Import linked list helpers from the intel DDX.

Borrowed from i830.h, except for list_for_each_entry().

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>

include/Makefile.am

@@ -27,6 +27,7 @@ sdk_HEADERS =		\
 	globals.h	\
 	input.h		\
 	inputstr.h	\
+	list.h		\
 	misc.h		\
 	miscstruct.h	\
 	opaque.h	\

include/list.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright © 2010 Intel Corporation
+ * Copyright © 2010 Francisco Jerez <currojerez@riseup.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef _LIST_H_
+#define _LIST_H_
+
+/* classic doubly-link circular list */
+struct list {
+    struct list *next, *prev;
+};
+
+static void
+list_init(struct list *list)
+{
+    list->next = list->prev = list;
+}
+
+static inline void
+__list_add(struct list *entry,
+	    struct list *prev,
+	    struct list *next)
+{
+    next->prev = entry;
+    entry->next = next;
+    entry->prev = prev;
+    prev->next = entry;
+}
+
+static inline void
+list_add(struct list *entry, struct list *head)
+{
+    __list_add(entry, head, head->next);
+}
+
+static inline void
+__list_del(struct list *prev, struct list *next)
+{
+    next->prev = prev;
+    prev->next = next;
+}
+
+static inline void
+list_del(struct list *entry)
+{
+    __list_del(entry->prev, entry->next);
+    list_init(entry);
+}
+
+static inline Bool
+list_is_empty(struct list *head)
+{
+    return head->next == head;
+}
+
+#ifndef container_of
+#define container_of(ptr, type, member) \
+    (type *)((char *)(ptr) - (char *) &((type *)0)->member)
+#endif
+
+#define list_entry(ptr, type, member) \
+    container_of(ptr, type, member)
+
+#define list_first_entry(ptr, type, member) \
+    list_entry((ptr)->next, type, member)
+
+#define __container_of(ptr, sample, member)				\
+    (void *)((char *)(ptr)						\
+	     - ((char *)&(sample)->member - (char *)(sample)))
+
+#define list_for_each_entry(pos, head, member)				\
+    for (pos = __container_of((head)->next, pos, member);		\
+	 &pos->member != (head);					\
+	 pos = __container_of(pos->member.next, pos, member))
+
+#endif