list_bl: Add hlist_bl_add_before/behind helpers

	hlist_bl_set_first(h, n);

}

static inline void hlist_bl_add_before(struct hlist_bl_node *n,

				       struct hlist_bl_node *next)

{

	struct hlist_bl_node **pprev = next->pprev;

	n->pprev = pprev;

	n->next = next;

	next->pprev = &n->next;

	/* pprev may be `first`, so be careful not to lose the lock bit */

	WRITE_ONCE(*pprev,

		   (struct hlist_bl_node *)

			((uintptr_t)n | ((uintptr_t)*pprev & LIST_BL_LOCKMASK)));

}

static inline void hlist_bl_add_behind(struct hlist_bl_node *n,

				       struct hlist_bl_node *prev)

{

	n->next = prev->next;

	n->pprev = &prev->next;

	prev->next = n;

	if (n->next)

		n->next->pprev = &n->next;

}

static inline void __hlist_bl_del(struct hlist_bl_node *n)

{

	struct hlist_bl_node *next = n->next;