1 files changed, 707 insertions, 0 deletions

diff --git a/include/linux/list.h b/include/linux/list.h
new file mode 100644
index 000000000000..dd7cd54fa831
--- /dev/null
+++ b/include/linux/list.h
@@ -0,0 +1,707 @@
+#ifndef _LINUX_LIST_H
+#define _LINUX_LIST_H
+
+#ifdef __KERNEL__
+
+#include <linux/stddef.h>
+#include <linux/prefetch.h>
+#include <asm/system.h>
+
+/*
+ * These are non-NULL pointers that will result in page faults
+ * under normal circumstances, used to verify that nobody uses
+ * non-initialized list entries.
+ */
+#define LIST_POISON1  ((void *) 0x00100100)
+#define LIST_POISON2  ((void *) 0x00200200)
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+struct list_head {
+        struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+        struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+        (ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add(struct list_head *new,
+                              struct list_head *prev,
+                              struct list_head *next)
+{
+        next->prev = new;
+        new->next = next;
+        new->prev = prev;
+        prev->next = new;
+}
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+        __list_add(new, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+        __list_add(new, head->prev, head);
+}
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add_rcu(struct list_head * new,
+                struct list_head * prev, struct list_head * next)
+{
+        new->next = next;
+        new->prev = prev;
+        smp_wmb();
+        next->prev = new;
+        prev->next = new;
+}
+
+/**
+ * list_add_rcu - add a new entry to rcu-protected list
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+static inline void list_add_rcu(struct list_head *new, struct list_head *head)
+{
+        __list_add_rcu(new, head, head->next);
+}
+
+/**
+ * list_add_tail_rcu - add a new entry to rcu-protected list
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_tail_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+static inline void list_add_tail_rcu(struct list_head *new,
+                                        struct list_head *head)
+{
+        __list_add_rcu(new, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_del(struct list_head * prev, struct list_head * next)
+{
+        next->prev = prev;
+        prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is
+ * in an undefined state.
+ */
+static inline void list_del(struct list_head *entry)
+{
+        __list_del(entry->prev, entry->next);
+        entry->next = LIST_POISON1;
+        entry->prev = LIST_POISON2;
+}
+
+/**
+ * list_del_rcu - deletes entry from list without re-initialization
+ * @entry: the element to delete from the list.
+ *
+ * Note: list_empty on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_del_rcu()
+ * or list_add_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ *
+ * Note that the caller is not permitted to immediately free
+ * the newly deleted entry.  Instead, either synchronize_kernel()
+ * or call_rcu() must be used to defer freeing until an RCU
+ * grace period has elapsed.
+ */
+static inline void list_del_rcu(struct list_head *entry)
+{
+        __list_del(entry->prev, entry->next);
+        entry->prev = LIST_POISON2;
+}
+
+/*
+ * list_replace_rcu - replace old entry by new one
+ * @old : the element to be replaced
+ * @new : the new element to insert
+ *
+ * The old entry will be replaced with the new entry atomically.
+ */
+static inline void list_replace_rcu(struct list_head *old, struct list_head *new){
+        new->next = old->next;
+        new->prev = old->prev;
+        smp_wmb();
+        new->next->prev = new;
+        new->prev->next = new;
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static inline void list_del_init(struct list_head *entry)
+{
+        __list_del(entry->prev, entry->next);
+        INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_move - delete from one list and add as another's head
+ * @list: the entry to move
+ * @head: the head that will precede our entry
+ */
+static inline void list_move(struct list_head *list, struct list_head *head)
+{
+        __list_del(list->prev, list->next);
+        list_add(list, head);
+}
+
+/**
+ * list_move_tail - delete from one list and add as another's tail
+ * @list: the entry to move
+ * @head: the head that will follow our entry
+ */
+static inline void list_move_tail(struct list_head *list,
+                                  struct list_head *head)
+{
+        __list_del(list->prev, list->next);
+        list_add_tail(list, head);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static inline int list_empty(const struct list_head *head)
+{
+        return head->next == head;
+}
+
+/**
+ * list_empty_careful - tests whether a list is
+ * empty _and_ checks that no other CPU might be
+ * in the process of still modifying either member
+ *
+ * NOTE: using list_empty_careful() without synchronization
+ * can only be safe if the only activity that can happen
+ * to the list entry is list_del_init(). Eg. it cannot be used
+ * if another CPU could re-list_add() it.
