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(kref: &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
218

source code of linux/include/rdma/uverbs_types.h