xref: /freebsd/sys/contrib/dpdk_rte_lpm/rte_tailq.h (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #ifndef _RTE_TAILQ_H_
6 #define _RTE_TAILQ_H_
7 
8 /**
9  * @file
10  *  Here defines rte_tailq APIs for only internal use
11  *
12  */
13 
14 #ifdef __cplusplus
15 extern "C" {
16 #endif
17 
18 #include <sys/queue.h>
19 //#include <stdio.h>
20 #include <netinet6/rte_debug.h>
21 
22 /** dummy structure type used by the rte_tailq APIs */
23 struct rte_tailq_entry {
24 	TAILQ_ENTRY(rte_tailq_entry) next; /**< Pointer entries for a tailq list */
25 	void *data; /**< Pointer to the data referenced by this tailq entry */
26 };
27 /** dummy */
28 TAILQ_HEAD(rte_tailq_entry_head, rte_tailq_entry);
29 
30 #define RTE_TAILQ_NAMESIZE 32
31 
32 /**
33  * The structure defining a tailq header entry for storing
34  * in the rte_config structure in shared memory. Each tailq
35  * is identified by name.
36  * Any library storing a set of objects e.g. rings, mempools, hash-tables,
37  * is recommended to use an entry here, so as to make it easy for
38  * a multi-process app to find already-created elements in shared memory.
39  */
40 struct rte_tailq_head {
41 	struct rte_tailq_entry_head tailq_head; /**< NOTE: must be first element */
42 	char name[RTE_TAILQ_NAMESIZE];
43 };
44 
45 struct rte_tailq_elem {
46 	/**
47 	 * Reference to head in shared mem, updated at init time by
48 	 * rte_eal_tailqs_init()
49 	 */
50 	struct rte_tailq_head *head;
51 	TAILQ_ENTRY(rte_tailq_elem) next;
52 	const char name[RTE_TAILQ_NAMESIZE];
53 };
54 
55 /**
56  * Return the first tailq entry cast to the right struct.
57  */
58 #define RTE_TAILQ_CAST(tailq_entry, struct_name) \
59 	(struct struct_name *)&(tailq_entry)->tailq_head
60 
61 /**
62  * Utility macro to make looking up a tailqueue for a particular struct easier.
63  *
64  * @param name
65  *   The name of tailq
66  *
67  * @param struct_name
68  *   The name of the list type we are using. (Generally this is the same as the
69  *   first parameter passed to TAILQ_HEAD macro)
70  *
71  * @return
72  *   The return value from rte_eal_tailq_lookup, typecast to the appropriate
73  *   structure pointer type.
74  *   NULL on error, since the tailq_head is the first
75  *   element in the rte_tailq_head structure.
76  */
77 #define RTE_TAILQ_LOOKUP(name, struct_name) \
78 	RTE_TAILQ_CAST(rte_eal_tailq_lookup(name), struct_name)
79 
80 /**
81  * Dump tail queues to a file.
82  *
83  * @param f
84  *   A pointer to a file for output
85  */
86 //void rte_dump_tailq(FILE *f);
87 
88 /**
89  * Lookup for a tail queue.
90  *
91  * Get a pointer to a tail queue header of a tail
92  * queue identified by the name given as an argument.
93  * Note: this function is not multi-thread safe, and should only be called from
94  * a single thread at a time
95  *
96  * @param name
97  *   The name of the queue.
98  * @return
99  *   A pointer to the tail queue head structure.
100  */
101 struct rte_tailq_head *rte_eal_tailq_lookup(const char *name);
102 
103 /**
104  * Register a tail queue.
105  *
106  * Register a tail queue from shared memory.
107  * This function is mainly used by EAL_REGISTER_TAILQ macro which is used to
108  * register tailq from the different dpdk libraries. Since this macro is a
109  * constructor, the function has no access to dpdk shared memory, so the
110  * registered tailq can not be used before call to rte_eal_init() which calls
111  * rte_eal_tailqs_init().
112  *
113  * @param t
114  *   The tailq element which contains the name of the tailq you want to
115  *   create (/retrieve when in secondary process).
116  * @return
117  *   0 on success or -1 in case of an error.
118  */
119 int rte_eal_tailq_register(struct rte_tailq_elem *t);
120 
121 #define EAL_REGISTER_TAILQ(t) \
122 RTE_INIT(tailqinitfn_ ##t) \
123 { \
124 	if (rte_eal_tailq_register(&t) < 0) \
125 		rte_panic("Cannot initialize tailq: %s\n", t.name); \
126 }
127 
128 /* This macro permits both remove and free var within the loop safely.*/
129 #ifndef TAILQ_FOREACH_SAFE
130 #define TAILQ_FOREACH_SAFE(var, head, field, tvar)		\
131 	for ((var) = TAILQ_FIRST((head));			\
132 	    (var) && ((tvar) = TAILQ_NEXT((var), field), 1);	\
133 	    (var) = (tvar))
134 #endif
135 
136 #ifdef __cplusplus
137 }
138 #endif
139 
140 #endif /* _RTE_TAILQ_H_ */
141