+ *
+ * @head: the list to test.
+ */
+static inline int list_empty_careful(const struct list_head *head)
+{
+        struct list_head *next = head->next;
+        return (next == head) && (next == head->prev);
+}
+
+static inline void __list_splice(struct list_head *list,
+                                 struct list_head *head)
+{
+        struct list_head *first = list->next;
+        struct list_head *last = list->prev;
+        struct list_head *at = head->next;
+
+        first->prev = head;
+        head->next = first;
+
+        last->next = at;
+        at->prev = last;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice(struct list_head *list, struct list_head *head)
+{
+        if (!list_empty(list))
+                __list_splice(list, head);
+}
+
+/**
+ * list_splice_init - join two lists and reinitialise the emptied list.
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_init(struct list_head *list,
+                                    struct list_head *head)
+{
+        if (!list_empty(list)) {
+                __list_splice(list, head);
+                INIT_LIST_HEAD(list);
+        }
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr:        the &struct list_head pointer.
+ * @type:       the type of the struct this is embedded in.
+ * @member:     the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+        container_of(ptr, type, member)
+
+/**
+ * list_for_each        -       iterate over a list
+ * @pos:        the &struct list_head to use as a loop counter.
+ * @head:       the head for your list.
+ */
+#define list_for_each(pos, head) \
+        for (pos = (head)->next; prefetch(pos->next), pos != (head); \
+                pos = pos->next)
+
+/**
+ * __list_for_each      -       iterate over a list
+ * @pos:        the &struct list_head to use as a loop counter.
+ * @head:       the head for your list.
+ *
+ * This variant differs from list_for_each() in that it's the
+ * simplest possible list iteration code, no prefetching is done.
+ * Use this for code that knows the list to be very short (empty
+ * or 1 entry) most of the time.
+ */
+#define __list_for_each(pos, head) \
+        for (pos = (head)->next; pos != (head); pos = pos->next)
+
+/**
+ * list_for_each_prev   -       iterate over a list backwards
+ * @pos:        the &struct list_head to use as a loop counter.
+ * @head:       the head for your list.
+ */
+#define list_for_each_prev(pos, head) \
+        for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
+                pos = pos->prev)
+
+/**
+ * list_for_each_safe   -       iterate over a list safe against removal of list entry
+ * @pos:        the &struct list_head to use as a loop counter.
+ * @n:          another &struct list_head to use as temporary storage
+ * @head:       the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+        for (pos = (head)->next, n = pos->next; pos != (head); \
+                pos = n, n = pos->next)
+
+/**
+ * list_for_each_entry  -       iterate over list of given type
+ * @pos:        the type * to use as a loop counter.
+ * @head:       the head for your list.
+ * @member:     the name of the list_struct within the struct.
+ */
+#define list_for_each_entry(pos, head, member)                          \
+        for (pos = list_entry((head)->next, typeof(*pos), member);      \
+             prefetch(pos->member.next), &pos->member != (head);        \
+             pos = list_entry(pos->member.next, typeof(*pos), member))
+
+/**
+ * list_for_each_entry_reverse - iterate backwards over list of given type.
+ * @pos:        the type * to use as a loop counter.
+ * @head:       the head for your list.
+ * @member:     the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_reverse(pos, head, member)                  \
+        for (pos = list_entry((head)->prev, typeof(*pos), member);      \
+             prefetch(pos->member.prev), &pos->member != (head);        \
+             pos = list_entry(pos->member.prev, typeof(*pos), member))
+
+/**
+ * list_prepare_entry - prepare a pos entry for use as a start point in
+ *                      list_for_each_entry_continue
+ * @pos:        the type * to use as a start point
+ * @head:       the head of the list
+ * @member:     the name of the list_struct within the struct.
