swab.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2#ifndef _ASM_RISCV_SWAB_H
 3#define _ASM_RISCV_SWAB_H
 4
 5#include <linux/types.h>
 6#include <linux/compiler.h>
 7#include <asm/cpufeature-macros.h>
 8#include <asm/hwcap.h>
 9#include <asm-generic/swab.h>
10
11#if defined(CONFIG_TOOLCHAIN_HAS_ZBB) && defined(CONFIG_RISCV_ISA_ZBB) && !defined(NO_ALTERNATIVE)
12
13// Duplicated from include/uapi/linux/swab.h
14#define ___constant_swab16(x) ((__u16)(				\
15	(((__u16)(x) & (__u16)0x00ffU) << 8) |			\
16	(((__u16)(x) & (__u16)0xff00U) >> 8)))
17
18#define ___constant_swab32(x) ((__u32)(				\
19	(((__u32)(x) & (__u32)0x000000ffUL) << 24) |		\
20	(((__u32)(x) & (__u32)0x0000ff00UL) <<  8) |		\
21	(((__u32)(x) & (__u32)0x00ff0000UL) >>  8) |		\
22	(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
23
24#define ___constant_swab64(x) ((__u64)(				\
25	(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) |	\
26	(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) |	\
27	(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) |	\
28	(((__u64)(x) & (__u64)0x00000000ff000000ULL) <<  8) |	\
29	(((__u64)(x) & (__u64)0x000000ff00000000ULL) >>  8) |	\
30	(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) |	\
31	(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) |	\
32	(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56)))
33
34#define ARCH_SWAB(size, value)						\
35({									\
36	unsigned long x = value;					\
37									\
38	if (riscv_has_extension_likely(RISCV_ISA_EXT_ZBB)) {            \
39		asm volatile (".option push\n"				\
40			      ".option arch,+zbb\n"			\
41			      "rev8 %0, %1\n"				\
42			      ".option pop\n"				\
43			      : "=r" (x) : "r" (x));			\
44		x = x >> (BITS_PER_LONG - size);			\
45	} else {                                                        \
46		x = ___constant_swab##size(value);                      \
47	}								\
48	x;								\
49})
50
51static __always_inline __u16 __arch_swab16(__u16 value)
52{
53	return ARCH_SWAB(16, value);
54}
55
56static __always_inline __u32 __arch_swab32(__u32 value)
57{
58	return ARCH_SWAB(32, value);
59}
60
61#ifdef CONFIG_64BIT
62static __always_inline __u64 __arch_swab64(__u64 value)
63{
64	return ARCH_SWAB(64, value);
65}
66#else
67static __always_inline __u64 __arch_swab64(__u64 value)
68{
69	__u32 h = value >> 32;
70	__u32 l = value & ((1ULL << 32) - 1);
71
72	return ((__u64)(__arch_swab32(l)) << 32) | ((__u64)(__arch_swab32(h)));
73}
74#endif
75
76#define __arch_swab64 __arch_swab64
77#define __arch_swab32 __arch_swab32
78#define __arch_swab16 __arch_swab16
79
80#undef ___constant_swab16
81#undef ___constant_swab32
82#undef ___constant_swab64
83
84#undef ARCH_SWAB
85
86#endif /* defined(CONFIG_TOOLCHAIN_HAS_ZBB) && defined(CONFIG_RISCV_ISA_ZBB) && !defined(NO_ALTERNATIVE) */
87#endif /* _ASM_RISCV_SWAB_H */