Xenbus implementation ported from Linux to Mini-os, simple thread support introduced

to simplify the porting. 64 bit version of Mini-os now compiles, but does not work
because of the pagetables and some bits of scheduler not being written.

Signed-off-by: Grzegorz Milos <gm281@cam.ac.uk>

1 files changed, 31 insertions, 0 deletions

diff --git a/extras/mini-os/include/err.h b/extras/mini-os/include/err.h
new file mode 100644
index 0000000000..c329c57d88
--- /dev/null
+++ b/extras/mini-os/include/err.h
@@ -0,0 +1,31 @@
+#ifndef _ERR_H
+#define _ERR_H
+
+#include <errno.h>
+
+/*
+ * Kernel pointers have redundant information, so we can use a
+ * scheme where we can return either an error code or a dentry
+ * pointer with the same return value.
+ *
+ * This should be a per-architecture thing, to allow different
+ * error and pointer decisions.
+ */
+#define IS_ERR_VALUE(x) ((x) > (unsigned long)-1000L)
+
+static inline void *ERR_PTR(long error)
+{
+	return (void *) error;
+}
+
+static inline long PTR_ERR(const void *ptr)
+{
+	return (long) ptr;
+}
+
+static inline long IS_ERR(const void *ptr)
+{
+	return IS_ERR_VALUE((unsigned long)ptr);
+}
+
+#endif /* _LINUX_ERR_H */