1/*
  2 * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
  3 *
  4 * This software is available to you under a choice of one of two
  5 * licenses.  You may choose to be licensed under the terms of the GNU
  6 * General Public License (GPL) Version 2, available from the file
  7 * COPYING in the main directory of this source tree, or the
  8 * OpenIB.org BSD license below:
  9 *
 10 *     Redistribution and use in source and binary forms, with or
 11 *     without modification, are permitted provided that the following
 12 *     conditions are met:
 13 *
 14 *      - Redistributions of source code must retain the above
 15 *        copyright notice, this list of conditions and the following
 16 *        disclaimer.
 17 *
 18 *      - Redistributions in binary form must reproduce the above
 19 *        copyright notice, this list of conditions and the following
 20 *        disclaimer in the documentation and/or other materials
 21 *        provided with the distribution.
 22 *
 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 30 * SOFTWARE.
 31 */
 32
 33#ifndef _UVERBS_TYPES_
 34#define _UVERBS_TYPES_
 35
 36#include <linux/kernel.h>
 37#include <rdma/ib_verbs.h>
 38
 39struct uverbs_obj_type;
 40
 41struct uverbs_obj_type_class {
 42	/*
 43	 * Get an ib_uobject that corresponds to the given id from ucontext,
 44	 * These functions could create or destroy objects if required.
 45	 * The action will be finalized only when commit, abort or put fops are
 46	 * called.
 47	 * The flow of the different actions is:
 48	 * [alloc]:	 Starts with alloc_begin. The handlers logic is than
 49	 *		 executed. If the handler is successful, alloc_commit
 50	 *		 is called and the object is inserted to the repository.
 51	 *		 Once alloc_commit completes the object is visible to
 52	 *		 other threads and userspace.
 53	 e		 Otherwise, alloc_abort is called and the object is
 54	 *		 destroyed.
 55	 * [lookup]:	 Starts with lookup_get which fetches and locks the
 56	 *		 object. After the handler finished using the object, it
 57	 *		 needs to call lookup_put to unlock it. The exclusive
 58	 *		 flag indicates if the object is locked for exclusive
 59	 *		 access.
 60	 * [remove]:	 Starts with lookup_get with exclusive flag set. This
 61	 *		 locks the object for exclusive access. If the handler
 62	 *		 code completed successfully, remove_commit is called
 63	 *		 and the ib_uobject is removed from the context's
 64	 *		 uobjects repository and put. The object itself is
 65	 *		 destroyed as well. Once remove succeeds new krefs to
 66	 *		 the object cannot be acquired by other threads or
 67	 *		 userspace and the hardware driver is removed from the
 68	 *		 object. Other krefs on the object may still exist.
 69	 *		 If the handler code failed, lookup_put should be
 70	 *		 called. This callback is used when the context
 71	 *		 is destroyed as well (process termination,
 72	 *		 reset flow).
 73	 */
 74	struct ib_uobject *(*alloc_begin)(const struct uverbs_obj_type *type,
 75					  struct ib_ucontext *ucontext);
 76	void (*alloc_commit)(struct ib_uobject *uobj);
 77	void (*alloc_abort)(struct ib_uobject *uobj);
 78
 79	struct ib_uobject *(*lookup_get)(const struct uverbs_obj_type *type,
 80					 struct ib_ucontext *ucontext, int id,
 81					 bool exclusive);
 82	void (*lookup_put)(struct ib_uobject *uobj, bool exclusive);
 83	/*
 84	 * Must be called with the exclusive lock held. If successful uobj is
 85	 * invalid on return. On failure uobject is left completely
 86	 * unchanged
 87	 */
 88	int __must_check (*remove_commit)(struct ib_uobject *uobj,
 89					  enum rdma_remove_reason why);
 90	u8    needs_kfree_rcu;
 91};
 92
 93struct uverbs_obj_type {
 94	const struct uverbs_obj_type_class * const type_class;
 95	size_t	     obj_size;
 96	unsigned int destroy_order;
 97};
 98
 99/*
100 * Objects type classes which support a detach state (object is still alive but
101 * it's not attached to any context need to make sure:
102 * (a) no call through to a driver after a detach is called
103 * (b) detach isn't called concurrently with context_cleanup
104 */
105
106struct uverbs_obj_idr_type {
107	/*
108	 * In idr based objects, uverbs_obj_type_class points to a generic
109	 * idr operations. In order to specialize the underlying types (e.g. CQ,
110	 * QPs, etc.), we add destroy_object specific callbacks.
