1 files changed, 80 insertions, 0 deletions

diff --git a/net/rds/xlist.h b/net/rds/xlist.h
new file mode 100644
index 00000000000..e6b5190dadd
--- /dev/null
+++ b/net/rds/xlist.h
@@ -0,0 +1,80 @@
+#ifndef _LINUX_XLIST_H
+#define _LINUX_XLIST_H
+
+#include <linux/stddef.h>
+#include <linux/poison.h>
+#include <linux/prefetch.h>
+#include <asm/system.h>
+
+struct xlist_head {
+        struct xlist_head *next;
+};
+
+static inline void INIT_XLIST_HEAD(struct xlist_head *list)
+{
+        list->next = NULL;
+}
+
+static inline int xlist_empty(struct xlist_head *head)
+{
+        return head->next == NULL;
+}
+
+static inline void xlist_add(struct xlist_head *new, struct xlist_head *tail,
+                             struct xlist_head *head)
+{
+        struct xlist_head *cur;
+        struct xlist_head *check;
+
+        while (1) {
+                cur = head->next;
+                tail->next = cur;
+                check = cmpxchg(&head->next, cur, new);
+                if (check == cur)
+                        break;
+        }
+}
+
+static inline struct xlist_head *xlist_del_head(struct xlist_head *head)
+{
+        struct xlist_head *cur;
+        struct xlist_head *check;
+        struct xlist_head *next;
+
+        while (1) {
+                cur = head->next;
+                if (!cur)
+                        goto out;
+
+                next = cur->next;
+                check = cmpxchg(&head->next, cur, next);
+                if (check == cur)
+                        goto out;
+        }
+out:
+        return cur;
+}
+
+static inline struct xlist_head *xlist_del_head_fast(struct xlist_head *head)
+{
+        struct xlist_head *cur;
+
+        cur = head->next;
+        if (!cur)
+                return NULL;
+
+        head->next = cur->next;
+        return cur;
+}
+
+static inline void xlist_splice(struct xlist_head *list,
+                                struct xlist_head *head)
+{
+        struct xlist_head *cur;
+
+        WARN_ON(head->next);
+        cur = xchg(&list->next, NULL);
+        head->next = cur;
+}
+
+#endif