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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 | 15 | #include <linux/types.h> |
a24d22b2 | 16 | #include <crypto/sha2.h> |
41ea0f6c | 17 | #include <crypto/sha256_base.h> |
c147028c MS |
18 | #include <asm/byteorder.h> |
19 | #include <asm/switch_to.h> | |
20 | #include <linux/hardirq.h> | |
21 | ||
22 | /* | |
23 | * MAX_BYTES defines the number of bytes that are allowed to be processed | |
24 | * between preempt_disable() and preempt_enable(). SHA256 takes ~2,000 | |
25 | * operations per 64 bytes. e500 cores can issue two arithmetic instructions | |
26 | * per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2). | |
27 | * Thus 1KB of input data will need an estimated maximum of 18,000 cycles. | |
28 | * Headroom for cache misses included. Even with the low end model clocked | |
29 | * at 667 MHz this equals to a critical time window of less than 27us. | |
30 | * | |
31 | */ | |
32 | #define MAX_BYTES 1024 | |
33 | ||
34 | extern void ppc_spe_sha256_transform(u32 *state, const u8 *src, u32 blocks); | |
35 | ||
36 | static void spe_begin(void) | |
37 | { | |
38 | /* We just start SPE operations and will save SPE registers later. */ | |
39 | preempt_disable(); | |
40 | enable_kernel_spe(); | |
41 | } | |
42 | ||
43 | static void spe_end(void) | |
44 | { | |
dc4fbba1 | 45 | disable_kernel_spe(); |
c147028c MS |
46 | /* reenable preemption */ |
47 | preempt_enable(); | |
48 | } | |
49 | ||
50 | static inline void ppc_sha256_clear_context(struct sha256_state *sctx) | |
51 | { | |
52 | int count = sizeof(struct sha256_state) >> 2; | |
53 | u32 *ptr = (u32 *)sctx; | |
54 | ||
55 | /* make sure we can clear the fast way */ | |
56 | BUILD_BUG_ON(sizeof(struct sha256_state) % 4); | |
57 | do { *ptr++ = 0; } while (--count); | |
58 | } | |
59 | ||
c147028c MS |
60 | static int ppc_spe_sha256_update(struct shash_desc *desc, const u8 *data, |
61 | unsigned int len) | |
62 | { | |
63 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
64 | const unsigned int offset = sctx->count & 0x3f; | |
65 | const unsigned int avail = 64 - offset; | |
66 | unsigned int bytes; | |
67 | const u8 *src = data; | |
68 | ||
69 | if (avail > len) { | |
70 | sctx->count += len; | |
71 | memcpy((char *)sctx->buf + offset, src, len); | |
72 | return 0; | |
73 | } | |
74 | ||
75 | sctx->count += len; | |
76 | ||
77 | if (offset) { | |
78 | memcpy((char *)sctx->buf + offset, src, avail); | |
79 | ||
80 | spe_begin(); | |
81 | ppc_spe_sha256_transform(sctx->state, (const u8 *)sctx->buf, 1); | |
82 | spe_end(); | |
83 | ||
84 | len -= avail; | |
85 | src += avail; | |
86 | } | |
87 | ||
88 | while (len > 63) { | |
89 | /* cut input data into smaller blocks */ | |
90 | bytes = (len > MAX_BYTES) ? MAX_BYTES : len; | |
91 | bytes = bytes & ~0x3f; | |
92 | ||
93 | spe_begin(); | |
94 | ppc_spe_sha256_transform(sctx->state, src, bytes >> 6); | |
95 | spe_end(); | |
96 | ||
97 | src += bytes; | |
98 | len -= bytes; | |
578f23d3 | 99 | } |
c147028c MS |
100 | |
101 | memcpy((char *)sctx->buf, src, len); | |
102 | return 0; | |
103 | } | |
104 | ||
105 | static int ppc_spe_sha256_final(struct shash_desc *desc, u8 *out) | |
106 | { | |
107 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
108 | const unsigned int offset = sctx->count & 0x3f; | |
109 | char *p = (char *)sctx->buf + offset; | |
110 | int padlen; | |
111 | __be64 *pbits = (__be64 *)(((char *)&sctx->buf) + 56); | |
112 | __be32 *dst = (__be32 *)out; | |
113 | ||
114 | padlen = 55 - offset; | |
115 | *p++ = 0x80; | |
116 | ||
117 | spe_begin(); | |
118 | ||
119 | if (padlen < 0) { | |
120 | memset(p, 0x00, padlen + sizeof (u64)); | |
121 | ppc_spe_sha256_transform(sctx->state, sctx->buf, 1); | |
122 | p = (char *)sctx->buf; | |
123 | padlen = 56; | |
