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>

2 files changed, 41 insertions, 40 deletions

diff --git a/extras/mini-os/lib/sys.c b/extras/mini-os/lib/sys.c
index b7b3aff50a..2329a78c21 100644
--- a/extras/mini-os/lib/sys.c
+++ b/extras/mini-os/lib/sys.c
@@ -234,7 +234,7 @@ int read(int fd, void *buf, size_t nbytes)
                     break;
                 schedule();
             }
-            remove_waiter(w);
+            remove_waiter(w, console_queue);
             return ret;
         }
 #ifdef HAVE_LWIP
@@ -705,12 +705,12 @@ int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
     fd_set myread, mywrite, myexcept;
     struct thread *thread = get_current();
     s_time_t start = NOW(), stop;
-    DEFINE_WAIT(w1);
-    DEFINE_WAIT(w2);
-    DEFINE_WAIT(w3);
-    DEFINE_WAIT(w4);
-    DEFINE_WAIT(w5);
-    DEFINE_WAIT(w6);
+    DEFINE_WAIT(netfront_w);
+    DEFINE_WAIT(event_w);
+    DEFINE_WAIT(blkfront_w);
+    DEFINE_WAIT(xenbus_watch_w);
+    DEFINE_WAIT(kbdfront_w);
+    DEFINE_WAIT(console_w);
 
     assert(thread == main_thread);
 
@@ -727,12 +727,12 @@ int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
     /* Tell people we're going to sleep before looking at what they are
      * saying, hence letting them wake us if events happen between here and
      * schedule() */
-    add_waiter(w1, netfront_queue);
-    add_waiter(w2, event_queue);
-    add_waiter(w3, blkfront_queue);
-    add_waiter(w4, xenbus_watch_queue);
-    add_waiter(w5, kbdfront_queue);
-    add_waiter(w6, console_queue);
+    add_waiter(netfront_w, netfront_queue);
+    add_waiter(event_w, event_queue);
+    add_waiter(blkfront_w, blkfront_queue);
+    add_waiter(xenbus_watch_w, xenbus_watch_queue);
+    add_waiter(kbdfront_w, kbdfront_queue);
+    add_waiter(console_w, console_queue);
 
     if (readfds)
         myread = *readfds;
@@ -814,12 +814,12 @@ int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
     ret = -1;
 
 out:
-    remove_waiter(w1);
-    remove_waiter(w2);
-    remove_waiter(w3);
-    remove_waiter(w4);
-    remove_waiter(w5);
-    remove_waiter(w6);
+    remove_waiter(netfront_w, netfront_queue);
+    remove_waiter(event_w, event_queue);
+    remove_waiter(blkfront_w, blkfront_queue);
+    remove_waiter(xenbus_watch_w, xenbus_watch_queue);
+    remove_waiter(kbdfront_w, kbdfront_queue);
+    remove_waiter(console_w, console_queue);
     return ret;
 }
 
diff --git a/extras/mini-os/lib/xmalloc.c b/extras/mini-os/lib/xmalloc.c
index c7d3fc1b30..015cd31bb9 100644
--- a/extras/mini-os/lib/xmalloc.c
+++ b/extras/mini-os/lib/xmalloc.c
@@ -44,16 +44,18 @@
 #include <mini-os/xmalloc.h>
 
 #ifndef HAVE_LIBC
-static MINIOS_LIST_HEAD(freelist);
 /* static spinlock_t freelist_lock = SPIN_LOCK_UNLOCKED; */
 
 struct xmalloc_hdr
 {
     /* Total including this hdr, unused padding and second hdr. */
     size_t size;
-    struct minios_list_head freelist;
+    MINIOS_TAILQ_ENTRY(struct xmalloc_hdr) freelist;
 } __cacheline_aligned;
 
