[src/trunk]: src/sys/external/bsd/drm2/include/linux Reimplement GPL <linux/l...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6e703d9bb393
branches:  trunk
changeset: 1027771:6e703d9bb393
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Dec 19 00:27:36 2021 +0000

description:
Reimplement GPL <linux/llist.h> using only the upstream comments.

Hope I gathered what this is trying to do...!

diffstat:

 sys/external/bsd/drm2/include/linux/llist.h |  116 ++++++++++++++++++++++++++++
 1 files changed, 116 insertions(+), 0 deletions(-)

diffs (120 lines):

diff -r cc1ddb8767c2 -r 6e703d9bb393 sys/external/bsd/drm2/include/linux/llist.h
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/external/bsd/drm2/include/linux/llist.h       Sun Dec 19 00:27:36 2021 +0000
@@ -0,0 +1,116 @@
+/*     $NetBSD: llist.h,v 1.1 2021/12/19 00:27:36 riastradh Exp $      */
+
+/*-
+ * Copyright (c) 2018 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Taylor R. Campbell.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef        _LINUX_LLIST_H_
+#define        _LINUX_LLIST_H_
+
+#include <sys/atomic.h>
+#include <sys/null.h>
+
+struct llist_head {
+       struct llist_node       *llh_first;
+};
+
+struct llist_node {
+       struct llist_node       *llh_next;
+};
+
+static inline void
+init_llist_head(struct llist_head *head)
+{
+
+       head->llh_first = NULL;
+}
+
+#define        llist_entry(NODE, TYPE, FIELD)  container_of(NODE, TYPE, FIELD)
+
+static inline bool
+llist_empty(struct llist_head *head)
+{
+       bool empty;
+
+       empty = (head->llh_first == NULL);
+       membar_enter();
+
+       return empty;
+}
+
+static inline bool
+llist_add(struct llist_node *node, struct llist_head *head)
+{
+       struct llist_node *first;
+
+       do {
+               first = head->llh_first;
+               node->llh_next = first;
+               membar_exit();
+       } while (atomic_cas_ptr(&head->llh_first, first, node) != first);
+
+       return first == NULL;
+}
+
+static inline struct llist_node *
+llist_del_all(struct llist_head *head)
+{
+       struct llist_node *first;
+
+       first = atomic_swap_ptr(&head->llh_first, NULL);
+       membar_enter();
+
+       return first;
+}
+
+static inline struct llist_node *
+llist_del_first(struct llist_head *head)
+{
+       struct llist_node *first;
+
+       do {
+               first = head->llh_first;
+               membar_datadep_consumer();
+       } while (atomic_cas_ptr(&head->llh_first, first, first->llh_next)
+           != first);
+       membar_enter();
+
+       return first;
+}
+
+#define        llist_for_each_entry_safe(ENTRY, TMP, NODE, FIELD)                    \
+       for ((ENTRY) = ((NODE) == NULL ? NULL :                               \
+                       llist_entry(NODE, typeof(*(ENTRY)), FIELD));          \
+               (ENTRY) == NULL ? 0 :                                         \
+                   (membar_datadep_consumer(),                               \
+                       (TMP) = list_entry((ENTRY)->FIELD.llh_next,           \
+                           typeof(*(ENTRY)), FIELD),                         \
+                       1),                                                   \
+                (ENTRY) = (TMP))
+
+#endif /* _LINUX_LLIST_H_ */