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 
12 struct uverbs_obj_type;
13 struct uverbs_api_object;
14 
15 enum 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  */
57 struct 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 
78 struct 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 
90 struct 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 
108 struct 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);
112 void rdma_lookup_put_uobject(struct ib_uobject *uobj,
113 			     enum rdma_lookup_mode mode);
114 struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_api_object *obj,
115 					    struct uverbs_attr_bundle *attrs);
116 void rdma_alloc_abort_uobject(struct ib_uobject *uobj,
117 			      struct uverbs_attr_bundle *attrs,
118 			      bool hw_obj_valid);
119 void rdma_alloc_commit_uobject(struct ib_uobject *uobj,
120 			       struct uverbs_attr_bundle *attrs);
121 void 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  */
uverbs_uobject_get(struct ib_uobject * uobject)131 static inline void uverbs_uobject_get(struct ib_uobject *uobject)
132 {
133 	kref_get(&uobject->ref);
134 }
135 void uverbs_uobject_put(struct ib_uobject *uobject);
136 
137 struct uverbs_obj_fd_type {
138 	/*
139 	 * In fd based objects, uverbs_obj_type_ops points to generic
140 	 * fd operations. In order to specialize the underlying types (e.g.
141 	 * completion_channel), we use fops, name and flags for fd creation.
142 	 * destroy_object is called when the uobject is to be destroyed,
143 	 * because the driver is removed or the FD is closed.
144 	 */
145 	struct uverbs_obj_type  type;
146 	void (*destroy_object)(struct ib_uobject *uobj,
147 			       enum rdma_remove_reason why);
148 	const struct file_operations	*fops;
149 	const char			*name;
150 	int				flags;
151 };
152 
153 extern const struct uverbs_obj_type_class uverbs_idr_class;
154 extern const struct uverbs_obj_type_class uverbs_fd_class;
155 int uverbs_uobject_fd_release(struct inode *inode, struct file *filp);
156 
157 #define UVERBS_BUILD_BUG_ON(cond) (sizeof(char[1 - 2 * !!(cond)]) -	\
158 				   sizeof(char))
159 #define UVERBS_TYPE_ALLOC_FD(_obj_size, _destroy_object, _fops, _name, _flags) \
160 	((&((const struct uverbs_obj_fd_type)				\
161 	 {.type = {							\
162 		.type_class = &uverbs_fd_class,				\
163 		.obj_size = (_obj_size) +				\
164 			UVERBS_BUILD_BUG_ON((_obj_size) <               \
165 					    sizeof(struct ib_uobject)), \
166 	 },								\
167 	 .destroy_object = _destroy_object,				\
168 	 .fops = _fops,							\
169 	 .name = _name,							\
170 	 .flags = _flags}))->type)
171 #define UVERBS_TYPE_ALLOC_IDR_SZ(_size, _destroy_object)	\
172 	((&((const struct uverbs_obj_idr_type)				\
173 	 {.type = {							\
174 		.type_class = &uverbs_idr_class,			\
175 		.obj_size = (_size) +					\
176 			UVERBS_BUILD_BUG_ON((_size) <			\
177 					    sizeof(struct ib_uobject))	\
178 	 },								\
179 	 .destroy_object = _destroy_object,}))->type)
180 #define UVERBS_TYPE_ALLOC_IDR(_destroy_object)			\
181 	 UVERBS_TYPE_ALLOC_IDR_SZ(sizeof(struct ib_uobject),	\
182 				  _destroy_object)
183 
184 #endif
185