1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Glue code for SHA-1 implementation for SPE instructions (PPC)
5 * Based on generic implementation.
7 * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
10 #include <crypto/internal/hash.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
14 #include <linux/cryptohash.h>
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>
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.
31 #define MAX_BYTES 2048
33 extern void ppc_spe_sha1_transform(u32 *state, const u8 *src, u32 blocks);
35 static void spe_begin(void)
37 /* We just start SPE operations and will save SPE registers later. */
42 static void spe_end(void)
45 /* reenable preemption */
49 static inline void ppc_sha1_clear_context(struct sha1_state *sctx)
51 int count = sizeof(struct sha1_state) >> 2;
52 u32 *ptr = (u32 *)sctx;
54 /* make sure we can clear the fast way */
55 BUILD_BUG_ON(sizeof(struct sha1_state) % 4);
56 do { *ptr++ = 0; } while (--count);
59 static int ppc_spe_sha1_init(struct shash_desc *desc)
61 struct sha1_state *sctx = shash_desc_ctx(desc);
63 sctx->state[0] = SHA1_H0;
64 sctx->state[1] = SHA1_H1;
65 sctx->state[2] = SHA1_H2;
66 sctx->state[3] = SHA1_H3;
67 sctx->state[4] = SHA1_H4;
73 static int ppc_spe_sha1_update(struct shash_desc *desc, const u8 *data,
76 struct sha1_state *sctx = shash_desc_ctx(desc);
77 const unsigned int offset = sctx->count & 0x3f;
78 const unsigned int avail = 64 - offset;
84 memcpy((char *)sctx->buffer + offset, src, len);
91 memcpy((char *)sctx->buffer + offset, src, avail);
94 ppc_spe_sha1_transform(sctx->state, (const u8 *)sctx->buffer, 1);
102 bytes = (len > MAX_BYTES) ? MAX_BYTES : len;
103 bytes = bytes & ~0x3f;
106 ppc_spe_sha1_transform(sctx->state, src, bytes >> 6);
113 memcpy((char *)sctx->buffer, src, len);
117 static int ppc_spe_sha1_final(struct shash_desc *desc, u8 *out)
119 struct sha1_state *sctx = shash_desc_ctx(desc);
120 const unsigned int offset = sctx->count & 0x3f;
121 char *p = (char *)sctx->buffer + offset;
123 __be64 *pbits = (__be64 *)(((char *)&sctx->buffer) + 56);
124 __be32 *dst = (__be32 *)out;
126 padlen = 55 - offset;
132 memset(p, 0x00, padlen + sizeof (u64));
133 ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1);
134 p = (char *)sctx->buffer;
138 memset(p, 0, padlen);
139 *pbits = cpu_to_be64(sctx->count << 3);
140 ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1);
144 dst[0] = cpu_to_be32(sctx->state[0]);
145 dst[1] = cpu_to_be32(sctx->state[1]);
146 dst[2] = cpu_to_be32(sctx->state[2]);
147 dst[3] = cpu_to_be32(sctx->state[3]);
148 dst[4] = cpu_to_be32(sctx->state[4]);
150 ppc_sha1_clear_context(sctx);
154 static int ppc_spe_sha1_export(struct shash_desc *desc, void *out)
156 struct sha1_state *sctx = shash_desc_ctx(desc);
158 memcpy(out, sctx, sizeof(*sctx));
162 static int ppc_spe_sha1_import(struct shash_desc *desc, const void *in)
164 struct sha1_state *sctx = shash_desc_ctx(desc);
166 memcpy(sctx, in, sizeof(*sctx));
170 static struct shash_alg alg = {
171 .digestsize = SHA1_DIGEST_SIZE,
172 .init = ppc_spe_sha1_init,
173 .update = ppc_spe_sha1_update,
174 .final = ppc_spe_sha1_final,
175 .export = ppc_spe_sha1_export,
176 .import = ppc_spe_sha1_import,
177 .descsize = sizeof(struct sha1_state),
178 .statesize = sizeof(struct sha1_state),
181 .cra_driver_name= "sha1-ppc-spe",
183 .cra_blocksize = SHA1_BLOCK_SIZE,
184 .cra_module = THIS_MODULE,
188 static int __init ppc_spe_sha1_mod_init(void)
190 return crypto_register_shash(&alg);
193 static void __exit ppc_spe_sha1_mod_fini(void)
195 crypto_unregister_shash(&alg);
198 module_init(ppc_spe_sha1_mod_init);
199 module_exit(ppc_spe_sha1_mod_fini);
201 MODULE_LICENSE("GPL");
202 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm, SPE optimized");
204 MODULE_ALIAS_CRYPTO("sha1");
205 MODULE_ALIAS_CRYPTO("sha1-ppc-spe");