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1 | /* |
2 | * Glue code for SHA-1 implementation for SPE instructions (PPC) | |
3 | * | |
4 | * Based on generic implementation. | |
5 | * | |
6 | * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the Free | |
10 | * Software Foundation; either version 2 of the License, or (at your option) | |
11 | * any later version. | |
12 | * | |
13 | */ | |
14 | ||
15 | #include <crypto/internal/hash.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/cryptohash.h> | |
20 | #include <linux/types.h> | |
21 | #include <crypto/sha.h> | |
22 | #include <asm/byteorder.h> | |
23 | #include <asm/switch_to.h> | |
24 | #include <linux/hardirq.h> | |
25 | ||
26 | /* | |
27 | * MAX_BYTES defines the number of bytes that are allowed to be processed | |
28 | * between preempt_disable() and preempt_enable(). SHA1 takes ~1000 | |
29 | * operations per 64 bytes. e500 cores can issue two arithmetic instructions | |
30 | * per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2). | |
31 | * Thus 2KB of input data will need an estimated maximum of 18,000 cycles. | |
32 | * Headroom for cache misses included. Even with the low end model clocked | |
33 | * at 667 MHz this equals to a critical time window of less than 27us. | |
34 | * | |
35 | */ | |
36 | #define MAX_BYTES 2048 | |
37 | ||
38 | extern void ppc_spe_sha1_transform(u32 *state, const u8 *src, u32 blocks); | |
39 | ||
40 | static void spe_begin(void) | |
41 | { | |
42 | /* We just start SPE operations and will save SPE registers later. */ | |
43 | preempt_disable(); | |
44 | enable_kernel_spe(); | |
45 | } | |
46 | ||
47 | static void spe_end(void) | |
48 | { | |
dc4fbba1 | 49 | disable_kernel_spe(); |
50ba29aa MS |
50 | /* reenable preemption */ |
51 | preempt_enable(); | |
52 | } | |
53 | ||
54 | static inline void ppc_sha1_clear_context(struct sha1_state *sctx) | |
55 | { | |
56 | int count = sizeof(struct sha1_state) >> 2; | |
57 | u32 *ptr = (u32 *)sctx; | |
58 | ||
59 | /* make sure we can clear the fast way */ | |
60 | BUILD_BUG_ON(sizeof(struct sha1_state) % 4); | |
61 | do { *ptr++ = 0; } while (--count); | |
62 | } | |
63 | ||
64 | static int ppc_spe_sha1_init(struct shash_desc *desc) | |
65 | { | |
66 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
67 | ||
68 | sctx->state[0] = SHA1_H0; | |
69 | sctx->state[1] = SHA1_H1; | |
70 | sctx->state[2] = SHA1_H2; | |
71 | sctx->state[3] = SHA1_H3; | |
72 | sctx->state[4] = SHA1_H4; | |
73 | sctx->count = 0; | |
74 | ||
75 | return 0; | |
76 | } | |
77 | ||
78 | static int ppc_spe_sha1_update(struct shash_desc *desc, const u8 *data, | |
79 | unsigned int len) | |
80 | { | |
81 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
82 | const unsigned int offset = sctx->count & 0x3f; | |
83 | const unsigned int avail = 64 - offset; | |
84 | unsigned int bytes; | |
85 | const u8 *src = data; | |
86 | ||
87 | if (avail > len) { | |
88 | sctx->count += len; | |
89 | memcpy((char *)sctx->buffer + offset, src, len); | |
90 | return 0; | |
91 | } | |
92 | ||
93 | sctx->count += len; | |
94 | ||
95 | if (offset) { | |
96 | memcpy((char *)sctx->buffer + offset, src, avail); | |
97 | ||
98 | spe_begin(); | |
99 | ppc_spe_sha1_transform(sctx->state, (const u8 *)sctx->buffer, 1); | |
100 | spe_end(); | |
101 | ||
102 | len -= avail; | |
103 | src += avail; | |
104 | } | |
