1 files changed, 72 insertions, 0 deletions

diff --git a/fs/jffs2/pushpull.h b/fs/jffs2/pushpull.h
new file mode 100644
index 000000000000..c0c2a9158dff
--- /dev/null
+++ b/fs/jffs2/pushpull.h
@@ -0,0 +1,72 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright (C) 2001, 2002 Red Hat, Inc.
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ * $Id: pushpull.h,v 1.10 2004/11/16 20:36:11 dwmw2 Exp $
+ *
+ */
+
+#ifndef __PUSHPULL_H__
+#define __PUSHPULL_H__
+
+#include <linux/errno.h>
+
+struct pushpull {
+        unsigned char *buf;
+        unsigned int buflen;
+        unsigned int ofs;
+        unsigned int reserve;
+};
+
+
+static inline void init_pushpull(struct pushpull *pp, char *buf, unsigned buflen, unsigned ofs, unsigned reserve)
+{
+        pp->buf = buf;
+        pp->buflen = buflen;
+        pp->ofs = ofs;
+        pp->reserve = reserve;
+}
+
+static inline int pushbit(struct pushpull *pp, int bit, int use_reserved)
+{
+        if (pp->ofs >= pp->buflen - (use_reserved?0:pp->reserve)) {
+                return -ENOSPC;
+        }
+
+        if (bit) {
+                pp->buf[pp->ofs >> 3] |= (1<<(7-(pp->ofs &7)));
+        }
+        else {
+                pp->buf[pp->ofs >> 3] &= ~(1<<(7-(pp->ofs &7)));
+        }
+        pp->ofs++;
+
+        return 0;
+}
+
+static inline int pushedbits(struct pushpull *pp)
+{
+        return pp->ofs;
+}
+
+static inline int pullbit(struct pushpull *pp)
+{
+        int bit;
+
+        bit = (pp->buf[pp->ofs >> 3] >> (7-(pp->ofs & 7))) & 1;
+
+        pp->ofs++;
+        return bit;
+}
+
+static inline int pulledbits(struct pushpull *pp)
+{
+        return pp->ofs;
+}
+
+#endif /* __PUSHPULL_H__ */