diff options
Diffstat (limited to 'include/linux/list.h')
| -rw-r--r-- | include/linux/list.h | 104 |
1 files changed, 87 insertions, 17 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index aab2db21b013..084971f333fe 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -419,6 +419,20 @@ static inline void list_splice_init(struct list_head *list, pos = n, n = list_entry(n->member.next, typeof(*n), member)) /** + * list_for_each_entry_safe_continue - iterate over list of given type + * continuing after existing point safe against removal of list entry + * @pos: the type * to use as a loop counter. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_safe_continue(pos, n, head, member) \ + for (pos = list_entry(pos->member.next, typeof(*pos), member), \ + n = list_entry(pos->member.next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.next, typeof(*n), member)) + +/** * list_for_each_rcu - iterate over an rcu-protected list * @pos: the &struct list_head to use as a loop counter. * @head: the head for your list. @@ -428,12 +442,14 @@ static inline void list_splice_init(struct list_head *list, * as long as the traversal is guarded by rcu_read_lock(). */ #define list_for_each_rcu(pos, head) \ - for (pos = (head)->next; prefetch(pos->next), pos != (head); \ - pos = rcu_dereference(pos->next)) + for (pos = (head)->next; \ + prefetch(rcu_dereference(pos)->next), pos != (head); \ + pos = pos->next) #define __list_for_each_rcu(pos, head) \ - for (pos = (head)->next; pos != (head); \ - pos = rcu_dereference(pos->next)) + for (pos = (head)->next; \ + rcu_dereference(pos) != (head); \ + pos = pos->next) /** * list_for_each_safe_rcu - iterate over an rcu-protected list safe @@ -447,8 +463,9 @@ static inline void list_splice_init(struct list_head *list, * as long as the traversal is guarded by rcu_read_lock(). */ #define list_for_each_safe_rcu(pos, n, head) \ - for (pos = (head)->next, n = pos->next; pos != (head); \ - pos = rcu_dereference(n), n = pos->next) + for (pos = (head)->next; \ + n = rcu_dereference(pos)->next, pos != (head); \ + pos = n) /** * list_for_each_entry_rcu - iterate over rcu list of given type @@ -460,11 +477,11 @@ static inline void list_splice_init(struct list_head *list, * the _rcu list-mutation primitives such as list_add_rcu() * as long as the traversal is guarded by rcu_read_lock(). */ -#define list_for_each_entry_rcu(pos, head, member) \ - for (pos = list_entry((head)->next, typeof(*pos), member); \ - prefetch(pos->member.next), &pos->member != (head); \ - pos = rcu_dereference(list_entry(pos->member.next, \ - typeof(*pos), member))) +#define list_for_each_entry_rcu(pos, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member); \ + prefetch(rcu_dereference(pos)->member.next), \ + &pos->member != (head); \ + pos = list_entry(pos->member.next, typeof(*pos), member)) /** @@ -478,8 +495,9 @@ static inline void list_splice_init(struct list_head *list, * as long as the traversal is guarded by rcu_read_lock(). */ #define list_for_each_continue_rcu(pos, head) \ - for ((pos) = (pos)->next; prefetch((pos)->next), (pos) != (head); \ - (pos) = rcu_dereference((pos)->next)) + for ((pos) = (pos)->next; \ + prefetch(rcu_dereference((pos))->next), (pos) != (head); \ + (pos) = (pos)->next) /* * Double linked lists with a single pointer list head. @@ -620,6 +638,57 @@ static inline void hlist_add_after(struct hlist_node *n, next->next->pprev = &next->next; } +/** + * hlist_add_before_rcu - adds the specified element to the specified hlist + * before the specified node while permitting racing traversals. + * @n: the new element to add to the hash list. + * @next: the existing element to add the new element before. + * + * The caller must take whatever precautions are necessary + * (such as holding appropriate locks) to avoid racing + * with another list-mutation primitive, such as hlist_add_head_rcu() + * or hlist_del_rcu(), running on this same list. + * However, it is perfectly legal to run concurrently with + * the _rcu list-traversal primitives, such as + * hlist_for_each_rcu(), used to prevent memory-consistency + * problems on Alpha CPUs. + */ +static inline void hlist_add_before_rcu(struct hlist_node *n, + struct hlist_node *next) +{ + n->pprev = next->pprev; + n->next = next; + smp_wmb(); + next->pprev = &n->next; + *(n->pprev) = n; +} + +/** + * hlist_add_after_rcu - adds the specified element to the specified hlist + * after the specified node while permitting racing traversals. + * @prev: the existing element to add the new element after. + * @n: the new element to add to the hash list. + * + * The caller must take whatever precautions are necessary + * (such as holding appropriate locks) to avoid racing + * with another list-mutation primitive, such as hlist_add_head_rcu() + * or hlist_del_rcu(), running on this same list. + * However, it is perfectly legal to run concurrently with + * the _rcu list-traversal primitives, such as + * hlist_for_each_rcu(), used to prevent memory-consistency + * problems on Alpha CPUs. + */ +static inline void hlist_add_after_rcu(struct hlist_node *prev, + struct hlist_node *n) +{ + n->next = prev->next; + n->pprev = &prev->next; + smp_wmb(); + prev->next = n; + if (n->next) + n->next->pprev = &n->next; +} + #define hlist_entry(ptr, type, member) container_of(ptr,type,member) #define hlist_for_each(pos, head) \ @@ -631,8 +700,9 @@ static inline void hlist_add_after(struct hlist_node *n, pos = n) #define hlist_for_each_rcu(pos, head) \ - for ((pos) = (head)->first; pos && ({ prefetch((pos)->next); 1; }); \ - (pos) = rcu_dereference((pos)->next)) + for ((pos) = (head)->first; \ + rcu_dereference((pos)) && ({ prefetch((pos)->next); 1; }); \ + (pos) = (pos)->next) /** * hlist_for_each_entry - iterate over list of given type @@ -697,9 +767,9 @@ static inline void hlist_add_after(struct hlist_node *n, */ #define hlist_for_each_entry_rcu(tpos, pos, head, member) \ for (pos = (head)->first; \ - pos && ({ prefetch(pos->next); 1;}) && \ + rcu_dereference(pos) && ({ prefetch(pos->next); 1;}) && \ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ - pos = rcu_dereference(pos->next)) + pos = pos->next) #else #warning "don't include kernel headers in userspace" |