2 * AES CBC 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>
31 #include "aesp8-ppc.h"
33 struct p8_aes_cbc_ctx {
34 struct crypto_blkcipher *fallback;
35 struct aes_key enc_key;
36 struct aes_key dec_key;
39 static int p8_aes_cbc_init(struct crypto_tfm *tfm)
42 struct crypto_blkcipher *fallback;
43 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
45 if (!(alg = crypto_tfm_alg_name(tfm))) {
46 printk(KERN_ERR "Failed to get algorithm name.\n");
51 crypto_alloc_blkcipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
52 if (IS_ERR(fallback)) {
54 "Failed to allocate transformation for '%s': %ld\n",
55 alg, PTR_ERR(fallback));
56 return PTR_ERR(fallback);
59 crypto_blkcipher_set_flags(
61 crypto_blkcipher_get_flags((struct crypto_blkcipher *)tfm));
62 ctx->fallback = fallback;
67 static void p8_aes_cbc_exit(struct crypto_tfm *tfm)
69 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
72 crypto_free_blkcipher(ctx->fallback);
77 static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key,
81 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
86 ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
87 ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
92 ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
96 static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
97 struct scatterlist *dst,
98 struct scatterlist *src, unsigned int nbytes)
101 struct blkcipher_walk walk;
102 struct p8_aes_cbc_ctx *ctx =
103 crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
104 struct blkcipher_desc fallback_desc = {
105 .tfm = ctx->fallback,
110 if (in_interrupt()) {
111 ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src,
114 blkcipher_walk_init(&walk, dst, src, nbytes);
115 ret = blkcipher_walk_virt(desc, &walk);
116 while ((nbytes = walk.nbytes)) {
120 aes_p8_cbc_encrypt(walk.src.virt.addr,
122 nbytes & AES_BLOCK_MASK,
123 &ctx->enc_key, walk.iv, 1);
124 disable_kernel_vsx();
128 nbytes &= AES_BLOCK_SIZE - 1;
129 ret = blkcipher_walk_done(desc, &walk, nbytes);
136 static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
137 struct scatterlist *dst,
138 struct scatterlist *src, unsigned int nbytes)
141 struct blkcipher_walk walk;
142 struct p8_aes_cbc_ctx *ctx =
143 crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
144 struct blkcipher_desc fallback_desc = {
145 .tfm = ctx->fallback,
150 if (in_interrupt()) {
151 ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src,
154 blkcipher_walk_init(&walk, dst, src, nbytes);
155 ret = blkcipher_walk_virt(desc, &walk);
156 while ((nbytes = walk.nbytes)) {
160 aes_p8_cbc_encrypt(walk.src.virt.addr,
162 nbytes & AES_BLOCK_MASK,
163 &ctx->dec_key, walk.iv, 0);
164 disable_kernel_vsx();
168 nbytes &= AES_BLOCK_SIZE - 1;
169 ret = blkcipher_walk_done(desc, &walk, nbytes);
177 struct crypto_alg p8_aes_cbc_alg = {
178 .cra_name = "cbc(aes)",
179 .cra_driver_name = "p8_aes_cbc",
180 .cra_module = THIS_MODULE,
181 .cra_priority = 2000,
182 .cra_type = &crypto_blkcipher_type,
183 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
185 .cra_blocksize = AES_BLOCK_SIZE,
186 .cra_ctxsize = sizeof(struct p8_aes_cbc_ctx),
187 .cra_init = p8_aes_cbc_init,
188 .cra_exit = p8_aes_cbc_exit,
190 .ivsize = AES_BLOCK_SIZE,
191 .min_keysize = AES_MIN_KEY_SIZE,
192 .max_keysize = AES_MAX_KEY_SIZE,
193 .setkey = p8_aes_cbc_setkey,
194 .encrypt = p8_aes_cbc_encrypt,
195 .decrypt = p8_aes_cbc_decrypt,