *uverbs_alloc_spec_tree(unsigned int num_trees,
 	uverbs_free_spec_tree(root_spec);
 	return ERR_PTR(res);
 }
-EXPORT_SYMBOL(uverbs_alloc_spec_tree);

drivers/infiniband/core/uverbs_main.c

@@ -994,6 +994,36 @@ static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
 			 __stringify(IB_USER_VERBS_ABI_VERSION));
 
+static int ib_uverbs_create_uapi(struct ib_device *device,
+				 struct ib_uverbs_device *uverbs_dev)
+{
+	const struct uverbs_object_tree_def **specs;
+	struct uverbs_root_spec *specs_root;
+	unsigned int num_specs = 1;
+	unsigned int i;
+
+	if (device->driver_specs)
+		for (i = 0; device->driver_specs[i]; i++)
+			num_specs++;
+
+	specs = kmalloc_array(num_specs, sizeof(*specs), GFP_KERNEL);
+	if (!specs)
+		return -ENOMEM;
+
+	specs[0] = uverbs_default_get_objects();
+	if (device->driver_specs)
+		for (i = 0; device->driver_specs[i]; i++)
+			specs[i+1] = device->driver_specs[i];
+
+	specs_root = uverbs_alloc_spec_tree(num_specs, specs);
+	kfree(specs);
+	if (IS_ERR(specs_root))
+		return PTR_ERR(specs_root);
+
+	uverbs_dev->specs_root = specs_root;
+	return 0;
+}
+
 static void ib_uverbs_add_one(struct ib_device *device)
 {
 	int devnum;
@@ -1036,6 +1066,9 @@ static void ib_uverbs_add_one(struct ib_device *device)
 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
 
+	if (ib_uverbs_create_uapi(device, uverbs_dev))
+		goto err;
+
 	cdev_init(&uverbs_dev->cdev, NULL);
 	uverbs_dev->cdev.owner = THIS_MODULE;
 	uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
@@ -1055,23 +1088,6 @@ static void ib_uverbs_add_one(struct ib_device *device)
 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
 		goto err_class;
 
-	if (!device->driver_specs_root) {
-		const struct uverbs_object_tree_def *default_root[] = {
-			uverbs_default_get_objects()};
-
-		uverbs_dev->specs_root = uverbs_alloc_spec_tree(1,
-								default_root);
-		if (IS_ERR(uverbs_dev->specs_root))
-			goto err_class;
-	} else {
-		uverbs_dev->specs_root = device->driver_specs_root;
-		/*
-		 * Take responsibility to free the specs allocated by the
-		 * driver.
-		 */
-		device->driver_specs_root = NULL;
-	}
-
 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
 
 	return;

drivers/infiniband/core/uverbs_std_types.c

@@ -316,4 +316,3 @@ const struct uverbs_object_tree_def *uverbs_default_get_objects(void)
 {
 	return &uverbs_default_objects;
 }
-EXPORT_SYMBOL_GPL(uverbs_default_get_objects);

drivers/infiniband/hw/mlx5/main.c

@@ -5523,37 +5523,29 @@ ADD_UVERBS_ATTRIBUTES_SIMPLE(
 	UVERBS_ATTR_FLAGS_IN(MLX5_IB_ATTR_CREATE_FLOW_ACTION_FLAGS,
 			     enum mlx5_ib_uapi_flow_action_flags));
 
-#define NUM_TREES	5
 static int populate_specs_root(struct mlx5_ib_dev *dev)
 {
-	const struct uverbs_object_tree_def *default_root[NUM_TREES + 1] = {
-		uverbs_default_get_objects()};
-	size_t num_trees = 1;
+	const struct uverbs_object_tree_def **trees = dev->driver_trees;
+	size_t num_trees = 0;
 
-	if (mlx5_accel_ipsec_device_caps(dev->mdev) & MLX5_ACCEL_IPSEC_CAP_DEVICE &&
-	    !WARN_ON(num_trees >= ARRAY_SIZE(default_root)))
-		default_root[num_trees++] = &mlx5_ib_flow_action;
+	if (mlx5_accel_ipsec_device_caps(dev->mdev) &
+	    MLX5_ACCEL_IPSEC_CAP_DEVICE)
+		trees[num_trees++] = &mlx5_ib_flow_action;
 
-	if (MLX5_CAP_DEV_MEM(dev->mdev, memic) &&
-	    !WARN_ON(num_trees >= ARRAY_SIZE(default_root)))
-		default_root[num_trees++] = &mlx5_ib_dm;
+	if (MLX5_CAP_DEV_MEM(dev->mdev, memic))
+		trees[num_trees++] = &mlx5_ib_dm;
 
 	if (MLX5_CAP_GEN_64(dev->mdev, general_obj_types) &
-			    MLX5_GENERAL_OBJ_TYPES_CAP_UCTX &&
-	    !WARN_ON(num_trees >= ARRAY_SIZE(default_root)))
-		default_root[num_trees++] = mlx5_ib_get_devx_tree();
+	    MLX5_GENERAL_OBJ_TYPES_CAP_UCTX)
+		trees[num_trees++] = mlx5_ib_get_devx_tree();
 
-	num_trees += mlx5_ib_get_flow_trees(default_root + num_trees);
+	num_trees += mlx5_ib_get_flow_trees(trees + num_trees);
 
-	dev->ib_dev.driver_specs_root =
-		uverbs_alloc_spec_tree(num_trees, default_root);
+	WARN_ON(num_trees >= ARRAY_SIZE(dev->driver_trees));
+	trees[num_trees] = NULL;
+	dev->ib_dev.driver_specs = trees;
 
-	return PTR_ERR_OR_ZERO(dev->ib_dev.driver_specs_root);
-}
-
-static void depopulate_specs_root(struct mlx5_ib_dev *dev)
-{
-	uverbs_free_spec_tree(dev->ib_dev.driver_specs_root);
+	return 0;
 }
 
 static int mlx5_ib_read_counters(struct ib_counters *counters,
@@ -6092,11 +6084,6 @@ int mlx5_ib_stage_ib_reg_init(struct mlx5_ib_dev *dev)
 	return ib_register_device(&dev->ib_dev, NULL);
 }
 
-static void mlx5_ib_stage_depopulate_specs(struct mlx5_ib_dev *dev)
-{
-	depopulate_specs_root(dev);
-}
-
 void mlx5_ib_stage_pre_ib_reg_umr_cleanup(struct mlx5_ib_dev *dev)
 {
 	destroy_umrc_res(dev);
@@ -6231,7 +6218,7 @@ static const struct mlx5_ib_profile pf_profile = {
 		     mlx5_ib_stage_pre_ib_reg_umr_cleanup),
 	STAGE_CREATE(MLX5_IB_STAGE_SPECS,
 		     mlx5_ib_stage_populate_specs,
-		     mlx5_ib_stage_depopulate_specs),
+		     NULL),
 	STAGE_CREATE(MLX5_IB_STAGE_IB_REG,
 		     mlx5_ib_stage_ib_reg_init,
 		     mlx5_ib_stage_ib_reg_cleanup),
@@ -6279,7 +6266,7 @@ static const struct mlx5_ib_profile nic_rep_profile = {
 		     mlx5_ib_stage_pre_ib_reg_umr_cleanup),
 	STAGE_CREATE(MLX5_IB_STAGE_SPECS,
 		     mlx5_ib_stage_populate_specs,
-		     mlx5_ib_stage_depopulate_specs),
+		     NULL),
 	STAGE_CREATE(MLX5_IB_STAGE_IB_REG,
 		     mlx5_ib_stage_ib_reg_init,
 		     mlx5_ib_stage_ib_reg_cleanup),

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -860,6 +860,7 @@ to_mcounters(struct ib_counters *ibcntrs)
 
 struct mlx5_ib_dev {
 	struct ib_device		ib_dev;
+	const struct uverbs_object_tree_def *driver_trees[6];
 	struct mlx5_core_dev		*mdev;
 	struct mlx5_roce		roce[MLX5_MAX_PORTS];
 	int				num_ports;

include/rdma/ib_verbs.h

@@ -2580,7 +2580,7 @@ struct ib_device {
 	const struct cpumask *(*get_vector_affinity)(struct ib_device *ibdev,
 						     int comp_vector);
 
-	struct uverbs_root_spec		*driver_specs_root;
+	const struct uverbs_object_tree_def *const *driver_specs;
 	enum rdma_driver_id		driver_id;
 };