backports: add crc7_be()

This was added in:
commit 1836eea209546b870dd83f3f4ef234d6598a560d
Author: George Spelvin <linux@horizon.com>
Date:   Sat May 10 10:32:57 2014 -0400

    lib/crc7: Shift crc7() output left 1 bit

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

diff --git a/backport/backport-include/linux/crc7.h b/backport/backport-include/linux/crc7.h
new file mode 100644 (file)
index 0000000..12747f8
--- /dev/null
+++ b/backport/backport-include/linux/crc7.h
@@ -0,0 +1,14 @@
+#ifndef _BACKPORT_LINUX_CRC7_H
+#define _BACKPORT_LINUX_CRC7_H
+#include_next <linux/crc7.h>
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,16,0)
+#define crc7_be LINUX_BACKPORT(crc7_be)
+static inline u8 crc7_be(u8 crc, const u8 *buffer, size_t len)
+{
+       return crc7(crc, buffer, len) << 1;
+}
+#endif /* < 3.16 */
+
+#endif /* _BACKPORT_LINUX_CRC7_H */