105 | ||
106 | while (len > 63) { | |
107 | bytes = (len > MAX_BYTES) ? MAX_BYTES : len; | |
108 | bytes = bytes & ~0x3f; | |
109 | ||
110 | spe_begin(); | |
111 | ppc_spe_sha1_transform(sctx->state, src, bytes >> 6); | |
112 | spe_end(); | |
113 | ||
114 | src += bytes; | |
115 | len -= bytes; | |
116 | }; | |
117 | ||
118 | memcpy((char *)sctx->buffer, src, len); | |
119 | return 0; | |
120 | } | |
121 | ||
122 | static int ppc_spe_sha1_final(struct shash_desc *desc, u8 *out) | |
123 | { | |
124 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
125 | const unsigned int offset = sctx->count & 0x3f; | |
126 | char *p = (char *)sctx->buffer + offset; | |
127 | int padlen; | |
128 | __be64 *pbits = (__be64 *)(((char *)&sctx->buffer) + 56); | |
129 | __be32 *dst = (__be32 *)out; | |
130 | ||
131 | padlen = 55 - offset; | |
132 | *p++ = 0x80; | |
133 | ||
134 | spe_begin(); | |
135 | ||
136 | if (padlen < 0) { | |
137 | memset(p, 0x00, padlen + sizeof (u64)); | |
138 | ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1); | |
139 | p = (char *)sctx->buffer; | |
140 | padlen = 56; | |
141 | } | |
142 | ||
143 | memset(p, 0, padlen); | |
144 | *pbits = cpu_to_be64(sctx->count << 3); | |
145 | ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1); | |
146 | ||
147 | spe_end(); | |
148 | ||
149 | dst[0] = cpu_to_be32(sctx->state[0]); | |
150 | dst[1] = cpu_to_be32(sctx->state[1]); | |
151 | dst[2] = cpu_to_be32(sctx->state[2]); | |
152 | dst[3] = cpu_to_be32(sctx->state[3]); | |
153 | dst[4] = cpu_to_be32(sctx->state[4]); | |
154 | ||
155 | ppc_sha1_clear_context(sctx); | |
156 | return 0; | |
157 | } | |
158 | ||
159 | static int ppc_spe_sha1_export(struct shash_desc *desc, void *out) | |
160 | { | |
161 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
162 | ||
163 | memcpy(out, sctx, sizeof(*sctx)); | |
164 | return 0; | |
165 | } | |
166 | ||
167 | static int ppc_spe_sha1_import(struct shash_desc *desc, const void *in) | |
168 | { | |
169 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
170 | ||
171 | memcpy(sctx, in, sizeof(*sctx)); | |
172 | return 0; | |
173 | } | |
174 | ||
175 | static struct shash_alg alg = { | |
176 | .digestsize = SHA1_DIGEST_SIZE, | |
177 | .init = ppc_spe_sha1_init, | |
178 | .update = ppc_spe_sha1_update, | |
179 | .final = ppc_spe_sha1_final, | |
180 | .export = ppc_spe_sha1_export, | |
181 | .import = ppc_spe_sha1_import, | |
182 | .descsize = sizeof(struct sha1_state), | |
183 | .statesize = sizeof(struct sha1_state), | |
184 | .base = { | |
185 | .cra_name = "sha1", | |
186 | .cra_driver_name= "sha1-ppc-spe", | |
187 | .cra_priority = 300, | |
188 | .cra_flags = CRYPTO_ALG_TYPE_SHASH, | |
189 | .cra_blocksize = SHA1_BLOCK_SIZE, | |
190 | .cra_module = THIS_MODULE, | |
191 | } | |
192 | }; | |
193 | ||
194 | static int __init ppc_spe_sha1_mod_init(void) | |
195 | { | |
196 | return crypto_register_shash(&alg); | |
197 | } | |
198 | ||
199 | static void __exit ppc_spe_sha1_mod_fini(void) | |
200 | { | |
201 | crypto_unregister_shash(&alg); | |
202 | } | |
203 | ||
204 | module_init(ppc_spe_sha1_mod_init); | |
205 | module_exit(ppc_spe_sha1_mod_fini); | |
206 | ||
207 | MODULE_LICENSE("GPL"); | |
208 | MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm, SPE optimized"); | |
209 | ||
210 | MODULE_ALIAS_CRYPTO("sha1"); | |
211 | MODULE_ALIAS_CRYPTO("sha1-ppc-spe"); |