/*-
* Copyright (c) 2017 Broadcom. All rights reserved.
* The term "Broadcom" refers to Broadcom Limited and/or its subsidiaries.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
/**
* @file
*
* OCS linked list API
*
*/
#if !defined(__OCS_LIST_H__)
#define __OCS_LIST_H__
#define OCS_LIST_DEBUG
#if defined(OCS_LIST_DEBUG)
#define ocs_list_magic_decl uint32_t magic;
#define OCS_LIST_LIST_MAGIC 0xcafe0000
#define OCS_LIST_LINK_MAGIC 0xcafe0001
#define ocs_list_set_list_magic list->magic = OCS_LIST_LIST_MAGIC
#define ocs_list_set_link_magic list->magic = OCS_LIST_LINK_MAGIC
#define ocs_list_assert(cond, ...) \
if (!(cond)) { \
return __VA_ARGS__; \
}
#else
#define ocs_list_magic_decl
#define ocs_list_assert(cond, ...)
#define ocs_list_set_list_magic
#define ocs_list_set_link_magic
#endif
/**
* @brief list/link structure
*
* used for both the list object, and the link object(s). offset
* is specified when the list is initialized; this implies that a list
* will always point to objects of the same type. offset is not used
* when ocs_list_t is used as a link (ocs_list_link_t).
*
*/
typedef struct ocs_list_s ocs_list_t;
struct ocs_list_s {
ocs_list_magic_decl /*<< used if debugging is enabled */
ocs_list_t *next; /*<< pointer to head of list (or next if link) */
ocs_list_t *prev; /*<< pointer to tail of list (or previous if link) */
uint32_t offset; /*<< offset in bytes to the link element of the objects in list */
};
typedef ocs_list_t ocs_list_link_t;
/* item2link - return pointer to link given pointer to an item */
#define item2link(list, item) ((ocs_list_t*) (((uint8_t*)(item)) + (list)->offset))
/* link2item - return pointer to item given pointer to a link */
#define link2item(list, link) ((void*) (((uint8_t*)(link)) - (list)->offset))
/**
* @brief Initialize a list
*
* A list object is initialized. Helper define is used to call _ocs_list_init() with
* offsetof(type, link)
*
* @param list Pointer to list
* @param offset Offset in bytes in item to the link element
*
* @return none
*/
static inline void
_ocs_list_init(ocs_list_t *list, uint32_t offset)
{
ocs_list_assert(list);
ocs_list_set_list_magic;
list->next = list;
list->prev = list;
list->offset = offset;
}
#define ocs_list_init(head, type, link) _ocs_list_init(head, offsetof(type, link))
/**
* @ingroup os
* @brief Test if a list is empty
*
* @param list Pointer to list head
*
* @return 1 if empty, 0 otherwise
*/
static inline int32_t
ocs_list_empty(ocs_list_t *list)
{
ocs_list_assert(list, 1);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC, 1);
return list->next == list;
}
/**
* @ingroup os
* @brief Test if a list is valid (ready for use)
*
* @param list Pointer to list head
*
* @return true if list is usable, false otherwise
*/
static inline int
ocs_list_valid(ocs_list_t *list)
{
return (list->magic == OCS_LIST_LIST_MAGIC);
}
/**
* @brief Insert link between two other links
*
* Inserts a link in between two other links
*
* @param a Pointer to first link
* @param b Pointer to next link
* @param c Pointer to link to insert between a and b
*
* @return none
*/
static inline void
_ocs_list_insert_link(ocs_list_t *a, ocs_list_t *b, ocs_list_t *c)
{
ocs_list_assert(a);
ocs_list_assert((a->magic == OCS_LIST_LIST_MAGIC) || (a->magic == OCS_LIST_LINK_MAGIC));
ocs_list_assert(a->next);
ocs_list_assert(a->prev);
ocs_list_assert(b);
ocs_list_assert((b->magic == OCS_LIST_LIST_MAGIC) || (b->magic == OCS_LIST_LINK_MAGIC));
ocs_list_assert(b->next);
ocs_list_assert(b->prev);
ocs_list_assert(c);
ocs_list_assert((c->magic == OCS_LIST_LIST_MAGIC) || (c->magic == OCS_LIST_LINK_MAGIC));
ocs_list_assert(!c->next);
ocs_list_assert(!c->prev);
ocs_list_assert(a->offset == b->offset);
ocs_list_assert(b->offset == c->offset);
c->next = a->next;
c->prev = b->prev;
a->next = c;
b->prev = c;
}
#if defined(OCS_LIST_DEBUG)
/**
* @brief Initialize a list link for debug purposes
*
* For debugging a linked list link element has a magic number that is initialized,
* and the offset value initialzied and used for subsequent assertions.
*
*
* @param list Pointer to list head
* @param link Pointer to link to be initialized
*
* @return none
*/
static inline void
ocs_list_init_link(ocs_list_t *list, ocs_list_t *link)
{
ocs_list_assert(list);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC);
ocs_list_assert(link);
if (link->magic == 0) {
link->magic = OCS_LIST_LINK_MAGIC;
link->offset = list->offset;
link->next = NULL;
link->prev = NULL;
}
}
#else
#define ocs_list_init_link(...)
#endif
/**
* @ingroup os
* @brief Add an item to the head of the list
*
* @param list Pointer to list head
* @param item Item to add
*/
static inline void
ocs_list_add_head(ocs_list_t *list, void *item)
{
ocs_list_t *link;
ocs_list_assert(list);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC);
ocs_list_assert(item);
link = item2link(list, item);
ocs_list_init_link(list, link);
ocs_list_assert(link->magic == OCS_LIST_LINK_MAGIC);
ocs_list_assert(link->offset == list->offset);
ocs_list_assert(link->next == NULL);
ocs_list_assert(link->prev == NULL);
_ocs_list_insert_link(list, list->next, item2link(list, item));
}
/**
* @ingroup os
* @brief Add an item to the tail of the list
*
* @param list Head of the list
* @param item Item to add
*/
static inline void
ocs_list_add_tail(ocs_list_t *list, void *item)
{
ocs_list_t *link;
ocs_list_assert(list);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC);
ocs_list_assert(item);
link = item2link(list, item);
ocs_list_init_link(list, link);
ocs_list_assert(link->magic == OCS_LIST_LINK_MAGIC);
ocs_list_assert(link->offset == list->offset);
ocs_list_assert(link->next == NULL);
ocs_list_assert(link->prev == NULL);
_ocs_list_insert_link(list->prev, list, link);
}
/**
* @ingroup os
* @brief Return the first item in the list
*
* @param list Head of the list
*
* @return pointer to the first item, NULL otherwise
*/
static inline void *
ocs_list_get_head(ocs_list_t *list)
{
ocs_list_assert(list, NULL);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC, NULL);
return ocs_list_empty(list) ? NULL : link2item(list, list->next);
}
/**
* @ingroup os
* @brief Return the first item in the list
*
* @param list head of the list
*
* @return pointer to the last item, NULL otherwise
*/
static inline void *
ocs_list_get_tail(ocs_list_t *list)
{
ocs_list_assert(list, NULL);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC, NULL);
return ocs_list_empty(list) ? NULL : link2item(list, list->prev);
}
/**
* @ingroup os
* @brief Return the last item in the list
*
* @param list Pointer to list head
*
* @return pointer to the last item, NULL otherwise
*/
static inline void *ocs_list_tail(ocs_list_t *list)
{
ocs_list_assert(list, NULL);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC, NULL);
return ocs_list_empty(list) ? NULL : link2item(list, list->prev);
}
/**
* @ingroup os
* @brief Get the next item on the list
*
* @param list head of the list
* @param item current item
*
* @return pointer to the next item, NULL otherwise
*/
static inline void *ocs_list_next(ocs_list_t *list, void *item)
{
ocs_list_t *link;
if (item == NULL) {
return NULL;
}
ocs_list_assert(list, NULL);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC, NULL);
ocs_list_assert(item, NULL);
link = item2link(list, item);
ocs_list_assert(link->magic == OCS_LIST_LINK_MAGIC, NULL);
ocs_list_assert(link->offset == list->offset, NULL);
ocs_list_assert(link->next, NULL);
ocs_list_assert(link->prev, NULL);
if ((link->next) == list) {
return NULL;
}
return link2item(list, link->next);
}
/**
* @ingroup os
* @brief Remove and return an item from the head of the list
*
* @param list head of the list
*
* @return pointer to returned item, or NULL if list is empty
*/
#define ocs_list_remove_head(list) ocs_list_remove(list, ocs_list_get_head(list))
/**
* @ingroup os
* @brief Remove an item from the list
*
* @param list Head of the list
* @param item Item to remove
*
* @return pointer to item, or NULL if item is not found.
*/
static inline void *ocs_list_remove(ocs_list_t *list, void *item)
{
ocs_list_t *link;
ocs_list_t *prev;
ocs_list_t *next;
if (item == NULL) {
return NULL;
}
ocs_list_assert(list, NULL);
ocs_list_assert(list->magic == OCS_LIST_LIST_MAGIC, NULL);
link = item2link(list, item);
ocs_list_assert(link->magic == OCS_LIST_LINK_MAGIC, NULL);
ocs_list_assert(link->offset == list->offset, NULL);
ocs_list_assert(link->next, NULL);
ocs_list_assert(link->prev, NULL);
prev = link->prev;
next = link->next;
prev->next = next;
next->prev = prev;
link->next = link->prev = NULL;
return item;
}
/**
* @brief Iterate a linked list
*
* Iterate a linked list.
*
* @param list Pointer to list
* @param item Pointer to iterated item
*
* note, item is NULL after full list is traversed.
* @return none
*/
#define ocs_list_foreach(list, item) \
for (item = ocs_list_get_head((list)); item; item = ocs_list_next((list), item) )
/**
* @brief Iterate a linked list safely
*
* Iterate a linked list safely, meaning that the iterated item
* may be safely removed from the list.
*
* @param list Pointer to list
* @param item Pointer to iterated item
* @param nxt Pointer to saveed iterated item
*
* note, item is NULL after full list is traversed.
*
* @return none
*/
#define ocs_list_foreach_safe(list, item, nxt) \
for (item = ocs_list_get_head(list), nxt = item ? ocs_list_next(list, item) : NULL; item; \
item = nxt, nxt = ocs_list_next(list, item))
/**
* @brief Test if object is on a list
*
* Returns True if object is on a list
*
* @param link Pointer to list link
*
* @return returns True if object is on a list
*/
static inline int32_t
ocs_list_on_list(ocs_list_link_t *link)
{
return (link->next != NULL);
}
#endif /* __OCS_LIST_H__ */
