xref: /aosp_15_r20/external/flashrom/include/platform/swap.h (revision 0d6140be3aa665ecc836e8907834fcd3e3b018fc)
1 /*
2  * This file is part of the flashrom project.
3  *
4  * Copyright (C) 2009 Carl-Daniel Hailfinger
5  * Copyright (C) 2022 secunet Security Networks AG
6  * (written by Thomas Heijligen <[email protected])
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; version 2 of the License.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 /*
19  * inline functions and macros shared by endian conversion functions
20  */
21 
22 #ifndef ___SWAP_H___
23 #define ___SWAP_H___ 1
24 
25 #include <stdint.h>
26 
27 /* swap bytes */
28 /* OpenBSD has conflicting definitions for swapX, _swap_X and __swapX */
___swap8(const uint8_t value)29 static inline uint8_t ___swap8(const uint8_t value)
30 {
31 	return  (value & (uint8_t)0xffU);
32 }
33 
___swap16(const uint16_t value)34 static inline uint16_t ___swap16(const uint16_t value)
35 {
36 	return  ((value & (uint16_t)0x00ffU) << 8) |
37 		((value & (uint16_t)0xff00U) >> 8);
38 }
39 
___swap32(const uint32_t value)40 static inline uint32_t ___swap32(const uint32_t value)
41 {
42 	return  ((value & (uint32_t)0x000000ffUL) << 24) |
43 		((value & (uint32_t)0x0000ff00UL) <<  8) |
44 		((value & (uint32_t)0x00ff0000UL) >>  8) |
45 		((value & (uint32_t)0xff000000UL) >> 24);
46 }
47 
___swap64(const uint64_t value)48 static inline uint64_t ___swap64(const uint64_t value)
49 {
50 	return  ((value & (uint64_t)0x00000000000000ffULL) << 56) |
51 		((value & (uint64_t)0x000000000000ff00ULL) << 40) |
52 		((value & (uint64_t)0x0000000000ff0000ULL) << 24) |
53 		((value & (uint64_t)0x00000000ff000000ULL) <<  8) |
54 		((value & (uint64_t)0x000000ff00000000ULL) >>  8) |
55 		((value & (uint64_t)0x0000ff0000000000ULL) >> 24) |
56 		((value & (uint64_t)0x00ff000000000000ULL) >> 40) |
57 		((value & (uint64_t)0xff00000000000000ULL) >> 56);
58 }
59 
60 /*
61  * macro to return the same value as passed.
62  *
63  * `___return_same(cpu_to_le, 8)`
64  *	expands to
65  * `uint8_t cpu_to_le8 (const uint8_t value) { return value; }`
66  */
67 #define ___return_same(name, bits) \
68 	uint##bits##_t name##bits (const uint##bits##_t value) { return value; }
69 
70 /*
71  * macro to return the swapped value as passed.
72  *
73  * `___return_swapped(cpu_to_be, 8)`
74  *	expands to
75  * `uint8_t cpu_to_be8 (const uint8_t value) { return ___swap8 (value); }`
76  */
77 #define ___return_swapped(name, bits) \
78 	uint##bits##_t name##bits (const uint##bits##_t value) { return ___swap##bits (value); }
79 
80 #endif /* !___SWAP_H___ */
81