xref: /dpdk/lib/eal/include/rte_class.h (revision 02d36ef6a9528e0f4a3403956e66bcea5fadbf8c)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright 2018 Gaëtan Rivet
3  */
4 
5 #ifndef _RTE_CLASS_H_
6 #define _RTE_CLASS_H_
7 
8 /**
9  * @file
10  *
11  * DPDK device class interface.
12  *
13  * This file describes the interface of the device class
14  * abstraction layer.
15  *
16  * A device class defines the type of function a device
17  * will be used for e.g.: Ethernet adapter (eth),
18  * cryptographic co-processor (crypto), etc.
19  */
20 
21 #ifdef __cplusplus
22 extern "C" {
23 #endif
24 
25 #include <rte_compat.h>
26 #include <rte_dev.h>
27 
28 /** Double linked list of classes */
29 RTE_TAILQ_HEAD(rte_class_list, rte_class);
30 
31 /**
32  * A structure describing a generic device class.
33  */
34 struct rte_class {
35 	RTE_TAILQ_ENTRY(rte_class) next; /**< Next device class in linked list */
36 	const char *name; /**< Name of the class */
37 	rte_dev_iterate_t dev_iterate; /**< Device iterator. */
38 };
39 
40 /**
41  * Class comparison function.
42  *
43  * @param cls
44  *	Class under test.
45  *
46  * @param data
47  *	Data to compare against.
48  *
49  * @return
50  *	0 if the class matches the data.
51  *	!0 if the class does not match.
52  *	<0 if ordering is possible and the class is lower than the data.
53  *	>0 if ordering is possible and the class is greater than the data.
54  */
55 typedef int (*rte_class_cmp_t)(const struct rte_class *cls, const void *data);
56 
57 /**
58  * Class iterator to find a particular class.
59  *
60  * This function compares each registered class to find one that matches
61  * the data passed as parameter.
62  *
63  * If the comparison function returns zero this function will stop iterating
64  * over any more classes. To continue a search the class of a previous search
65  * can be passed via the start parameter.
66  *
67  * @param start
68  *	Starting point for the iteration.
69  *
70  * @param cmp
71  *	Comparison function.
72  *
73  * @param data
74  *	 Data to pass to comparison function.
75  *
76  * @return
77  *	 A pointer to a rte_class structure or NULL in case no class matches
78  */
79 __rte_experimental
80 struct rte_class *
81 rte_class_find(const struct rte_class *start, rte_class_cmp_t cmp,
82 	       const void *data);
83 
84 /**
85  * Find the registered class for a given name.
86  */
87 __rte_experimental
88 struct rte_class *
89 rte_class_find_by_name(const char *name);
90 
91 /**
92  * Register a Class handle.
93  *
94  * @param cls
95  *   A pointer to a rte_class structure describing the class
96  *   to be registered.
97  */
98 __rte_experimental
99 void rte_class_register(struct rte_class *cls);
100 
101 /**
102  * Unregister a Class handle.
103  *
104  * @param cls
105  *   A pointer to a rte_class structure describing the class
106  *   to be unregistered.
107  */
108 __rte_experimental
109 void rte_class_unregister(struct rte_class *cls);
110 
111 /**
112  * Helper for Class registration.
113  * The constructor has lower priority than Bus constructors.
114  * The constructor has higher priority than PMD constructors.
115  */
116 #define RTE_REGISTER_CLASS(nm, cls) \
117 RTE_INIT_PRIO(classinitfn_ ##nm, CLASS) \
118 {\
119 	(cls).name = RTE_STR(nm); \
120 	rte_class_register(&cls); \
121 }
122 
123 #define RTE_UNREGISTER_CLASS(nm, cls) \
124 RTE_FINI_PRIO(classfinifn_ ##nm, CLASS) \
125 { \
126 	rte_class_unregister(&cls); \
127 }
128 
129 #ifdef __cplusplus
130 }
131 #endif
132 
133 #endif /* _RTE_CLASS_H_ */
134