1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 /* Try to choose an implementation variant via Kconfig */
4 #ifdef CONFIG_CRC32_SLICEBY8
5 # define CRC_LE_BITS 64
6 # define CRC_BE_BITS 64
7 #endif
8 #ifdef CONFIG_CRC32_SLICEBY4
9 # define CRC_LE_BITS 32
10 # define CRC_BE_BITS 32
11 #endif
12 #ifdef CONFIG_CRC32_SARWATE
13 # define CRC_LE_BITS 8
14 # define CRC_BE_BITS 8
15 #endif
16 #ifdef CONFIG_CRC32_BIT
17 # define CRC_LE_BITS 1
18 # define CRC_BE_BITS 1
19 #endif
20
21 /*
22 * How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64.
23 * For less performance-sensitive, use 4 or 8 to save table size.
24 * For larger systems choose same as CPU architecture as default.
25 * This works well on X86_64, SPARC64 systems. This may require some
26 * elaboration after experiments with other architectures.
27 */
28 #ifndef CRC_LE_BITS
29 # ifdef CONFIG_64BIT
30 # define CRC_LE_BITS 64
31 # else
32 # define CRC_LE_BITS 32
33 # endif
34 #endif
35 #ifndef CRC_BE_BITS
36 # ifdef CONFIG_64BIT
37 # define CRC_BE_BITS 64
38 # else
39 # define CRC_BE_BITS 32
40 # endif
41 #endif
42
43 /*
44 * Little-endian CRC computation. Used with serial bit streams sent
45 * lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC.
46 */
47 #if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \
48 CRC_LE_BITS & CRC_LE_BITS-1
49 # error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}"
50 #endif
51
52 /*
53 * Big-endian CRC computation. Used with serial bit streams sent
54 * msbit-first. Be sure to use cpu_to_be32() to append the computed CRC.
55 */
56 #if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \
57 CRC_BE_BITS & CRC_BE_BITS-1
58 # error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}"
59 #endif
60
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