124 | } | |
125 | ||
126 | memset(p, 0, padlen); | |
127 | *pbits = cpu_to_be64(sctx->count << 3); | |
128 | ppc_spe_sha256_transform(sctx->state, sctx->buf, 1); | |
129 | ||
130 | spe_end(); | |
131 | ||
132 | dst[0] = cpu_to_be32(sctx->state[0]); | |
133 | dst[1] = cpu_to_be32(sctx->state[1]); | |
134 | dst[2] = cpu_to_be32(sctx->state[2]); | |
135 | dst[3] = cpu_to_be32(sctx->state[3]); | |
136 | dst[4] = cpu_to_be32(sctx->state[4]); | |
137 | dst[5] = cpu_to_be32(sctx->state[5]); | |
138 | dst[6] = cpu_to_be32(sctx->state[6]); | |
139 | dst[7] = cpu_to_be32(sctx->state[7]); | |
140 | ||
141 | ppc_sha256_clear_context(sctx); | |
142 | return 0; | |
143 | } | |
144 | ||
145 | static int ppc_spe_sha224_final(struct shash_desc *desc, u8 *out) | |
146 | { | |
e5476552 | 147 | __be32 D[SHA256_DIGEST_SIZE >> 2]; |
c147028c MS |
148 | __be32 *dst = (__be32 *)out; |
149 | ||
150 | ppc_spe_sha256_final(desc, (u8 *)D); | |
151 | ||
152 | /* avoid bytewise memcpy */ | |
153 | dst[0] = D[0]; | |
154 | dst[1] = D[1]; | |
155 | dst[2] = D[2]; | |
156 | dst[3] = D[3]; | |
157 | dst[4] = D[4]; | |
158 | dst[5] = D[5]; | |
159 | dst[6] = D[6]; | |
160 | ||
161 | /* clear sensitive data */ | |
162 | memzero_explicit(D, SHA256_DIGEST_SIZE); | |
163 | return 0; | |
164 | } | |
165 | ||
166 | static int ppc_spe_sha256_export(struct shash_desc *desc, void *out) | |
167 | { | |
168 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
169 | ||
170 | memcpy(out, sctx, sizeof(*sctx)); | |
171 | return 0; | |
172 | } | |
173 | ||
174 | static int ppc_spe_sha256_import(struct shash_desc *desc, const void *in) | |
175 | { | |
176 | struct sha256_state *sctx = shash_desc_ctx(desc); | |
177 | ||
178 | memcpy(sctx, in, sizeof(*sctx)); | |
179 | return 0; | |
180 | } | |
181 | ||
182 | static struct shash_alg algs[2] = { { | |
183 | .digestsize = SHA256_DIGEST_SIZE, | |
41ea0f6c | 184 | .init = sha256_base_init, |
c147028c MS |
185 | .update = ppc_spe_sha256_update, |
186 | .final = ppc_spe_sha256_final, | |
187 | .export = ppc_spe_sha256_export, | |
188 | .import = ppc_spe_sha256_import, | |
189 | .descsize = sizeof(struct sha256_state), | |
190 | .statesize = sizeof(struct sha256_state), | |
191 | .base = { | |
192 | .cra_name = "sha256", | |
193 | .cra_driver_name= "sha256-ppc-spe", | |
194 | .cra_priority = 300, | |
c147028c MS |
195 | .cra_blocksize = SHA256_BLOCK_SIZE, |
196 | .cra_module = THIS_MODULE, | |
197 | } | |
198 | }, { | |
199 | .digestsize = SHA224_DIGEST_SIZE, | |
41ea0f6c | 200 | .init = sha224_base_init, |
c147028c MS |
201 | .update = ppc_spe_sha256_update, |
202 | .final = ppc_spe_sha224_final, | |
203 | .export = ppc_spe_sha256_export, | |
204 | .import = ppc_spe_sha256_import, | |
205 | .descsize = sizeof(struct sha256_state), | |
206 | .statesize = sizeof(struct sha256_state), | |
207 | .base = { | |
208 | .cra_name = "sha224", | |
209 | .cra_driver_name= "sha224-ppc-spe", | |
210 | .cra_priority = 300, | |
c147028c MS |
211 | .cra_blocksize = SHA224_BLOCK_SIZE, |
212 | .cra_module = THIS_MODULE, | |
213 | } | |
214 | } }; | |
215 | ||
216 | static int __init ppc_spe_sha256_mod_init(void) | |
217 | { | |
218 | return crypto_register_shashes(algs, ARRAY_SIZE(algs)); | |
219 | } | |
220 | ||
221 | static void __exit ppc_spe_sha256_mod_fini(void) | |
222 | { | |
223 | crypto_unregister_shashes(algs, ARRAY_SIZE(algs)); | |
224 | } | |
225 | ||
226 | module_init(ppc_spe_sha256_mod_init); | |
227 | module_exit(ppc_spe_sha256_mod_fini); | |
228 | ||
229 | MODULE_LICENSE("GPL"); | |
230 | MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm, SPE optimized"); | |
231 | ||
232 | MODULE_ALIAS_CRYPTO("sha224"); | |
233 | MODULE_ALIAS_CRYPTO("sha224-ppc-spe"); | |
234 | MODULE_ALIAS_CRYPTO("sha256"); | |
235 | MODULE_ALIAS_CRYPTO("sha256-ppc-spe"); |