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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
c147028c MS |
2 | /* |
3 | * Glue code for SHA-256 implementation for SPE instructions (PPC) | |
4 | * | |
5 | * Based on generic implementation. The assembler module takes care | |
6 | * about the SPE registers so it can run from interrupt context. | |
7 | * | |
8 | * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de> | |
c147028c MS |
9 | */ |
10 | ||
11 | #include <crypto/internal/hash.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/mm.h> | |
c147028c MS |
15 | #include <linux/types.h> |
16 | #include <crypto/sha.h> | |
17 | #include <asm/byteorder.h> | |
18 | #include <asm/switch_to.h> | |
19 | #include <linux/hardirq.h> | |
20 | ||
21 | /* | |
22 | * MAX_BYTES defines the number of bytes that are allowed to be processed | |
23 | * between preempt_disable() and preempt_enable(). SHA256 takes ~2,000 | |
24 | * operations per 64 bytes. e500 cores can issue two arithmetic instructions | |
25 | * per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2). | |
26 | * Thus 1KB of input data will need an estimated maximum of 18,000 cycles. | |
27 | * Headroom for cache misses included. Even with the low end model clocked | |
28 | * at 667 MHz this equals to a critical time window of less than 27us. | |
29 | * | |
30 | */ | |
31 | #define MAX_BYTES 1024 | |
32 | ||
33 | extern void ppc_spe_sha256_transform(u32 *state, const u8 *src, u32 blocks); | |
34 | ||
35 | static void spe_begin(void) | |
36 | { | |
37 | /* We just start SPE operations and will save SPE registers later. */ | |
38 | preempt_disable(); | |
39 | enable_kernel_spe(); | |
40 | } | |
41 | ||
42 | static void spe_end(void) | |
43 | { | |
dc4fbba1 | 44 | disable_kernel_spe(); |
c147028c MS |
45 | /* reenable preemption */ |
46 | preempt_enable(); | |
47 | } | |
48 | ||
49 | static inline void ppc_sha256_clear_context(struct sha256_state *sctx) | |
50 | { | |
51 | int count = sizeof(struct sha256_state) >> 2; | |
52 | u32 *ptr = (u32 *)sctx; | |
53 | ||
54 | /* make sure we can clear the fast way */ | |
55 | BUILD_BUG_ON(sizeof(struct sha256_state) % 4); | |
56 | do { *ptr++ = 0; } while (--count); | |
57 | } | |
58 | ||
59 | static int ppc_spe_sha256_init(struct shash_desc *desc) | |
60 | { | |
61 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
62 | ||
63 | sctx->state[0] = SHA256_H0; | |
64 | sctx->state[1] = SHA256_H1; | |
65 | sctx->state[2] = SHA256_H2; | |
66 | sctx->state[3] = SHA256_H3; | |
67 | sctx->state[4] = SHA256_H4; | |
68 | sctx->state[5] = SHA256_H5; | |
69 | sctx->state[6] = SHA256_H6; | |
70 | sctx->state[7] = SHA256_H7; | |
71 | sctx->count = 0; | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | static int ppc_spe_sha224_init(struct shash_desc *desc) | |
77 | { | |
78 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
79 | ||
80 | sctx->state[0] = SHA224_H0; | |
81 | sctx->state[1] = SHA224_H1; | |
82 | sctx->state[2] = SHA224_H2; | |
83 | sctx->state[3] = SHA224_H3; | |
84 | sctx->state[4] = SHA224_H4; | |
85 | sctx->state[5] = SHA224_H5; | |
86 | sctx->state[6] = SHA224_H6; | |
87 | sctx->state[7] = SHA224_H7; | |
88 | sctx->count = 0; | |
89 | ||
90 | return 0; | |
91 | } | |
92 | ||
93 | static int ppc_spe_sha256_update(struct shash_desc *desc, const u8 *data, | |
94 | unsigned int len) | |
95 | { | |
96 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
97 | const unsigned int offset = sctx->count & 0x3f; | |
98 | const unsigned int avail = 64 - offset; | |
99 | unsigned int bytes; | |
100 | const u8 *src = data; | |
101 | ||
102 | if (avail > len) { | |
103 | sctx->count += len; | |
104 | memcpy((char *)sctx->buf + offset, src, len); | |
105 | return 0; | |
106 | } | |
107 | ||
108 | sctx->count += len; | |
109 | ||
110 | if (offset) { | |
111 | memcpy((char *)sctx->buf + offset, src, avail); | |
112 | ||
113 | spe_begin(); | |
114 | ppc_spe_sha256_transform(sctx->state, (const u8 *)sctx->buf, 1); | |
115 | spe_end(); | |
116 | ||
117 | len -= avail; | |
118 | src += avail; | |
119 | } | |
120 | ||
121 | while (len > 63) { | |
122 | /* cut input data into smaller blocks */ | |
123 | bytes = (len > MAX_BYTES) ? MAX_BYTES : len; | |
124 | bytes = bytes & ~0x3f; | |
125 | ||
126 | spe_begin(); | |
127 | ppc_spe_sha256_transform(sctx->state, src, bytes >> 6); | |
128 | spe_end(); | |
129 | ||
130 | src += bytes; | |
131 | len -= bytes; | |
132 | }; | |
133 | ||
134 | memcpy((char *)sctx->buf, src, len); | |
