2 * GHASH routines supporting VMX instructions on the Power 8
4 * Copyright (C) 2015 International Business Machines Inc.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 only.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
22 #include <linux/types.h>
23 #include <linux/err.h>
24 #include <linux/crypto.h>
25 #include <linux/delay.h>
26 #include <linux/hardirq.h>
27 #include <asm/switch_to.h>
28 #include <crypto/aes.h>
29 #include <crypto/scatterwalk.h>
30 #include <crypto/internal/hash.h>
31 #include <crypto/b128ops.h>
33 #define IN_INTERRUPT in_interrupt()
35 #define GHASH_BLOCK_SIZE (16)
36 #define GHASH_DIGEST_SIZE (16)
37 #define GHASH_KEY_LEN (16)
39 void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
40 void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
41 void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
42 const u8 *in,size_t len);
46 struct crypto_shash *fallback;
49 struct p8_ghash_desc_ctx {
51 u8 buffer[GHASH_DIGEST_SIZE];
53 struct shash_desc fallback_desc;
56 static int p8_ghash_init_tfm(struct crypto_tfm *tfm)
59 struct crypto_shash *fallback;
60 struct crypto_shash *shash_tfm = __crypto_shash_cast(tfm);
61 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
63 if (!(alg = crypto_tfm_alg_name(tfm))) {
64 printk(KERN_ERR "Failed to get algorithm name.\n");
68 fallback = crypto_alloc_shash(alg, 0 ,CRYPTO_ALG_NEED_FALLBACK);
69 if (IS_ERR(fallback)) {
70 printk(KERN_ERR "Failed to allocate transformation for '%s': %ld\n",
71 alg, PTR_ERR(fallback));
72 return PTR_ERR(fallback);
74 printk(KERN_INFO "Using '%s' as fallback implementation.\n",
75 crypto_tfm_alg_driver_name(crypto_shash_tfm(fallback)));
77 crypto_shash_set_flags(fallback,
78 crypto_shash_get_flags((struct crypto_shash *) tfm));
79 ctx->fallback = fallback;
81 shash_tfm->descsize = sizeof(struct p8_ghash_desc_ctx)
82 + crypto_shash_descsize(fallback);
87 static void p8_ghash_exit_tfm(struct crypto_tfm *tfm)
89 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
92 crypto_free_shash(ctx->fallback);
97 static int p8_ghash_init(struct shash_desc *desc)
99 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
100 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
103 memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
104 dctx->fallback_desc.tfm = ctx->fallback;
105 dctx->fallback_desc.flags = desc->flags;
106 return crypto_shash_init(&dctx->fallback_desc);
109 static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
112 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));
114 if (keylen != GHASH_KEY_LEN)
118 enable_kernel_altivec();
120 gcm_init_p8(ctx->htable, (const u64 *) key);
122 return crypto_shash_setkey(ctx->fallback, key, keylen);
125 static int p8_ghash_update(struct shash_desc *desc,
126 const u8 *src, unsigned int srclen)
129 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
130 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
133 return crypto_shash_update(&dctx->fallback_desc, src, srclen);
136 if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
137 memcpy(dctx->buffer + dctx->bytes, src, srclen);
138 dctx->bytes += srclen;
141 memcpy(dctx->buffer + dctx->bytes, src,
142 GHASH_DIGEST_SIZE - dctx->bytes);
144 enable_kernel_altivec();
146 gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
149 src += GHASH_DIGEST_SIZE - dctx->bytes;
150 srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
153 len = srclen & ~(GHASH_DIGEST_SIZE - 1);
156 enable_kernel_altivec();
158 gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
164 memcpy(dctx->buffer, src, srclen);
165 dctx->bytes = srclen;
171 static int p8_ghash_final(struct shash_desc *desc, u8 *out)
174 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
175 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
178 return crypto_shash_final(&dctx->fallback_desc, out);
181 for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
184 enable_kernel_altivec();
186 gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
191 memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
196 struct shash_alg p8_ghash_alg = {
197 .digestsize = GHASH_DIGEST_SIZE,
198 .init = p8_ghash_init,
199 .update = p8_ghash_update,
200 .final = p8_ghash_final,
201 .setkey = p8_ghash_setkey,
202 .descsize = sizeof(struct p8_ghash_desc_ctx),
205 .cra_driver_name = "p8_ghash",
206 .cra_priority = 1000,
207 .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_NEED_FALLBACK,
208 .cra_blocksize = GHASH_BLOCK_SIZE,
209 .cra_ctxsize = sizeof(struct p8_ghash_ctx),
210 .cra_module = THIS_MODULE,
211 .cra_init = p8_ghash_init_tfm,
212 .cra_exit = p8_ghash_exit_tfm,