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 <sys/queue.h>
26 
27 #include <rte_dev.h>
28 
29 /** Double linked list of classes */
30 TAILQ_HEAD(rte_class_list, rte_class);
31 
32 /**
33  * A structure describing a generic device class.
34  */
35 struct rte_class {
36 	TAILQ_ENTRY(rte_class) next; /**< Next device class in linked list */
37 	const char *name; /**< Name of the class */
38 	rte_dev_iterate_t dev_iterate; /**< Device iterator. */
39 };
40 
41 /**
42  * Class comparison function.
43  *
44  * @param cls
45  *	Class under test.
46  *
47  * @param data
48  *	Data to compare against.
49  *
50  * @return
51  *	0 if the class matches the data.
52  *	!0 if the class does not match.
53  *	<0 if ordering is possible and the class is lower than the data.
54  *	>0 if ordering is possible and the class is greater than the data.
55  */
56 typedef int (*rte_class_cmp_t)(const struct rte_class *cls, const void *data);
57 
58 /**
59  * Class iterator to find a particular class.
60  *
61  * This function compares each registered class to find one that matches
62  * the data passed as parameter.
63  *
64  * If the comparison function returns zero this function will stop iterating
65  * over any more classes. To continue a search the class of a previous search
66  * can be passed via the start parameter.
67  *
68  * @param start
69  *	Starting point for the iteration.
70  *
71  * @param cmp
72  *	Comparison function.
73  *
74  * @param data
75  *	 Data to pass to comparison function.
76  *
77  * @return
78  *	 A pointer to a rte_class structure or NULL in case no class matches
79  */
80 __rte_experimental
81 struct rte_class *
82 rte_class_find(const struct rte_class *start, rte_class_cmp_t cmp,
83 	       const void *data);
84 
85 /**
86  * Find the registered class for a given name.
87  */
88 __rte_experimental
89 struct rte_class *
90 rte_class_find_by_name(const char *name);
91 
92 /**
93  * Register a Class handle.
94  *
95  * @param cls
96  *   A pointer to a rte_class structure describing the class
97  *   to be registered.
98  */
99 __rte_experimental
100 void rte_class_register(struct rte_class *cls);
101 
102 /**
103  * Unregister a Class handle.
104  *
105  * @param cls
106  *   A pointer to a rte_class structure describing the class
107  *   to be unregistered.
108  */
109 __rte_experimental
110 void rte_class_unregister(struct rte_class *cls);
111 
112 /**
113  * Helper for Class registration.
114  * The constructor has lower priority than Bus constructors.
115  * The constructor has higher priority than PMD constructors.
116  */
117 #define RTE_REGISTER_CLASS(nm, cls) \
118 RTE_INIT_PRIO(classinitfn_ ##nm, CLASS) \
119 {\
120 	(cls).name = RTE_STR(nm); \
121 	rte_class_register(&cls); \
122 }
123 
124 #define RTE_UNREGISTER_CLASS(nm, cls) \
125 RTE_FINI_PRIO(classfinifn_ ##nm, CLASS) \
126 { \
127 	rte_class_unregister(&cls); \
128 }
129 
130 #ifdef __cplusplus
131 }
132 #endif
133 
134 #endif /* _RTE_CLASS_H_ */
135