+ */
+#define list_prepare_entry(pos, head, member) \
+        ((pos) ? : list_entry(head, typeof(*pos), member))
+
+/**
+ * list_for_each_entry_continue -       iterate over list of given type
+ *                      continuing after existing point
+ * @pos:        the type * to use as a loop counter.
+ * @head:       the head for your list.
+ * @member:     the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_continue(pos, head, member)                 \
+        for (pos = list_entry(pos->member.next, typeof(*pos), member);  \
+             prefetch(pos->member.next), &pos->member != (head);        \
+             pos = list_entry(pos->member.next, typeof(*pos), member))
+
+/**
+ * list_for_each_entry_safe - iterate over list of given type 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(pos, n, head, member)                  \
+        for (pos = list_entry((head)->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.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * 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_rcu(pos, head) \
+        for (pos = (head)->next; prefetch(pos->next), pos != (head); \
+                pos = rcu_dereference(pos->next))
+
+#define __list_for_each_rcu(pos, head) \
+        for (pos = (head)->next; pos != (head); \
+                pos = rcu_dereference(pos->next))
+
+/**
+ * list_for_each_safe_rcu       -       iterate over an rcu-protected list safe
+ *                                      against removal of list entry
+ * @pos:        the &struct list_head to use as a loop counter.
+ * @n:          another &struct list_head to use as temporary storage
+ * @head:       the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * 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_safe_rcu(pos, n, head) \
+        for (pos = (head)->next, n = pos->next; pos != (head); \
+                pos = rcu_dereference(n), n = pos->next)
+
+/**
+ * list_for_each_entry_rcu      -       iterate over rcu list of given type
+ * @pos:        the type * to use as a loop counter.
+ * @head:       the head for your list.
+ * @member:     the name of the list_struct within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * 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)))
+
+
+/**
+ * list_for_each_continue_rcu   -       iterate over an rcu-protected list
+ *                      continuing after existing point.
+ * @pos:        the &struct list_head to use as a loop counter.
+ * @head:       the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * 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_continue_rcu(pos, head) \
+        for ((pos) = (pos)->next; prefetch((pos)->next), (pos) != (head); \
+                (pos) = rcu_dereference((pos)->next))
+
+/*
+ * Double linked lists with a single pointer list head.
+ * Mostly useful for hash tables where the two pointer list head is
+ * too wasteful.
+ * You lose the ability to access the tail in O(1).
+ */
+
+struct hlist_head {
+        struct hlist_node *first;
+};
+
+struct hlist_node {
+        struct hlist_node *next, **pprev;
+};
+
+#define HLIST_HEAD_INIT { .first = NULL }
+#define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
+#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
+#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)
+
+static inline int hlist_unhashed(const struct hlist_node *h)
+{
+        return !h->pprev;
+}
+
+static inline int hlist_empty(const struct hlist_head *h)
+{
+        return !h->first;
+}
+
+static inline void __hlist_del(struct hlist_node *n)
+{
+        struct hlist_node *next = n->next;
+        struct hlist_node **pprev = n->pprev;
+        *pprev = next;
+        if (next)
+                next->pprev = pprev;
+}
+
+static inline void hlist_del(struct hlist_node *n)
+{
+        __hlist_del(n);
+        n->next = LIST_POISON1;
+        n->pprev = LIST_POISON2;
+}
+
+/**
+ * hlist_del_rcu - deletes entry from hash list without re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: list_unhashed() on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking 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_entry().
+ */
+static inline void hlist_del_rcu(struct hlist_node *n)
+{
+        __hlist_del(n);
+        n->pprev = LIST_POISON2;
+}
+
+static inline void hlist_del_init(struct hlist_node *n)
+{
+        if (n->pprev)  {
+                __hlist_del(n);
+                INIT_HLIST_NODE(n);
+        }
+}
+
+static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
+{
+        struct hlist_node *first = h->first;
+        n->next = first;
+        if (first)
+                first->pprev = &n->next;
+        h->first = n;
+        n->pprev = &h->first;
+}
+
+
+/**
+ * hlist_add_head_rcu - adds the specified element to the specified hlist,
+ * while permitting racing traversals.