111	 */
112	struct uverbs_obj_type  type;
113
114	/* Free driver resources from the uobject, make the driver uncallable,
115	 * and move the uobject to the detached state. If the object was
116	 * destroyed by the user's request, a failure should leave the uobject
117	 * completely unchanged.
118	 */
119	int __must_check (*destroy_object)(struct ib_uobject *uobj,
120					   enum rdma_remove_reason why);
121};
122
123struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type,
124					   struct ib_ucontext *ucontext,
125					   int id, bool exclusive);
126void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool exclusive);
127struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_obj_type *type,
128					    struct ib_ucontext *ucontext);
129void rdma_alloc_abort_uobject(struct ib_uobject *uobj);
130int __must_check rdma_remove_commit_uobject(struct ib_uobject *uobj);
131int rdma_alloc_commit_uobject(struct ib_uobject *uobj);
132int rdma_explicit_destroy(struct ib_uobject *uobject);
133
134struct uverbs_obj_fd_type {
135	/*
136	 * In fd based objects, uverbs_obj_type_ops points to generic
137	 * fd operations. In order to specialize the underlying types (e.g.
138	 * completion_channel), we use fops, name and flags for fd creation.
139	 * context_closed is called when the context is closed either when
140	 * the driver is removed or the process terminated.
141	 */
142	struct uverbs_obj_type  type;
143	int (*context_closed)(struct ib_uobject_file *uobj_file,
144			      enum rdma_remove_reason why);
145	const struct file_operations	*fops;
146	const char			*name;
147	int				flags;
148};
149
150extern const struct uverbs_obj_type_class uverbs_idr_class;
151extern const struct uverbs_obj_type_class uverbs_fd_class;
152
153#define UVERBS_BUILD_BUG_ON(cond) (sizeof(char[1 - 2 * !!(cond)]) -	\
154				   sizeof(char))
155#define UVERBS_TYPE_ALLOC_FD(_order, _obj_size, _context_closed, _fops, _name, _flags)\
156	((&((const struct uverbs_obj_fd_type)				\
157	 {.type = {							\
158		.destroy_order = _order,				\
159		.type_class = &uverbs_fd_class,				\
160		.obj_size = (_obj_size) +				\
161			UVERBS_BUILD_BUG_ON((_obj_size) < sizeof(struct ib_uobject_file)), \
162	 },								\
163	 .context_closed = _context_closed,				\
164	 .fops = _fops,							\
165	 .name = _name,							\
166	 .flags = _flags}))->type)
167#define UVERBS_TYPE_ALLOC_IDR_SZ(_size, _order, _destroy_object)	\
168	((&((const struct uverbs_obj_idr_type)				\
169	 {.type = {							\
170		.destroy_order = _order,				\
171		.type_class = &uverbs_idr_class,			\
172		.obj_size = (_size) +					\
173			UVERBS_BUILD_BUG_ON((_size) <			\
174					    sizeof(struct ib_uobject))	\
175	 },								\
176	 .destroy_object = _destroy_object,}))->type)
177#define UVERBS_TYPE_ALLOC_IDR(_order, _destroy_object)			\
178	 UVERBS_TYPE_ALLOC_IDR_SZ(sizeof(struct ib_uobject), _order,	\
179				  _destroy_object)
180
181#endif