[PATCH 11/16] byteorder: provide a linux/byteorder.h with {be, le}_to_cpu() and cpu_to_{be, le}() macros

Cody P Schafer dev at codyps.com
Wed May 28 10:22:06 EST 2014


Rather manually specifying the size of the integer to be converted, key
off of the type size. Reduces duplicate size info and the occurance of
certain types of bugs (using the wrong sized conversion).

CC: Sukadev Bhattiprolu <sukadev at linux.vnet.ibm.com>
Signed-off-by: Cody P Schafer <dev at codyps.com>
---
 include/linux/byteorder.h | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 include/linux/byteorder.h

diff --git a/include/linux/byteorder.h b/include/linux/byteorder.h
new file mode 100644
index 0000000..c7ab8da
--- /dev/null
+++ b/include/linux/byteorder.h
@@ -0,0 +1,34 @@
+#ifndef LINUX_BYTEORDER_H_
+#define LINUX_BYTEORDER_H_
+
+#include <asm/byteorder.h>
+
+#define be_to_cpu(v) \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint8_t) , v,	\
+	__builtin_choose_expr(sizeof(v) == sizeof(uint16_t), be16_to_cpu(v), \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint32_t), be32_to_cpu(v), \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint64_t), be64_to_cpu(v), \
+		(void)0))))
+
+#define le_to_cpu(v) \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint8_t) , v,	\
+	__builtin_choose_expr(sizeof(v) == sizeof(uint16_t), le16_to_cpu(v), \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint32_t), le32_to_cpu(v), \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint64_t), le64_to_cpu(v), \
+		(void)0))))
+
+#define cpu_to_le(v) \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint8_t) , v,	\
+	__builtin_choose_expr(sizeof(v) == sizeof(uint16_t), cpu_to_le16(v), \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint32_t), cpu_to_le32(v), \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint64_t), cpu_to_le64(v), \
+		(void)0))))
+
+#define cpu_to_be(v) \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint8_t) , v,	\
+	__builtin_choose_expr(sizeof(v) == sizeof(uint16_t), cpu_to_be16(v), \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint32_t), cpu_to_be32(v), \
+	__builtin_choose_expr(sizeof(v) == sizeof(uint64_t), cpu_to_be64(v), \
+		(void)0))))
+
+#endif
-- 
1.9.3



More information about the Linuxppc-dev mailing list