2 * Glue code for SHA-1 implementation for SPE instructions (PPC)
4 * Based on generic implementation.
6 * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
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)
15 #include <crypto/internal/hash.h>
16 #include <linux/init.h>
17 #include <linux/module.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>
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.
36 #define MAX_BYTES 2048
38 extern void ppc_spe_sha1_transform(u32 *state, const u8 *src, u32 blocks);
40 static void spe_begin(void)
42 /* We just start SPE operations and will save SPE registers later. */
47 static void spe_end(void)
49 /* reenable preemption */
53 static inline void ppc_sha1_clear_context(struct sha1_state *sctx)
55 int count = sizeof(struct sha1_state) >> 2;
56 u32 *ptr = (u32 *)sctx;
58 /* make sure we can clear the fast way */
59 BUILD_BUG_ON(sizeof(struct sha1_state) % 4);
60 do { *ptr++ = 0; } while (--count);
63 static int ppc_spe_sha1_init(struct shash_desc *desc)
65 struct sha1_state *sctx = shash_desc_ctx(desc);
67 sctx->state[0] = SHA1_H0;
68 sctx->state[1] = SHA1_H1;
69 sctx->state[2] = SHA1_H2;
70 sctx->state[3] = SHA1_H3;
71 sctx->state[4] = SHA1_H4;
77 static int ppc_spe_sha1_update(struct shash_desc *desc, const u8 *data,
80 struct sha1_state *sctx = shash_desc_ctx(desc);
81 const unsigned int offset = sctx->count & 0x3f;
82 const unsigned int avail = 64 - offset;
88 memcpy((char *)sctx->buffer + offset, src, len);
95 memcpy((char *)sctx->buffer + offset, src, avail);
98 ppc_spe_sha1_transform(sctx->state, (const u8 *)sctx->buffer, 1);
106 bytes = (len > MAX_BYTES) ? MAX_BYTES : len;
107 bytes = bytes & ~0x3f;
110 ppc_spe_sha1_transform(sctx->state, src, bytes >> 6);
117 memcpy((char *)sctx->buffer, src, len);
121 static int ppc_spe_sha1_final(struct shash_desc *desc, u8 *out)
123 struct sha1_state *sctx = shash_desc_ctx(desc);
124 const unsigned int offset = sctx->count & 0x3f;
125 char *p = (char *)sctx->buffer + offset;
127 __be64 *pbits = (__be64 *)(((char *)&sctx->buffer) + 56);
128 __be32 *dst = (__be32 *)out;
130 padlen = 55 - offset;
136 memset(p, 0x00, padlen + sizeof (u64));
137 ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1);
138 p = (char *)sctx->buffer;
142 memset(p, 0, padlen);
143 *pbits = cpu_to_be64(sctx->count << 3);
144 ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1);
148 dst[0] = cpu_to_be32(sctx->state[0]);
149 dst[1] = cpu_to_be32(sctx->state[1]);
150 dst[2] = cpu_to_be32(sctx->state[2]);
151 dst[3] = cpu_to_be32(sctx->state[3]);
152 dst[4] = cpu_to_be32(sctx->state[4]);
154 ppc_sha1_clear_context(sctx);
158 static int ppc_spe_sha1_export(struct shash_desc *desc, void *out)
160 struct sha1_state *sctx = shash_desc_ctx(desc);
162 memcpy(out, sctx, sizeof(*sctx));
166 static int ppc_spe_sha1_import(struct shash_desc *desc, const void *in)
168 struct sha1_state *sctx = shash_desc_ctx(desc);
170 memcpy(sctx, in, sizeof(*sctx));
174 static struct shash_alg alg = {
175 .digestsize = SHA1_DIGEST_SIZE,
176 .init = ppc_spe_sha1_init,
177 .update = ppc_spe_sha1_update,
178 .final = ppc_spe_sha1_final,
179 .export = ppc_spe_sha1_export,
180 .import = ppc_spe_sha1_import,
181 .descsize = sizeof(struct sha1_state),
182 .statesize = sizeof(struct sha1_state),
185 .cra_driver_name= "sha1-ppc-spe",
187 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
188 .cra_blocksize = SHA1_BLOCK_SIZE,
189 .cra_module = THIS_MODULE,
193 static int __init ppc_spe_sha1_mod_init(void)
195 return crypto_register_shash(&alg);
198 static void __exit ppc_spe_sha1_mod_fini(void)
200 crypto_unregister_shash(&alg);
203 module_init(ppc_spe_sha1_mod_init);
204 module_exit(ppc_spe_sha1_mod_fini);
206 MODULE_LICENSE("GPL");
207 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm, SPE optimized");
209 MODULE_ALIAS_CRYPTO("sha1");
210 MODULE_ALIAS_CRYPTO("sha1-ppc-spe");