135 | return 0; | |
136 | } | |
137 | ||
138 | static int ppc_spe_sha256_final(struct shash_desc *desc, u8 *out) | |
139 | { | |
140 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
141 | const unsigned int offset = sctx->count & 0x3f; | |
142 | char *p = (char *)sctx->buf + offset; | |
143 | int padlen; | |
144 | __be64 *pbits = (__be64 *)(((char *)&sctx->buf) + 56); | |
145 | __be32 *dst = (__be32 *)out; | |
146 | ||
147 | padlen = 55 - offset; | |
148 | *p++ = 0x80; | |
149 | ||
150 | spe_begin(); | |
151 | ||
152 | if (padlen < 0) { | |
153 | memset(p, 0x00, padlen + sizeof (u64)); | |
154 | ppc_spe_sha256_transform(sctx->state, sctx->buf, 1); | |
155 | p = (char *)sctx->buf; | |
156 | padlen = 56; | |
157 | } | |
158 | ||
159 | memset(p, 0, padlen); | |
160 | *pbits = cpu_to_be64(sctx->count << 3); | |
161 | ppc_spe_sha256_transform(sctx->state, sctx->buf, 1); | |
162 | ||
163 | spe_end(); | |
164 | ||
165 | dst[0] = cpu_to_be32(sctx->state[0]); | |
166 | dst[1] = cpu_to_be32(sctx->state[1]); | |
167 | dst[2] = cpu_to_be32(sctx->state[2]); | |
168 | dst[3] = cpu_to_be32(sctx->state[3]); | |
169 | dst[4] = cpu_to_be32(sctx->state[4]); | |
170 | dst[5] = cpu_to_be32(sctx->state[5]); | |
171 | dst[6] = cpu_to_be32(sctx->state[6]); | |
172 | dst[7] = cpu_to_be32(sctx->state[7]); | |
173 | ||
174 | ppc_sha256_clear_context(sctx); | |
175 | return 0; | |
176 | } | |
177 | ||
178 | static int ppc_spe_sha224_final(struct shash_desc *desc, u8 *out) | |
179 | { | |
180 | u32 D[SHA256_DIGEST_SIZE >> 2]; | |
181 | __be32 *dst = (__be32 *)out; | |
182 | ||
183 | ppc_spe_sha256_final(desc, (u8 *)D); | |
184 | ||
185 | /* avoid bytewise memcpy */ | |
186 | dst[0] = D[0]; | |
187 | dst[1] = D[1]; | |
188 | dst[2] = D[2]; | |
189 | dst[3] = D[3]; | |
190 | dst[4] = D[4]; | |
191 | dst[5] = D[5]; | |
192 | dst[6] = D[6]; | |
193 | ||
194 | /* clear sensitive data */ | |
195 | memzero_explicit(D, SHA256_DIGEST_SIZE); | |
196 | return 0; | |
197 | } | |
198 | ||
199 | static int ppc_spe_sha256_export(struct shash_desc *desc, void *out) | |
200 | { | |
201 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
202 | ||
203 | memcpy(out, sctx, sizeof(*sctx)); | |
204 | return 0; | |
205 | } | |
206 | ||
207 | static int ppc_spe_sha256_import(struct shash_desc *desc, const void *in) | |
208 | { | |
209 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
210 | ||
211 | memcpy(sctx, in, sizeof(*sctx)); | |
212 | return 0; | |
213 | } | |
214 | ||
215 | static struct shash_alg algs[2] = { { | |
216 | .digestsize = SHA256_DIGEST_SIZE, | |
217 | .init = ppc_spe_sha256_init, | |
218 | .update = ppc_spe_sha256_update, | |
219 | .final = ppc_spe_sha256_final, | |
220 | .export = ppc_spe_sha256_export, | |
221 | .import = ppc_spe_sha256_import, | |
222 | .descsize = sizeof(struct sha256_state), | |
223 | .statesize = sizeof(struct sha256_state), | |
224 | .base = { | |
225 | .cra_name = "sha256", | |
226 | .cra_driver_name= "sha256-ppc-spe", | |
227 | .cra_priority = 300, | |
c147028c MS |
228 | .cra_blocksize = SHA256_BLOCK_SIZE, |
229 | .cra_module = THIS_MODULE, | |
230 | } | |
231 | }, { | |
232 | .digestsize = SHA224_DIGEST_SIZE, | |
233 | .init = ppc_spe_sha224_init, | |
234 | .update = ppc_spe_sha256_update, | |
235 | .final = ppc_spe_sha224_final, | |
236 | .export = ppc_spe_sha256_export, | |
237 | .import = ppc_spe_sha256_import, | |
238 | .descsize = sizeof(struct sha256_state), | |
239 | .statesize = sizeof(struct sha256_state), | |
240 | .base = { | |
241 | .cra_name = "sha224", | |
242 | .cra_driver_name= "sha224-ppc-spe", | |
243 | .cra_priority = 300, | |
c147028c MS |
244 | .cra_blocksize = SHA224_BLOCK_SIZE, |
245 | .cra_module = THIS_MODULE, | |
246 | } | |
247 | } }; | |
248 | ||
249 | static int __init ppc_spe_sha256_mod_init(void) | |
250 | { | |
251 | return crypto_register_shashes(algs, ARRAY_SIZE(algs)); | |
252 | } | |
253 | ||
254 | static void __exit ppc_spe_sha256_mod_fini(void) | |
255 | { | |
256 | crypto_unregister_shashes(algs, ARRAY_SIZE(algs)); | |
257 | } | |
258 | ||
259 | module_init(ppc_spe_sha256_mod_init); | |
260 | module_exit(ppc_spe_sha256_mod_fini); | |
261 | ||
262 | MODULE_LICENSE("GPL"); | |
263 | MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm, SPE optimized"); | |
264 | ||
265 | MODULE_ALIAS_CRYPTO("sha224"); | |
266 | MODULE_ALIAS_CRYPTO("sha224-ppc-spe"); | |
267 | MODULE_ALIAS_CRYPTO("sha256"); | |
268 | MODULE_ALIAS_CRYPTO("sha256-ppc-spe"); |