include/linux/klist.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  *      klist.h - Some generic list helpers, extending struct list_head a bit.
   4  *
   5  *      Implementations are found in lib/klist.c
   6  *
   7  *      Copyright (C) 2005 Patrick Mochel
   8  */
   9
  10 #ifndef _LINUX_KLIST_H
  11 #define _LINUX_KLIST_H
  12
  13 #include <linux/spinlock.h>
  14 #include <linux/kref.h>
  15 #include <linux/list.h>
  16
  17 struct klist_node;
  18 struct klist {
  19         spinlock_t              k_lock;
  20         struct list_head        k_list;
  21         void                    (*get)(struct klist_node *);
  22         void                    (*put)(struct klist_node *);
  23 } __attribute__ ((aligned (sizeof(void *))));
  24
  25 #define KLIST_INIT(_name, _get, _put)                                   \
  26         { .k_lock       = __SPIN_LOCK_UNLOCKED(_name.k_lock),           \
  27           .k_list       = LIST_HEAD_INIT(_name.k_list),                 \
  28           .get          = _get,                                         \
  29           .put          = _put, }
  30
  31 #define DEFINE_KLIST(_name, _get, _put)                                 \
  32         struct klist _name = KLIST_INIT(_name, _get, _put)
  33
  34 extern void klist_init(struct klist *k, void (*get)(struct klist_node *),
  35                        void (*put)(struct klist_node *));
  36
  37 struct klist_node {
  38         void                    *n_klist;       /* never access directly */
  39         struct list_head        n_node;
  40         struct kref             n_ref;
  41 };
  42
  43 extern void klist_add_tail(struct klist_node *n, struct klist *k);
  44 extern void klist_add_head(struct klist_node *n, struct klist *k);
  45 extern void klist_add_behind(struct klist_node *n, struct klist_node *pos);
  46 extern void klist_add_before(struct klist_node *n, struct klist_node *pos);
  47
  48 extern void klist_del(struct klist_node *n);
  49 extern void klist_remove(struct klist_node *n);
  50
  51 extern int klist_node_attached(struct klist_node *n);
  52
  53
  54 struct klist_iter {
  55         struct klist            *i_klist;
  56         struct klist_node       *i_cur;
  57 };
  58
  59
  60 extern void klist_iter_init(struct klist *k, struct klist_iter *i);
  61 extern void klist_iter_init_node(struct klist *k, struct klist_iter *i,
  62                                  struct klist_node *n);
  63 extern void klist_iter_exit(struct klist_iter *i);
  64 extern struct klist_node *klist_prev(struct klist_iter *i);
  65 extern struct klist_node *klist_next(struct klist_iter *i);
  66
  67 #endif