fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / include / asm-xtensa / byteorder.h
blob765edf17a9a466b5497046c4c78a50185dc83a92
1 /*
2 * include/asm-xtensa/byteorder.h
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
8 * Copyright (C) 2001 - 2005 Tensilica Inc.
9 */
11 #ifndef _XTENSA_BYTEORDER_H
12 #define _XTENSA_BYTEORDER_H
14 #include <asm/types.h>
15 #include <linux/compiler.h>
17 static __inline__ __attribute_const__ __u32 ___arch__swab32(__u32 x)
19 __u32 res;
20 /* instruction sequence from Xtensa ISA release 2/2000 */
21 __asm__("ssai 8 \n\t"
22 "srli %0, %1, 16 \n\t"
23 "src %0, %0, %1 \n\t"
24 "src %0, %0, %0 \n\t"
25 "src %0, %1, %0 \n"
26 : "=&a" (res)
27 : "a" (x)
29 return res;
32 static __inline__ __attribute_const__ __u16 ___arch__swab16(__u16 x)
34 /* Given that 'short' values are signed (i.e., can be negative),
35 * we cannot assume that the upper 16-bits of the register are
36 * zero. We are careful to mask values after shifting.
39 /* There exists an anomaly between xt-gcc and xt-xcc. xt-gcc
40 * inserts an extui instruction after putting this function inline
41 * to ensure that it uses only the least-significant 16 bits of
42 * the result. xt-xcc doesn't use an extui, but assumes the
43 * __asm__ macro follows convention that the upper 16 bits of an
44 * 'unsigned short' result are still zero. This macro doesn't
45 * follow convention; indeed, it leaves garbage in the upport 16
46 * bits of the register.
48 * Declaring the temporary variables 'res' and 'tmp' to be 32-bit
49 * types while the return type of the function is a 16-bit type
50 * forces both compilers to insert exactly one extui instruction
51 * (or equivalent) to mask off the upper 16 bits. */
53 __u32 res;
54 __u32 tmp;
56 __asm__("extui %1, %2, 8, 8\n\t"
57 "slli %0, %2, 8 \n\t"
58 "or %0, %0, %1 \n"
59 : "=&a" (res), "=&a" (tmp)
60 : "a" (x)
63 return res;
66 #define __arch__swab32(x) ___arch__swab32(x)
67 #define __arch__swab16(x) ___arch__swab16(x)
69 #if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
70 # define __BYTEORDER_HAS_U64__
71 # define __SWAB_64_THRU_32__
72 #endif
74 #ifdef __XTENSA_EL__
75 # include <linux/byteorder/little_endian.h>
76 #elif defined(__XTENSA_EB__)
77 # include <linux/byteorder/big_endian.h>
78 #else
79 # error processor byte order undefined!
80 #endif
82 #endif /* _XTENSA_BYTEORDER_H */