xref: /dpdk/lib/eal/include/rte_class.h (revision 719834a6849e1daf4a70ff7742bbcc3ae7e25607)
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 #include <rte_dev.h>
22 
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26 
27 /** Double linked list of classes */
28 RTE_TAILQ_HEAD(rte_class_list, rte_class);
29 
30 /**
31  * A structure describing a generic device class.
32  */
33 struct rte_class {
34 	RTE_TAILQ_ENTRY(rte_class) next; /**< Next device class in linked list */
35 	const char *name; /**< Name of the class */
36 	rte_dev_iterate_t dev_iterate; /**< Device iterator. */
37 };
38 
39 /**
40  * Class comparison function.
41  *
42  * @param cls
43  *	Class under test.
44  *
45  * @param data
46  *	Data to compare against.
47  *
48  * @return
49  *	0 if the class matches the data.
50  *	!0 if the class does not match.
51  *	<0 if ordering is possible and the class is lower than the data.
52  *	>0 if ordering is possible and the class is greater than the data.
53  */
54 typedef int (*rte_class_cmp_t)(const struct rte_class *cls, const void *data);
55 
56 /**
57  * Class iterator to find a particular class.
58  *
59  * This function compares each registered class to find one that matches
60  * the data passed as parameter.
61  *
62  * If the comparison function returns zero this function will stop iterating
63  * over any more classes. To continue a search the class of a previous search
64  * can be passed via the start parameter.
65  *
66  * @param start
67  *	Starting point for the iteration.
68  *
69  * @param cmp
70  *	Comparison function.
71  *
72  * @param data
73  *	 Data to pass to comparison function.
74  *
75  * @return
76  *	 A pointer to a rte_class structure or NULL in case no class matches
77  */
78 struct rte_class *
79 rte_class_find(const struct rte_class *start, rte_class_cmp_t cmp,
80 	       const void *data);
81 
82 /**
83  * Find the registered class for a given name.
84  */
85 struct rte_class *
86 rte_class_find_by_name(const char *name);
87 
88 /**
89  * Register a Class handle.
90  *
91  * @param cls
92  *   A pointer to a rte_class structure describing the class
93  *   to be registered.
94  */
95 void rte_class_register(struct rte_class *cls);
96 
97 /**
98  * Unregister a Class handle.
99  *
100  * @param cls
101  *   A pointer to a rte_class structure describing the class
102  *   to be unregistered.
103  */
104 void rte_class_unregister(struct rte_class *cls);
105 
106 /**
107  * Helper for Class registration.
108  * The constructor has lower priority than Bus constructors.
109  * The constructor has higher priority than PMD constructors.
110  */
111 #define RTE_REGISTER_CLASS(nm, cls) \
112 RTE_INIT_PRIO(classinitfn_ ##nm, CLASS) \
113 {\
114 	(cls).name = RTE_STR(nm); \
115 	rte_class_register(&cls); \
116 }
117 
118 #define RTE_UNREGISTER_CLASS(nm, cls) \
119 RTE_FINI_PRIO(classfinifn_ ##nm, CLASS) \
120 { \
121 	rte_class_unregister(&cls); \
122 }
123 
124 #ifdef __cplusplus
125 }
126 #endif
127 
128 #endif /* _RTE_CLASS_H_ */
129