+static MINIOS_TAILQ_HEAD(,struct xmalloc_hdr) freelist =
+	MINIOS_TAILQ_HEAD_INITIALIZER(freelist);
+
 /* Unused padding data between the two hdrs. */
 
 struct xmalloc_pad
@@ -82,7 +84,7 @@ static void maybe_split(struct xmalloc_hdr *hdr, size_t size, size_t block)
         extra = (struct xmalloc_hdr *)((unsigned long)hdr + size);
         extra->size = leftover;
         /* spin_lock_irqsave(&freelist_lock, flags); */
-        minios_list_add(&extra->freelist, &freelist);
+        MINIOS_TAILQ_INSERT_HEAD(&freelist, extra, freelist);
         /* spin_unlock_irqrestore(&freelist_lock, flags); */
     }
     else
@@ -91,8 +93,6 @@ static void maybe_split(struct xmalloc_hdr *hdr, size_t size, size_t block)
     }
 
     hdr->size = size;
-    /* Debugging aid. */
-    hdr->freelist.next = hdr->freelist.prev = NULL;
 }
 
 static struct xmalloc_hdr *xmalloc_new_page(size_t size)
@@ -128,8 +128,6 @@ static void *xmalloc_whole_pages(size_t size, size_t align)
         return NULL;
 
     hdr->size = (1UL << (pageorder + PAGE_SHIFT));
-    /* Debugging aid. */
-    hdr->freelist.next = hdr->freelist.prev = NULL;
 
     ret = (char*)hdr + hdr_size;
     pad = (struct xmalloc_pad *) ret - 1;
@@ -155,14 +153,14 @@ void *_xmalloc(size_t size, size_t align)
 
     /* Search free list. */
     /* spin_lock_irqsave(&freelist_lock, flags); */
-    minios_list_for_each_entry_safe( i, tmp, &freelist, freelist )
+    MINIOS_TAILQ_FOREACH_SAFE(i, &freelist, freelist, tmp)
     {
         data_begin = align_up((uintptr_t)i + hdr_size, align);
 
         if ( data_begin + size > (uintptr_t)i + i->size )
             continue;
 
-        minios_list_del(&i->freelist);
+        MINIOS_TAILQ_REMOVE(&freelist, i, freelist);
         /* spin_unlock_irqrestore(&freelist_lock, flags); */
 
         uintptr_t size_before = (data_begin - hdr_size) - (uintptr_t)i;
@@ -173,7 +171,7 @@ void *_xmalloc(size_t size, size_t align)
             new_i->size = i->size - size_before;
             i->size = size_before;
             /* spin_lock_irqsave(&freelist_lock, flags); */
-            minios_list_add(&i->freelist, &freelist);
+            MINIOS_TAILQ_INSERT_HEAD(&freelist, i, freelist);
             /* spin_unlock_irqrestore(&freelist_lock, flags); */
             i = new_i;
         }
@@ -224,16 +222,9 @@ void xfree(const void *p)
         *(int*)0=0;
     }
 
-    /* Not previously freed. */
-    if(hdr->freelist.next || hdr->freelist.prev)
-    {
-        printk("Should not be previously freed\n");
-        *(int*)0=0;
-    }
-
     /* Merge with other free block, or put in list. */
     /* spin_lock_irqsave(&freelist_lock, flags); */
-    minios_list_for_each_entry_safe( i, tmp, &freelist, freelist )
+    MINIOS_TAILQ_FOREACH_SAFE(i, &freelist, freelist, tmp)
     {
         unsigned long _i   = (unsigned long)i;
         unsigned long _hdr = (unsigned long)hdr;
@@ -245,7 +236,7 @@ void xfree(const void *p)
         /* We follow this block?  Swallow it. */
         if ( (_i + i->size) == _hdr )
         {
-            minios_list_del(&i->freelist);
+            MINIOS_TAILQ_REMOVE(&freelist, i, freelist);
             i->size += hdr->size;
             hdr = i;
         }
@@ -253,7 +244,7 @@ void xfree(const void *p)
         /* We precede this block? Swallow it. */
         if ( (_hdr + hdr->size) == _i )
         {
-            minios_list_del(&i->freelist);
+            MINIOS_TAILQ_REMOVE(&freelist, i, freelist);
             hdr->size += i->size;
         }
     }
@@ -270,7 +261,7 @@ void xfree(const void *p)
     }
     else
     {
-        minios_list_add(&hdr->freelist, &freelist);
+        MINIOS_TAILQ_INSERT_HEAD(&freelist, hdr, freelist);
     }
 
     /* spin_unlock_irqrestore(&freelist_lock, flags); */
@@ -306,3 +297,13 @@ void *_realloc(void *ptr, size_t size)
     return new;
 }
 #endif
+
+/*
+ * Local variables:
+ * mode: C
+ * c-set-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */