ceph/src/spdk/dpdk/lib/librte_eal/include/rte_tailq.h

   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 <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_ */