1/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
  2/*
  3 * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
  4 */
  5
  6#ifndef _UVERBS_TYPES_
  7#define _UVERBS_TYPES_
  8
  9#include <linux/kernel.h>
 10#include <rdma/ib_verbs.h>
 11
 12struct uverbs_obj_type;
 13struct uverbs_api_object;
 14
 15enum rdma_lookup_mode {
 16	UVERBS_LOOKUP_READ,
 17	UVERBS_LOOKUP_WRITE,
 18	/*
 19	 * Destroy is like LOOKUP_WRITE, except that the uobject is not
 20	 * locked.  uobj_destroy is used to convert a LOOKUP_DESTROY lock into
 21	 * a LOOKUP_WRITE lock.
 22	 */
 23	UVERBS_LOOKUP_DESTROY,
 24};
 25
 26/*
 27 * The following sequences are valid:
 28 * Success flow:
 29 *   alloc_begin
 30 *   alloc_commit
 31 *    [..]
 32 * Access flow:
 33 *   lookup_get(exclusive=false) & uverbs_try_lock_object
 34 *   lookup_put(exclusive=false) via rdma_lookup_put_uobject
 35 * Destruction flow:
 36 *   lookup_get(exclusive=true) & uverbs_try_lock_object
 37 *   remove_commit
 38 *   remove_handle (optional)
 39 *   lookup_put(exclusive=true) via rdma_lookup_put_uobject
 40 *
 41 * Allocate Error flow #1
 42 *   alloc_begin
 43 *   alloc_abort
 44 * Allocate Error flow #2
 45 *   alloc_begin
 46 *   remove_commit
 47 *   alloc_abort
 48 * Allocate Error flow #3
 49 *   alloc_begin
 50 *   alloc_commit (fails)
 51 *   remove_commit
 52 *   alloc_abort
 53 *
 54 * In all cases the caller must hold the ufile kref until alloc_commit or
 55 * alloc_abort returns.
 56 */
 57struct uverbs_obj_type_class {
 58	struct ib_uobject *(*alloc_begin)(const struct uverbs_api_object *obj,
 59					  struct uverbs_attr_bundle *attrs);
 60	/* This consumes the kref on uobj */
 61	void (*alloc_commit)(struct ib_uobject *uobj);
 62	/* This does not consume the kref on uobj */
 63	void (*alloc_abort)(struct ib_uobject *uobj);
 64
 65	struct ib_uobject *(*lookup_get)(const struct uverbs_api_object *obj,
 66					 struct ib_uverbs_file *ufile, s64 id,
 67					 enum rdma_lookup_mode mode);
 68	void (*lookup_put)(struct ib_uobject *uobj, enum rdma_lookup_mode mode);
 69	/* This does not consume the kref on uobj */
 70	int __must_check (*destroy_hw)(struct ib_uobject *uobj,
 71				       enum rdma_remove_reason why,
 72				       struct uverbs_attr_bundle *attrs);
 73	void (*remove_handle)(struct ib_uobject *uobj);
 74	void (*swap_uobjects)(struct ib_uobject *obj_old,
 75			      struct ib_uobject *obj_new);
 76};
 77
 78struct uverbs_obj_type {
 79	const struct uverbs_obj_type_class * const type_class;
 80	size_t	     obj_size;
 81};
 82
 83/*
 84 * Objects type classes which support a detach state (object is still alive but
 85 * it's not attached to any context need to make sure:
 86 * (a) no call through to a driver after a detach is called
 87 * (b) detach isn't called concurrently with context_cleanup
 88 */
 89
 90struct uverbs_obj_idr_type {
 91	/*
 92	 * In idr based objects, uverbs_obj_type_class points to a generic
 93	 * idr operations. In order to specialize the underlying types (e.g. CQ,
 94	 * QPs, etc.), we add destroy_object specific callbacks.
 95	 */
 96	struct uverbs_obj_type  type;
 97
 98	/* Free driver resources from the uobject, make the driver uncallable,
 99	 * and move the uobject to the detached state. If the object was
100	 * destroyed by the user's request, a failure should leave the uobject
101	 * completely unchanged.
