Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * crc32.h
3 * See linux/lib/crc32.c for license and changes
4 */
5#ifndef _LINUX_CRC32_H
6#define _LINUX_CRC32_H
7
8#include <linux/types.h>
9#include <linux/bitrev.h>
10
11u32 __pure crc32_le_arch(u32 crc, const u8 *p, size_t len);
12u32 __pure crc32_le_base(u32 crc, const u8 *p, size_t len);
13u32 __pure crc32_be_arch(u32 crc, const u8 *p, size_t len);
14u32 __pure crc32_be_base(u32 crc, const u8 *p, size_t len);
15u32 __pure crc32c_le_arch(u32 crc, const u8 *p, size_t len);
16u32 __pure crc32c_le_base(u32 crc, const u8 *p, size_t len);
17
18static inline u32 __pure crc32_le(u32 crc, const u8 *p, size_t len)
19{
20 if (IS_ENABLED(CONFIG_CRC32_ARCH))
21 return crc32_le_arch(crc, p, len);
22 return crc32_le_base(crc, p, len);
23}
24
25static inline u32 __pure crc32_be(u32 crc, const u8 *p, size_t len)
26{
27 if (IS_ENABLED(CONFIG_CRC32_ARCH))
28 return crc32_be_arch(crc, p, len);
29 return crc32_be_base(crc, p, len);
30}
31
32/* TODO: leading underscores should be dropped once callers have been updated */
33static inline u32 __pure __crc32c_le(u32 crc, const u8 *p, size_t len)
34{
35 if (IS_ENABLED(CONFIG_CRC32_ARCH))
36 return crc32c_le_arch(crc, p, len);
37 return crc32c_le_base(crc, p, len);
38}
39
40/*
41 * crc32_optimizations() returns flags that indicate which CRC32 library
42 * functions are using architecture-specific optimizations. Unlike
43 * IS_ENABLED(CONFIG_CRC32_ARCH) it takes into account the different CRC32
44 * variants and also whether any needed CPU features are available at runtime.
45 */
46#define CRC32_LE_OPTIMIZATION BIT(0) /* crc32_le() is optimized */
47#define CRC32_BE_OPTIMIZATION BIT(1) /* crc32_be() is optimized */
48#define CRC32C_OPTIMIZATION BIT(2) /* __crc32c_le() is optimized */
49#if IS_ENABLED(CONFIG_CRC32_ARCH)
50u32 crc32_optimizations(void);
51#else
52static inline u32 crc32_optimizations(void) { return 0; }
53#endif
54
55/**
56 * crc32_le_combine - Combine two crc32 check values into one. For two
57 * sequences of bytes, seq1 and seq2 with lengths len1
58 * and len2, crc32_le() check values were calculated
59 * for each, crc1 and crc2.
60 *
61 * @crc1: crc32 of the first block
62 * @crc2: crc32 of the second block
63 * @len2: length of the second block
64 *
65 * Return: The crc32_le() check value of seq1 and seq2 concatenated,
66 * requiring only crc1, crc2, and len2. Note: If seq_full denotes
67 * the concatenated memory area of seq1 with seq2, and crc_full
68 * the crc32_le() value of seq_full, then crc_full ==
69 * crc32_le_combine(crc1, crc2, len2) when crc_full was seeded
70 * with the same initializer as crc1, and crc2 seed was 0. See
71 * also crc32_combine_test().
72 */
73u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len);
74
75static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2)
76{
77 return crc32_le_shift(crc1, len2) ^ crc2;
78}
79
80/**
81 * __crc32c_le_combine - Combine two crc32c check values into one. For two
82 * sequences of bytes, seq1 and seq2 with lengths len1
83 * and len2, __crc32c_le() check values were calculated
84 * for each, crc1 and crc2.
85 *
86 * @crc1: crc32c of the first block
87 * @crc2: crc32c of the second block
88 * @len2: length of the second block
89 *
90 * Return: The __crc32c_le() check value of seq1 and seq2 concatenated,
91 * requiring only crc1, crc2, and len2. Note: If seq_full denotes
92 * the concatenated memory area of seq1 with seq2, and crc_full
93 * the __crc32c_le() value of seq_full, then crc_full ==
94 * __crc32c_le_combine(crc1, crc2, len2) when crc_full was
95 * seeded with the same initializer as crc1, and crc2 seed
96 * was 0. See also crc32c_combine_test().
97 */
98u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len);
99
100static inline u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2)
101{
102 return __crc32c_le_shift(crc1, len2) ^ crc2;
103}
104
105#define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length)
106
107/*
108 * Helpers for hash table generation of ethernet nics:
109 *
110 * Ethernet sends the least significant bit of a byte first, thus crc32_le
111 * is used. The output of crc32_le is bit reversed [most significant bit
112 * is in bit nr 0], thus it must be reversed before use. Except for
113 * nics that bit swap the result internally...
114 */
115#define ether_crc(length, data) bitrev32(crc32_le(~0, data, length))
116#define ether_crc_le(length, data) crc32_le(~0, data, length)
117
118#endif /* _LINUX_CRC32_H */