alistair23-linux/include/linux/klist.h
Andy Shevchenko 2e0fed7f7c klist: implement klist_prev()
klist_prev() gets the previous element in the list. It is useful to traverse
through the list in reverse order, for example, to provide LIFO (last in first
out) variant of access.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-07-28 08:50:42 +01:00

70 lines
1.9 KiB
C

/*
* klist.h - Some generic list helpers, extending struct list_head a bit.
*
* Implementations are found in lib/klist.c
*
*
* Copyright (C) 2005 Patrick Mochel
*
* This file is rleased under the GPL v2.
*/
#ifndef _LINUX_KLIST_H
#define _LINUX_KLIST_H
#include <linux/spinlock.h>
#include <linux/kref.h>
#include <linux/list.h>
struct klist_node;
struct klist {
spinlock_t k_lock;
struct list_head k_list;
void (*get)(struct klist_node *);
void (*put)(struct klist_node *);
} __attribute__ ((aligned (sizeof(void *))));
#define KLIST_INIT(_name, _get, _put) \
{ .k_lock = __SPIN_LOCK_UNLOCKED(_name.k_lock), \
.k_list = LIST_HEAD_INIT(_name.k_list), \
.get = _get, \
.put = _put, }
#define DEFINE_KLIST(_name, _get, _put) \
struct klist _name = KLIST_INIT(_name, _get, _put)
extern void klist_init(struct klist *k, void (*get)(struct klist_node *),
void (*put)(struct klist_node *));
struct klist_node {
void *n_klist; /* never access directly */
struct list_head n_node;
struct kref n_ref;
};
extern void klist_add_tail(struct klist_node *n, struct klist *k);
extern void klist_add_head(struct klist_node *n, struct klist *k);
extern void klist_add_behind(struct klist_node *n, struct klist_node *pos);
extern void klist_add_before(struct klist_node *n, struct klist_node *pos);
extern void klist_del(struct klist_node *n);
extern void klist_remove(struct klist_node *n);
extern int klist_node_attached(struct klist_node *n);
struct klist_iter {
struct klist *i_klist;
struct klist_node *i_cur;
};
extern void klist_iter_init(struct klist *k, struct klist_iter *i);
extern void klist_iter_init_node(struct klist *k, struct klist_iter *i,
struct klist_node *n);
extern void klist_iter_exit(struct klist_iter *i);
extern struct klist_node *klist_prev(struct klist_iter *i);
extern struct klist_node *klist_next(struct klist_iter *i);
#endif