1 /*
2  * include/asm-microblaze/byteorder.h -- Endian id and conversion ops
3  *
4  *  Copyright (C) 2003  John Williams <jwilliams@itee.uq.edu.au>
5  *  Copyright (C) 2001  NEC Corporation
6  *  Copyright (C) 2001  Miles Bader <miles@gnu.org>
7  *
8  * This file is subject to the terms and conditions of the GNU General
9  * Public License.  See the file COPYING in the main directory of this
10  * archive for more details.
11  *
12  * Written by Miles Bader <miles@gnu.org>
13  * Microblaze port by John Williams
14  */
15 
16 #ifndef __MICROBLAZE_BYTEORDER_H__
17 #define __MICROBLAZE_BYTEORDER_H__
18 
19 #include <asm/types.h>
20 
21 #ifdef __GNUC__
22 
23 /* This is effectively a dupe of the arch-independent byteswap
24    code in include/linux/byteorder/swab.h, however we force a cast
25    of the result up to 32 bits.  This in turn forces the compiler
26    to explicitly clear the high 16 bits, which it wasn't doing otherwise.
27 
28    I think this is a symptom of a bug in mb-gcc.  JW 20040303
29 */
30 
31 
32 static __inline__ __u16 ___arch__swab16 (__u16 half_word)
33 {
34 	/* 32 bit temp to cast result, forcing clearing of high word */
35 	__u32 temp;
36 
37 	temp = ((half_word & 0x00FFU) << 8) | ((half_word & 0xFF00U) >> 8);
38 
39 	return (__u16) temp;
40 }
41 
42 #define __arch__swab16(x) ___arch__swab16(x)
43 
44 /* Microblaze has no arch-specific endian conversion insns */
45 
46 #if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
47 #  define __BYTEORDER_HAS_U64__
48 #  define __SWAB_64_THRU_32__
49 #endif
50 
51 #endif /* __GNUC__ */
52 
53 #ifdef __MICROBLAZEEL__
54 #include <linux/byteorder/little_endian.h>
55 #else
56 #include <linux/byteorder/big_endian.h>
57 #endif
58 
59 #endif /* __MICROBLAZE_BYTEORDER_H__ */
60