1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #include <linux/crc32.h> |
3 | #include <crypto/internal/hash.h> |
4 | #include <crypto/internal/simd.h> |
5 | #include <linux/init.h> |
6 | #include <linux/module.h> |
7 | #include <linux/string.h> |
8 | #include <linux/kernel.h> |
9 | #include <linux/cpufeature.h> |
10 | #include <asm/simd.h> |
11 | #include <asm/switch_to.h> |
12 | |
13 | #define CHKSUM_BLOCK_SIZE 1 |
14 | #define CHKSUM_DIGEST_SIZE 4 |
15 | |
16 | #define VMX_ALIGN 16 |
17 | #define VMX_ALIGN_MASK (VMX_ALIGN-1) |
18 | |
19 | #define VECTOR_BREAKPOINT 512 |
20 | |
21 | u32 __crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len); |
22 | |
23 | static u32 crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len) |
24 | { |
25 | unsigned int prealign; |
26 | unsigned int tail; |
27 | |
28 | if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) || !crypto_simd_usable()) |
29 | return __crc32c_le(crc, p, len); |
30 | |
31 | if ((unsigned long)p & VMX_ALIGN_MASK) { |
32 | prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK); |
33 | crc = __crc32c_le(crc, p, len: prealign); |
34 | len -= prealign; |
35 | p += prealign; |
36 | } |
37 | |
38 | if (len & ~VMX_ALIGN_MASK) { |
39 | preempt_disable(); |
40 | pagefault_disable(); |
41 | enable_kernel_altivec(); |
42 | crc = __crc32c_vpmsum(crc, p, len: len & ~VMX_ALIGN_MASK); |
43 | disable_kernel_altivec(); |
44 | pagefault_enable(); |
45 | preempt_enable(); |
46 | } |
47 | |
48 | tail = len & VMX_ALIGN_MASK; |
49 | if (tail) { |
50 | p += len & ~VMX_ALIGN_MASK; |
51 | crc = __crc32c_le(crc, p, len: tail); |
52 | } |
53 | |
54 | return crc; |
55 | } |
56 | |
57 | static int crc32c_vpmsum_cra_init(struct crypto_tfm *tfm) |
58 | { |
59 | u32 *key = crypto_tfm_ctx(tfm); |
60 | |
61 | *key = ~0; |
62 | |
63 | return 0; |
64 | } |
65 | |
66 | /* |
67 | * Setting the seed allows arbitrary accumulators and flexible XOR policy |
68 | * If your algorithm starts with ~0, then XOR with ~0 before you set |
69 | * the seed. |
70 | */ |
71 | static int crc32c_vpmsum_setkey(struct crypto_shash *hash, const u8 *key, |
72 | unsigned int keylen) |
73 | { |
74 | u32 *mctx = crypto_shash_ctx(tfm: hash); |
75 | |
76 | if (keylen != sizeof(u32)) |
77 | return -EINVAL; |
78 | *mctx = le32_to_cpup(p: (__le32 *)key); |
79 | return 0; |
80 | } |
81 | |
82 | static int crc32c_vpmsum_init(struct shash_desc *desc) |
83 | { |
84 | u32 *mctx = crypto_shash_ctx(tfm: desc->tfm); |
85 | u32 *crcp = shash_desc_ctx(desc); |
86 | |
87 | *crcp = *mctx; |
88 | |
89 | return 0; |
90 | } |
91 | |
92 | static int crc32c_vpmsum_update(struct shash_desc *desc, const u8 *data, |
93 | unsigned int len) |
94 | { |
95 | u32 *crcp = shash_desc_ctx(desc); |
96 | |
97 | *crcp = crc32c_vpmsum(crc: *crcp, p: data, len); |
98 | |
99 | return 0; |
100 | } |
101 | |
102 | static int __crc32c_vpmsum_finup(u32 *crcp, const u8 *data, unsigned int len, |
103 | u8 *out) |
104 | { |
105 | *(__le32 *)out = ~cpu_to_le32(crc32c_vpmsum(*crcp, data, len)); |
106 | |
107 | return 0; |
108 | } |
109 | |
110 | static int crc32c_vpmsum_finup(struct shash_desc *desc, const u8 *data, |
111 | unsigned int len, u8 *out) |
112 | { |
113 | return __crc32c_vpmsum_finup(crcp: shash_desc_ctx(desc), data, len, out); |
114 | } |
115 | |
116 | static int crc32c_vpmsum_final(struct shash_desc *desc, u8 *out) |
117 | { |
118 | u32 *crcp = shash_desc_ctx(desc); |
119 | |
120 | *(__le32 *)out = ~cpu_to_le32p(p: crcp); |
121 | |
122 | return 0; |
123 | } |
124 | |
125 | static int crc32c_vpmsum_digest(struct shash_desc *desc, const u8 *data, |
126 | unsigned int len, u8 *out) |
127 | { |
128 | return __crc32c_vpmsum_finup(crcp: crypto_shash_ctx(tfm: desc->tfm), data, len, |
129 | out); |
130 | } |
131 | |
132 | static struct shash_alg alg = { |
133 | .setkey = crc32c_vpmsum_setkey, |
134 | .init = crc32c_vpmsum_init, |
135 | .update = crc32c_vpmsum_update, |
136 | .final = crc32c_vpmsum_final, |
137 | .finup = crc32c_vpmsum_finup, |
138 | .digest = crc32c_vpmsum_digest, |
139 | .descsize = sizeof(u32), |
140 | .digestsize = CHKSUM_DIGEST_SIZE, |
141 | .base = { |
142 | .cra_name = "crc32c" , |
143 | .cra_driver_name = "crc32c-vpmsum" , |
144 | .cra_priority = 200, |
145 | .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, |
146 | .cra_blocksize = CHKSUM_BLOCK_SIZE, |
147 | .cra_ctxsize = sizeof(u32), |
148 | .cra_module = THIS_MODULE, |
149 | .cra_init = crc32c_vpmsum_cra_init, |
150 | } |
151 | }; |
152 | |
153 | static int __init crc32c_vpmsum_mod_init(void) |
154 | { |
155 | if (!cpu_has_feature(CPU_FTR_ARCH_207S)) |
156 | return -ENODEV; |
157 | |
158 | return crypto_register_shash(alg: &alg); |
159 | } |
160 | |
161 | static void __exit crc32c_vpmsum_mod_fini(void) |
162 | { |
163 | crypto_unregister_shash(alg: &alg); |
164 | } |
165 | |
166 | module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crc32c_vpmsum_mod_init); |
167 | module_exit(crc32c_vpmsum_mod_fini); |
168 | |
169 | MODULE_AUTHOR("Anton Blanchard <anton@samba.org>" ); |
170 | MODULE_DESCRIPTION("CRC32C using vector polynomial multiply-sum instructions" ); |
171 | MODULE_LICENSE("GPL" ); |
172 | MODULE_ALIAS_CRYPTO("crc32c" ); |
173 | MODULE_ALIAS_CRYPTO("crc32c-vpmsum" ); |
174 | |