102	 */
103	int __must_check (*destroy_object)(struct ib_uobject *uobj,
104					   enum rdma_remove_reason why,
105					   struct uverbs_attr_bundle *attrs);
106};
107
108struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_api_object *obj,
109					   struct ib_uverbs_file *ufile, s64 id,
110					   enum rdma_lookup_mode mode,
111					   struct uverbs_attr_bundle *attrs);
112void rdma_lookup_put_uobject(struct ib_uobject *uobj,
113			     enum rdma_lookup_mode mode);
114struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_api_object *obj,
115					    struct uverbs_attr_bundle *attrs);
116void rdma_alloc_abort_uobject(struct ib_uobject *uobj,
117			      struct uverbs_attr_bundle *attrs,
118			      bool hw_obj_valid);
119void rdma_alloc_commit_uobject(struct ib_uobject *uobj,
120			       struct uverbs_attr_bundle *attrs);
121void rdma_assign_uobject(struct ib_uobject *to_uobj,
122			 struct ib_uobject *new_uobj,
123			 struct uverbs_attr_bundle *attrs);
124
125/*
126 * uverbs_uobject_get is called in order to increase the reference count on
127 * an uobject. This is useful when a handler wants to keep the uobject's memory
128 * alive, regardless if this uobject is still alive in the context's objects
129 * repository. Objects are put via uverbs_uobject_put.
130 */
131static inline void uverbs_uobject_get(struct ib_uobject *uobject)
132{
133	kref_get(&uobject->ref);
134}
135void uverbs_uobject_put(struct ib_uobject *uobject);
136
137int uverbs_try_lock_object(struct ib_uobject *uobj, enum rdma_lookup_mode mode);
138
139struct uverbs_obj_fd_type {
140	/*
141	 * In fd based objects, uverbs_obj_type_ops points to generic
142	 * fd operations. In order to specialize the underlying types (e.g.
143	 * completion_channel), we use fops, name and flags for fd creation.
144	 * destroy_object is called when the uobject is to be destroyed,
145	 * because the driver is removed or the FD is closed.
146	 */
147	struct uverbs_obj_type  type;
148	void (*destroy_object)(struct ib_uobject *uobj,
149			       enum rdma_remove_reason why);
150	const struct file_operations	*fops;
151	const char			*name;
152	int				flags;
153};
154
155struct ib_uverbs_file {
156	struct kref				ref;
157	struct ib_uverbs_device		       *device;
158	struct mutex				ucontext_lock;
159	/*
160	 * ucontext must be accessed via ib_uverbs_get_ucontext() or with
161	 * ucontext_lock held
162	 */
163	struct ib_ucontext		       *ucontext;
164	struct ib_uverbs_async_event_file      *default_async_file;
165	struct list_head			list;
166
167	/*
168	 * To access the uobjects list hw_destroy_rwsem must be held for write
169	 * OR hw_destroy_rwsem held for read AND uobjects_lock held.
170	 * hw_destroy_rwsem should be called across any destruction of the HW
171	 * object of an associated uobject.
172	 */
173	struct rw_semaphore	hw_destroy_rwsem;
174	spinlock_t		uobjects_lock;
175	struct list_head	uobjects;
176
177	struct mutex umap_lock;
178	struct list_head umaps;
179	struct page *disassociate_page;
180
181	struct xarray		idr;
182
183	struct mutex disassociation_lock;
184};
185
186extern const struct uverbs_obj_type_class uverbs_idr_class;
187extern const struct uverbs_obj_type_class uverbs_fd_class;
188int uverbs_uobject_fd_release(struct inode *inode, struct file *filp);
189
190#define UVERBS_BUILD_BUG_ON(cond) (sizeof(char[1 - 2 * !!(cond)]) -	\
191				   sizeof(char))
192#define UVERBS_TYPE_ALLOC_FD(_obj_size, _destroy_object, _fops, _name, _flags) \
193	((&((const struct uverbs_obj_fd_type)				\
194	 {.type = {							\
195		.type_class = &uverbs_fd_class,				\
196		.obj_size = (_obj_size) +				\
197			UVERBS_BUILD_BUG_ON((_obj_size) <               \
198					    sizeof(struct ib_uobject)), \
199	 },								\
200	 .destroy_object = _destroy_object,				\
201	 .fops = _fops,							\
202	 .name = _name,							\
203	 .flags = _flags}))->type)
204#define UVERBS_TYPE_ALLOC_IDR_SZ(_size, _destroy_object)	\
205	((&((const struct uverbs_obj_idr_type)				\
206	 {.type = {							\
207		.type_class = &uverbs_idr_class,			\
208		.obj_size = (_size) +					\
209			UVERBS_BUILD_BUG_ON((_size) <			\
210					    sizeof(struct ib_uobject))	\
211	 },								\
212	 .destroy_object = _destroy_object,}))->type)
213#define UVERBS_TYPE_ALLOC_IDR(_destroy_object)			\
214	 UVERBS_TYPE_ALLOC_IDR_SZ(sizeof(struct ib_uobject),	\
215				  _destroy_object)
216
217#endif