[PATCHv4 6/6] byteorder: add copy_{endian} helpers

[Harvey Harrison <harvey.harrison@gmail.com>]

Add helpers for the idiom:
*(__le16 *)ptr = cpu_to_le16(val);

Can now be written as:
copy_le16(ptr, val);

Implemented as macros to allow val to be byteswapped at compile-time
when it is a constant.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
 include/linux/byteorder.h |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/include/linux/byteorder.h b/include/linux/byteorder.h
index b4713ce..8d3c847 100644
--- a/include/linux/byteorder.h
+++ b/include/linux/byteorder.h
@@ -278,6 +278,17 @@ static inline __be64 __cpu_to_be64p(const __u64 *p)
 # define htons(x) ___htons(x)
 # define ntohs(x) ___ntohs(x)
 
+/*
+ * Defined as macros to allow constant folding of the cpu_to_XXXX when
+ * possible.
+ */
+#define copy_le16(ptr, val)	(*(__le16 *)(ptr) = cpu_to_le16((u16)(val));)
+#define copy_le32(ptr, val)	(*(__le32 *)(ptr) = cpu_to_le32((u32)(val));)
+#define copy_le64(ptr, val)	(*(__le64 *)(ptr) = cpu_to_le64((u64)(val));)
+#define copy_be16(ptr, val)	(*(__be16 *)(ptr) = cpu_to_be16((u16)(val));)
+#define copy_be32(ptr, val)	(*(__be32 *)(ptr) = cpu_to_be32((u32)(val));)
+#define copy_be64(ptr, val)	(*(__be64 *)(ptr) = cpu_to_be64((u64)(val));)
+
 static inline void le16_add_cpu(__le16 *var, u16 val)
 {
 	*var = cpu_to_le16(le16_to_cpup(var) + val);
-- 
1.5.6.rc0.277.g804cf