+ * @n: the element to add to the hash list.
+ * @h: the list to add to.
+ *
+ * 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.  Regardless of the type of CPU, the
+ * list-traversal primitive must be guarded by rcu_read_lock().
+ */
+static inline void hlist_add_head_rcu(struct hlist_node *n,
+                                        struct hlist_head *h)
+{
+        struct hlist_node *first = h->first;
+        n->next = first;
+        n->pprev = &h->first;
+        smp_wmb();
+        if (first)
+                first->pprev = &n->next;
+        h->first = n;
+}
+
+/* next must be != NULL */
+static inline void hlist_add_before(struct hlist_node *n,
+                                        struct hlist_node *next)
+{
+        n->pprev = next->pprev;
+        n->next = next;
+        next->pprev = &n->next;
+        *(n->pprev) = n;
+}
+
+static inline void hlist_add_after(struct hlist_node *n,
+                                        struct hlist_node *next)
+{
+        next->next = n->next;
+        n->next = next;
+        next->pprev = &n->next;
+
+        if(next->next)
+                next->next->pprev  = &next->next;
+}
+
+#define hlist_entry(ptr, type, member) container_of(ptr,type,member)
+
+#define hlist_for_each(pos, head) \
+        for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
+             pos = pos->next)
+
+#define hlist_for_each_safe(pos, n, head) \
+        for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
+             pos = n)
+
+#define hlist_for_each_rcu(pos, head) \
+        for ((pos) = (head)->first; pos && ({ prefetch((pos)->next); 1; }); \
+                (pos) = rcu_dereference((pos)->next))
+
+/**
+ * hlist_for_each_entry - iterate over list of given type
+ * @tpos:       the type * to use as a loop counter.
+ * @pos:        the &struct hlist_node to use as a loop counter.
+ * @head:       the head for your list.
+ * @member:     the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry(tpos, pos, head, member)                    \
+        for (pos = (head)->first;                                        \
+             pos && ({ prefetch(pos->next); 1;}) &&                      \
+                ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+             pos = pos->next)
+
+/**
+ * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
+ * @tpos:       the type * to use as a loop counter.
+ * @pos:        the &struct hlist_node to use as a loop counter.
+ * @member:     the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_continue(tpos, pos, member)                 \
+        for (pos = (pos)->next;                                          \
+             pos && ({ prefetch(pos->next); 1;}) &&                      \
+                ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+             pos = pos->next)
+
+/**
+ * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
+ * @tpos:       the type * to use as a loop counter.
+ * @pos:        the &struct hlist_node to use as a loop counter.
+ * @member:     the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_from(tpos, pos, member)                     \
+        for (; pos && ({ prefetch(pos->next); 1;}) &&                    \
+                ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+             pos = pos->next)
+
+/**
+ * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @tpos:       the type * to use as a loop counter.
+ * @pos:        the &struct hlist_node to use as a loop counter.
+ * @n:          another &struct hlist_node to use as temporary storage
+ * @head:       the head for your list.
+ * @member:     the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_safe(tpos, pos, n, head, member)            \
+        for (pos = (head)->first;                                        \
+             pos && ({ n = pos->next; 1; }) &&                           \
+                ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+             pos = n)
+
+/**
+ * hlist_for_each_entry_rcu - iterate over rcu list of given type
+ * @pos:        the type * to use as a loop counter.
+ * @pos:        the &struct hlist_node to use as a loop counter.
+ * @head:       the head for your list.
+ * @member:     the name of the hlist_node within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as hlist_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define hlist_for_each_entry_rcu(tpos, pos, head, member)                \
+        for (pos = (head)->first;                                        \
+             pos && ({ prefetch(pos->next); 1;}) &&                      \
+                ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+             pos = rcu_dereference(pos->next))
+
+#else
+#warning "don't include kernel headers in userspace"
+#endif /* __KERNEL__ */
+#endif