Move functions for byte-swapping into common header file.

The byte-swapping functions were scattered all over the source tree, now they
are merged into a new common header file called byteswap.h.

Signed-off-by: <thuth@linux.vnet.ibm.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/include/byteorder.h b/include/byteorder.h
new file mode 100644
index 0000000..0d7ebee
--- /dev/null
+++ b/include/byteorder.h
@@ -0,0 +1,78 @@
+/******************************************************************************
+ * Copyright (c) 2011 IBM Corporation
+ * All rights reserved.
+ * This program and the accompanying materials
+ * are made available under the terms of the BSD License
+ * which accompanies this distribution, and is available at
+ * http://www.opensource.org/licenses/bsd-license.php
+ *
+ * Contributors:
+ *     IBM Corporation - initial implementation
+ *****************************************************************************/
+
+/*
+ * Common byteorder (endianess) macros
+ */
+
+#ifndef BYTEORDER_H
+#define BYTEORDER_H
+
+static inline uint16_t
+bswap_16 (uint16_t x)
+{
+	return ((x&0xff00) >> 8) | ((x&0xff) << 8);
+}
+
+static inline uint32_t
+bswap_32 (uint32_t x)
+{
+	return bswap_16(x >> 16) | (bswap_16(x) << 16);
+}
+
+static inline uint64_t
+bswap_64 (uint64_t x)
+{
+	return (uint64_t) bswap_32(x >> 32) | (uint64_t) bswap_32(x) << 32;
+}
+
+
+/* gcc defines __BIG_ENDIAN__ on big endian targets */
+#ifdef __BIG_ENDIAN__
+
+#define cpu_to_be16(x) (x)
+#define cpu_to_be32(x) (x)
+#define cpu_to_be64(x) (x)
+
+#define be16_to_cpu(x) (x)
+#define be32_to_cpu(x) (x)
+#define be64_to_cpu(x) (x)
+
+#define le16_to_cpu(x) bswap_16(x)
+#define le32_to_cpu(x) bswap_32(x)
+#define le64_to_cpu(x) bswap_64(x)
+
+#define cpu_to_le16(x) bswap_16(x)
+#define cpu_to_le32(x) bswap_32(x)
+#define cpu_to_le64(x) bswap_64(x)
+
+#else
+
+#define cpu_to_be16(x) bswap_16(x)
+#define cpu_to_be32(x) bswap_32(x)
+#define cpu_to_be64(x) bswap_64(x)
+
+#define be16_to_cpu(x) bswap_16(x)
+#define be32_to_cpu(x) bswap_32(x)
+#define be64_to_cpu(x) bswap_64(x)
+
+#define le16_to_cpu(x) (x)
+#define le32_to_cpu(x) (x)
+#define le64_to_cpu(x) (x)
+
+#define cpu_to_le16(x) (x)
+#define cpu_to_le32(x) (x)
+#define cpu_to_le64(x) (x)
+
+#endif  /* __BIG_ENDIAN__ */
+
+#endif  /* BYTEORDER_H */