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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
b01df1c1 DA |
2 | /* |
3 | * Calculate a CRC T10-DIF with vpmsum acceleration | |
4 | * | |
5 | * Copyright 2017, Daniel Axtens, IBM Corporation. | |
6 | * [based on crc32c-vpmsum_glue.c] | |
b01df1c1 DA |
7 | */ |
8 | ||
9 | #include <linux/crc-t10dif.h> | |
10 | #include <crypto/internal/hash.h> | |
626ddb2f | 11 | #include <crypto/internal/simd.h> |
b01df1c1 DA |
12 | #include <linux/init.h> |
13 | #include <linux/module.h> | |
14 | #include <linux/string.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/cpufeature.h> | |
626ddb2f | 17 | #include <asm/simd.h> |
b01df1c1 DA |
18 | #include <asm/switch_to.h> |
19 | ||
20 | #define VMX_ALIGN 16 | |
21 | #define VMX_ALIGN_MASK (VMX_ALIGN-1) | |
22 | ||
23 | #define VECTOR_BREAKPOINT 64 | |
24 | ||
25 | u32 __crct10dif_vpmsum(u32 crc, unsigned char const *p, size_t len); | |
26 | ||
27 | static u16 crct10dif_vpmsum(u16 crci, unsigned char const *p, size_t len) | |
28 | { | |
29 | unsigned int prealign; | |
30 | unsigned int tail; | |
31 | u32 crc = crci; | |
32 | ||
626ddb2f | 33 | if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) || !crypto_simd_usable()) |
b01df1c1 DA |
34 | return crc_t10dif_generic(crc, p, len); |
35 | ||
36 | if ((unsigned long)p & VMX_ALIGN_MASK) { | |
37 | prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK); | |
38 | crc = crc_t10dif_generic(crc, p, prealign); | |
39 | len -= prealign; | |
40 | p += prealign; | |
41 | } | |
42 | ||
43 | if (len & ~VMX_ALIGN_MASK) { | |
44 | crc <<= 16; | |
0f89f6e1 | 45 | preempt_disable(); |
b01df1c1 DA |
46 | pagefault_disable(); |
47 | enable_kernel_altivec(); | |
48 | crc = __crct10dif_vpmsum(crc, p, len & ~VMX_ALIGN_MASK); | |
0f89f6e1 | 49 | disable_kernel_altivec(); |
b01df1c1 | 50 | pagefault_enable(); |
0f89f6e1 | 51 | preempt_enable(); |
b01df1c1 DA |
52 | crc >>= 16; |
53 | } | |
54 | ||
55 | tail = len & VMX_ALIGN_MASK; | |
56 | if (tail) { | |
57 | p += len & ~VMX_ALIGN_MASK; | |
58 | crc = crc_t10dif_generic(crc, p, tail); | |
59 | } | |
60 | ||
61 | return crc & 0xffff; | |
62 | } | |
63 | ||
64 | static int crct10dif_vpmsum_init(struct shash_desc *desc) | |
65 | { | |
66 | u16 *crc = shash_desc_ctx(desc); | |
67 | ||
68 | *crc = 0; | |
69 | return 0; | |
70 | } | |
71 | ||
72 | static int crct10dif_vpmsum_update(struct shash_desc *desc, const u8 *data, | |
73 | unsigned int length) | |
74 | { | |
75 | u16 *crc = shash_desc_ctx(desc); | |
76 | ||
77 | *crc = crct10dif_vpmsum(*crc, data, length); | |
78 | ||
79 | return 0; | |
80 | } | |
81 | ||
82 | ||
83 | static int crct10dif_vpmsum_final(struct shash_desc *desc, u8 *out) | |
84 | { | |
85 | u16 *crcp = shash_desc_ctx(desc); | |
86 | ||
87 | *(u16 *)out = *crcp; | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static struct shash_alg alg = { | |
92 | .init = crct10dif_vpmsum_init, | |
93 | .update = crct10dif_vpmsum_update, | |
94 | .final = crct10dif_vpmsum_final, | |
95 | .descsize = CRC_T10DIF_DIGEST_SIZE, | |
96 | .digestsize = CRC_T10DIF_DIGEST_SIZE, | |
97 | .base = { | |
98 | .cra_name = "crct10dif", | |
99 | .cra_driver_name = "crct10dif-vpmsum", | |
100 | .cra_priority = 200, | |
101 | .cra_blocksize = CRC_T10DIF_BLOCK_SIZE, | |
102 | .cra_module = THIS_MODULE, | |
103 | } | |
104 | }; | |
105 | ||
106 | static int __init crct10dif_vpmsum_mod_init(void) | |
107 | { | |
108 | if (!cpu_has_feature(CPU_FTR_ARCH_207S)) | |
109 | return -ENODEV; | |
110 | ||
111 | return crypto_register_shash(&alg); | |
112 | } | |
113 | ||
114 | static void __exit crct10dif_vpmsum_mod_fini(void) | |
115 | { | |
116 | crypto_unregister_shash(&alg); | |
117 | } | |
118 | ||
119 | module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crct10dif_vpmsum_mod_init); | |
120 | module_exit(crct10dif_vpmsum_mod_fini); | |
121 | ||
122 | MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>"); | |
123 | MODULE_DESCRIPTION("CRCT10DIF using vector polynomial multiply-sum instructions"); | |
124 | MODULE_LICENSE("GPL"); | |
125 | MODULE_ALIAS_CRYPTO("crct10dif"); | |
126 | MODULE_ALIAS_CRYPTO("crct10dif-vpmsum"); |