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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
50ba29aa MS |
2 | /* |
3 | * Glue code for SHA-1 implementation for SPE instructions (PPC) | |
4 | * | |
5 | * Based on generic implementation. | |
6 | * | |
7 | * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de> | |
50ba29aa MS |
8 | */ |
9 | ||
10 | #include <crypto/internal/hash.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/mm.h> | |
50ba29aa | 14 | #include <linux/types.h> |
a24d22b2 | 15 | #include <crypto/sha1.h> |
41ea0f6c | 16 | #include <crypto/sha1_base.h> |
50ba29aa MS |
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(). SHA1 takes ~1000 | |
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 2KB 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 2048 | |
32 | ||
33 | extern void ppc_spe_sha1_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(); |
50ba29aa MS |
45 | /* reenable preemption */ |
46 | preempt_enable(); | |
47 | } | |
48 | ||
49 | static inline void ppc_sha1_clear_context(struct sha1_state *sctx) | |
50 | { | |
51 | int count = sizeof(struct sha1_state) >> 2; | |
52 | u32 *ptr = (u32 *)sctx; | |
53 | ||
54 | /* make sure we can clear the fast way */ | |
55 | BUILD_BUG_ON(sizeof(struct sha1_state) % 4); | |
56 | do { *ptr++ = 0; } while (--count); | |
57 | } | |
58 | ||
50ba29aa MS |
59 | static int ppc_spe_sha1_update(struct shash_desc *desc, const u8 *data, |
60 | unsigned int len) | |
61 | { | |
62 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
63 | const unsigned int offset = sctx->count & 0x3f; | |
64 | const unsigned int avail = 64 - offset; | |
65 | unsigned int bytes; | |
66 | const u8 *src = data; | |
67 | ||
68 | if (avail > len) { | |
69 | sctx->count += len; | |
70 | memcpy((char *)sctx->buffer + offset, src, len); | |
71 | return 0; | |
72 | } | |
73 | ||
74 | sctx->count += len; | |
75 | ||
76 | if (offset) { | |
77 | memcpy((char *)sctx->buffer + offset, src, avail); | |
78 | ||
79 | spe_begin(); | |
80 | ppc_spe_sha1_transform(sctx->state, (const u8 *)sctx->buffer, 1); | |
81 | spe_end(); | |
82 | ||
83 | len -= avail; | |
84 | src += avail; | |
85 | } | |
86 | ||
87 | while (len > 63) { | |
88 | bytes = (len > MAX_BYTES) ? MAX_BYTES : len; | |
89 | bytes = bytes & ~0x3f; | |
90 | ||
91 | spe_begin(); | |
92 | ppc_spe_sha1_transform(sctx->state, src, bytes >> 6); | |
93 | spe_end(); | |
94 | ||
95 | src += bytes; | |
96 | len -= bytes; | |
da3c6c83 | 97 | } |
50ba29aa MS |
98 | |
99 | memcpy((char *)sctx->buffer, src, len); | |
100 | return 0; | |
101 | } | |
102 | ||
103 | static int ppc_spe_sha1_final(struct shash_desc *desc, u8 *out) | |
104 | { | |
105 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
106 | const unsigned int offset = sctx->count & 0x3f; | |
107 | char *p = (char *)sctx->buffer + offset; | |
108 | int padlen; | |
109 | __be64 *pbits = (__be64 *)(((char *)&sctx->buffer) + 56); | |
110 | __be32 *dst = (__be32 *)out; | |
111 | ||
112 | padlen = 55 - offset; | |
113 | *p++ = 0x80; | |
114 | ||
115 | spe_begin(); | |
116 | ||
117 | if (padlen < 0) { | |
118 | memset(p, 0x00, padlen + sizeof (u64)); | |
119 | ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1); | |
120 | p = (char *)sctx->buffer; | |
121 | padlen = 56; | |
122 | } | |
123 | ||
124 | memset(p, 0, padlen); | |
125 | *pbits = cpu_to_be64(sctx->count << 3); | |
126 | ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1); | |
127 | ||
128 | spe_end(); | |
129 | ||
130 | dst[0] = cpu_to_be32(sctx->state[0]); | |
131 | dst[1] = cpu_to_be32(sctx->state[1]); | |
132 | dst[2] = cpu_to_be32(sctx->state[2]); | |
133 | dst[3] = cpu_to_be32(sctx->state[3]); | |
134 | dst[4] = cpu_to_be32(sctx->state[4]); | |
135 | ||
136 | ppc_sha1_clear_context(sctx); | |
137 | return 0; | |
138 | } | |
139 | ||
140 | static int ppc_spe_sha1_export(struct shash_desc *desc, void *out) | |
141 | { | |
142 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
143 | ||
144 | memcpy(out, sctx, sizeof(*sctx)); | |
145 | return 0; | |
146 | } | |
147 | ||
148 | static int ppc_spe_sha1_import(struct shash_desc *desc, const void *in) | |
149 | { | |
150 | struct sha1_state *sctx = shash_desc_ctx(desc); | |
151 | ||
152 | memcpy(sctx, in, sizeof(*sctx)); | |
153 | return 0; | |
154 | } | |
155 | ||
156 | static struct shash_alg alg = { | |
157 | .digestsize = SHA1_DIGEST_SIZE, | |
41ea0f6c | 158 | .init = sha1_base_init, |
50ba29aa MS |
159 | .update = ppc_spe_sha1_update, |
160 | .final = ppc_spe_sha1_final, | |
161 | .export = ppc_spe_sha1_export, | |
162 | .import = ppc_spe_sha1_import, | |
163 | .descsize = sizeof(struct sha1_state), | |
164 | .statesize = sizeof(struct sha1_state), | |
165 | .base = { | |
166 | .cra_name = "sha1", | |
167 | .cra_driver_name= "sha1-ppc-spe", | |
168 | .cra_priority = 300, | |
50ba29aa MS |
169 | .cra_blocksize = SHA1_BLOCK_SIZE, |
170 | .cra_module = THIS_MODULE, | |
171 | } | |
172 | }; | |
173 | ||
174 | static int __init ppc_spe_sha1_mod_init(void) | |
175 | { | |
176 | return crypto_register_shash(&alg); | |
177 | } | |
178 | ||
179 | static void __exit ppc_spe_sha1_mod_fini(void) | |
180 | { | |
181 | crypto_unregister_shash(&alg); | |
182 | } | |
183 | ||
184 | module_init(ppc_spe_sha1_mod_init); | |
185 | module_exit(ppc_spe_sha1_mod_fini); | |
186 | ||
187 | MODULE_LICENSE("GPL"); | |
188 | MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm, SPE optimized"); | |
189 | ||
190 | MODULE_ALIAS_CRYPTO("sha1"); | |
191 | MODULE_ALIAS_CRYPTO("sha1-ppc-spe"); |