mini-os: use BSD sys/queue.h instead of Linux list.h

The latter is GPL which makes the whole of mini-os GPL rather than BSD
as intended. In tree users are all GPL or GPL-compatible but we should
fix this so that mini-os is BSD. Do so by using the same BSD
sys/queue.h as we use in libxl.

Tested with the builtin mini-os test app and qemu stubdomain, both of which
appear to still function as expected.

Move tools/libxl/external and the associated sed script to
tools/include/xen-external to allow more sensible access from mini-os.

Also add s/NULL/0/ in the sed script due to NULL not always being
defined in stubdom code when mini-os/wait.h is included.

As well as the obvious ABI changes there are a few API updates
associated with the change:

  - struct rw_semaphore.wait_list is unused
  - remove_waiter needs to take the wait_queue_head

The latter requires a qemu update, so there is also a QEMU_TAG
update in this changeset.

I sprinkled some extra-emacs local variables around the files I edited
which didn't have them.

I think this should be backported to the stable branches since
external users of mini-os may have been mislead into thinking they
could safely link mini-os against GPL-incompatible code.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

1 files changed, 16 insertions, 10 deletions

diff --git a/extras/mini-os/include/waittypes.h b/extras/mini-os/include/waittypes.h
index 1215ffe0be..78d91c1542 100644
--- a/extras/mini-os/include/waittypes.h
+++ b/extras/mini-os/include/waittypes.h
@@ -6,21 +6,27 @@
 struct thread;
 struct wait_queue
 {
+    int waiting;
     struct thread *thread;
-    struct minios_list_head thread_list;
+    MINIOS_STAILQ_ENTRY(struct wait_queue) thread_list;
 };
 
-struct wait_queue_head
-{
-    /* TODO - lock required? */
-    struct minios_list_head thread_list;
-};
+/* TODO - lock required? */
+MINIOS_STAILQ_HEAD(wait_queue_head, struct wait_queue);
 
 #define DECLARE_WAIT_QUEUE_HEAD(name) \
-   struct wait_queue_head name =     \
-        { .thread_list = { &(name).thread_list, &(name).thread_list} }
+    struct wait_queue_head name = MINIOS_STAILQ_HEAD_INITIALIZER(name)
 
-#define __WAIT_QUEUE_HEAD_INITIALIZER(name) {                           \
-    .thread_list      = { &(name).thread_list, &(name).thread_list } }
+#define __WAIT_QUEUE_HEAD_INITIALIZER(name) MINIOS_STAILQ_HEAD_INITIALIZER(name)
 
 #endif
+
+/*
+ * Local variables:
+ * mode: C
+ * c-set-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */